Hoffman Amplifiers Tube Amplifier Forum
Amp Stuff => Tube Amp Building - Tweaks - Repairs => Topic started by: stevehoover on August 11, 2014, 01:28:42 pm
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?? Are both channels in phase on a stock Dominator circuit??
to me it looks like they are but wanted another opinion.
Thanks,
Steve
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No, they are not. (I'm assuming you mean for the purpose of jumping the two channels together for a fuller sound with more tone options)
Here's why...
Each channel goes thru a single inverting triode gain stage. So, when the signals come out of those single triodes, they are in phase. But, one channel is applied to the inverting input of the LTP PI and the other channel is applied to the non-inverting input of the LTP PI. So, when the two signals are recombined at the LTP PI plates they will be out of phase and a lot of the signal will be cancelled, resulting in a weak, tinny sound.
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Thanks Steve you were reading my mind.
I am revisiting a lightning build I did a few years ago. My tastes and hearing have changed and I am trying to figure out what to do with what I have. The lightning is a bit too bright and too modern sounding.
What is stumping me right now is where in the lightning circuit is all the high end response coming from?
even with the bright cap disconnected, mine is still very bright.
Thanks again for the quick response on the PI inputs....it was right there in front of me on the diagram, just hadn't though it through ;-)
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What is stumping me right now is where in the lightning circuit is all the high end response coming from?
even with the bright cap disconnected, mine is still very bright.
What are the values of the first gain stage plate coupling caps? A Watkins dominator schematic I have shows 680pf. Depending on the resistance to ground following that cap, you could have a high-pass filter losing all your low-end.