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Phono preamp in old receiver problem
Hi all,
I have an old Sharp AM/FM receiver with an 8-track player. Made in Japan ca. 1975 or something. It had a BSR turntable which was broken. I removed the seized turntable, cleaned the whole unit, sprayed all the pots, replaced the three little 6V bulbs behind the black/green tuner window, and it is fabulous. It's built like a tank and weighs a ton. The pots feel like military grade stuff. The function switches are simply unbelievable. The front panel is white (OK, bone now) with black controls, the box is all wood with the then-standard "vinyl wood veneer". I have a spare turntable which works perfectly. I intended to connect it to the phono preamp of this receiver. I did, but I am not getting sound. I am getting low-frequency pink noise, but no audio signal. What is even stranger is that I hear one of the channels "pop" when I dis/connect ONE of the two RCA audio cables going into the phono preamp of the receiver. I tested all the cables after extending them, and they are OK (see below). I tried connecting the turntable signal to the line input, and it DOES work. Of course, the signal is VERY low, but you CAN hear the LP playing with the volume full up. So either I DID somehow **** up the audio cable assembly (it tests OK though!) or the phono preamp is partially or totally NG, in which case there is probably nothing that can be done. The line inputs can be used for a CD/DVD player, the receiver works as a 4-speaker unit or 2 main/2 remote speakers, and it sounds great. AM and line in are loud as hell, FM volume is about 30% of that, but still usable. Does anyone have any idea what I should do first? I want to determine exactly /what/ in the chain from the *turntable audio cables/cable extensions/original RCA plugs and cable/circuit board* is NG. (The phonograph audio cables were only long enough to reach the bottom of the turntable, which was 3 inches above the main circuit board, now they have to reach to the back and out of the unit, so I had to add about 8 inches of cable - but I tested the cables, both channels, live /and/ ground, and I made NO mistakes - everything was connected/soldered correctly. If the phono preamp is dead, it's dead. The unit is still a /great/ AM (and decent FM) receiver and line-in amplifier, handles TWO sets of stereo speakers, and it will outlast all of us. I have yet to find an 8-track cartridge, but the mechanism and all the belts seem fine. Plus I don't think anyone needs an 8-track deck, while /quite/ a few people might enjoy having a receiver with a phono preamp. Unless the phono preamp IS dead, of course. But maybe someone can help me determine if it actually IS dead... I /tried/ to make this short, really! Any advice will be greatly appreciated. -- Any mental activity is easy if it need not be subjected to reality. |
Phono preamp in old receiver problem
On 9/8/2010 4:12 PM thanatoid spake thus:
If the phono preamp is dead, it's dead. The unit is still a /great/ AM (and decent FM) receiver and line-in amplifier, handles TWO sets of stereo speakers, and it will outlast all of us. I have yet to find an 8-track cartridge, but the mechanism and all the belts seem fine. Plus I don't think anyone needs an 8-track deck, while /quite/ a few people might enjoy having a receiver with a phono preamp. Unless the phono preamp IS dead, of course. But maybe someone can help me determine if it actually IS dead... One question is whether this unit uses a ceramic or magnetic phono cartridge. Most units of its vintage used magnetic, and that's my guess, but if it has a ceramic cartridge, you're not going to be able to use a magentic cartridge with its preamp. Another possibility is to get a small standalone phone preamp and plug it into the line input. Not what you want, but it would work. -- The fashion in killing has an insouciant, flirty style this spring, with the flaunting of well-defined muscle, wrapped in flags. - Comment from an article on Antiwar.com (http://antiwar.com) |
Phono preamp in old receiver problem
do you have an iPod, or other mp3 player or any other audio device that you
can hook up to the preamp, just to see if you get a better result ? If so, you should of course keep the output level of the mp3 player very low at least to begin with, and gradually increase the volume. Because it will be a line level signal to the preamp, it will overpower it quickly, but it may give you a hint as to what is going on..... could possibly eliminate defects in your turntable or the cable that you made, as all of that would be bypassed for the experiment... just an idea... report back please... James |
Phono preamp in old receiver problem
In article ,
thanatoid wrote: Does anyone have any idea what I should do first? I want to determine exactly /what/ in the chain from the *turntable audio cables/cable extensions/original RCA plugs and cable/circuit board* is NG. Well, I'd say that one of the two standard approaches would work. Which one you would use, depends on what sort of test equipment you have available. Probably the easiest approach is "work backwards". You'd use some sort of low-level signal injector (something which can create a few millivolts of audio), starting at the input selector switch (probably) and working backwards towards the turntable, and see how far back along this signal chain you can go before you stop getting audio output through the amplifier. The other way is "work forwards"... from the cartridge towards the preamp and amp, using an oscilliscope to see how far along the chain you can detect audio when you stimulate the cartridge (e.g. playing an LP, or touching the stylus gently with a brush). Take all of the appropriate safety precautions, of course! If the phono preamp is dead, it's dead. The unit is still a /great/ AM (and decent FM) receiver and line-in amplifier, handles TWO sets of stereo speakers, and it will outlast all of us. In a component of that type and age, I'd suspect one of two things as the most likely culprit: - A bad switch in the signal path (maybe in the preamp, or maybe at the turntable itself - if I recall correctly, some turntables have anti-thump muting switches which short the signal from the cartridge until the stylus is playing the groove), or - Dried out and "open" electrolytic capacitors, coupling one stage of the preamp to the next. There could also be a power supply problem affecting the phono preamp stage. -- Dave Platt AE6EO Friends of Jade Warrior home page: http://www.radagast.org/jade-warrior I do _not_ wish to receive unsolicited commercial email, and I will boycott any company which has the gall to send me such ads! |
Phono preamp in old receiver problem
"thanatoid" wrote in message
... Hi all, I have an old Sharp AM/FM receiver with an 8-track player. Made in Japan ca. 1975 or something. It had a BSR turntable which was broken. I removed the seized turntable, cleaned the whole unit, sprayed all the pots, replaced the three little 6V bulbs behind the black/green tuner window, and it is fabulous. It's built like a tank and weighs a ton. The pots feel like military grade stuff. The function switches are simply unbelievable. The front panel is white (OK, bone now) with black controls, the box is all wood with the then-standard "vinyl wood veneer". I have a spare turntable which works perfectly. I intended to connect it to the phono preamp of this receiver. I did, but I am not getting sound. I am getting low-frequency pink noise, but no audio signal. What is even stranger is that I hear one of the channels "pop" when I dis/connect ONE of the two RCA audio cables going into the phono preamp of the receiver. I tested all the cables after extending them, and they are OK (see below). I tried connecting the turntable signal to the line input, and it DOES work. Of course, the signal is VERY low, but you CAN hear the LP playing with the volume full up. So either I DID somehow **** up the audio cable assembly (it tests OK though!) or the phono preamp is partially or totally NG, in which case there is probably nothing that can be done. The line inputs can be used for a CD/DVD player, the receiver works as a 4-speaker unit or 2 main/2 remote speakers, and it sounds great. AM and line in are loud as hell, FM volume is about 30% of that, but still usable. Does anyone have any idea what I should do first? I want to determine exactly /what/ in the chain from the *turntable audio cables/cable extensions/original RCA plugs and cable/circuit board* is NG. (The phonograph audio cables were only long enough to reach the bottom of the turntable, which was 3 inches above the main circuit board, now they have to reach to the back and out of the unit, so I had to add about 8 inches of cable - but I tested the cables, both channels, live /and/ ground, and I made NO mistakes - everything was connected/soldered correctly. If the phono preamp is dead, it's dead. The unit is still a /great/ AM (and decent FM) receiver and line-in amplifier, handles TWO sets of stereo speakers, and it will outlast all of us. I have yet to find an 8-track cartridge, but the mechanism and all the belts seem fine. Plus I don't think anyone needs an 8-track deck, while /quite/ a few people might enjoy having a receiver with a phono preamp. Unless the phono preamp IS dead, of course. But maybe someone can help me determine if it actually IS dead... I /tried/ to make this short, really! Any advice will be greatly appreciated. -- Any mental activity is easy if it need not be subjected to reality. Perhaps the stylus on the replacement turntable is not quite seated properly. This would produce your symptom. No sound when plugged into the (ceramic) phono input, hear a pop w/ unplug, hear low sound on another input. I'm presuming your original turntable had a ceramic cartridge, but it would help to know if this is true; also what kind of cartridge is in your replacement table. Mark Z. Mark Z. |
Phono preamp in old receiver problem
Hello,
while I don't know your specific Sharp receiver (you did not specify the model number) many 'compact systems' with BSR changers used ceramic cartridges that give a line level output, so this receiver may not have a phono preamp at all. Regards, Tim Schwartz Bristol Electronics On 9/8/2010 7:12 PM, thanatoid wrote: Hi all, I have an old Sharp AM/FM receiver with an 8-track player. Made in Japan ca. 1975 or something. It had a BSR turntable which was broken. I removed the seized turntable, cleaned the whole unit, sprayed all the pots, replaced the three little 6V bulbs behind the black/green tuner window, and it is fabulous. It's built like a tank and weighs a ton. The pots feel like military grade stuff. The function switches are simply unbelievable. The front panel is white (OK, bone now) with black controls, the box is all wood with the then-standard "vinyl wood veneer". I have a spare turntable which works perfectly. I intended to connect it to the phono preamp of this receiver. I did, but I am not getting sound. I am getting low-frequency pink noise, but no audio signal. What is even stranger is that I hear one of the channels "pop" when I dis/connect ONE of the two RCA audio cables going into the phono preamp of the receiver. I tested all the cables after extending them, and they are OK (see below). I tried connecting the turntable signal to the line input, and it DOES work. Of course, the signal is VERY low, but you CAN hear the LP playing with the volume full up. So either I DID somehow **** up the audio cable assembly (it tests OK though!) or the phono preamp is partially or totally NG, in which case there is probably nothing that can be done. The line inputs can be used for a CD/DVD player, the receiver works as a 4-speaker unit or 2 main/2 remote speakers, and it sounds great. AM and line in are loud as hell, FM volume is about 30% of that, but still usable. Does anyone have any idea what I should do first? I want to determine exactly /what/ in the chain from the *turntable audio cables/cable extensions/original RCA plugs and cable/circuit board* is NG. (The phonograph audio cables were only long enough to reach the bottom of the turntable, which was 3 inches above the main circuit board, now they have to reach to the back and out of the unit, so I had to add about 8 inches of cable - but I tested the cables, both channels, live /and/ ground, and I made NO mistakes - everything was connected/soldered correctly. If the phono preamp is dead, it's dead. The unit is still a /great/ AM (and decent FM) receiver and line-in amplifier, handles TWO sets of stereo speakers, and it will outlast all of us. I have yet to find an 8-track cartridge, but the mechanism and all the belts seem fine. Plus I don't think anyone needs an 8-track deck, while /quite/ a few people might enjoy having a receiver with a phono preamp. Unless the phono preamp IS dead, of course. But maybe someone can help me determine if it actually IS dead... I /tried/ to make this short, really! Any advice will be greatly appreciated. |
Phono preamp in old receiver problem
thanatoid wrote:
I /tried/ to make this short, really! Are you sure the original turntable had a magnetic cartridge? - and if so, did it contain a preamp for it? - is there a feedback path through a switch that doesn't work, Sony did stuff like that on their taperecorders causing the record amp to oscillate if the switch was defective. Any advice will be greatly appreciated. Kind regards Peter Larsen |
Phono preamp in old receiver problem
David Nebenzahl wrote in
.com: snip One question is whether this unit uses a ceramic or magnetic phono cartridge. Most units of its vintage used magnetic, and that's my guess, but if it has a ceramic cartridge, you're not going to be able to use a magentic cartridge with its preamp. Another possibility is to get a small standalone phone preamp and plug it into the line input. Not what you want, but it would work. Thanks for the reply. See below for parts addressing both these suggestion, sort of. -- Update (very long, I apologize!) -- First of all, many thanks to all who replied. It is very much appreciated. Now for the /bad/ part. Something one person mentioned in his reply made me remember a rather *crucial* detail which I had forgotten (I am not completely senile yet, but I have been /incredibly/ busy for the last few weeks, and my brain is running out of RAM). It is this: BEFORE I removed the BSR turntable, I DID check to see whether there was AUDIO SIGNAL coming from it. There was, loud and clear - when I touched the stylus, it sounded like an earthquake. Very little "system noise", too. The turntable itself was "seized" - after I have (with some violence) managed to take it apart, I saw that the 2 main cog wheels of the belt-less motor were practically frozen together at a bizarre angle and would NOT budge. I have NO idea how that happened - and the 4" screwdriver shaft, 2 children's plastic letters with magnets, and assorted bits of 30+ year old food I found inside the receiver could NOT have had anything to do with it, either, since the BSR motor was fairly well enclosed within the /incredibly/ complicated mechanical design (a changer). Now that I have remembered this, it is obvious I screwed something up. I have never seen a ceramic cartridge, but I am 99.99% positive that BOTH the BSR and the Sony (ca. 1990) turntable carts are magnetic. So, since I have no signal but weird pink noise, I must have screwed up the cables. Or do you think I may have destroyed the preamp? (This may be a good moment to mention that I am using the term "phono preamp" in a generic sense. I always thought a phono preamp might be/would be a small enclosed piece of electronics, but in this receiver, it appears to be a part of the main circuit board - the two original (and now extended) cables from the BSR turntable stylus/arm are soldered right onto the circuit board, and go who-knows-where - presumably, into components which make up this receiver's "phone preamp" section.) (THIS may /also/ be a good moment to mention that while I have had some disastrous luck with simple things and astoundingly good luck with complicated things, I am NOT a technician, and do not own an oscilloscope - I check connections with two gator clips connected to a 1.5V battery with a flashlight bulb, and after over 30 years of "considering it", I finally bought a five dollar "voltmeter" which /appears/ to work - I found out a cheap 110V/22V AC/DC adapter outputs 25VDC when set to 12V output [when the input voltage is set to 110V] and 12.5VDC from its 9V setting [when the input voltage is set to 110V (it is 110V here)]. The Sony turntable (originally a component of a system, with a tiny power connector which plugs into the back of the main system unit and where I found out 12VDC is output) is running on a supposedly "regulated" fancy Radio Shack AC/DC adapter which puts out 11.8V DC. (When I reverse the polarity, the turntable spins backwards.) If anyone has read this far, please accept my deep thanks for your patience. I can't write more concisely - I realize it's an illness. Anyway - the question now is WHAT did I do to mess things up? Since I consider the receiver largely indestructible, I do not think I have *destroyed* anything, not to mention the voltages involved are totally minuscule and it being a solid state unit - as the front panel proudly states ;-) - there is little danger of blowing it up. Plus everything else works. My plan is as follows: 1. Cut the original "BSR cartridge/turntable to the main circuit board" cables, strip ends. 2. Attach gator clips to them and connect to the Sony turntable output cable. 3. Hopefully, hear sound. Extend cables again, making SURE I don't screw up this time. If I hear no sound, I will connect the 4 very thin cables from the original BSR cartridge (I saved the cart assembly and cables before I saw the turntable was connected to the circuit board with 2 standard cables with RCA plugs) to the cut cables leading to the circuit board and see if I hear anything. If I do, I will post for more advice. But for now, my question is: If after doing all this, I still get the /same/ pink noise (NOT hum - strange, huh?) and get NO audio, WHAT do I do? Thank you /very much/ for your patience, and my apologies for having forgotten a crucial part of the puzzle. Further help will be greatly appreciated. If anyone wants to see pix of the 2 cartridges or the circuit board where the phono audio cables are soldered into it, I can post them to photobucket or something, OR a binary group if you have binaries access. The replies are different in every one of the 5 groups, so I will post this followup to each group separately. I don't really understand how crossposting works, since I never do it, and eternal september /may/ be "funny" about crossposting to boot. -- Any mental activity is easy if it need not be subjected to reality. |
Phono preamp in old receiver problem
"James" wrote in
net: do you have an iPod, or other mp3 player or any other audio device that you can hook up to the preamp, just to see if you get a better result ? Thanks for the reply. Not really, also it is VERY tight and dark and weird in there. If so, you should of course keep the output level of the mp3 player very low at least to begin with, and gradually increase the volume. Because it will be a line level signal to the preamp, it will overpower it quickly, but it may give you a hint as to what is going on..... could possibly eliminate defects in your turntable or the cable that you made, as all of that would be bypassed for the experiment... just an idea... report back please... Here it is... VERY long, sorry! -- Update (very long, I apologize!) -- First of all, many thanks to all who replied. It is very much appreciated. Now for the /bad/ part. Something one person mentioned in his reply made me remember a rather *crucial* detail which I had forgotten (I am not completely senile yet, but I have been /incredibly/ busy for the last few weeks, and my brain is running out of RAM). It is this: BEFORE I removed the BSR turntable, I DID check to see whether there was AUDIO SIGNAL coming from it. There was, loud and clear - when I touched the stylus, it sounded like an earthquake. Very little "system noise", too. The turntable itself was "seized" - after I have (with some violence) managed to take it apart, I saw that the 2 main cog wheels of the belt-less motor were practically frozen together at a bizarre angle and would NOT budge. I have NO idea how that happened - and the 4" screwdriver shaft, 2 children's plastic letters with magnets, and assorted bits of 30+ year old food I found inside the receiver could NOT have had anything to do with it, either, since the BSR motor was fairly well enclosed within the /incredibly/ complicated mechanical design (a changer). Now that I have remembered this, it is obvious I screwed something up. I have never seen a ceramic cartridge, but I am 99.99% positive that BOTH the BSR and the Sony (ca. 1990) turntable carts are magnetic. So, since I have no signal but weird pink noise, I must have screwed up the cables. Or do you think I may have destroyed the preamp? (This may be a good moment to mention that I am using the term "phono preamp" in a generic sense. I always thought a phono preamp might be/would be a small enclosed piece of electronics, but in this receiver, it appears to be a part of the main circuit board - the two original (and now extended) cables from the BSR turntable stylus/arm are soldered right onto the circuit board, and go who-knows-where - presumably, into components which make up this receiver's "phone preamp" section.) (THIS may /also/ be a good moment to mention that while I have had some disastrous luck with simple things and astoundingly good luck with complicated things, I am NOT a technician, and do not own an oscilloscope - I check connections with two gator clips connected to a 1.5V battery with a flashlight bulb, and after over 30 years of "considering it", I finally bought a five dollar "voltmeter" which /appears/ to work - I found out a cheap 110V/22V AC/DC adapter outputs 25VDC when set to 12V output [when the input voltage is set to 110V] and 12.5VDC from its 9V setting [when the input voltage is set to 110V (it is 110V here)]. The Sony turntable (originally a component of a system, with a tiny power connector which plugs into the back of the main system unit and where I found out 12VDC is output) is running on a supposedly "regulated" fancy Radio Shack AC/DC adapter which puts out 11.8V DC. (When I reverse the polarity, the turntable spins backwards.) If anyone has read this far, please accept my deep thanks for your patience. I can't write more concisely - I realize it's an illness. Anyway - the question now is WHAT did I do to mess things up? Since I consider the receiver largely indestructible, I do not think I have *destroyed* anything, not to mention the voltages involved are totally minuscule and it being a solid state unit - as the front panel proudly states ;-) - there is little danger of blowing it up. Plus everything else works. My plan is as follows: 1. Cut the original "BSR cartridge/turntable to the main circuit board" cables, strip ends. 2. Attach gator clips to them and connect to the Sony turntable output cable. 3. Hopefully, hear sound. Extend cables again, making SURE I don't screw up this time. If I hear no sound, I will connect the 4 very thin cables from the original BSR cartridge (I saved the cart assembly and cables before I saw the turntable was connected to the circuit board with 2 standard cables with RCA plugs) to the cut cables leading to the circuit board and see if I hear anything. If I do, I will post for more advice. But for now, my question is: If after doing all this, I still get the /same/ pink noise (NOT hum - strange, huh?) and get NO audio, WHAT do I do? Thank you /very much/ for your patience, and my apologies for having forgotten a crucial part of the puzzle. Further help will be greatly appreciated. If anyone wants to see pix of the 2 cartridges or the circuit board where the phono audio cables are soldered into it, I can post them to photobucket or something, OR a binary group if you have binaries access. The replies are different in every one of the 5 groups, so I will post this followup to each group separately. I don't really understand how crossposting works, since I never do it, and eternal september /may/ be "funny" about crossposting to boot. -- Any mental activity is easy if it need not be subjected to reality. |
Phono preamp in old receiver problem
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Phono preamp in old receiver problem
"Brian Gaff" wrote in
: Thanks for replying. Well, it is most unlikely that both the channels woold go down together now I'd imagine. Right. Firstly, if you do not get a buzz when you touch the live of these connections, then something is not as expected. Sharp did tend to do stuff in funny ways though, and as has been said elsewhere you need to find out what the turntable actually did. Was there, for example, as I found on an old Teleton unit of similar vintage, a little extra cable from the turntable to the circuit board? No, there are two (grey and brown, thankfully labeled L and R) RCA cables which plugged into the bottom of the BSR turntable where the 4 wires from the cartridge were soldered to the other side of the 2 RCA connector. I cut them and extended them. And something went wrong, see below. This little line appeared to mute the pick up input in some way, presumably via a switch on the pick up bearing or similar. I got the impression it used an optical switch, but as the unit blew a power amp module shortly afterwards, I never investigated further.. No, someone else suggested the muting device, but I do not think this unit had that... It is an amazing piece of vintage quality TODAY but it was a cheapish thing in its day... As for 8 track carts, most have seized up by now I'd imagine as the tape was lubricated. Akai used to make an 8 track recorder which sounded quite good, but the recording time per track was rubbish and the mechanics were designed to wear out by the looks of it. I am curious to see what the deal is here, IF I can find an 8- track cart. (About 15 yrs ago I knew a guy who had an 8-track of Lou Reed's "Metal Machine Music" !!!!) Quite how you cleaned things is hard to see. I am good at cleaning stuff, and I have a pro circuit board cleaner. I did not use WD-40 - although I /have/ done so in the past, with perfect results. -- Update (very long, I apologize!) -- First of all, many thanks to all who replied. It is very much appreciated. Now for the /bad/ part. Something one person mentioned in his reply made me remember a rather *crucial* detail which I had forgotten (I am not completely senile yet, but I have been /incredibly/ busy for the last few weeks, and my brain is running out of RAM). It is this: BEFORE I removed the BSR turntable, I DID check to see whether there was AUDIO SIGNAL coming from it. There was, loud and clear - when I touched the stylus, it sounded like an earthquake. Very little "system noise", too. The turntable itself was "seized" - after I have (with some violence) managed to take it apart, I saw that the 2 main cog wheels of the belt-less motor were practically frozen together at a bizarre angle and would NOT budge. I have NO idea how that happened - and the 4" screwdriver shaft, 2 children's plastic letters with magnets, and assorted bits of 30+ year old food I found inside the receiver could NOT have had anything to do with it, either, since the BSR motor was fairly well enclosed within the /incredibly/ complicated mechanical design (a changer). Now that I have remembered this, it is obvious I screwed something up. I have never seen a ceramic cartridge, but I am 99.99% positive that BOTH the BSR and the Sony (ca. 1990) turntable carts are magnetic. So, since I have no signal but weird pink noise, I must have screwed up the cables. Or do you think I may have destroyed the preamp? (This may be a good moment to mention that I am using the term "phono preamp" in a generic sense. I always thought a phono preamp might be/would be a small enclosed piece of electronics, but in this receiver, it appears to be a part of the main circuit board - the two original (and now extended) cables from the BSR turntable stylus/arm are soldered right onto the circuit board, and go who-knows-where - presumably, into components which make up this receiver's "phone preamp" section.) (THIS may /also/ be a good moment to mention that while I have had some disastrous luck with simple things and astoundingly good luck with complicated things, I am NOT a technician, and do not own an oscilloscope - I check connections with two gator clips connected to a 1.5V battery with a flashlight bulb, and after over 30 years of "considering it", I finally bought a five dollar "voltmeter" which /appears/ to work - I found out a cheap 110V/22V AC/DC adapter outputs 25VDC when set to 12V output [when the input voltage is set to 110V] and 12.5VDC from its 9V setting [when the input voltage is set to 110V (it is 110V here)]. The Sony turntable (originally a component of a system, with a tiny power connector which plugs into the back of the main system unit and where I found out 12VDC is output) is running on a supposedly "regulated" fancy Radio Shack AC/DC adapter which puts out 11.8V DC. (When I reverse the polarity, the turntable spins backwards.) If anyone has read this far, please accept my deep thanks for your patience. I can't write more concisely - I realize it's an illness. Anyway - the question now is WHAT did I do to mess things up? Since I consider the receiver largely indestructible, I do not think I have *destroyed* anything, not to mention the voltages involved are totally minuscule and it being a solid state unit - as the front panel proudly states ;-) - there is little danger of blowing it up. Plus everything else works. My plan is as follows: 1. Cut the original "BSR cartridge/turntable to the main circuit board" cables, strip ends. 2. Attach gator clips to them and connect to the Sony turntable output cable. 3. Hopefully, hear sound. Extend cables again, making SURE I don't screw up this time. If I hear no sound, I will connect the 4 very thin cables from the original BSR cartridge (I saved the cart assembly and cables before I saw the turntable was connected to the circuit board with 2 standard cables with RCA plugs) to the cut cables leading to the circuit board and see if I hear anything. If I do, I will post for more advice. But for now, my question is: If after doing all this, I still get the /same/ pink noise (NOT hum - strange, huh?) and get NO audio, WHAT do I do? Thank you /very much/ for your patience, and my apologies for having forgotten a crucial part of the puzzle. Further help will be greatly appreciated. If anyone wants to see pix of the 2 cartridges or the circuit board where the phono audio cables are soldered into it, I can post them to photobucket or something, OR a binary group if you have binaries access. The replies are different in every one of the 5 groups, so I will post this followup to each group separately. I don't really understand how crossposting works, since I never do it, and eternal september /may/ be "funny" about crossposting to boot. -- Any mental activity is easy if it need not be subjected to reality. |
Phono preamp in old receiver problem
"Mark Zacharias" wrote in
: Thanks for the reply. snip Perhaps the stylus on the replacement turntable is not quite seated properly. It works perfectly with its original system (see below). This would produce your symptom. No sound when plugged into the (ceramic) phono input, hear a pop w/ unplug, hear low sound on another input. Hmm. The two cartridges, while different, both appear to be magnetic. I can post photos (see below). I'm presuming your original turntable had a ceramic cartridge, but it would help to know if this is true; also what kind of cartridge is in your replacement table. I am 99.99% sure both are magnetic, but I can post photos. Please take the time to read the following. -- Update (very long, I apologize!) -- First of all, many thanks to all who replied. It is very much appreciated. Now for the /bad/ part. Something one person mentioned in his reply made me remember a rather *crucial* detail which I had forgotten (I am not completely senile yet, but I have been /incredibly/ busy for the last few weeks, and my brain is running out of RAM). It is this: BEFORE I removed the BSR turntable, I DID check to see whether there was AUDIO SIGNAL coming from it. There was, loud and clear - when I touched the stylus, it sounded like an earthquake. Very little "system noise", too. The turntable itself was "seized" - after I have (with some violence) managed to take it apart, I saw that the 2 main cog wheels of the belt-less motor were practically frozen together at a bizarre angle and would NOT budge. I have NO idea how that happened - and the 4" screwdriver shaft, 2 children's plastic letters with magnets, and assorted bits of 30+ year old food I found inside the receiver could NOT have had anything to do with it, either, since the BSR motor was fairly well enclosed within the /incredibly/ complicated mechanical design (a changer). Now that I have remembered this, it is obvious I screwed something up. I have never seen a ceramic cartridge, but I am 99.99% positive that BOTH the BSR and the Sony (ca. 1990) turntable carts are magnetic. So, since I have no signal but weird pink noise, I must have screwed up the cables. Or do you think I may have destroyed the preamp? (This may be a good moment to mention that I am using the term "phono preamp" in a generic sense. I always thought a phono preamp might be/would be a small enclosed piece of electronics, but in this receiver, it appears to be a part of the main circuit board - the two original (and now extended) cables from the BSR turntable stylus/arm are soldered right onto the circuit board, and go who-knows-where - presumably, into components which make up this receiver's "phone preamp" section.) (THIS may /also/ be a good moment to mention that while I have had some disastrous luck with simple things and astoundingly good luck with complicated things, I am NOT a technician, and do not own an oscilloscope - I check connections with two gator clips connected to a 1.5V battery with a flashlight bulb, and after over 30 years of "considering it", I finally bought a five dollar "voltmeter" which /appears/ to work - I found out a cheap 110V/22V AC/DC adapter outputs 25VDC when set to 12V output [when the input voltage is set to 110V] and 12.5VDC from its 9V setting [when the input voltage is set to 110V (it is 110V here)]. The Sony turntable (originally a component of a system, with a tiny power connector which plugs into the back of the main system unit and where I found out 12VDC is output) is running on a supposedly "regulated" fancy Radio Shack AC/DC adapter which puts out 11.8V DC. (When I reverse the polarity, the turntable spins backwards.) If anyone has read this far, please accept my deep thanks for your patience. I can't write more concisely - I realize it's an illness. Anyway - the question now is WHAT did I do to mess things up? Since I consider the receiver largely indestructible, I do not think I have *destroyed* anything, not to mention the voltages involved are totally minuscule and it being a solid state unit - as the front panel proudly states ;-) - there is little danger of blowing it up. Plus everything else works. My plan is as follows: 1. Cut the original "BSR cartridge/turntable to the main circuit board" cables, strip ends. 2. Attach gator clips to them and connect to the Sony turntable output cable. 3. Hopefully, hear sound. Extend cables again, making SURE I don't screw up this time. If I hear no sound, I will connect the 4 very thin cables from the original BSR cartridge (I saved the cart assembly and cables before I saw the turntable was connected to the circuit board with 2 standard cables with RCA plugs) to the cut cables leading to the circuit board and see if I hear anything. If I do, I will post for more advice. But for now, my question is: If after doing all this, I still get the /same/ pink noise (NOT hum - strange, huh?) and get NO audio, WHAT do I do? Thank you /very much/ for your patience, and my apologies for having forgotten a crucial part of the puzzle. Further help will be greatly appreciated. If anyone wants to see pix of the 2 cartridges or the circuit board where the phono audio cables are soldered into it, I can post them to photobucket or something, OR a binary group if you have binaries access. The replies are different in every one of the 5 groups, so I will post this followup to each group separately. I don't really understand how crossposting works, since I never do it, and eternal september /may/ be "funny" about crossposting to boot. -- Any mental activity is easy if it need not be subjected to reality. |
Phono preamp in old receiver problem
Tim Schwartz wrote in
: Thanks for your reply. while I don't know your specific Sharp receiver (you did not specify the model number) many 'compact systems' with BSR changers used ceramic cartridges that give a line level output, so this receiver may not have a phono preamp at all. AHA! This WOULD explain /everything/! (Including WHY there does NOT appear to be an identifiable "phone preamp", just the 2 cables going into the circuitry.) The model number is SG-164U. Can you confirm the ceramic cart thing? And is there ANYTHING I can do to make a magnetic cartridge work with this unit? (Buying a phono preamp is OOTQ, it would cost more than a new DVD player, but perhaps I could make one? Would you happen to have a schematic/link to one?) For /all/ the gory details: -- Update (very long, I apologize!) -- First of all, many thanks to all who replied. It is very much appreciated. Now for the /bad/ part. Something one person mentioned in his reply made me remember a rather *crucial* detail which I had forgotten (I am not completely senile yet, but I have been /incredibly/ busy for the last few weeks, and my brain is running out of RAM). It is this: BEFORE I removed the BSR turntable, I DID check to see whether there was AUDIO SIGNAL coming from it. There was, loud and clear - when I touched the stylus, it sounded like an earthquake. Very little "system noise", too. The turntable itself was "seized" - after I have (with some violence) managed to take it apart, I saw that the 2 main cog wheels of the belt-less motor were practically frozen together at a bizarre angle and would NOT budge. I have NO idea how that happened - and the 4" screwdriver shaft, 2 children's plastic letters with magnets, and assorted bits of 30+ year old food I found inside the receiver could NOT have had anything to do with it, either, since the BSR motor was fairly well enclosed within the /incredibly/ complicated mechanical design (a changer). Now that I have remembered this, it is obvious I screwed something up. I have never seen a ceramic cartridge, but I am 99.99% positive that BOTH the BSR and the Sony (ca. 1990) turntable carts are magnetic. So, since I have no signal but weird pink noise, I must have screwed up the cables. Or do you think I may have destroyed the preamp? (This may be a good moment to mention that I am using the term "phono preamp" in a generic sense. I always thought a phono preamp might be/would be a small enclosed piece of electronics, but in this receiver, it appears to be a part of the main circuit board - the two original (and now extended) cables from the BSR turntable stylus/arm are soldered right onto the circuit board, and go who-knows-where - presumably, into components which make up this receiver's "phone preamp" section.) (THIS may /also/ be a good moment to mention that while I have had some disastrous luck with simple things and astoundingly good luck with complicated things, I am NOT a technician, and do not own an oscilloscope - I check connections with two gator clips connected to a 1.5V battery with a flashlight bulb, and after over 30 years of "considering it", I finally bought a five dollar "voltmeter" which /appears/ to work - I found out a cheap 110V/22V AC/DC adapter outputs 25VDC when set to 12V output [when the input voltage is set to 110V] and 12.5VDC from its 9V setting [when the input voltage is set to 110V (it is 110V here)]. The Sony turntable (originally a component of a system, with a tiny power connector which plugs into the back of the main system unit and where I found out 12VDC is output) is running on a supposedly "regulated" fancy Radio Shack AC/DC adapter which puts out 11.8V DC. (When I reverse the polarity, the turntable spins backwards.) If anyone has read this far, please accept my deep thanks for your patience. I can't write more concisely - I realize it's an illness. Anyway - the question now is WHAT did I do to mess things up? Since I consider the receiver largely indestructible, I do not think I have *destroyed* anything, not to mention the voltages involved are totally minuscule and it being a solid state unit - as the front panel proudly states ;-) - there is little danger of blowing it up. Plus everything else works. My plan is as follows: 1. Cut the original "BSR cartridge/turntable to the main circuit board" cables, strip ends. 2. Attach gator clips to them and connect to the Sony turntable output cable. 3. Hopefully, hear sound. Extend cables again, making SURE I don't screw up this time. If I hear no sound, I will connect the 4 very thin cables from the original BSR cartridge (I saved the cart assembly and cables before I saw the turntable was connected to the circuit board with 2 standard cables with RCA plugs) to the cut cables leading to the circuit board and see if I hear anything. If I do, I will post for more advice. But for now, my question is: If after doing all this, I still get the /same/ pink noise (NOT hum - strange, huh?) and get NO audio, WHAT do I do? Thank you /very much/ for your patience, and my apologies for having forgotten a crucial part of the puzzle. Further help will be greatly appreciated. If anyone wants to see pix of the 2 cartridges or the circuit board where the phono audio cables are soldered into it, I can post them to photobucket or something, OR a binary group if you have binaries access. The replies are different in every one of the 5 groups, so I will post this followup to each group separately. I don't really understand how crossposting works, since I never do it, and eternal september /may/ be "funny" about crossposting to boot. -- Any mental activity is easy if it need not be subjected to reality. |
Phono preamp in old receiver problem
"thanatoid" wrote
And is there ANYTHING I can do to make a magnetic cartridge work with this unit? (Buying a phono preamp is OOTQ, it would cost more than a new DVD player, but perhaps I could make one? Would you happen to have a schematic/link to one?) Low-cost phono pre-amps are readily available. As you appear to live in the US could I suggest looking at what Radio Shack has to offer? You should be able to get a simple phono pre-amp on a small PCB (no case, connectors or power supply) for a *lot* less than the cost of a DVD player and for little more than the retail cost of the components. David. |
Phono preamp in old receiver problem
"David Looser" wrote in
: snip Low-cost phono pre-amps are readily available. As you appear to live in the US could I suggest looking at what Radio Shack has to offer? You should be able to get a simple phono pre-amp on a small PCB (no case, connectors or power supply) for a *lot* less than the cost of a DVD player and for little more than the retail cost of the components. I use eternal september but I live in a god forsaken horrible 3rd world country (without a SINGLE Usenet server, paid or otherwise) where everything is either unavailable, does not work (returns or exchanges are not a known concept here) or costs 2-5 times what it does in civilization. Are you saying the unit DOES use a ceramic cartridge? Is it possible to put a ceramic cartridge in the Sony turntable? (I can probably find a car. cart. /somewhere/...) -- Any mental activity is easy if it need not be subjected to reality. |
Phono preamp in old receiver problem
"Peter Larsen" wrote in
k: snip Are you sure the original turntable had a magnetic cartridge? - and if so, did it contain a preamp for it? Thanks for replying. I'm /not at all/ sure now. Someone in another group just said he is almost certain the Sharp units of that vintage used ceramic cartridges, which would explain /everything/. Also, please see below (heavily edited for you ;-) : (...) Something one person mentioned in his reply made me remember a rather *crucial* detail which I had forgotten (I am not completely senile yet, but I have been /incredibly/ busy for the last few weeks, and my brain is running out of RAM). It is this: BEFORE I removed the BSR turntable, I DID check to see whether there was AUDIO SIGNAL coming from it. There was, loud and clear - when I touched the stylus, it sounded like an earthquake. Very little "system noise", too. Now that I have remembered this, it is obvious I screwed something up. I have never seen a ceramic cartridge, but I am 99.99% positive that BOTH the BSR and the Sony (ca. 1990) turntable carts are magnetic. So, since I have no signal but weird pink noise, I must have screwed up the cables. Or do you think I may have destroyed the preamp? (This may be a good moment to mention that I am using the term "phono preamp" in a generic sense. I always thought a phono preamp might be/would be a small enclosed piece of electronics, but in this receiver, it appears to be a part of the main circuit board - the two original (and now extended) cables from the BSR turntable stylus/arm are soldered right onto the circuit board, and go who-knows-where - presumably, into components which make up this receiver's "phone preamp" section.) (...) -- Any mental activity is easy if it need not be subjected to reality. |
Phono preamp in old receiver problem
"thanatoid" wrote in message
Now that I have remembered this, it is obvious I screwed something up. I have never seen a ceramic cartridge, but I am 99.99% positive that BOTH the BSR and the Sony (ca. 1990) turntable carts are magnetic. So, since I have no signal but weird pink noise, I must have screwed up the cables. Or do you think I may have destroyed the preamp? How old is the BSR? Most of the BSR turntables I am familiar with from the 60s and 70s were cheaper than cheap and had ceramic cartridges. |
Phono preamp in old receiver problem
|
Phono preamp in old receiver problem
On 9/9/2010 10:08 AM thanatoid spake thus:
"David Looser" wrote in : snip Low-cost phono pre-amps are readily available. As you appear to live in the US could I suggest looking at what Radio Shack has to offer? You should be able to get a simple phono pre-amp on a small PCB (no case, connectors or power supply) for a *lot* less than the cost of a DVD player and for little more than the retail cost of the components. I use eternal september but I live in a god forsaken horrible 3rd world country (without a SINGLE Usenet server, paid or otherwise) where everything is either unavailable, does not work (returns or exchanges are not a known concept here) or costs 2-5 times what it does in civilization. Are you saying the unit DOES use a ceramic cartridge? Is it possible to put a ceramic cartridge in the Sony turntable? (I can probably find a car. cart. /somewhere/...) Couple points to try to allay further confusion: 1. Even a ceramic cartridge requires a preamp, but one that has different equalization from one for a magnetic cartridge. A ceramic cartridge does *not* output a line-level signal. 2. As someone else said, you can get small, standalone phono preamps (for mag. carts) for not very much. No need for a fancy-schmancy full-featured preamp. You could permanently wire it into the unit and would be on your way. 3. Ceramic cartridges aren't as good (fidelity-wise) as magnetics, and aren't as kind to your records either (less compliance). So try to use a decent magnetic cartridge. -- The fashion in killing has an insouciant, flirty style this spring, with the flaunting of well-defined muscle, wrapped in flags. - Comment from an article on Antiwar.com (http://antiwar.com) |
Phono preamp in old receiver problem
"Brian Gaff" wrote in
: snip I guess you could have shorted the inputs out in some way though. Its a pity you don't have the circuit as this might help. Brian There are service manuals listed on the web, but they are $15 and up. I am fixing this Sharp to sell it - I do not need it, although it is probably a better 20-30W/side power amp than anything you can buy now for under $100 or so. And it has outputs for 2 sets of speakers - very nice feature. I doubt I will get much - if ANYTHING - for it, but I hate throwing nice old stuff away. OTOH, people just do NOT appreciate treasures like this. Someone just GAVE it to me. I may end up keeping it, it is cute as hell, and works great as AM radio or line-in amplifier. I have another (better than the Sony) turntable plugged into a perfectly good stereo which I am using to transfer old vinyl to mp3. (My old ears can't hear the difference much anymore.) Thanks for your comments. -- Any mental activity is easy if it need not be subjected to reality. |
Phono preamp in old receiver problem
"Arny Krueger" wrote in
: snip How old is the BSR? Most of the BSR turntables I am familiar with from the 60s and 70s were cheaper than cheap and had ceramic cartridges. The BSR was factory-mounted on top of the Sharp SG-164U receiver/8-track unit. My guess is that it is from 1970 (+/- 5 years). -- Any mental activity is easy if it need not be subjected to reality. |
Phono preamp in old receiver problem
"thanatoid" wrote in message ... Hi all, I have an old Sharp AM/FM receiver with an 8-track player. Made in Japan ca. 1975 or something. It had a BSR turntable which was broken. I removed the seized turntable, cleaned the whole unit, sprayed all the pots, replaced the three little 6V bulbs behind the black/green tuner window, and it is fabulous. It's built like a tank and weighs a ton. The pots feel like military grade stuff. The function switches are simply unbelievable. The front panel is white (OK, bone now) with black controls, the box is all wood with the then-standard "vinyl wood veneer". I have a spare turntable which works perfectly. I intended to connect it to the phono preamp of this receiver. I did, but I am not getting sound. I am getting low-frequency pink noise, but no audio signal. What is even stranger is that I hear one of the channels "pop" when I dis/connect ONE of the two RCA audio cables going into the phono preamp of the receiver. I tested all the cables after extending them, and they are OK (see below). I tried connecting the turntable signal to the line input, and it DOES work. Of course, the signal is VERY low, but you CAN hear the LP playing with the volume full up. So either I DID somehow **** up the audio cable assembly (it tests OK though!) or the phono preamp is partially or totally NG, in which case there is probably nothing that can be done. The line inputs can be used for a CD/DVD player, the receiver works as a 4-speaker unit or 2 main/2 remote speakers, and it sounds great. AM and line in are loud as hell, FM volume is about 30% of that, but still usable. Does anyone have any idea what I should do first? I want to determine exactly /what/ in the chain from the *turntable audio cables/cable extensions/original RCA plugs and cable/circuit board* is NG. (The phonograph audio cables were only long enough to reach the bottom of the turntable, which was 3 inches above the main circuit board, now they have to reach to the back and out of the unit, so I had to add about 8 inches of cable - but I tested the cables, both channels, live /and/ ground, and I made NO mistakes - everything was connected/soldered correctly. If the phono preamp is dead, it's dead. The unit is still a /great/ AM (and decent FM) receiver and line-in amplifier, handles TWO sets of stereo speakers, and it will outlast all of us. I have yet to find an 8-track cartridge, but the mechanism and all the belts seem fine. Plus I don't think anyone needs an 8-track deck, while /quite/ a few people might enjoy having a receiver with a phono preamp. Unless the phono preamp IS dead, of course. But maybe someone can help me determine if it actually IS dead... I /tried/ to make this short, really! Any advice will be greatly appreciated. Whenever I try to mate two or more pieces of equipment that were not originally made for one another, I have a problem with grounds. You should attempt to get the schematics of both pieces of equipment, and make sure the grounding of both pieces is compatible. |
Phono preamp in old receiver problem
David Nebenzahl wrote in
.com: snip Couple points to try to allay further confusion: 1. Even a ceramic cartridge requires a preamp, but one that has different equalization from one for a magnetic cartridge. A ceramic cartridge does *not* output a line-level signal. I just found that out on a web site. But I am still not sure if the cartridge IS ceramic. I guess I will have to strip the 4 long thin wires from the original cartridge (I saved it) and connect it to the now- extended cable. If it works - and /something/ tells me it will, the cables were high quality so even I could not screw up the simple solder jobs - then the BSR cart is ceramic and the matter ends there. The unit will make a *great* AM/line in receiver, and an acceptable FM receiver. It has a very cool retro look, being white with black knobs. /And/ it has 2 sets of speaker outputs. 2. As someone else said, you can get small, standalone phono preamps (for mag. carts) for not very much. No need for a fancy-schmancy full-featured preamp. You could permanently wire it into the unit and would be on your way. As I said to DL: I use eternal september but I live in a god forsaken horrible 3rd world country (without a SINGLE Usenet server, paid or otherwise) where everything is either unavailable, does not work (returns or exchanges are not a known concept here) or costs 2-5 times what it does in civilization. I saw one online for US$30. It would cost me at least $75 here, with a 3 month special order wait and no warranty/return. If I buy it online myself, assuming they even ship here, it will get stolen by local "postal employees". FedEx is not worth the cost, see last paragraph. 3. Ceramic cartridges aren't as good (fidelity-wise) as magnetics, and aren't as kind to your records either (less compliance). So try to use a decent magnetic cartridge. I know - but this is just a little hobby project - I like old stuff and I hate to throw away something that works. I have a stereo with a Dolby B/C deck and a Philips turntable which I am using to transfer my old vinyl and cassettes to mp3. Nothing great, but it does the job, even though it is about 20 years old - "Made in Japan" ;-) -- Any mental activity is easy if it need not be subjected to reality. |
Phono preamp RESOLVED - thanks to all who helped!
"Bill Graham" wrote in
: Whenever I try to mate two or more pieces of equipment that were not originally made for one another, I have a problem with grounds. You should attempt to get the schematics of both pieces of equipment, and make sure the grounding of both pieces is compatible. From my experience, ground is ground, plus no one here will even realize the old ceramic cart housing did NOT come with the Sony tt. *IF* it ever gets to that. Anyway - problem resolved. The ****ing BSR cartridge is ceramic. I had forgotten such things were ever manufactured. (I saved the cartridge before destroying the BSR tt, and just tested it. Sigh. Perfect. For finger on needle, NG for playing /records/ of course... Cart comes with a (5th) ground wire.) So now I have to buy a new stylus, and figure out how to attach the BSR cart housing to a Sony tt arm. Or not, and just use it as a super cool retro AM/line in system. Thanks to all who helped! -- Any mental activity is easy if it need not be subjected to reality. |
Phono preamp in old receiver problem
"thanatoid" wrote in message
"Arny Krueger" wrote in : snip How old is the BSR? Most of the BSR turntables I am familiar with from the 60s and 70s were cheaper than cheap and had ceramic cartridges. The BSR was factory-mounted on top of the Sharp SG-164U receiver/8-track unit. My guess is that it is from 1970 (+/- 5 years). Indubitably a ceramic cartridge. |
Phono preamp in old receiver problem
"Arny Krueger" wrote in
: "thanatoid" wrote in message "Arny Krueger" wrote in : snip How old is the BSR? Most of the BSR turntables I am familiar with from the 60s and 70s were cheaper than cheap and had ceramic cartridges. The BSR was factory-mounted on top of the Sharp SG-164U receiver/8-track unit. My guess is that it is from 1970 (+/- 5 years). Indubitably a ceramic cartridge. Correct. See my post from last night with "resolved" in title. BTW, I remember always hearing BSRs were crap, but this one seemed not bad - except for the fact that it had seized up (can ANYONE explain what may have happened?), it appeared very well- built. The best turntable /I/ ever owned was a Swiss Lenco with a little weight on a string for anti-skating. It was sold for under $100 in 1974, too! -- Any mental activity is easy if it need not be subjected to reality. |
Phono preamp in old receiver problem
On 9/10/2010 8:14 AM thanatoid spake thus:
The best turntable /I/ ever owned was a Swiss Lenco with a little weight on a string for anti-skating. It was sold for under $100 in 1974, too! Hmm; my best turntable, the one I have now, a Thorens TD 166, also uses the little weight-on-a-string (nylon monofilament, ackshooly) for anti-skating. Simple, clever and effective system. (Mine has 3 different weights and a bunch of notches on the pegs that the strings run over for lots of possible adjustment.) -- The fashion in killing has an insouciant, flirty style this spring, with the flaunting of well-defined muscle, wrapped in flags. - Comment from an article on Antiwar.com (http://antiwar.com) |
Phono preamp in old receiver problem
David Nebenzahl wrote in
.com: On 9/10/2010 8:14 AM thanatoid spake thus: The best turntable /I/ ever owned was a Swiss Lenco with a little weight on a string for anti-skating. It was sold for under $100 in 1974, too! Hmm; my best turntable, the one I have now, a Thorens TD 166, also uses the little weight-on-a-string (nylon monofilament, ackshooly) for anti-skating. Simple, clever and effective system. (Mine has 3 different weights and a bunch of notches on the pegs that the strings run over for lots of possible adjustment.) Mine didn't have 3 weights, perhaps 2 - it's been a while - I sold it after 1 year since I was moving, and have regretted it ever since then! BTW, this is GREAT: "The fashion in killing has an insouciant, flirty style this spring, with the flaunting of well-defined muscle, wrapped in flags." I will have to check out the site. Ever heard of Momus, a British genius? "This year's fashion in crime will be Less child abuse, more blasphemy Morality is vanity The ugly given flattery grow vain" (full lyrics @ http://www.phespirit.info/momus/19900101.htm) -- Any mental activity is easy if it need not be subjected to reality. |
Phono preamp RESOLVED - thanks to all who helped!
Well some ceramics were not at all bad. The deram for one.
Of course I'd imagine it would be easy enough to make a little amp for the magnetic cart and match it to the high impedence input of the sharp. I'm a little perplexed though why the Sharp did not hum like mad with nothing connected at all. Brian -- Brian Gaff....Note, this account does not accept Bcc: email. graphics are great, but the blind can't hear them Email: __________________________________________________ __________________________________________________ __________ "thanatoid" wrote in message ... "Bill Graham" wrote in : Whenever I try to mate two or more pieces of equipment that were not originally made for one another, I have a problem with grounds. You should attempt to get the schematics of both pieces of equipment, and make sure the grounding of both pieces is compatible. From my experience, ground is ground, plus no one here will even realize the old ceramic cart housing did NOT come with the Sony tt. *IF* it ever gets to that. Anyway - problem resolved. The ****ing BSR cartridge is ceramic. I had forgotten such things were ever manufactured. (I saved the cartridge before destroying the BSR tt, and just tested it. Sigh. Perfect. For finger on needle, NG for playing /records/ of course... Cart comes with a (5th) ground wire.) So now I have to buy a new stylus, and figure out how to attach the BSR cart housing to a Sony tt arm. Or not, and just use it as a super cool retro AM/line in system. Thanks to all who helped! -- Any mental activity is easy if it need not be subjected to reality. |
Phono preamp RESOLVED - thanks to all who helped!
"Brian Gaff" wrote in
: Well some ceramics were not at all bad. The deram for one. Of course I'd imagine it would be easy enough to make a little amp for the magnetic cart and match it to the high impedence input of the sharp. I'm a little perplexed though why the Sharp did not hum like mad with nothing connected at all. I have 0 experience with ceramic carts. but the Sharp seems to be a VERY well built unit overall. I would choose it, AS IS, over /anything/ under $150 made today. -- Any mental activity is easy if it need not be subjected to reality. |
Phono preamp in old receiver problem
"thanatoid" wrote in message ... Ever heard of Momus, a British genius? "This year's fashion in crime will be Less child abuse, more blasphemy Morality is vanity The ugly given flattery grow vain" (full lyrics @ http://www.phespirit.info/momus/19900101.htm) Yes. Nicholas Currie from Paisley. I have worked with him. He is a very interesting, highly contraversial character. Iain |
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