Choosing bypass Capacitors for 100uf films

[Dneu2011]

Hello everyone. This is my first post on the Bottlehead forum and first Bottlehead build. I ordered the Crack on the Black Friday special and have already looked into the obvious upgrades everyone else has been doing in no particular order:

1. Alps blue 50k pot upgrade ($15 ish)
2. 2.2uf Wima on the Power cap ($4.00 ish)
3. 100uf 400v Jantzen film capacitors to replace the electrolytic in the ouput stage ($60ish)
4. Speedball ($125) - may wait for the sale

My big question is about the bypass capacitors to add to the films. I have some .68uf Jantzen film caps left over from a preamp that were barely used. Would these be ok to use as bypass caps? I think I paid $20 each and love to re-use them if they would work.

Another question, where would I be able to get some nice stands/holders to put the large 100uf film caps on when adding them? Has anyone else found some cheap ones online or come up with another cheap/easy way to mount them?

Thanks.

[bloodhawk]

I bypassed mine with the Audyn Copper 1 uF 630 V ones, really like the improvements. Vs using only Mundorf MKP 100uF 250V, the signature tightened up really well and the sound stage felt much more refined. YMMV of course.

[photoduo]

using only Mundorf MKP 100uF 250V

I found that the Mundorf MKP 100uF's are almost impossible to find in 250v anymore.
I did just find a closeout on Mundorf MKP's but they are 120uF 250v.
Can anyone let me know if this is acceptable and if so what the effects might be.

[Paul Birkeland]

120uF/250V will work just the same.  They will probably be a little bit bigger than the 100uF/250V.

[photoduo]

Excellent  .....They are 3mm larger in dia. but 2mm less in length.
Thanks for the instantaneous reply.

[brightcity]

The Michael Percy "website" says to use no more than 1/100 of the larger value as a coupling cap.

He has an amazing price on Solen film caps of that value. Personally I prefer Solen, never heard Janzten. The Audio Note Copper foils I have took alittle getting used to. Solen is a very fun cap internally tuned to a lower frequency (warm tuning) than most of the other boutique film caps. Accomplished through foil slits at various positions on the inner to outer sections of the winding.

They are also cheaper than the Jantzens you mentioned. This saved cash could afford you a Khozmo stepped attenuator. Stepped attenuators are in my opinion is the best upgrade for any amp ever. You can find the Khozmos on the partsconnexion website as I have heard that the Khozmo website is alittle flaky.

Please let me know where you found Jantzen caps as I have a tubedepot guitar amp I am building. And as always trust your own ears for what you want.

If only bottlehead offered a stepped attenuator for the Crack.

[Paul Joppa]

...
If only bottlehead offered a stepped attenuator for the Crack.

Your wish is our command:

https://bottlehead.com/?product=submissive-volumesource-control-kit

[brightcity]

Thank you, I forgot about that one