I think Fahey was talking about the "2022", link #19 on the page you posted earlier: Marshall Schematics - Tube amp Schematics
Here is a direct link to the 2022: https://el34world.com/charts/Schematics/files/Marshall/Marshall_20w_2022.pdf
The one you just posted (JMP 2100) is a much more powerful amplifier using a pair of EL34 output valves. Huge, heavy, expensive to build, and you'll need to buy serious hearing protection and rent a sports arena in the bad part of town in order turn it up past "2" on the volume control.
Okay, I was exaggerating a wee bit for entertainment. But no kidding, this is the amp that made a thousand guitarists go deaf, or spend the rest of their lives with tinnitus (ringing / whistling / screeching / hissing in the ears, caused by damage due to exposure to very loud sounds.) It was designed and sold decades ago, when P.A. systems were in their infancy, and the guitarist had to be loud enough to reach the entire audience.
Times have changed, our lives are crowded now, there are people everywhere, and not much empty open space in which to get loud. And there's a lot less tolerance for very loud noises these days. IMHO, it makes no sense to build an amp so loud that you can't actually use it in any normal situation.
I don't think you mentioned how you plan to use your amp - on stage with a drummer? On stage without a drummer? At home? That information might help you decide which road to go down. (And it might help others to give you well-informed suggestions.)
If you are wide open to choices, have you looked at the old AX84 forum designs? The AX84 P1, for instance, uses a single EL84, puts out a loud 5 - 7 watts, and seems to have a lot of borrowed Marshall DNA in its design. There is a very comprehensive document to guide builders of the amp, which contains everything from schematics to layouts to a bill of materials (BOM).
Google will turn up plenty of You Tube videos of AX84 P1s, most of them featuring very really bad beginner-level guitar playing with out-of-tune guitars, but at least you can get an idea of the amp's sound.
I'm thinking about building something inspired by the P1 myself. After listening to several You Tube clips, I think it covers most of the range of guitar sounds I use.
-Gnobuddy
Thanks again for correcting me,, I was going by the "Lead and Bass" description,,, and missed the extra stage, and EL34 designation... Don't get old,, it really sux...
I'm just building them to play with at home,, some buddies like to hear/play the old amps...
Just something to keep an old mind occupied...
I'll try to correct the previous posts, but not sure I can access them...
NOTE,,, Disregard post #22,, I posted the wrong schematic... can't access it to correct....
I'm just building them to play with at home,, some buddies like to hear/play the old amps...
Just something to keep an old mind occupied...
I'll try to correct the previous posts, but not sure I can access them...
NOTE,,, Disregard post #22,, I posted the wrong schematic... can't access it to correct....
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Oh, I'm well on the way already. It was bad enough five years ago when the lady at the ICBC (British Columbia's equivalent to the Department of Motor Vehicles) looked at me and said "Hair colour - Grey" as she filled out the form for my driver's license. Now "grey" is starting to be too kind a description...next visit to the ICBC will change that to "white", I'm sure.
Depending on what sort of home you have, keeping the amp from getting too LOUD may turn out to be the biggest challenge.
Real estate is insanely expensive in my corner of the world. A small house on its own little patch of land costs well north of a million dollars (no exaggeration). The best I could do is a small apartment, and I was lucky to be able to get into even that.
Living in an apartment, of course, means I have people living on both sides and above me. My 15-watt Fender Princeton was far, far too loud. So was my slightly less-loud Super Champ XD. So I built a 2-watt guitar amp - it was too loud.
Not long ago I breadboarded a 200 mW (one fifth of a watt) guitar amp. It was fine for clean tones, but even that was too loud when overdriven.
The 200 mW amp was quieter than an acoustic guitar at full blast - which is also too loud for my apartment.
A very good idea, indeed! You know what they say, "Use it, or lose it!"
You may already know - playing music uses almost all of your brain, much more of it than just about any other activity. It's very good for you!
Right after you make a new post, you have an "Edit" button that let's you make corrections. It times out after a fairly short period, though. After that, only one of the moderators can edit or delete that post.
-Gnobuddy
HA,,, Yep well it beats,, hair... None!!!,,, I have a single house,, but its still too close for my liking... Well, I used to enjoy rebuilding cars,, but that's a bit much now,, as all my buddys moved away,,, and there is no more access to a lift... Yep, I see how the edit works on this forum,, but we didn't find the mistake in time!!!! and I am more than computer illiterate,, I try to send schems to my son so he can make double size copies at work and send them to me... Hate to keep trying to keep up with my mistakes tho... I corrected it as well as I could, from here...
Still plan to build the 20W tube chassis, but now we got an option...
I got a chance to order the broken pots,,, just to see if they are the only problem with this SS chassis,,, I got the A1M pots yesterday, and got them installed,,, the other two are are "on their way!!!" So I clipped a couple pots in to try the amp and it seems to work fine,,, I'm going to build a more stable mounting system for the PCB, so it won't be so easily damaged...
Still plan to build the 20W tube chassis, but now we got an option...
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