by EWBrown » Sat Sep 29, 2012 2:42 pm
I finally tried the floating paraphase 12V6GT PP circuit out, with a 275-0-275V power trannie (for a B+ of 340VDC, and approx 20V drop through the 500 ohm cahtode resistios, for approx 40 mA per 12V6GT. and a Hammond 1608 (8K P-P to 4/8 ohms)PP OPT, connected for ultralinear operation.
It actually worked, and sounded pretty good, but I could get only about 4-5 Watts out of it, before it started noticeably clipping.
The next step would be to use a CCS for the 12SL7 cathodes joined together, to make it more like a classic long-tail phase splitter.
Rather than start hacking up the board, I'll just let it be, and I decided to revert it back to being a stereo SE amp, and I'll go with the original intended purposing of a trioded, or UL 12V6GTs, as this has worked very well for me, in an earlier completed project.
FWIW, I referred back to the original 1949 ARRL Amateur Radio Handbook modulator circuit (6B4Gs and 12SL7 floating paraphase), and the construction article stated that it was good for about 6 watts, before distortion. So perhaps 4-5 watts with 12V6GTs was about what I should have expected.
/ed B
Last edited by
EWBrown on Tue Oct 07, 2014 4:37 pm, edited 1 time in total.
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