Gr8Scott
Wookieologist
Ears are ringing like mad. I really need to wear ear plugs when I use this amp. I've modded the heck out of this amp and it sounds pretty darned good thus far. Much more like a real deal JCM-800 with that customary Marshall roar. I completely retubed it when I finished the mods and two of the new pre-tubes died in the V2 slot (actually V5 according to Peavey) after roughly two hours of play time each. I could have gotten two bad tubes because I can't see anything obviously wrong with what I've done mod-wise and it sounds great until the volume fades out. I'm trying a pre-tube now that has been used in other amps with success to see if it lives very long. If it lasts for while, I'm gonna call it quits and button the amp up for now. If it dies, I'll test each tube pin and see if I can find strange voltages etc.
I've found a way to put a LAR/MAR PPIMV in place of the existing master volume. I'll probably do that before I finally button this amp up for good and have a custom enclosure made for me by a friend with a cabinet shop. It would be nice to tame this 120 watt monster's volume down to more manageable levels without destroying the tone it has. The custom enclosure will allow me to shed a ton of excess weight this amp has as the original enclosure literally weighs the same as the chassis loaded with transformers and tubes etc. I'll find something lightweight and durable to use. Most enclosures are maybe 1/5 of the total weight of the amp head.
I've been looking to see if the master volume has a bright cap installed somewhere to make it sound really piercing at lower volumes. I can't see anything in the schematic or on the layout that really catches my eye other than the fact that the master volume is built in to the EQ section and is definitely pre-phase inverter. Being that close to the EQ section must be having an adverse effect on the tone of the amp when the volume is low. Cranked up, the tone is awe-inspiring and thick.
I've found a way to put a LAR/MAR PPIMV in place of the existing master volume. I'll probably do that before I finally button this amp up for good and have a custom enclosure made for me by a friend with a cabinet shop. It would be nice to tame this 120 watt monster's volume down to more manageable levels without destroying the tone it has. The custom enclosure will allow me to shed a ton of excess weight this amp has as the original enclosure literally weighs the same as the chassis loaded with transformers and tubes etc. I'll find something lightweight and durable to use. Most enclosures are maybe 1/5 of the total weight of the amp head.
I've been looking to see if the master volume has a bright cap installed somewhere to make it sound really piercing at lower volumes. I can't see anything in the schematic or on the layout that really catches my eye other than the fact that the master volume is built in to the EQ section and is definitely pre-phase inverter. Being that close to the EQ section must be having an adverse effect on the tone of the amp when the volume is low. Cranked up, the tone is awe-inspiring and thick.