Wiring output transformer...

[Bob M.]

I have a new homebrew amp w/ 2 6L6 tubes in push-pull configuration. My speaker choice is a single 12" @ 8 ohms. In stock, I have a Hammond 1620 output transformer. This tranny has 4, 8 and 16 ohm secondary output taps. The primary resistance of this transformer is 6,600 C.T. Using this transformer, should I wire the 8 ohm taps or would it work better wiring another tap for an 8 ohm speaker/2x 6L6s?

Thanks,

Bob M.

[MWJB]

Try the 8ohm tap, then try the 16ohm tap (3.3K primary Z)...the one that sounds the best is the right one. But, if you plan to use a parallel wired extension cab, with another 8ohm speaker (4ohm total load), every now & then, stick to the 8ohm tap.

[Bruce / Mission Amps]

I've used at least a couple dozen of those 1620 OTs and I have a feeling your 6L6 amp will sound good with either the 3k3 or the 6k6 and the 8 ohm load.
And with no fear of damage to anything.
Just pick either ratio for a tone you like... I preferred the 6K6 load myself in my 6L6 amps BUT, using different rectifiers, running about 410vdc to 440vdc and the adjustable bias, it allowed me to use 6V6s too.
A great asset.

[Bob M.]

Gents,

Thanks to both of you for your informative replies - just what I was hoping for!

I doubt I'll ever use this amp with an extension cab but I did consider alternately running 6V6s when building the amp, designing the bias circuit, etc but during my listening tests when finished, in this particular circuit, the 6L6s completely outshined the 6V6s.

Bob M.