Power transformer inside chassis?

[Steve Blackdog]

Evening all,

I am having a go at designing a hybrid guitar amp. 12AX7 pre-amp fed by one transformer and solid state power amp, fed by a separate transformer. Obviously, no output transformer as output stage is S/S.

I know that tube amp PTs live on the outside of the chassis, but what is preventing me putting the trannies inside the chassis?

cheers

steve

[Helmholtz]

I know that tube amp PTs live on the outside of the chassis, but what is preventing me putting the trannies inside the chassis?

A steel chassis provides some magnetic shielding of the internals against PT leakage hum and outside mounting improves convection cooling.

When mounting PTs inside the chassis it's advisable to use either toroidal core transformers or PTs with endbells and/or fluxbands and place them far from the sensitive input stages.

[J M Fahey]

95% of SS amps fit the transformer inside the chassis/cabinet, no big deal.

Just take the usual precautions in layout and grounding.

[Steve Blackdog]

Thanks chaps. I will try it inside. If it is a problem, I can always move it outside later!

All the best

steve

[The Dude]

I'll add: There are plenty of tube preamps with the PT's mounted internally.

[Chuck H]

This^^^^^^^^^^^^^^^^^^
(Duderino beat me to it. Oh, he's cool if I'm not into the whole brevity thing )

Just pay attention to what Helmholtz said. PT one end, preamp on the other. Don't daisy chain any ground leads between them.