This is interesting. I didnt purchase any caps specifically for bypassing the last PS electrolytic in Crack. I have a bunch of film caps around but most are very low value or too high of a value that I didnt consider them for bypassing. So, I experimented with what I had on hand. One of these was indeed a .01uf audiocap theta (I have a few of these left over, used some as crossover bypass caps). I also tried the same value Dayton film and foil as well as a 1.0uf Solen or Axon. I even tried a low value tubular mylar cap. To be honest, I really didnt notice any real improvement with any of these caps. Certianly though, I didnt hear any negatives, just simply perceived no real difference at all. I wrote this off as maybe the value being too low. I increased the cap size by going away from the audio caps I had and I finally heard what I perceived as a subtle improvement in when I bypassed with a Panasonic 2.2 or 2.0uF (cant remember which) polyprop film cap. I attributed this subtle improvement to the caps maybe filtering some high frequency noise. But again, I attributed it to the larger cap value moreso than the "status" of the cap itself. I later picked up some larger value Solen and Mundorf caps, around 2 or 2.2 uF with the intent on replacing the panasonic in Crack and using these in other bottlehead kits. I never got around to replacing the Panny though as it did provide the subtle improvement I mentioned. I can revist the small value Theta I guess and give it another listen. However, I have a feeling I may be comparing the Theta to, what effectively amounts to, listening with no bypass cap seeing how my non golden ears heard no difference with the Theta, and those other caps I initially tried. But prompted by this topic, I may consider experimenting with the PS bypass caps I installed in FPIII and Seduction. I installed a Mundorf MKP in one and a Solen in the other as bypass caps as part of the original build, again, thinking it was probably more of the caps uF value than the cap itself. Understand ... Im not saying that improvements cant be had with different and/or more expensive caps. Just saying that I didnt hear that difference with the smaller value caps I tried in Crack. But again, I think it may be worth some experimenting with FPIII and Seduction since I didnt do any comparative listening in those amps. Of course, everyones ears and systems are different. I know that there are a few here that have used basic MKP caps, Solen, Mundorf etc. as bypass caps for the PS electrolytic. They may very well be hearing positives using these caps instead of the negatives impressions expressed here by Matthew just as he is hearing improvement with .01uf Thetas where I heard no real difference. Just based on the experimenting I did with Crack, I have to say that the small improvement I noted with the PS bypass cap doesnt compare to the improvement when replacing the lytic output caps with large MKP film caps. The stock lytics sound good, but replacing with Film caps made for a very nice improvement. Not earth shattering but a good bit beyond what I would consider "subtle". To me, it was a much larger difference/imporvement compared to bypassing the PS lytic. Again, we all have different ears and different systems but I wouldnt write off considering replacing the output lytics with film caps because of positive results achieved with bypassing the PS cap. I tend to reach the diminishing returns justification "defense" sooner than most others in this hobby but I wouldnt consider being there before upgrading the output caps to films after doing so myself. It was on my short list based on others results and for me, well worth it.
Of course, just my non tech savvy opinions and YMMV widely.
