Trimax Type One amps racked up

[Barney Loveland]

Finally put together this rack for my own use. Recapped with Sprague's and wired up they sound great as is. DI is bypassing transformer and straight to 1st tube.

[Chris H]

nice work. how much gain do these give?

[Barney Loveland]

Bout 40db. Going to live with them a while before I start tweaking.

[Chris H]

Bout 40db. Going to live with them a while before I start tweaking.

Ok, & you could go from the output of one to the input of the other for, say low output ribbons?

[EvLoutonian]

How are these TRiMaX amps going?

Cheers,
evan. MELB

[Barney Loveland]

Digging them so far. Drums are great through them. Haven't done much else tracking wise. DI for bass is ok, tube sounding, but not my 1st pick. Tried removing feedback and output load changes but they ended up stock again until i have time to play some more.

[EvLoutonian]

I picked up a TYPE 1"A" (with TRIMAX transformers).
Has anyone come across this variant before?

I'm not sure if it's a complete anomaly, or just a less commonly found version.

Differences from the ones I see pictured here (of Barney's) are that on mine the output transformer is a different style, running front to back, instead of across the unit. The Transformer number is TA733B (20k ohms / 5k ohms into 600 / 150 ohms).
Also, the circuit board runs along the left hand side of this transformer rather than behind it, as I see on Barney's.
Also the face plate just reads Balanced Amplifier TYPE 1A in white text against a black background.
Seems odd.

The tubes are both 12AT7's, to add to the mystery.

Doesn't compute with any of the schematics or info I've seen.
I can post some pic's..

Cheers,
Evan.

[Barney Loveland]

Can you post a pic, if for nothing else my own and others education. Will look for a 1A in my files.

[EvLoutonian]

Cheers Barney, I'll do it now..
I'll snap off photo's showing all the major components.

Do the transformers in your TYPE 1 amps indicate what windings are connected?
Because I'm thinking, if my transformers are the same / compatible with the original design, I could just get this one back to the original specifications of the TYPE 1 circuit and take it from there.

May be more sensible than trying to figure out what's been done to this one.

[EvLoutonian]

TRIMAX TYPE 1A preamp











Lemme know any thoughts on this - is it an oddball, or do I just need to track down the correct documentation on this 1A version?

[Barney Loveland]

Quick guess is that it's a mod. Need to find someone who knows the Trimax history and see if it is the real deal or one that has been fixed because the output transformer broke and modded the circuit to suit or for kicks. You could trace it out to see what they've done?

[EvLoutonian]

Thanks Barney.
Do you know if the standard output transformer was 20k / 5k on the primary or not?
(ie. on your's?)

I've never traced a circuit before, but I guess this'd be a good a place as any to start, hey!?