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Sweet. The complication I'm seeing is that there are mutiple ground points differing from the connections in the schematic. Same grounds but in different places. This means some components need to be lifted from their current connection to hook things up in accordance with the mod. Not a lot more work but it does make it hard to demonstrate in the actual chassis. I've already identified the circuits in question but still working out clear instruction.
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"Take two placebos, works twice as well." Enzo
"Now get off my lawn with your silicooties and boom-chucka speakers and computers masquerading as amplifiers" Justin Thomas
"If you're not interested in opinions and the experience of others, why even start a thread?
You can't just expect consent." Helmholtz -
This thing has "ground loops" all over & I'm surprised it's as quiet as it is already. If I end up doing major surgery, I'll probably end up doing my usual ground scheme, running all the PI & earlier grounds to the input jack (or as close as practical) & the power amp & supply grounds elsewhere. I find that's worked quite well in all my other builds.
That Thor I worked on, I ended up abandoning all "good practice" & ran a ground wire about a foot around the inside of the chassis & I forget where I connected it. But it ended up being a humdinger for a noisy PT. Hey, it worked & the amp sounded great, so...
Jusrin"Wow it's red! That doesn't look like the standard Marshall red. It's more like hooker lipstick/clown nose/poodle pecker red." - Chuck H. -
"Of course that means playing **LOUD** , best but useless solution to modern sissy snowflake players." - J.M. Fahey -
"All I ever managed to do with that amp was... kill small rodents within a 50 yard radius of my practice building." - Tone Meister -Comment
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Hey All Involved,
I wired up the inputs like a Fender except w. 47K/1M. I'd already upped the cathode bypass cap when I'd recapped it. The input switcheroo made a huge difference! It's significantly gutsier now, without losing its lo-fi charm. I was able to get some nice tones out of it, & if someone else wants to put some better speakers in it, it'd probably be pretty nice! The tone controls are VERY Ampeg, different, but effective. The bass control stops adding volume around halfway up, past that it adds very subtle lows, kinda like a "Warm" control.
Chuck, regarding your sims, I'd have to scope it, but I'm not hearing anything out of the ordinary for a low-cost late 60s amp. Granted, I didn't blast it because neighbors. I'm wondering if they did the inputs as they did just because a bass puts out a significantly hotter signal than a guitar? Also, the inputs on this one were definitely the same - no Hi/Lo here; there are now. My 75 is the same - even though it seems to be wired like a "normal" Fender per the schematic. That seems silly to me... Someone is seriously gonna plug 2 basses into this thing?
I'll probably dress it up a bit & throw it up on FB Marketplace & see if I get some bites. If not, I'll keep on reworking it & try again. But I think it's pretty cool as is, and I've learned a bit about input circuits. Thanks y'all!
Jusrin"Wow it's red! That doesn't look like the standard Marshall red. It's more like hooker lipstick/clown nose/poodle pecker red." - Chuck H. -
"Of course that means playing **LOUD** , best but useless solution to modern sissy snowflake players." - J.M. Fahey -
"All I ever managed to do with that amp was... kill small rodents within a 50 yard radius of my practice building." - Tone Meister -Comment
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