5E3 Prebuild Questions - Decoupling, Filtering, etc

[johnboy]

So I built a Champ a while back using KOC's layout, which inlcluded decoupling the gain stages and the use of a DC stand-off for the heaters.

This amp is really, really, quiet and the line in my house is very noisy with most other amps.

So now I'm planning a 5E3 build and I'm wondering if it's worth doing the same decoupling to the Deluxe - that is - will it really matter? Will this all add up to too much filtering? Same as the DC stand-off - is a grounded centretap just as good for noise suppression on the filaments, so why bother?

Or, should I just leave well enough alone and go with one of the standard layouts that are around?

Johnboy

[loudthud]

The DC standoff does knock a couple of dB off the residual hum. In a 5E3, alot of builders just connect the CT to the cathodes of the 6V6 tubes. The magic of KOC's grounding happends at the rectifier end. Look around this board and you'll find lots of threads started by novice builders who tied the HV center tap to a transformer bolt and had hum issues. The 5E3 doesn't have enough gain to require a tight layout with close by de-coupling.

It's a little bit of work and you'll need to make your own eyelet board or modify one of the ones available. I've had good results modifying exsisting boards to use radial lead caps.

A word of warning: Don't increase the value of the filter caps any more than necessary or some of the 5E3 magic will escape.

[johnboy]

Thanks loudthud;

I think I'll forget about the decoupling then, but add the standoff - only a couple of extra parts, and I've got some extra G10 lying aorund, so I'll probably make the board and layout from scratch.

Thanks for the warning on over-filtering...

Johnboy