Hoffman Amplifiers Tube Amplifier Forum
Amp Stuff => Tube Amp Building - Tweaks - Repairs => Topic started by: dude on March 03, 2018, 02:05:06 pm
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Original Plexi 1987 had 4 inputs, two for bright channel, two for dark and most used a jumper cable to get both.
I noticed that most all builds of the Plexi 6V6 use one input, jumped internally.
Just wondering if I were to use 4 inputs, like the original, I could put a toggle switch on the back of this head, jumping the channels.
I guess it's just preference. I never played a plexi. Is it worth the extra effort to have a bright and dark channel only? Or...
if you had one input (both channels), turning one all the way down, would that give you either all bright or dark as if that's the case, no use to use more than one input.
I know I can get crazy, but never played an amp with bright and dark volumes together.
al
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turning one all the way down
IMO neither sound good on their own, the magic is in the mix. 4 jacks is just wasting time n money that's better spent on playing and strings :icon_biggrin:
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It's the perfectionism in me that's my worst enemy, :laugh: . I need to go with the flow, there's not enough room with an AO-43 chassis anyway for four inputs, better usage would be to space the pot's further apart.
I know the 6V6 plexi has been beat to death here numerous times, I'll search the forum for info on builds.
Anyway, I cleaned the eyelet/cone bd (as sluckey mentioned, compressed air, did a great job) and got a few tall eyelets to use where needed, in the middle. Laid out everything, made a layout diagram to fit the old Hammond cone bd, I took pictures as I progressed.
Trying to make this conversion the neatest I can, usually my conversions are like a rat's nest, ha. I see all the great work here and it's time I got a little neater.
al
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I cleaned up the choke from the AO43 and it's much bigger than Hoffman's small Fender choke I have . Was wonder if the color of the wiring the Hammond has, a red and blue wire while Hoffman's has both blk, does it have anything to do with which way I hook it up?. Never seen any color wire on a choke other than black
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The red lead is much longer than the blue lead. Use accordingly. :icon_biggrin:
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Guess you know that choke, how many AO43's were you hands in. :icon_biggrin:
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Three. My Smoky got the last of those chokes. It really doesn't matter which lead is connected where. I was just messin' with ya.
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I’m also building 6v6 plexi, but I will order 1987 chassis. I dont know is there a benefit of using 4 instead of 1 input jack
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I’m also building 6v6 plexi, but I will order 1987 chassis. I dont know is there a benefit of using 4 instead of 1 input jack
If you use a real 1987 chassis you will need something to plug up those four input jack holes. May as well use phone jacks. :wink:
And if your buddy will simultaneously be playing through this amp, you will need multiple jacks.
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It's simple to use 2 jack sockets, one for each channel and use their switching contacts so that if only one input is used, the signal will feed both channels, but if both jacks are used then each channel is independent.
Useful to have both channels available, eg for external AB switching, jamming with a buddy.
https://imgur.com/a/Q2AiE
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With a real 1987 Plexi chassis you'll get 4 inputs. Just wire input jacks as the layout you use. You'll have each channel, Normal and Bright with a high and low input. To get both channels at once, the magic, just use the high input channel to guitar and take a 3" guitar jumper cable and jump that channel's low input to the other channels high input.
Bingo, both channels, with two volumes to blend, Normal (or dark) and bright. Add a master volume and there's another choice... :icon_biggrin:
al
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Attached is a schematic with input jacks on the "Normal" channel that is the same idea as pdf64's, but with a different jack.