I can't think of any reason why your idea wouldn't work. No one else has chimed in with a reason, either. Sounds like it's time to melt some lead!
Once you verify that it works as expected, maybe you could try making drive to one triode swichable - I think last time this idea came up someone who tried it said it wasn't a big difference, but it should be the same amount of difference as there is between the two inputs in the classic Hi/Lo input scheme seen on many amps.
Keep us posted!
W
Best way to combine two dissimilar channels into PI?
Moderators: pompeiisneaks, Colossal
Re: Best way to combine two dissimilar channels into PI?
Well, I chickened out and put 100k resistors after each plate cap and prior to the volume pot. So, the two triodes are "mixed" after all.
Someone, please do tell me why one needs mixer resistors. I'm sure there is a reason...
As for the amp, I think it sounds great! Not too low-gain at all. Very nice, actually. I ran one 6SN7 triode with a 500pf polystyrene plate cap and a 2k7/25uf Sprague Atom cathode, and the other triode with a .002uf 6PS plate cap and a 2k7/.1uf Mallory M150 cathode. Neat, so far, at "wife and kid are sleeping" volume. I'll get a better feel tomorrow...but so far it sounds, and more importantly, FEELS better than the straight parallel setup.
Someone, please do tell me why one needs mixer resistors. I'm sure there is a reason...
As for the amp, I think it sounds great! Not too low-gain at all. Very nice, actually. I ran one 6SN7 triode with a 500pf polystyrene plate cap and a 2k7/25uf Sprague Atom cathode, and the other triode with a .002uf 6PS plate cap and a 2k7/.1uf Mallory M150 cathode. Neat, so far, at "wife and kid are sleeping" volume. I'll get a better feel tomorrow...but so far it sounds, and more importantly, FEELS better than the straight parallel setup.
Tempus edax rerum
Re: Best way to combine two dissimilar channels into PI?
Interesting. So the 1st triode has lows cut by the small coupling cap, but has full cathode bypass. The 2nd has more bass output via a normal size coupling cap, but has partial bypass. It would probably be informative to drive them individually so you could hear what each triode is contributing to the mix. If each had it's own merits, maybe Andy's idea of replacing the two mix resistors with a balance control would be neat.
You've inspired me. I'm tempted to gear up something like this with two halves of an 'AX7 and plug it into my amp just to see what kind of possibilities are there.
Have fun with the more extensive testing* once the family is awake and, as always, let us know how it goes.
W
* ain't it great to have a scientific-sounding reason to play yer guitar really loud?
You've inspired me. I'm tempted to gear up something like this with two halves of an 'AX7 and plug it into my amp just to see what kind of possibilities are there.
Have fun with the more extensive testing* once the family is awake and, as always, let us know how it goes.
W
* ain't it great to have a scientific-sounding reason to play yer guitar really loud?