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Old 31st January 2012, 06:53 PM   #61
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Originally Posted by Zen Mod View Post
which OPT you're using ?
I don't own any SE iron and am not presently funded for this sort of research, so I have to get creative.

The plate is powered through a plate choke and the output xfmer is a hammond 1610, P-P gapless xfmer using one half of the 10k P-P primary only. 8'ish ohm loudspeaker is on the 4 ohm output winding placing the load north of 5k ohms and south of 10k. The plate choke represents a parallel load as well that I don't know the Z of, so perhaps the real tube load is just under 5k.

You asked and I could have stopped at Hammond 1610...

A vintage 4 uF @ 600 VDC Sangamo (like Sprague Vit-Q) foil, oil and kraft paper metal can cap is used as a DC block in parafeed connection back the the o/p tube cathode.

BTW, my initial tube wiring was G1+G2 tied together and used as control grid. G3 was grounded to cathode neg term. The tube refused to draw plate current even at zero bias and only made grunts with peak positive audio modulation. Since G3 is an actual grid, not beam forming plates, this makes sense. As mentioned before, the fix was go in g1 as normal, tie g2 ang g3 to the plate. Marvelous!

I have not brought a sinewave generator or o-scope near this thing yet. All my perception so far is by ear and I'm pleased/encouraged by what I'm hearing.
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Old 31st January 2012, 07:19 PM   #62
Zen Mod is offline Zen Mod  Serbia
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considering that my question was more in sense "which plate load you are using " , I'm more than pleased with an answer
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Old 31st January 2012, 09:47 PM   #63
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My SE experiments used a 5K Edcor OPT. Power output was 8 WPC in triode. See post #7.

My P-P experiments used a 6600 ohm OPT and generated about 25 to 30 WPC.
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Old 22nd February 2012, 11:11 AM   #64
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I'm building my new SE 307A with 4.5K trannies ...
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