On May 15, 10:18 pm, Tim wrote:
I am trying to get the old guy back up and running so I give it to
someone who has no stereo equipment, but wants to play some LPs. There
is no audio output at all, not even the usual hum. I did some research
on the output stage which uses the 50EH5 tubes. Most of the schematics I
have seen use an isolation transformer to power the tubes. This one does
not have a power transformer in it at all. All of tubes light up, and I
have checked them with my (don't laugh) Radio Shack Tube Tester. Most of
the tubes are fine, but 1 of the 50EH5 shows as gaseous and shorted. I
would like a schematic if possible, or some direction from anyone who
may recall how this company designed the stuff.

Another strange thing is that most of the schematics have the 2 50EH5
heaters wired in series with a high wattage resistor so they run off a
125 v ac or dc source. If I pull one of the tubes out of the chassis,
the other one stays lit.

I love working on this old stuff, but I need some guidance here. I
figured that if 1 of the tubes is bad, the other channel should be ok.

Thanks,

- Tim -

--
Email - (remove the nospam part)

You don't say how many other tubes there are. There may be two
parallel strings of tubes. Do any of the tubes go out when you [pull
one of the 50 EH5's?


H. R. Hofmann