
September 9th 10, 03:51 PM
posted to uk.rec.audio
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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
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September 9th 10, 05:08 PM
posted to uk.rec.audio
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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.
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September 9th 10, 07:11 PM
posted to uk.rec.audio
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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)
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September 9th 10, 11:55 PM
posted to uk.rec.audio
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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.
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September 9th 10, 11:51 PM
posted to uk.rec.audio
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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.
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September 11th 10, 06:27 PM
posted to uk.rec.audio
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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.
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September 12th 10, 02:25 AM
posted to uk.rec.audio
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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.
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