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In Reply to: RE: Nichicon vs Chemi-con Electrolytic cap posted by drlowmu on December 17, 2014 at 09:14:11
Sonically speaking a slow recovery power supply using too much filtering is bad news.
Follow Ups:
"Sonically speaking a slow recovery power supply using too much filtering is bad news."
I guess an electric car with a smaller battery will go further?
This old tired Jeff Medwin theory is simply flawed. An amplifier or any electrical circuit will take what ever power it needs and that's all. It doesn't matter if that power or energy is stored in a capacitor or the current demand happens to come at the peak of the charge point. The VA rating of the power transformer must satisfy the needs of the amp circuit period. And if it does, "too much" filter capacitance makes no difference in terms of current delivery. Too little capacitance and the assocaited "charge pumping" is however a problem and is exactly what makes the LSES sound "dynamic".
Is it bad my amplifier is plugged into a major power grid across several states with comparably unlimited current reserve to the amplifier needs? Should I power my amplifier off a small Honda generator to balance the power supply to the current demand? Would that sound better?
Now if we want to talk about the effects of power supply impedance and how that effects the output stage, that's another matter and warrants some discussion of deeper issues. But that's not the same thing.
Do you build tube amps Gusser?
Do you build tube amps Gusser?Ahh, yeah, I do!
That's my former biamped system in my HT built in 2006. It has since been retired for DIY SS amps. I got tired of the re-tube costs.
I do run a DIY EL34 based amp in the music room.
Edits: 12/18/14
Fantastico. Love the passion.
What SS amp did you replace THAT with?
Funk ya!
Then the saying goes all power supplies sound the same. I am not a fan of ultra low power supplies with 10 volts of AC ripple either.
Hi,
I agree with you about 10 VAC of ripple. ANY idea what the ripple would be, to the Finals, to the Driver, on a modern LSES supply?
Answer : its about 800-900 mVAC to the Finals, no problem at all on high efficiency speakers, since the output transformer steps it down.
Second answer : its about one to two mVAC to the Driver, and the Driver's B+ is fully shunt regulated with a zero feedback, one part regulator, which gives fabulous stability and a wonderful low end.
The mu of 100 Driver "needs" that low mVAC, the mu of 4 Finals needs to be under 1 VAC if SE, and 2.5 VAC or less if Push Pull.
10 VAC would be bad. You weren't thinking 'ole Jeff is running 10 VAC as you wrote, were you ??
Regards,
Jeff Medwin
All power supplies do not sound the same.In fact a power supply with additional filter capacitance will better handle peaks.
And as I said, power supply impedance effects the so called "sound" especially in SET's.
Let's just be clear on what a LSES is and how it works. It is not a "properly designed" power supply for the intended load. It is current starved and that is exactly what produces the desired effect - artificial dynamics.
You could argue successfully that if turning an amplifier into a dynamics processor is the goal, then the power supply IS "properly designed" for that purpose.
What ever.
Again just be clear on how a LSES works and what in turn it does to the amplified audio signal. If that's what you want, then the LSES is in fact an elegant way to synthesize dynamics without resorting to analog VCA technologies, aka DBX, or digital processing techniques.
P.S. There is never a panacea in engineering either. The artificial dynamics boost comes at a price - more ripple induced hum and possibly more clipping.
Edits: 12/17/14
actually gusser, I'm starting to think "clipping" is part of the reason people prefer SE over push pull.
I especially think the 12ax7 DC into a 2a3 does soft clipping extremely well. (particularly with the bandwith limiting of small cap cathode bypass)
I don't agree with your assessment on the power supply, but there is some truth in the fact that the whole cap bundle, power supply, insufficient drive for miller etc all are a form of EQing.
Fine to disagree with my theory of how it sounds.
What is your technical analysis of the LSES power supply?
well... I think:
- due to class A and low current draw
- low mu finals allow for less filtering
- ac filaments means there is a noise floor regardless
- small chokes filter HF well
- ultra clean driver stage
that DFs supply works just fine for a 2a3 or 45. I don't think there is any "dynamics expansion."
I'm also working on my first amp with an l-critical choke input right now, so I'm not hard line. I do believe the supply works and is plenty quiet.
also in fairness, I'm actually running the power supply Jeff has now abandoned. So I'm working with a 2 henry choke.. (along with the flywheel input deal)
on a final note, I'll never cut up factory chokes or power transformer leadouts again either. :)
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