Amp project

[Rockfactor]

Thanks, this all,the good discussion I was hoping to start. As I said I have a basic understanding, just trying to come up with a good, usable and flexible amp. The plan is to see if I can reuse most of the stuff from the JCM900 in some way to keep costs down. This may not be possible but that's the starting plan anyway.
The JCM900 has the 25/50W switch that changes from pentode to triode mode (I use the 25W mode) but can still only run the amp at 2.5 and it's still very loud. The JCM900 is a pcb based amp so I am contemplating rebuilding the power amp section using turrets etc so I can modify a bit more readily (the PPI volume sounds like a good idea) for use when I am using the modeller as the preamp.
Then after that I could mod / build preamps to try and get the sound I'm chasing when not using the modeller.
It's as much about learning / experimenting as it is about the final result.


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[DrNomis_44]

Thanks, this all,the good discussion I was hoping to start. As I said I have a basic understanding, just trying to come up with a good, usable and flexible amp. The plan is to see if I can reuse most of the stuff from the JCM900 in some way to keep costs down. This may not be possible but that's the starting plan anyway.
The JCM900 has the 25/50W switch that changes from pentode to triode mode (I use the 25W mode) but can still only run the amp at 2.5 and it's still very loud. The JCM900 is a pcb based amp so I am contemplating rebuilding the power amp section using turrets etc so I can modify a bit more readily (the PPI volume sounds like a good idea) for use when I am using the modeller as the preamp.
Then after that I could mod / build preamps to try and get the sound I'm chasing when not using the modeller.
It's as much about learning / experimenting as it is about the final result.


Sent from my iPad using Tapatalk

I seem to remember looking at the JCM900 schematics, and noting that the hi-gain channels used an unusual silicon-diode bridge-rectifier configuration to generate clipping-distortion in the hi-gain preamp, this can sound harsh compared to the natural-distortion you get by overdriving 12AX7 tubes, Mike Soldano took a different approach when designing his Soldano SLO 100 amp, using cascaded 12AX7 gain stages.