Hoffman Amplifiers Tube Amplifier Forum

Amp Stuff => Tube Amp Building - Tweaks - Repairs => Topic started by: chocopower on December 06, 2016, 03:07:02 pm

Title: Unknown amp. Interesting chassis construction.
Post by: chocopower on December 06, 2016, 03:07:02 pm

Hi there,

I get this for cheap.

I identify the tubes using seller photos and think could be a good project.
When arrives i check and seems everything is there but the power transformer.
Maybe this module connect to a bigger console using the 14 pins connector and use a external power supply.
Those are the codes printed in the transformers.

O.T. (the bigger one with cover): T01 - 211446 - 47307 9/70 - 97139

Z01 (The one with a yellow connector. I don´t know what it is. Maybe a input transformer for impedance matching?): 124049. The connectors are labeled as TB01 - TB02 - TB03

Choke (or what i think is a choke. The one in the middle): no number code. Just a code for each connector. TB04 - TB05

Any idea where it came. It seems some kind of militar stuff.

Thanks!

Title: Re: Unknown amp. Interesting chassis construction.
Post by: chocopower on December 06, 2016, 03:07:46 pm

more pics.

Title: Re: Unknown amp. Interesting chassis construction.
Post by: eleventeen on December 06, 2016, 07:49:12 pm

Looks kind of cool.Post a pix of that nameplate on the side.


That appears to be a slide-in module, as the blue connector is the same type as on Tektronix scope plug-ins. Thus, the side OPPOSITE that connector is where you should find any controls if there are any. The narrow side.


You may in fact have something there. We think "military" because the 6AU6 is specified "6AU6WA" the "W" meaning ruggedized...
You would almost never see that on a piece of ordinary commercial gear. Plus the way the wiring is tied up.


The 6005 are apparently ruggedized 6AQ5's and appear to have the same pinout as (cheap) 6AQ5 tubes.


It*could* be a pentode > triode-triode > push pull 6AQ5 little audio amp.
It *could* be a moderate duty voltage regulator circuit.
It *could something else altogether that I don't recognize.

Title: Re: Unknown amp. Interesting chassis construction.
Post by: PRR on December 06, 2016, 09:47:27 pm

Had something like that, less sturdy, which was a servo amp for motor control. (A real lost field.)

As said it is a little power amp, though the OT impedance is likely not useful, and bandwidth may be poor.

Title: Re: Unknown amp. Interesting chassis construction.
Post by: kagliostro on December 07, 2016, 04:30:47 pm

I think those capacitors looks really cool


Franco

Title: Re: Unknown amp. Interesting chassis construction.
Post by: eleventeen on December 07, 2016, 08:17:31 pm

Another clue: It's not the control section of a voltage regulator; it would almost certainly have an 0A2 or 0B2 gas regulator tube if it was. It almost certainly *is* an amplifier, then. Either audio or a servo amplifier like PRR said.