18Watt.com

Ok so I just scored an old RCA (I think it was a victrola?) record player console style. It has 2 6bq5s (which from what I gather are actually the same tubes as el84s). It has kind of a wierd setup to me, it has the transformers and the power tubes on one chassis and the radio and record player hooked up to the 12ax7's on another board (well it's the first time i've seen one this way)

I do not have a schematic for it but what I was wondering was how can I tell if it is a PP output transfomer or a SE? If it's PP then i definitly scored big if it's se then it was still worth the three seconds it took to grab it out of the trash (and I always thought everyone else was lucky).

Thanks for any info on this also I know there are probably a half dozen threads on this already but I need to learn how to narrow my search better.

Hi,

It's ALWAYS worth going bin diving for tube stuff

Obvious signs of SE operation are connection to one tube per channel. If the transformers have already been removed, look at the laminations. Do they have a gap? Is there a visible strip of paper in between the E and I lamination? If so, it was made for SE.

Cheers!

Take a look at the connections to the 6BQ5s pin 7 and see if they are connected to seperate leads on the OT. If they are you've got a PP configuration.

If pin 7 on both tubes is connected to one side of the OT then you would have a parallel SE config. The schematics for the 18/36 watt amps you will find here in the download section are mostly, if not all PP. For examples of SE config look at the P1 Extreme and Hi-Octane amps under "legacy projects" on the www.ax84.com site.

Sounds like you may have made a nice little score there especially if the trannys and tubes are in good shape!

Thank you both for the info =)

the tubes and transformers both look good. When I get home from work today i'll check to see what kind they are.