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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 1 response by gregl3a

gregl3a
1 posts
 

If your looking to upgrade coupling caps you can also play with the value of the

caps because they play a critical role in output impedance. For example,  I purchased a tube preamp which sounded terrible, no dynamics, no amplification.

Turns out there was an impedance mismatch between my amp(LSA class D) and the newly purchased preamp. After some research, I purchased a slightly upgraded cap with an increased value and surprisingly, it worked and am extremely happy with the outcome. Wanted to give my 2 cents cause coupling caps play a critical role, whether you're upgrading or changing the value, dismissing it's importance is  just anti-audiophile.

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