Amps and effects
Got two Rats of different generations on the bench for repair. The v2 to the left, not working at all. The other one did not reach unity gain.
I had to replace a malfunctioning jfet source follower on the output stage on the old Rat.
The other one had already been messed with. There were several copper traces on the circuit board that had to be mended, the opamp was burnt and wires not connected. Managed to bring it back to life again.
/Krister
Finally had some time to mount the hardware in my new tube pedal design, Lady Dirt. Strange how every build sounds so much better boxed up with some nice graphics.
Earlier posts post1 post2 post3
/Krister
Got this one in for repair
Led would not lit at and it did not pass any sound. Opened it up and took some voltage readings. It did not get any coltage due to a bad battery clip.
After replacing the battery clip it powered up but the led L1 would not lit. Turns out the led was damaged. Had it replaced and adjusted so the circuit would go into bypass mode when the foot is of.
I like the way that the bypass circuitry is built. Never seen a led/ldr combo used with a hex inverter to control the switching fets, works fine on a wah pedal.
Also fixed some new screws for the bottom lid, the old ones where missing.
/Krister
A great chorus pedal the Boss CE-2. Got this one recapped, rebiased and modified from ACA to PSA specs.
/Krister
Got this one in for repair, would not make a sound.
Sometimes it’s an easy fix, when opening the back I found the 12AX7 preamptube at the bottom of the chassie. Just put it back in place and it was ready o rock.
I opened it up and took a look at the circuit. Besides from the single 12AX7 preamptube and the EL84 power tube there’s two JRC4558 opamps on the circuit board, so what we got is a hybrid of solid state and tubes.
/Krister
Uptated the Modulation page with the Maestro PS-1A
/Krister
A sneak preview of the chassis for my new pedal. Lady Dirt!
Earlier posts: Designing a new tube pedal update 1 , Designing a new tube pedal
/Krister