Originally Posted by milosz
Couple things I'd like your opinion on-
Have you found that using a film cap as the last cap in the PSU is sufficient, or do you need to replace all the electrolytics with film?
I've seen quite a few designs where the aluminum electrolytics in the PSU and the on-board "demand" electrolytics in solid state amps are bypassed with one or two film caps- does that ameliorate the sonic problems caused by electrolytics or is it just wishful thinking?
And last but not least- Black Gates are gone, but there are now other "audio grade" electrolytics - Silmic & Cerafine from Elna, and Muse from Nichicon - have you heard these? Do you think they offer sonic benefit over the regular good quality but otherwise garden-variety Panasonic caps?
All right, one last go at the electrolytic/film capacitor "debate" and then I'll forever shut up about it. And to keep jcx happy, I freely admit that all my experience in this area is empirical and annecdotal.
My response to the first question is that the last cap in the PSU, which is directly in the audio path, is by far the most affected by upgrading an electrolytic to a film cap. When I first started building SET amps in the early 90's I made numerous direct comparisons (usually with simple "brute-force" supplies) of the two types in this position. The difference was easy to hear, and the film cap was always the winner. You could also hear it (to a lesser degree) in a push-pull, zero feedback DHT amp. Since then, since all my amps are DIY, and I'm not concerned about space or economy issues, I usually use film caps in all positions. Probably doesn't make much difference as long as the last one is film.
I've never experimented with using film caps as electrolytic bypasses. I've read mixed results about the effectiveness of film bypasses
I've used all the brands of electrolytics you mentioned. I can't tell any difference between them and decent "garden-variety" electrolytics. Black Gates (and perhaps it was just my aching wallet talking) seemed to have a bit less of the usual "glare" or "sheen" that I associate with electrolytics.
Again to be clear, I am not criticizing any commercial product or designer for using electrolytics. If I was a commercial builder I'd use them too.There's really no choice. As a DIYer I am free to choose any capacitors I want, and I choose film whenever possible..