Question About Capacitor Upgrade in Tube Amp


Hi,

I am preparing to do a coupling capacitor upgrade on a recently purchased tube integrated amp. The two 0.22uF on the preamp tubes are fairly straight forward. But I noticed another similar model 0.33uF cap on the large filter capacitor for the B+ supply that is installed across the hot lead to ground.

Does this cap on the B+ just block high frequency noise from the power supply or does it have any effect on the amp tone? Is there any reason to "upgrade" this cap?

I know it may be hard to tell exactly what is going on without a schematic.

Also any recommendations on a good cap to use in the upgrade of the coupling caps? I was looking at Mundorf SilverGoldOil for the quality at not too crazy a price. The amp already sounds good but lacks a little clarity that I think a coupling cap swap will help with. It is SET 300B amp.

Thank you!

 

calieng

if you are trying to upgrade the coupling caps, the amps are to cheap in quality,  i don’t recommend it.   To me it’s a big waste of time, money and effort.  This is just my opinion!! 

@calieng 

I am going to respectfully disagree with the above comment that disparages upgrading your amplifier’s coupling capacitors. Tube amplifiers in general and particularly SET amplifiers have very straightforward/simple circuit layouts. With regard to the SET amplifier there is a lower part count.

Essentially one could argue that because of this, each part individually takes on more importance particularly in the audio signal path. I believe that changing to a higher quality coupling capacitor is a very good idea and money well spent. 
 

if you take the time to research and do further reading/investigation you will find a better capacitor that will contribute to improved sound quality. I’ve had splendid success with the Duelund CAST copper foils. Considerations are available space for a given capacitor and the cost. No doubt there are other excellent choices available.

I suggest that you reach out to @grannyring via site email. He is most definitely a knowledgeable and helpful resource.

Charles

I have inexpensive Jantzen (2.2) red colored caps in my Bottlehead Paramours that sound excellent.

Been thinking about going SS, but if I don't I may try the Jantzen silver colored caps which are said to have a bit more detail.

I don't recall what was in their originally (been using them for 20 years now).

I looked @ Audyn  copper when they first came out, but 2 of them cost twice as much as I paid for the amps/mono-blocks.

However, if you go with Zipost's advice don't stop there as you can also downgrade your speakers, cables, source gear and maybe even the tubes if you are lucky.

 

DeKay