Olson stereo amps & docs ?

[FlaCharlie]

It looks like there's little technical information about Olson tube amplifiers.
I'm trying to go through an unidentified model equiped with a 5AR4 rectifyer, four EL84 PP and 5 12AX7 (all testing good).

The amplifier I'm working on doesn't have exactly the same housing / front place as this specimen but the chassis looks identical.

Any infos ? Thanks !

Here's a schematic which may be the same or similar to the one you have. It does use all the same tubes, anyway. It's not a complete Sams, just the schematic. There are two other schematics with it. It's a pdf, which can be enlarged to show detail.

 

[david winter]

Thanks a lot for your advises and documentation.
I found the culprits. Sure enough I had to miss somthing obvious: the output transformers, probably because the amp was working a little at the begining.
One output transformer was open on a section of its primary and the other had one section partially shorted on the primary.
There wasn't much room in the amp but had a pair of Audax TU-101 which allowed wiring the screen grids in "ultra linear" mode.
Hum is gone and sound pretty good. Thanks again !