What I have found useful:
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!
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- 99 posts total
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 |
- 99 posts total

