Sonic description of precision power supply

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dbeasley
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Sonic description of precision power supply

Post by dbeasley »

Like the thread title says, what is the supposed advantage of using this style of power supply? Is running all the capacitors in series and supposedly reducing ESR contributing something to the feel or response of the amp? Just trying to understand the qualitative aspect here. Thanks.

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martin manning
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Re: Sonic description of precision power supply

Post by martin manning »

I don't believe there should be any difference as long as the filters are the same size. The reservoir is made up of two series caps in both, and the other filters are only slightly different (2x 47u = 23.5u vs. 22u), which is within the tolerance of the caps. ESR's would be additivefor the series connection. I have heard someone claim there is a difference in sound, but I can't see how.
mojotom
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Re: Sonic description of precision power supply

Post by mojotom »

I felt more initial attack and a bit stiffer amp with the PS supply. Considering the amps already have a very direct feel I tend to prefer the classic PS but the two amps I build back then were not exactly the same besides the PS and I didn't compare them side by side so this is more a deduction than a fact.
dbeasley
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Re: Sonic description of precision power supply

Post by dbeasley »

Would it be reasonable to argue that the newer "precision" supply was more about using more common, readily available components?

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jam-mill
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Re: Sonic description of precision power supply

Post by jam-mill »

Maybe Dumble got a deal on a bunch of lower voltage caps and found a way to use them.
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martin manning
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Re: Sonic description of precision power supply

Post by martin manning »

Stacking power supply caps is definitely about getting increased voltage capability and taking advantage of cheaper and more readily available radial caps.
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Re: Sonic description of precision power supply

Post by Mark »

I thought the stacked caps would take up less real estate.
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Re: Sonic description of precision power supply

Post by pompeiisneaks »

Mark wrote: Wed Aug 23, 2017 10:43 pm I thought the stacked caps would take up less real estate.
That's also definitely a benefit, the computer style radial caps are just way smaller than the more commonly used axial caps in amps. They work just as well, and cost less too. I'm looking to possibly start using more of them as well.

The filter capacitors job is to just remove ripple, it doesn't massively impact the tone of the amp in any way, other than tightening up the response and removing sag.

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xtian
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Re: Sonic description of precision power supply

Post by xtian »

Mark wrote: Wed Aug 23, 2017 10:43 pm I thought the stacked caps would take up less real estate.
Radial caps are typically smaller than equivalent axial, and take even less room when standing on end. "Stacked" is not a spacial adjective here, but electronic.
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Re: Sonic description of precision power supply

Post by jam-mill »

xtian wrote: Wed Aug 23, 2017 10:54 pm
Mark wrote: Wed Aug 23, 2017 10:43 pm I thought the stacked caps would take up less real estate.
Radial caps are typically smaller than equivalent axial, and take even less room when standing on end. "Stacked" is not a spacial adjective here, but electronic.

He said "stacked" :P
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Charlie Wilson
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Re: Sonic description of precision power supply

Post by Charlie Wilson »

pompeiisneaks wrote: Wed Aug 23, 2017 10:53 pm
Mark wrote: Wed Aug 23, 2017 10:43 pm I thought the stacked caps would take up less real estate.
That's also definitely a benefit, the computer style radial caps are just way smaller than the more commonly used axial caps in amps. They work just as well, and cost less too. I'm looking to possibly start using more of them as well.

The filter capacitors job is to just remove ripple, it doesn't massively impact the tone of the amp in any way, other than tightening up the response and removing sag.

~Phil
Hello, not sure if I totally agree with this. Yes the filter caps smooth out ripple but I also see them as your signals pathway to and from ground. I have found that different makes of filter caps of the same value sound and feel different in an amplifier. Example, I had some 22uf F&T caps in my amp and swapped them for some Jensens. The sound was clearer and the amp sustained better than it did before. I also think that having bleeder resistors across every cap has to have some effect on the tone and or feel of the amp. Lastly, so you have a power supply board that enables you to use cheaper caps but you make it an absolute pain in the you know what to replace them when the time comes.
CW
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Re: Sonic description of precision power supply

Post by pompeiisneaks »

Charlie Wilson wrote: Thu Aug 24, 2017 6:46 pm
pompeiisneaks wrote: Wed Aug 23, 2017 10:53 pm
Mark wrote: Wed Aug 23, 2017 10:43 pm I thought the stacked caps would take up less real estate.
That's also definitely a benefit, the computer style radial caps are just way smaller than the more commonly used axial caps in amps. They work just as well, and cost less too. I'm looking to possibly start using more of them as well.

The filter capacitors job is to just remove ripple, it doesn't massively impact the tone of the amp in any way, other than tightening up the response and removing sag.

~Phil
Hello, not sure if I totally agree with this. Yes the filter caps smooth out ripple but I also see them as your signals pathway to and from ground. I have found that different makes of filter caps of the same value sound and feel different in an amplifier. Example, I had some 22uf F&T caps in my amp and swapped them for some Jensens. The sound was clearer and the amp sustained better than it did before. I also think that having bleeder resistors across every cap has to have some effect on the tone and or feel of the amp. Lastly, so you have a power supply board that enables you to use cheaper caps but you make it an absolute pain in the you know what to replace them when the time comes.
CW
Maybe I'm misunderstanding it, but the signal should only go that route IF it can't make it to the next stage via the coupling capacitors. Therefore, that route to ground is a failure state. The successful route to ground should be via the OT transformer out through the tubes and then to the speaker with it's ground no? In a correctly functioning amp no signal should go through the filter capacitors at all, except what can't find a route to the next stage. There is also some route to ground for the cathode of course, but that's only part of the signal chain, the other opposite phased output goes through the anode. The only other case I can think of is a cathode follower, and the anode output goes straight to that ground you mention, but also never makes it to the output tubes and is just lost.

As for replacement, if you set the caps up so that the eyelets are slightly outside the size of the body of the cap, you can just bend the leads, get the cap into those new holes and still have direct top access for removal. That's just a design consideration.

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Re: RE: Re: Sonic description of precision power supply

Post by tmod »

pompeiisneaks wrote:
Charlie Wilson wrote: Thu Aug 24, 2017 6:46 pm
pompeiisneaks wrote: Wed Aug 23, 2017 10:53 pm

That's also definitely a benefit, the computer style radial caps are just way smaller than the more commonly used axial caps in amps. They work just as well, and cost less too. I'm looking to possibly start using more of them as well.

The filter capacitors job is to just remove ripple, it doesn't massively impact the tone of the amp in any way, other than tightening up the response and removing sag.

~Phil
Hello, not sure if I totally agree with this. Yes the filter caps smooth out ripple but I also see them as your signals pathway to and from ground. I have found that different makes of filter caps of the same value sound and feel different in an amplifier. Example, I had some 22uf F&T caps in my amp and swapped them for some Jensens. The sound was clearer and the amp sustained better than it did before. I also think that having bleeder resistors across every cap has to have some effect on the tone and or feel of the amp. Lastly, so you have a power supply board that enables you to use cheaper caps but you make it an absolute pain in the you know what to replace them when the time comes.
CW
Maybe I'm misunderstanding it, but the signal should only go that route IF it can't make it to the next stage via the coupling capacitors. Therefore, that route to ground is a failure state. The successful route to ground should be via the OT transformer out through the tubes and then to the speaker with it's ground no? In a correctly functioning amp no signal should go through the filter capacitors at all, except what can't find a route to the next stage. There is also some route to ground for the cathode of course, but that's only part of the signal chain, the other opposite phased output goes through the anode. The only other case I can think of is a cathode follower, and the anode output goes straight to that ground you mention, but also never makes it to the output tubes and is just lost.

As for replacement, if you set the caps up so that the eyelets are slightly outside the size of the body of the cap, you can just bend the leads, get the cap into those new holes and still have direct top access for removal. That's just a design consideration.

~Phil
I've always been taught to view each stage as it's own signal generator, controlled by the previous one. There's no ac-current flowing from stage to stage, just a signal getting reproduced, and each stage has it's cap as a ground point for ac as well as dc...

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Re: Sonic description of precision power supply

Post by Charlie Wilson »

pompeiisneaks wrote: Thu Aug 24, 2017 6:58 pm
Charlie Wilson wrote: Thu Aug 24, 2017 6:46 pm
pompeiisneaks wrote: Wed Aug 23, 2017 10:53 pm

That's also definitely a benefit, the computer style radial caps are just way smaller than the more commonly used axial caps in amps. They work just as well, and cost less too. I'm looking to possibly start using more of them as well.

The filter capacitors job is to just remove ripple, it doesn't massively impact the tone of the amp in any way, other than tightening up the response and removing sag.

~Phil
Hello, not sure if I totally agree with this. Yes the filter caps smooth out ripple but I also see them as your signals pathway to and from ground. I have found that different makes of filter caps of the same value sound and feel different in an amplifier. Example, I had some 22uf F&T caps in my amp and swapped them for some Jensens. The sound was clearer and the amp sustained better than it did before. I also think that having bleeder resistors across every cap has to have some effect on the tone and or feel of the amp. Lastly, so you have a power supply board that enables you to use cheaper caps but you make it an absolute pain in the you know what to replace them when the time comes.
CW
Maybe I'm misunderstanding it, but the signal should only go that route IF it can't make it to the next stage via the coupling capacitors. Therefore, that route to ground is a failure state. The successful route to ground should be via the OT transformer out through the tubes and then to the speaker with it's ground no? In a correctly functioning amp no signal should go through the filter capacitors at all, except what can't find a route to the next stage. There is also some route to ground for the cathode of course, but that's only part of the signal chain, the other opposite phased output goes through the anode. The only other case I can think of is a cathode follower, and the anode output goes straight to that ground you mention, but also never makes it to the output tubes and is just lost.

As for replacement, if you set the caps up so that the eyelets are slightly outside the size of the body of the cap, you can just bend the leads, get the cap into those new holes and still have direct top access for removal. That's just a design consideration.

~Phil
Hello, I still think I'm not sure about this. If that were the case than caps with different ESR would not make an amp sound any different and I know they do. Try putting some fresh F&TS in a guys JCM800 after he is used to the the worn caps that have been in there for 20 years. I think the idea with replacing the caps was that the entire board be removed. Notice the eyelets for the ground points on the outside edge of the board.
CW
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Re: Sonic description of precision power supply

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Charlie Wilson wrote: Thu Aug 24, 2017 7:30 pm
Hello, I still think I'm not sure about this. If that were the case than caps with different ESR would not make an amp sound any different and I know they do. Try putting some fresh F&TS in a guys JCM800 after he is used to the the worn caps that have been in there for 20 years. I think the idea with replacing the caps was that the entire board be removed. Notice the eyelets for the ground points on the outside edge of the board.
CW
They absolutely should because of the change to the capacitors, if you're replacing say a new capacitor with a new capacitor, it likely wouldn't change much, but the newer capacitors are going to work more efficiently, and therefore likely introduce less noise into the circuit themselves. I still don't think I see how that changes the sound itself other than removing noise/distortion coming from bad/old/dry caps. This is a different topic, though, imo than the 'tonal changes capacitors cause in a circuit' if you consider them all new, and just changing brands and maybe even capacitance values.
tmod wrote: I've always been taught to view each stage as it's own signal generator, controlled by the previous one. There's no ac-current flowing from stage to stage, just a signal getting reproduced, and each stage has it's cap as a ground point for ac as well as dc...

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The grounding of DC is 100% correct, but again, if the AC doesn't go through to the next stage, then you have no output. If there's a convenient low resistance path to ground, the signal always flows that way and you'd get nothing. For the AC signal to couple to the next stage, it has to be able to have a higher priority (lower resistance) path to the grid of the next stage than going through the anode resistor to the filter cap ground.

Unless I'm misunderstanding something, as mentioned before. I'd definitely like to understand what that is, though, if I'm mistaken.

~Phil
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