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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

Showing 2 responses by eworkflow

eworkflow
10 posts
 

Capacitors have their own technology, dynamics and very often audible characyeristics. Anybody who disagree most likely never replaced one in the audio path of their high-quality equipment piece.

As for capacitor used to shunt DC power supply, they are necessary to eliminate high-frequency noise present there, but never affect the sound quality as much as a different coupling (serial) capacitor used in the audio path.

eworkflow
10 posts
 

@ieales I don’t know what social setting you acquired your accusatory tone from, but your ridiculous accusations of me being irresponsible have no merit. First, I wouldn’t suggest changing it to anything different nor ever stating that capacitors do not affect sound in the audio path. So, in short, I am "irresponsible" for saying that the primary role of low-capacitance capacitor shunting DC power supply is to filter HF noise. Secondly, please present a literature source to confirm your "power supply impedance and phase" being audibly affected by a low-capacitance shunt capacitor or just shut up. I am well aware of the fact that power supply quality will affect sound, but you are taking your holier-than-thou mission too far.

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