5AR4 & 5U4G Rectifier Questions...

[Guiness]

I have been helping my son tweak his first tube ampifier. It is a SE 6L6. It has a 5U4G tube rectifer in it right now (CLCRC). And I want to swap in a 5AR4 in its place. Give it the slow turn on that comes with the tube. The first cap is less than 60uf, it is a 20uf. So all should be fine, right. Also is the voltage drop going to be greater? If so, can you estimate how much?

Thanks

 

[Joel]

The voltage drop will be less, by probably 15 volts or so.

 

[Guiness]

You were very close Joel. I measured 17V higher. I just swaped out the first 20uf cap for a 3uf cap and all is good. I like it so far.

 

[Gabevee]

Question:

Why did you go from 20µF to 3µF???

Gabe

 

[fdegrove]

Hi.

Why did you go from 20µF to 3µF???

It, makes the PSU less efficient.

Cheers,

 

[Guiness]

Yup...

When I added the 5ar4 by B+ was around 383 or so voltages. I like this amp to run around 350V. So changing the 20uf to a 3uf lowered the 383V to 350V.

 

[Gabevee]

Ah! OK.

Thanks,
Gabe