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!
BEFORE worrying about bypass or blocking caps, ALWAYS ensure the electrolytic PSU filter caps are up to snuff. Way too many tube amps have inadequate primary filter capacitance. Dropping the 120Hz by 10dB is far preferable to 100kHz by a couple. Too often they are under voltage, too high ESR, too small, etc. |
@ieales Absolutely. Total agreement here. LC - LC forever! |
@ieales - I'd be real interested to understand how adding some film decoupling caps cross the B+ supply could cause a tube circuit to oscillate. |
