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Preamp Output Capacitor: Mundorf Supreme vs. Supreme Silver Oil

Anyone compared the bass response of these two caps?  I bought the Supremes for trial purposes and really loved what they did to my system's imaging (front to back layering) and immediately bought the Silver Gold Oil Supremes.  Unfortunately while they were smoother, more beautiful, and even better at imaging, they had no bass (actually, they lost bass as they broke in).  Anyone know how the Silver Oil's fit into the line?  

I'm using them in a Don Sach's DS2 Preamp ( https://systems.audiogon.com/systems/7983).  

Thanks.
128x128cal3713
audioguy777
3 posts
 
[quote]The sound character of the particular output capacitor will have a much greater effect than the different measured cutoff frequency with a 100K load (23 vs 8 Hz).
For example, a Mundorf Silver/Gold/Oil sounds “thin” regardless of cutoff frequency; an older InfiniCap would sound even more thin and lightweight. On the other hand, a .68uf Copper V-Cap with a 100K load will have deep, powerful, full-bodied bass despite the measured response being down 3db at 23 Hz.[/quote]

They both affect the sonics to a great degree. If one is taking a full sounding capacitor to produce bass, the mids and highs will also be negatively affected. A capacitor does not somehow alter its sonic character above bass.

One has to perform specialized, sophisticated listening tests to determine which capacitors are accurate in absolute terms and which are not. One must perform testing in a variety of conditions in the lab.

As just One reference test in the lab, we place a resistor across a full range driver and vary the resistance to determine what is perceivable. It has been clearly demonstrated that altering that resistors resistance by less than a millionth of an ohm affects the tonal balance and thus what one perceives. The tonal balanced has been altered. Other methods verifies our findings.

We are talking razor thin tonal balance changes across octaves. Close enough doesn’t make it. In either case of slight bass heavy or too thin, the voices/instruments will not be live sounding.
And is not that what many are searching for.

As such, it is not surprising why individuals perceive differences between components when the specs state a "loose" +/- 0,1db from 20-20khz. The so called rule of thumb with capacitors is anything but an accurate rule of thumb.

If a 0,68uf copper capacitor (100k load) has deep, powerful, full bodied bass then that capacitor is artificially flavoring the sound.
A truly accurate capacitor of that value will sound thin, not full bodied.
Unfortunately, Peter made several capacitors, including at least two Infini Capacitors with different covering colors. One is so accurate that we could not discern any difference, and the other is not.

[quote] You’re right! That should teach me to do math in my head. I dropped a digit.

Of course that makes the issue of the value of the cap even less significant sonically. With tube gear where the input impedance is typically 100K or more, a 0.68uf coupling cap is fine.[/quote]

One of the first things I look at in a component is what size is the coupling capacitors and the following grid (load) resistor.

Oh, it is still significant if one wishes to have the most accurate, natural, live sound possible in their living room. Of course, the rest of the design has to be just as good. No covering mistakes in the design here. Cheers

ag

ps. A couple of Mundorf capacitors I have checked are pretty darn accurate, and not super expensive.



atmasphere's avatar
atmasphere
11,644 posts
 
Could someone explain why adding a 0.01uF capacitor in parallel/bypass with a 2.2uF capacitor improves sound quality?
@kalali   It doesn't! Any capacitor has a certain 'speed' defined by a  combination of its dielectric constant and series resistance. This varies from cap to cap (inductance plays a role too; this is caused by the fact that the cap is rolled in a spiral fashion) and even from value to value of caps of similar construction.

BTW this is quite measurable (notwithstanding the known effects of the specifications on paper :) ) and one way to do it is to measure bandwidth. Some caps roll off the signal a lot quicker than others. The bigger the capacitor, the more profoundly its affected by these aspects.


Since smaller caps tend to be faster than larger caps, essentially a phase shift is introduced by the inclusion of a smaller cap in parallel with a larger cap. In a power supply this is advantageous, but as a coupling cap in a nutshell it smears the signal (and being real, the signal is messed with by the cap regardless). The more transparent your setup, the easier it is to hear this!


If this is done in a circuit that employs loop feedback, the phase shift introduced can interfere with the phase margin of the circuit; YIKES! this could lead to oscillation.


So as a result, unless you are compensating for a deficiency elsewhere in the circuit or system, the best approach is to give it your best shot and simply install the best capacitor you can and keep it as low a value as is practical.


This is also why increasing the value of a coupling cap (for example to extend bass response) isn't always a good idea. Circuits behave according to math  and the use of coupling caps is a really good example.
cal3713's avatar
cal3713 OP
1,421 posts
 
@atmasphere You keep slowly (and totally indirectly) convincing me to try your direct coupled pre. Unfortunately I'm quitting my job in May (and applying for new ones now), or I'd be saving up for a trial. 
grannyring's avatar
grannyring
6,442 posts
 
All I can say is it sounds better in my highly resolving system. It just does. Experience and try for yourself.  This is the only way to know for you . 
atmasphere's avatar
atmasphere
11,644 posts
 
Experience and try for yourself.  This is the only way to know for you .
@grannyring  A lot of people are of this opinion. I've just found that the more transparent the system is, the more you hear that paralleled caps  don't have the desired effect. But I'm sure neither of us want to argue about it- in fact I suspect my viewpoint on this topic could easily be unpopular.

People tend to think that since we make some pretty esoteric products like our fully balanced triode zero feedback OTLs, that we might be doing more listening than measurement or something like that. But to get to where we are takes engineering- and that requires math. If I can't make it work on paper, I have trouble with the idea that it will work in practice. I don't like it when things work and I don't have a good explanation- I remember the first time I heard a power cord make a difference and it really bothered me until I sorted out why. I'd love to be proven wrong on this capacitor thing but so far that hasn't worked out- we certainly *have* tried it and more than once with exactly the same results, 22 years apart. It doesn't work out on paper either, so I've maintained this position for a very long time.


One area that might be a variable is output transformers. They have capacitive effects of their own (both inter-winding and to ground) so it may be that in a transformer-coupled amp there is a benefit as one is compensating for a transformer. I've not worked that out as I try to stay away from transformers if I can.
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