I had some time tonight to check the power output of my ST-70. (Unit has the stock circuit, rebuilt with new components, a cap board and new tubes E.H. EL34 outputs)

8 ohm tap w/ 8 ohm non inductive load was 38 Watts for each channel. Both channels voltage measurement were very close when calculating power.

I was curious what mono looked like and I read what the manual had to say about using 8 ohm taps in parallel for 4 ohm speakers etc. I tried a combo and here is what I measured:

8 ohm taps in parallel w/ 8 ohm load = 55 watts

4 ohm taps in parallel w/ 8 ohm load = 38 watts

8 ohm taps in parallel w/ 4 ohm load = 72 watts

4 ohm taps in parallel w/ 4 ohm load = 56 watts

I don't have the 16 ohm taps available for speaker connection after installing banana posts, so no measurements were made.

Anybody else measure their ST-70? Comments on my findings? I'd be curious to see if this is repeatable on someone's ST-70...

Thanks,

Dave