What is the sound of one resistor attenuating
"The shunt volume control has only one resistor in series with the input of the gain stage. This could then be a high quality Vishay, for example. Try it you might be surprised.
Regards,
Jam"
The series resistor forms a voltage divider with the resistance to ground that sets the volume level. Both resistors are in the signal path. The often quoted nonsense about only the series resistor needing to be high quality and the resistor to ground not being, or being less; in the signal path is one of those audio urban legends that defy logic to anyone with a knowledge of ohms law.
The Cyberspace Wanderer
"The shunt volume control has only one resistor in series with the input of the gain stage. This could then be a high quality Vishay, for example. Try it you might be surprised.
Regards,
Jam"
The series resistor forms a voltage divider with the resistance to ground that sets the volume level. Both resistors are in the signal path. The often quoted nonsense about only the series resistor needing to be high quality and the resistor to ground not being, or being less; in the signal path is one of those audio urban legends that defy logic to anyone with a knowledge of ohms law.
The Cyberspace Wanderer
AMT-freak said:
sorry for my poor English and my mistake.
to correct my last post: the 'Pioneer CZ-5' should be the 'Pioneer CZ-1 ' pre amp,which made in Japan in the 70's or 80's.
'Gm amp'....I can't explain in English.'Gm' is the important parameter of FET, maybe I should say 'Notron amp' .
Here is the Pioneer CZ-1 circuit printed in a Chinese audio magazine.
Attachments
@Peter:
Did you use a linear or log pot / stepped attenuator?
I remember there wasn't that big a difference between a linear pot and a log one when I once tried, but a reversed log characteristic probably feels strange..?
@X.G.
The Pioneer circuit looks similar, but then again I remember my encounters with Pioneer "Hifi" and I doubt if they implemented it right
Did you use a linear or log pot / stepped attenuator?
I remember there wasn't that big a difference between a linear pot and a log one when I once tried, but a reversed log characteristic probably feels strange..?
@X.G.
The Pioneer circuit looks similar, but then again I remember my encounters with Pioneer "Hifi" and I doubt if they implemented it right
Guys,
I agree that the shunt element is still part if the circuit but you all fail to see the point. Compared to a some sort of switched attenuator that that has multiple resistors in series with the signal path. If you don't believe me put a 10k resistor in series with the input of your preampl listen then put 10 1k resistors in series with the input of the same preamp and listen again.
Most of you like to comment but few seemed to have built and actually listened to the comparison. BAT a well known manufacturer as well as Pass Labs seem to concur and produce products with a similar setup.
As always ignorance is bliss........for a change lets try building something rather than simulating or conjucture. As I recall Black Gates do make a difference but when they were first introduced ..........you know what I mean.
Regards,
Jam
I agree that the shunt element is still part if the circuit but you all fail to see the point. Compared to a some sort of switched attenuator that that has multiple resistors in series with the signal path. If you don't believe me put a 10k resistor in series with the input of your preampl listen then put 10 1k resistors in series with the input of the same preamp and listen again.
Most of you like to comment but few seemed to have built and actually listened to the comparison. BAT a well known manufacturer as well as Pass Labs seem to concur and produce products with a similar setup.
As always ignorance is bliss........for a change lets try building something rather than simulating or conjucture. As I recall Black Gates do make a difference but when they were first introduced ..........you know what I mean.
Regards,
Jam
I don't see a reason why both series and shunt element couldn't be switched so only 2 resistors are always in a signal path. As far as I know in PassLabs preamp the shunt resistance still consists of series resistors; 6 and 10 respectively, separated by a buffer. There are still 4 resistors in series though (and a buffer).
OTOH, Connoisseur preamp by jcarr, IIRC is featuring series attenuator with custom made metal foil resistors. So more or less its designer's choice, as to what works best for him.
OTOH, Connoisseur preamp by jcarr, IIRC is featuring series attenuator with custom made metal foil resistors. So more or less its designer's choice, as to what works best for him.
Peter,
Funny both solutions you mention make the volume control closer to a shunt control................so what's your point.
The use of SMD's also get rid of the end cap problem faced with standard resistors..........................you just proved my point..........but all kidding aside, try the experiment or call Victor Khomenko at BAT.
Fron BAT...
What makes the BAT electronic shunt volume attenuator so special?
In most preamplifiers the volume control works as gatekeeper of sound quality. Any damage done to the sound by an improperly implemented volume control will then be further amplified by the gain stage. This is why we had to develop our own solution to this critical function (please see the i-series white paper for more information on this subject). We were not satisfied with the traditional implementations available and undertook a costly but rewarding search. In our opinion, the best way to implement the volume control in a preamplifier is through an electronic shunt attenuator that puts only one high quality resistor in series with the signal. In many traditional implementations there will be dozens or even hundreds of components inserted in the signal path, plus multiple solder joints. A typical integrated circuit (IC) volume control found in many high-end preamplifiers may also place operational amplifiers in series with the signal. This would contradict our philosophy of a short and unobstructed signal path. The low cost of integrated circuit volume controls makes them attractive in low cost products. However, a $5 volume control hardly deserves a place in any true high-end preamplifier.
Regards,
Jam
Funny both solutions you mention make the volume control closer to a shunt control................so what's your point.
The use of SMD's also get rid of the end cap problem faced with standard resistors..........................you just proved my point..........but all kidding aside, try the experiment or call Victor Khomenko at BAT.
Fron BAT...
What makes the BAT electronic shunt volume attenuator so special?
In most preamplifiers the volume control works as gatekeeper of sound quality. Any damage done to the sound by an improperly implemented volume control will then be further amplified by the gain stage. This is why we had to develop our own solution to this critical function (please see the i-series white paper for more information on this subject). We were not satisfied with the traditional implementations available and undertook a costly but rewarding search. In our opinion, the best way to implement the volume control in a preamplifier is through an electronic shunt attenuator that puts only one high quality resistor in series with the signal. In many traditional implementations there will be dozens or even hundreds of components inserted in the signal path, plus multiple solder joints. A typical integrated circuit (IC) volume control found in many high-end preamplifiers may also place operational amplifiers in series with the signal. This would contradict our philosophy of a short and unobstructed signal path. The low cost of integrated circuit volume controls makes them attractive in low cost products. However, a $5 volume control hardly deserves a place in any true high-end preamplifier.
Regards,
Jam
Life is like a box of Chocolates....!
For further information, this is the link to the BAT white paper on the subject.
http://www.balanced.com/resources/whitepapers/i-white.pdf
For further information, this is the link to the BAT white paper on the subject.
http://www.balanced.com/resources/whitepapers/i-white.pdf
jam said:
Actually, I fail to see your point. At certain position, Connoisseur attenuator is using 20 resistors in series with a signal path and it's a very highly regarded preamp. I don't know how close it gets to shunt control.
I know you like to see the prove of your point, but the way you discuss it, seems like you don't present any point and create the argument only. I'd rather see some interesting implementations instead.
Reading through BAT paper, APOX comes to mind.
Not to mention all the switch / relay contacts.
Jam, I see your point now. I had a simple pot in my mind, as shown in the schematic. For a pot, I think there's no big difference between ordinary and shunt topology.
In my last preamp, I used a circuit as in the Constand impedance relay attenuator thread, but I found it sonically inferior to an input and output buffered high quality pot (Panasonic CP). It depends on implementation, of course, but looking at the number of components in the signal path and board size, I'd rather go back to a simple pot this time.
Btw, I usually clearly point out whether a statement is based on actual listening, whether it is an educated guess, or whether it is pure speculation.
Peter,
I suggested an experinent..........................so try it!
You keep bringing up the Connoisseur but I just told you why why it is a closer approach to a shunt. I bet you haven't heard one compared to a shunt control.
You seem to want to argue for some reason, I have presented my points and suggested reading, so stop being childish and proceed with the experiment.
Regards,
Jam
I suggested an experinent..........................so try it!
You keep bringing up the Connoisseur but I just told you why why it is a closer approach to a shunt. I bet you haven't heard one compared to a shunt control.
You seem to want to argue for some reason, I have presented my points and suggested reading, so stop being childish and proceed with the experiment.
Regards,
Jam
I'm actually using shunt attenuator. The diffference between mine and Connoisseur is that I'm only using one series resistor (5K S102 Vishay) while they use multiple resistors, depending on position.
Still don't see your point. I already did your experiment in the past. Still, results depend on components being used. There is no one answer, so stop acting like a child yourself.
Still don't see your point. I already did your experiment in the past. Still, results depend on components being used. There is no one answer, so stop acting like a child yourself.
AMT-freak,
The main reason I suggested a shunt in your application is because of the buffer, without it the minimum impedence seen by source component would be the series resistor, which could be pretty low and load down your source components.
In any case a buffer is a good idea, if you can make it transparent enough.
Regards,
Jam
The main reason I suggested a shunt in your application is because of the buffer, without it the minimum impedence seen by source component would be the series resistor, which could be pretty low and load down your source components.
In any case a buffer is a good idea, if you can make it transparent enough.
Regards,
Jam
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