hello i have a jcm2000 dsl that has been nothing but problems. I'm no longer a channel changing amp guy, and primarily a bassist these days, so I've done some pondering and I'd really like to gut the thing and use the transformers (and a jcm800 choke i purchased for a long ago scrapped project) to build this nifty jcm800 super bass (I'm thinking kt66s for it too but that's not what I'm having trouble with). problem i keep running into is that the only schematic available is rather difficult/impossible to read (especially around the tone stack/mid slope values... the rest I'm sure i could make educated guesses about since it's the tone controls that make this head unique). anybody able to help me with these values? I've attached the schematic from drtube. I'll also note that i plan to filter the B+ better. the entire preamp is on one node and i do not like that
jcm800 1992 super bass schematic
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thetragichero
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jcm800 1992 super bass schematic
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PRR wrote: Plotting loadlines is only for the truly desperate, or terminally bored.
Re: jcm800 1992 super bass schematic
Have you tried one? My recollection of that amp / those tone controls is that it was hard to set it up for a good sound.
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thetragichero
- Posts: 476
- Joined: Tue Sep 10, 2019 7:46 pm
Re: jcm800 1992 super bass schematic
i have not but since i have the donor chassis and transformer i figured why not try out a $1300 (price i see on reverb) amp that i basically only have to buy pots for because the rest of the stuff is on hand?
some complaints is that it's darker than most marshalls which is fine for me: my p pickup is more miss-forward than thuddy and i have a hole for an extra preamp tube so i figured having a "bright channel" triode + cathode follower (to keep phase the same as the stock circuit), "bright channel volume," and some way to just the channels like a 4-hole Marshall would give me the ability to dial in more highs of i need
from what i understand this model gets loud and clean so if i need grit I've got fuzz pedals (i think i have enough chassis holes for a master volume anyway)
my goal is to turn something that's been sitting dead for almost 10 years into something useful/intriguing. the mid controls and baxandall tone stack look exactly that to me
some complaints is that it's darker than most marshalls which is fine for me: my p pickup is more miss-forward than thuddy and i have a hole for an extra preamp tube so i figured having a "bright channel" triode + cathode follower (to keep phase the same as the stock circuit), "bright channel volume," and some way to just the channels like a 4-hole Marshall would give me the ability to dial in more highs of i need
from what i understand this model gets loud and clean so if i need grit I've got fuzz pedals (i think i have enough chassis holes for a master volume anyway)
my goal is to turn something that's been sitting dead for almost 10 years into something useful/intriguing. the mid controls and baxandall tone stack look exactly that to me
PRR wrote: Plotting loadlines is only for the truly desperate, or terminally bored.