Hoffman Amplifiers Tube Amplifier Forum
Amp Stuff => Tube Amp Building - Tweaks - Repairs => Topic started by: Brownie on March 05, 2025, 04:57:53 pm
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Is it possible to make a 5E3 with a single input jack, and just mix the channels at will by twirling the volume pots? Would I just take the lead form the jack and run it through pins 2&7? I want to split the cathodes and choose different caps, sort of in the plexi way. It began life as a 5F2 chassis that I put a couple extra socket holes into for a Harvard build...
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I think you could build it similar to the November input section. Basically a 1 input Plexi design.
https://sluckeyamps.com/november/november.pdf
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Thanks for that, Al. I've never seen the November print but I was thinking about copying the Huss/Sluckey 6V6 Plexi which is much the same. The 470K mixing resistors will have to be placed after the dual stack Tone comtrols before hitting pin 2 of V2 I suppose.
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Yes, and you could either do something else interesting with the spare input triode, e.g.;
1) parallel input stage, or
2) adding it in as a further 'in-between stage' in the pre-amp (e.g.: input triode>vol/tone>recovery triode>driver triode>cathodyne>...), or
3) having the 1st 12AX7/AY7 tube as a sort of brown princeton single channel (input triode>vol/tone>recovery triode) and using the 2nd 12AX7 as a '2-triode PI' (e.g. LTP or paraphase inverter)
2 or 3 would make a gruntier sounding amp with 2 being more gainy and 3 being more bluesy - either having way more gain than you need to overdrive the 6V6s, (but IMO the paraphase PI makes a cool sounding PI with push pull cathode biased output tubes, and even sounds good for blues harp)
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I was just going to keep it like a 5E3 with a cathodyne PI and mixing different sounding channels. Is the paraphase PI the one in an Ampeg J-12? I wasn't bothering with trem in this one cos I've repurposed one of the input jack holes. If you can refer me to a schematic of what you're talking about, I'd have another alternative to study.
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Paraphase PI examples
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Is it possible to make a 5E3 ... It began life as a 5F2 chassis that I put a couple extra socket holes into for a Harvard build...
Having built a number of amps in tweed chassis, I can't imagine building a bigger tweed amp in a smaller tweed amp's chassis.
Just doesn't seem like my idea of a good time.
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A Harvard it is then, maybe with Cathode/fixes bias switch..
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If you have extra room for a switch/pot, there's probably better ways to use it.
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Just to complicate you a bit the life :icon_biggrin:
https://el34world.com/Forum/index.php?topic=17360.msg173749#msg173749 (https://el34world.com/Forum/index.php?topic=17360.msg173749#msg173749)
(http://i.imgur.com/lx0Onyg.jpg)
Franco
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A 5F2 chassis is slightly wider than a 5F1 so you might just fit 2 x octal and 2 x noval sockets in there with SS rectifier. The 5F2 panel already has 2 x inputs and volume and tone control. The small space would mean you’d want to plan it carefully but it’s doable methinks.
I think you could have a 6G2 input channel with most of the control components mounted on the pots with input shielding cable going direct to V1, and room on the board for all the other parts including either a long tail pair or a paraphase inverter (again with some components mounted direct to the tube sockets).
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Just because I had spare time...