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Looking for a small bit of gain
I have a mixer here which is din based but a sound box for the computer
which is line based and at full up there is not enough level. What I was looking for is a little amplifier which I could put in between one and the other to leave and forget that has no hum hiss or other nasty habits. Anyone seen anything like this around? Brian -- ----- - This newsgroup posting comes to you directly from... The Sofa of Brian Gaff... Blind user, so no pictures please! |
Looking for a small bit of gain
In article ,
Brian Gaff wrote: I have a mixer here which is din based but a sound box for the computer which is line based and at full up there is not enough level. What I was looking for is a little amplifier which I could put in between one and the other to leave and forget that has no hum hiss or other nasty habits. Anyone seen anything like this around? Brian You'd think they'd be common, given how often this sort of thing arises. But they don't seem to be. -- *Time is fun when you're having flies... Kermit Dave Plowman London SW To e-mail, change noise into sound. |
Looking for a small bit of gain
Humph, well i thought it was me.
a single transistor stage with, say an emitter follower would suffice though these days the over designers would probably use an Ic. Brian -- ----- - This newsgroup posting comes to you directly from... The Sofa of Brian Gaff... Blind user, so no pictures please! "Dave Plowman (News)" wrote in message ... In article , Brian Gaff wrote: I have a mixer here which is din based but a sound box for the computer which is line based and at full up there is not enough level. What I was looking for is a little amplifier which I could put in between one and the other to leave and forget that has no hum hiss or other nasty habits. Anyone seen anything like this around? Brian You'd think they'd be common, given how often this sort of thing arises. But they don't seem to be. -- *Time is fun when you're having flies... Kermit Dave Plowman London SW To e-mail, change noise into sound. |
Looking for a small bit of gain
On Tue, 4 Jul 2017 19:23:34 +0100, "Brian Gaff"
wrote: a single transistor stage with, say an emitter follower would suffice though these days the over designers would probably use an Ic. Brian Under-designers, you mean. With an IC you don't have to do any design - just set two resistors to give you the gain you want. And that is exactly how I would do this - it's by far the best way. d --- This email has been checked for viruses by Avast antivirus software. https://www.avast.com/antivirus |
Looking for a small bit of gain
If you don't want the faff of getting the bits and building it then
N47FL at £6.99 from Maplin will do the job. Uses a NE5532 amp chip so should be very low noise. Supply is 3-25V so any old PSU you have lying around.... -- Woody harrogate3 at ntlworld dot com |
Looking for a small bit of gain
On Tue, 4 Jul 2017 20:27:14 +0100, "Woody"
wrote: If you don't want the faff of getting the bits and building it then N47FL at £6.99 from Maplin will do the job. Uses a NE5532 amp chip so should be very low noise. Supply is 3-25V so any old PSU you have lying around.... That is exactly what brian is looking for d --- This email has been checked for viruses by Avast antivirus software. https://www.avast.com/antivirus |
Looking for a small bit of gain
On 04/07/2017 20:27, Woody wrote:
If you don't want the faff of getting the bits and building it then N47FL at £6.99 from Maplin will do the job. Uses a NE5532 amp chip so should be very low noise. Supply is 3-25V so any old PSU you have lying around.... "Fun to solder…" Not an expression I would use :-) -- Graeme Wall This account not read. |
Looking for a small bit of gain
"Don Pearce" wrote in message ... On Tue, 4 Jul 2017 20:27:14 +0100, "Woody" wrote: If you don't want the faff of getting the bits and building it then N47FL at £6.99 from Maplin will do the job. Uses a NE5532 amp chip so should be very low noise. Supply is 3-25V so any old PSU you have lying around.... That is exactly what brian is looking for Was it Brian that was looking for it? I thought it was Duncan or Dave. Brian might have a problem with it as it is in kit form! -- Woody harrogate3 at ntlworld dot com |
Looking for a small bit of gain
On Tue, 4 Jul 2017 20:41:11 +0100, "Woody"
wrote: "Don Pearce" wrote in message ... On Tue, 4 Jul 2017 20:27:14 +0100, "Woody" wrote: If you don't want the faff of getting the bits and building it then N47FL at £6.99 from Maplin will do the job. Uses a NE5532 amp chip so should be very low noise. Supply is 3-25V so any old PSU you have lying around.... That is exactly what brian is looking for Was it Brian that was looking for it? I thought it was Duncan or Dave. Brian might have a problem with it as it is in kit form! I'm sure he can find someone happy to put that together. d --- This email has been checked for viruses by Avast antivirus software. https://www.avast.com/antivirus |
Looking for a small bit of gain
"Graeme Wall" wrote in message ... On 04/07/2017 20:27, Woody wrote: If you don't want the faff of getting the bits and building it then N47FL at £6.99 from Maplin will do the job. Uses a NE5532 amp chip so should be very low noise. Supply is 3-25V so any old PSU you have lying around.... "Fun to solder." Not an expression I would use :-) -- Graeme Wall This account not read. I would be grateful if contributors would make sure they attribute comments to their sources. The quote above is exactly what I wrote and I said nothing about 'fun to solder.' Mind you if you have been taught and know how to solder properly it is easy and can be 'fun.' -- Woody harrogate3 at ntlworld dot com |
Looking for a small bit of gain
Bah humbug.
It just seems to be like building a floating hotel and using it as a garden shed. Brian -- ----- - This newsgroup posting comes to you directly from... The Sofa of Brian Gaff... Blind user, so no pictures please! "Don Pearce" wrote in message ... On Tue, 4 Jul 2017 19:23:34 +0100, "Brian Gaff" wrote: a single transistor stage with, say an emitter follower would suffice though these days the over designers would probably use an Ic. Brian Under-designers, you mean. With an IC you don't have to do any design - just set two resistors to give you the gain you want. And that is exactly how I would do this - it's by far the best way. d --- This email has been checked for viruses by Avast antivirus software. https://www.avast.com/antivirus |
Looking for a small bit of gain
OK look into that. I wonder what current it uses, Might well run on a pp3
battery then. Brian -- ----- - This newsgroup posting comes to you directly from... The Sofa of Brian Gaff... Blind user, so no pictures please! "Woody" wrote in message ... If you don't want the faff of getting the bits and building it then N47FL at £6.99 from Maplin will do the job. Uses a NE5532 amp chip so should be very low noise. Supply is 3-25V so any old PSU you have lying around.... -- Woody harrogate3 at ntlworld dot com |
Looking for a small bit of gain
On Wed, 5 Jul 2017 08:31:34 +0100, "Brian Gaff"
wrote: Bah humbug. It just seems to be like building a floating hotel and using it as a garden shed. Brian Those days are long gone. Op-amps are basic building blocks these days. They are much better characterized than individual transistors, and generally come out as a cheaper and easier option. d --- This email has been checked for viruses by Avast antivirus software. https://www.avast.com/antivirus |
Looking for a small bit of gain
In article , Don Pearce
wrote: On Tue, 4 Jul 2017 19:23:34 +0100, "Brian Gaff" wrote: a single transistor stage with, say an emitter follower would suffice though these days the over designers would probably use an Ic. Brian Under-designers, you mean. With an IC you don't have to do any design - just set two resistors to give you the gain you want. And that is exactly how I would do this - it's by far the best way. If it were me I'd probably buy one of the cheap kits I used for http://www.audiomisc.co.uk/HFN/HeadDAC2/HeadDAC2.html Jim -- Please use the address on the audiomisc page if you wish to email me. Electronics https://www.st-andrews.ac.uk/~www_pa...o/electron.htm Armstrong Audio http://www.audiomisc.co.uk/Armstrong/armstrong.html Audio Misc http://www.audiomisc.co.uk/index.html |
Looking for a small bit of gain
On Wed, 05 Jul 2017 10:11:34 +0100, Jim Lesurf
wrote: In article , Don Pearce wrote: On Tue, 4 Jul 2017 19:23:34 +0100, "Brian Gaff" wrote: a single transistor stage with, say an emitter follower would suffice though these days the over designers would probably use an Ic. Brian Under-designers, you mean. With an IC you don't have to do any design - just set two resistors to give you the gain you want. And that is exactly how I would do this - it's by far the best way. If it were me I'd probably buy one of the cheap kits I used for http://www.audiomisc.co.uk/HFN/HeadDAC2/HeadDAC2.html I don't know if the board is laid out for gain, but your headphone amp shows a unity-gain circuit only. I can't imagine they failed to make provision for gain, though. d --- This email has been checked for viruses by Avast antivirus software. https://www.avast.com/antivirus |
Looking for a small bit of gain
On 5/07/2017 4:23 AM, Brian Gaff wrote:
Humph, well i thought it was me. a single transistor stage with, say an emitter follower would suffice though these days the over designers would probably use an Ic. Brian **And just to nit-pick: With a single transistor, operating as emitter follower, you have a Voltage gain of less than 1. Just sayin'. I think you mean 'common emitter'. An OP amp is very, very easy, cheap and simple to implement. Distortion is almost non-existent too. -- Trevor Wilson www.rageaudio.com.au |
Looking for a small bit of gain
In article , Don Pearce
wrote: If it were me I'd probably buy one of the cheap kits I used for http://www.audiomisc.co.uk/HFN/HeadDAC2/HeadDAC2.html I don't know if the board is laid out for gain, but your headphone amp shows a unity-gain circuit only. I can't imagine they failed to make provision for gain, though. I altered the circuit. As supplied the components and diagram give some gain. In effect its a cheap way of getting a set of components and board for a stereo gain block. Jim -- Please use the address on the audiomisc page if you wish to email me. Electronics https://www.st-andrews.ac.uk/~www_pa...o/electron.htm Armstrong Audio http://www.audiomisc.co.uk/Armstrong/armstrong.html Audio Misc http://www.audiomisc.co.uk/index.html |
Looking for a small bit of gain
In article ,
Don Pearce wrote: On Wed, 05 Jul 2017 10:11:34 +0100, Jim Lesurf wrote: In article , Don Pearce wrote: On Tue, 4 Jul 2017 19:23:34 +0100, "Brian Gaff" wrote: a single transistor stage with, say an emitter follower would suffice though these days the over designers would probably use an Ic. Brian Under-designers, you mean. With an IC you don't have to do any design - just set two resistors to give you the gain you want. And that is exactly how I would do this - it's by far the best way. If it were me I'd probably buy one of the cheap kits I used for http://www.audiomisc.co.uk/HFN/HeadDAC2/HeadDAC2.html I don't know if the board is laid out for gain, but your headphone amp shows a unity-gain circuit only. I can't imagine they failed to make provision for gain, though. Something always worries me about using a 5 volt single supply for line level audio - assuming it is used neat. In the old days, 24v was the sort of norm for pro stuff. Admittedly line level is higher with that. But when ICs came along was +/-15v or more. Remember reading a criticism of the Quad 33 pre-amp citing its 12v as being too low. -- *Wood burns faster when you have to cut and chop it yourself. Dave Plowman London SW To e-mail, change noise into sound. |
Looking for a small bit of gain
In article , Dave Plowman (News)
wrote: If it were me I'd probably buy one of the cheap kits I used for http://www.audiomisc.co.uk/HFN/HeadDAC2/HeadDAC2.html I don't know if the board is laid out for gain, but your headphone amp shows a unity-gain circuit only. I can't imagine they failed to make provision for gain, though. Something always worries me about using a 5 volt single supply for line level audio - assuming it is used neat. In the old days, 24v was the sort of norm for pro stuff. Admittedly line level is higher with that. But when ICs came along was +/-15v or more. The HeadDAC2 situation has the max input level set by the DAC I chose. Which is also powered by the same circa 5V line. It doesn't clip early in practice. In other circumstances I prefer a twin-rail. So I've used the same kit as a basis for a heaphone amp and HF filter for my ARMX6, but in this case using +/- 5V. Again, I know what the max input level will be. Remember reading a criticism of the Quad 33 pre-amp citing its 12v as being too low. That really depends on factors like if there is an active gain stage before any volume controls and what else might limit the max input, what the clipping behaviour is like, etc. The problem here in general commercial kit is to guess what the user will connect. I've had a case of someone connecting mains power to a LS output, which isn't what the designer expects to have to cater for! 8-] The 33 also comes from an age well before the CD audio standard of 2V signals. But does offer the magic of the 'keymatic'... FWIW In the Armstrong 700 preamp I used +/- 21V rails and had a volume control before the active stages. (Except for RIAA, which also has +/- 21V rails.) Sadly that didn't stop a reviewer talking nonsense about its clipping levels. But then, that's magazine reviewing, innit! 8-] Jim -- Please use the address on the audiomisc page if you wish to email me. Electronics https://www.st-andrews.ac.uk/~www_pa...o/electron.htm Armstrong Audio http://www.audiomisc.co.uk/Armstrong/armstrong.html Audio Misc http://www.audiomisc.co.uk/index.html |
Looking for a small bit of gain
On Wed, 05 Jul 2017 13:23:10 +0100, "Dave Plowman (News)"
wrote: In article , Don Pearce wrote: On Wed, 05 Jul 2017 10:11:34 +0100, Jim Lesurf wrote: In article , Don Pearce wrote: On Tue, 4 Jul 2017 19:23:34 +0100, "Brian Gaff" wrote: a single transistor stage with, say an emitter follower would suffice though these days the over designers would probably use an Ic. Brian Under-designers, you mean. With an IC you don't have to do any design - just set two resistors to give you the gain you want. And that is exactly how I would do this - it's by far the best way. If it were me I'd probably buy one of the cheap kits I used for http://www.audiomisc.co.uk/HFN/HeadDAC2/HeadDAC2.html I don't know if the board is laid out for gain, but your headphone amp shows a unity-gain circuit only. I can't imagine they failed to make provision for gain, though. Something always worries me about using a 5 volt single supply for line level audio - assuming it is used neat. In the old days, 24v was the sort of norm for pro stuff. Admittedly line level is higher with that. But when ICs came along was +/-15v or more. Remember reading a criticism of the Quad 33 pre-amp citing its 12v as being too low. This is true, but given that the signal is too low, it is probably reasonably safe to do this. I have to say, though, I would not run it off 5V - I would give it at least +/- 12V. d --- This email has been checked for viruses by Avast antivirus software. https://www.avast.com/antivirus |
Looking for a small bit of gain
On 05/07/2017 07:22, Woody wrote:
"Graeme Wall" wrote in message ... On 04/07/2017 20:27, Woody wrote: If you don't want the faff of getting the bits and building it then N47FL at £6.99 from Maplin will do the job. Uses a NE5532 amp chip so should be very low noise. Supply is 3-25V so any old PSU you have lying around.... "Fun to solder." Not an expression I would use :-) -- Graeme Wall This account not read. I would be grateful if contributors would make sure they attribute comments to their sources. The quote above is exactly what I wrote and I said nothing about 'fun to solder.' That's what it said on the page linked to. Mind you if you have been taught and know how to solder properly it is easy and can be 'fun.' I have been taught and know how to but it is still just a chore. -- Graeme Wall This account not read. |
Looking for a small bit of gain
In article ,
Brian Gaff wrote: Sigh, I'll have to talk nice to some sighted people with soldering irons then won't I? Not quite figured out how they make up 22 bits for such a devce. Still. If you want one built, Brian, I'll happily do it for you. -- *Oh, what a tangled website we weave when first we practice * Dave Plowman London SW To e-mail, change noise into sound. |
Looking for a small bit of gain
On Wed, 05 Jul 2017 08:48:36 +0100, Bob Latham wrote:
In article , Don Pearce wrote: On Tue, 4 Jul 2017 19:23:34 +0100, "Brian Gaff" wrote: a single transistor stage with, say an emitter follower would suffice though these days the over designers would probably use an Ic. Brian I'm confused again. When I went to school an emitter follower had no voltage gain, it had current gain for want of a better expression. Under-designers, you mean. With an IC you don't have to do any design - just set two resistors to give you the gain you want. And that is exactly how I would do this - it's by far the best way. Yes. Use non inverting config for lowest noise and then if I recall correctly gain = 1 + (R-feedback / R-ground). No problems as you do not require a gain of less than 1. And, as it's being fed from the presumed Hi-Z DIN output designed to act as a constant current source to feed Lo-Z DIN inputs, a simple Hi-Z input unity gain buffer amp may be all that's required to feed a mid-Z phono input with enough signal voltage. The only benefits I can see with the DIN standard of constant current sources feeding low impedance inputs is the automatic muting of interference to unused inputs and the ability to join several sources, each with their own volume control, to a single input to provide crude but effective audio mixing (which makes the phrase "Sound mixer with DIN output" a little oxymoronic to say the least - perhaps such a mixer is simply a bunch of inputs going to simple volume controls with their outputs all wired directly to the one output socket pin?). -- Johnny B Good |
Looking for a small bit of gain
On Wed, 05 Jul 2017 20:31:26 +1000, Trevor Wilson wrote:
On 5/07/2017 4:23 AM, Brian Gaff wrote: Humph, well i thought it was me. a single transistor stage with, say an emitter follower would suffice though these days the over designers would probably use an Ic. Brian **And just to nit-pick: With a single transistor, operating as emitter follower, you have a Voltage gain of less than 1. Just sayin'. I think you mean 'common emitter'. Brian has a point, assuming he's aware of the difference between the DIN system and the phono plug based system, namely DIN's use of Hi-Z sources driving Lo-Z sinks versus the use of Lo-Z voltage sources driving Hi-Z phono inputs. An OP amp is very, very easy, cheap and simple to implement. Distortion is almost non-existent too. The less than unity gain of an emitter follower is typically 95 to 98 percent of the input voltage, depending on the emitter load resistance and the beta gain of the transistor used. Even with a gain of only 0.90, interposing such an amp between a 100K DIN output and a 10K phono input will provide a 20dB boost in signal level (even when both are 50K, there'll still be a good 5dB advantage). Using an op-amp circuit with non inverting Hi-Z input unity gain will only add a dB or so boost at most to the classic emitter follower amplifier solution so there's not a lot to choose between them other than the fact that adding a simple variable resistor to the op=amp circuit provides variable gain from unity upwards (say a 6 or 12dB boosting range of adjustment). A single PP3 (or, optionally-but not essential, two PP3s in the case of the op-amp solution) should be able to provide dozens, if not hundreds of hours of fun between changes of battery with such a self contained boosting amplifier module. If a more permanent battery-less solution is desired, I'd say the best option would be to fit it inside the mixer box and provide the additional phono socket(s) alongside of the existing DIN socket, rather than use a seperate 9 to 12 volt noise free wallwart psu. -- Johnny B Good |
Looking for a small bit of gain
In article , Woody
scribeth thus "Don Pearce" wrote in message ... On Tue, 4 Jul 2017 20:27:14 +0100, "Woody" wrote: If you don't want the faff of getting the bits and building it then N47FL at £6.99 from Maplin will do the job. Uses a NE5532 amp chip so should be very low noise. Supply is 3-25V so any old PSU you have lying around.... That is exactly what brian is looking for Was it Brian that was looking for it? I thought it was Duncan or Dave. Brian might have a problem with it as it is in kit form! They do one with flying leads on it, still require soldering mind... -- Tony Sayer |
Looking for a small bit of gain
In article , Dave Plowman (News)
scribeth thus In article , Don Pearce wrote: On Wed, 05 Jul 2017 10:11:34 +0100, Jim Lesurf wrote: In article , Don Pearce wrote: On Tue, 4 Jul 2017 19:23:34 +0100, "Brian Gaff" wrote: a single transistor stage with, say an emitter follower would suffice though these days the over designers would probably use an Ic. Brian Under-designers, you mean. With an IC you don't have to do any design - just set two resistors to give you the gain you want. And that is exactly how I would do this - it's by far the best way. If it were me I'd probably buy one of the cheap kits I used for http://www.audiomisc.co.uk/HFN/HeadDAC2/HeadDAC2.html I don't know if the board is laid out for gain, but your headphone amp shows a unity-gain circuit only. I can't imagine they failed to make provision for gain, though. Something always worries me about using a 5 volt single supply for line level audio - assuming it is used neat. In the old days, 24v was the sort of norm for pro stuff. Admittedly line level is higher with that. But when ICs came along was +/-15v or more. Remember reading a criticism of the Quad 33 pre-amp citing its 12v as being too low. Someone does a modified power supply for that now!... -- Tony Sayer |
Looking for a small bit of gain
I'd not want to dismantle the mixer, it might just kill it off, its rather
elderly but functional nonetheless. I like what I'm used to as modern stuff if not just software is often not tactile enough for me. Brian -- ----- - This newsgroup posting comes to you directly from... The Sofa of Brian Gaff... Blind user, so no pictures please! "Johnny B Good" wrote in message ... On Wed, 05 Jul 2017 20:31:26 +1000, Trevor Wilson wrote: On 5/07/2017 4:23 AM, Brian Gaff wrote: Humph, well i thought it was me. a single transistor stage with, say an emitter follower would suffice though these days the over designers would probably use an Ic. Brian **And just to nit-pick: With a single transistor, operating as emitter follower, you have a Voltage gain of less than 1. Just sayin'. I think you mean 'common emitter'. Brian has a point, assuming he's aware of the difference between the DIN system and the phono plug based system, namely DIN's use of Hi-Z sources driving Lo-Z sinks versus the use of Lo-Z voltage sources driving Hi-Z phono inputs. An OP amp is very, very easy, cheap and simple to implement. Distortion is almost non-existent too. The less than unity gain of an emitter follower is typically 95 to 98 percent of the input voltage, depending on the emitter load resistance and the beta gain of the transistor used. Even with a gain of only 0.90, interposing such an amp between a 100K DIN output and a 10K phono input will provide a 20dB boost in signal level (even when both are 50K, there'll still be a good 5dB advantage). Using an op-amp circuit with non inverting Hi-Z input unity gain will only add a dB or so boost at most to the classic emitter follower amplifier solution so there's not a lot to choose between them other than the fact that adding a simple variable resistor to the op=amp circuit provides variable gain from unity upwards (say a 6 or 12dB boosting range of adjustment). A single PP3 (or, optionally-but not essential, two PP3s in the case of the op-amp solution) should be able to provide dozens, if not hundreds of hours of fun between changes of battery with such a self contained boosting amplifier module. If a more permanent battery-less solution is desired, I'd say the best option would be to fit it inside the mixer box and provide the additional phono socket(s) alongside of the existing DIN socket, rather than use a seperate 9 to 12 volt noise free wallwart psu. -- Johnny B Good |
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