Forum upgraded to SMF 2.1.2!
Started by El Scorcho, March 18, 2018, 09:32:21 AM
Quote from: Enzo on May 02, 2018, 01:02:58 PMThe huge gain problem is less a design flaw than it is people trying to improve the amp. In that 5000 series of amps, you might see 1458 op amp. I recommend getting exactly that to replace them. people "upgrade" to 4558, 4560. 4580, and then their amps become unstable at gain.Stick with the 1458 there.
Quote from: El Scorcho on April 24, 2018, 01:30:07 PMI'll go back and find that image, jazz bass. In the meantime, I was on the Marshall forum trying to find out anything I could about the JM69 pcb and not having much luck-until I stumbled across a post about a guy with a similar problem to mine, only with his bass amp. The schematic was for his 5503 30 watt bass amp listed a certain pcb, but his had a JM69 board instead, and the components didn't match. So I ran down that schematic, and found it is much more similar to mine. In fact, the transistor values that seemed out of place on the 5010 schematic match. I think the Red McKenzie version of the 5010 is essentially a bass amp.
Quote from: El Scorcho on March 21, 2018, 04:09:25 AMIt works-It just has an unpleasant sound. Even on the lower gain input there is a cruddy blanket of harsh fuzz wrapped around what would otherwise be a useable tone. Some of the parts seem a bit 'aftermarket'.