Gain Controls Vs Volume Controls

[Cogito]

I really like the CDE caps, best is use the versions with voltage ratings 1000V and above. Use these first, then consider upgrading in your DIY builds. You may not need to.

Shashi, I am a little concerned about the version of the Miflex caps you are using, I believe these are for speaker crossover application. For tube applications I would use the 600V version. The thicker and higher voltage films generally are better for tube circuits. There is a big size difference.

David

Thx David. I intended to get the 600V version caps but placed the 250V caps in the cart mistake. They are shipped back for exchange.

BTW, I am leaning towards Deuland CAST-PIO-Ag BYPASS Series caps for bypassing the Jupiters. They are expensive, but what the heck, these are life-time purchases like Walt said.

Last edited by Cogito on May 16th, 2024, 9:34 am, edited 1 time in total.

[Cogito]

Question Sashi: what is the input impedance of the load? Are you sure that the 1uF caps are sufficient to give you full bass response?

Load is 75k Ohms, no issues with the bass.

Don't forget the power supply caps. They are a part of the circuit and need to be bypassed. I don't know what your circuit is, but if you can replace the B+ caps (assuming they are electrolytic) with DC Link caps, you'll be pleasantly surprised at the improvement. Again, bypass the final stage of the filter with a small value (say, 0.1uF) Miflex or better.

Stuart

So, you are telling me I need to spend more on the caps?
Fortunately, there are no smoothing caps after the tube rectifier. It not a standard power supply we see in tube amps and preamps, but as a result, the preamp is very quiet, and the details come thru.

[dberning]

Speaking of caps, I have a 25uF, 2kV oil cap I would like to give away. Might be the cat's meow as a bypass for a much larger energy storage for a tube amp.

D

[Cogito]

Would they be good to bypass 470uF Caps. I have 2 of those in CLC filter.

[David McGown]

Shashi,

They are probably bigger than your preamp.

25uF 2kV caps PIO are BIG.

David

[Cogito]

I didnt observer the 2kV part.