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Tweaks for systems, rooms and Do It Yourself (DIY) help. FAQ.

Re: Consensus on the best diodes for tube amps?

62.6.139.12

Konnichiwa,

Any old diode is fine, AS LONG as you put in series with the bridge's positive output ONE soft switching diode and add suitable snummbers. The RC snubbers John Camille proposed are okay, you can get a lot more milage out of using suitable symmetrical LC snubbers with X/Y arrangement filter cap's. They also help reducing any other noise entering the +B line by producing a 4th order Lowass, differential and common mode.

You can get several mH highish current Chokes from Panasonic, combine with a few 100nF on the Ttransformer side of things and place an RC snubber (R = aparent DCR of Transformer, C select so not too much current flows) across the transformer secondary. For the other filter cap's simply run a decent sim (P-Spice?) to make sure the whole LC Filter is overdamped (usually requires quite large value Film Cap's, but so what). You can also modify the filter damping by adding series resistors to the chokes.

The resultant "optimum snubbered and filtered generic bridge rectifiers" tend to sound cleaner than most valve rectifiers and combine most advantages of Valve and Solid state rectifiers. The downsides are in the fact that you are introducing a very complex filter circuit and that you still need a slow-start circuit. I personally would, all else being equal, vote for Valve rectifiers....

Sayonara


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