joelorigo
Well-known member
I had not been able to do any pedal building for about 6 weeks due to work, travel, Covid and more work, so this week I was able to finish 2 that were in progress. One was a second Mahayana that I built for my brother in law because he liked the one I made for myself so much. The other was this.
I bought a lot of 10 MP38A transistors from an eBay seller in Ukraine for the Ge one, and had a random selections of ones on hand to try for the silicon pair. I also finally got a TC1 and was able to select a MP38A that is close in hfe (about 74) to what the build doc says (79). For the silicon ones the build doc says 312 and 318. The closest to those numbers I have is a BC183B that is about 317 and a BC018B that is about 228. So the only real difference I have is one of the silicon transistors is significantly lower than one in the original model. (Or is it significant? I also have ones even lower and ones higher. What would higher or lower gain values do?)
I biased to about 4.5 and it sounds good! Pretty much like the demos I think. I'll compare more later. And also adjust the bias and see what that does.
Then after I tightened all the nuts and put the knobs on, I realized I spelled "Aberration" wrong. So I have a "Aberraton" fuzz. It's been that kind of day today. But, I'm happy to have the pedal done and that it works!
I bought a lot of 10 MP38A transistors from an eBay seller in Ukraine for the Ge one, and had a random selections of ones on hand to try for the silicon pair. I also finally got a TC1 and was able to select a MP38A that is close in hfe (about 74) to what the build doc says (79). For the silicon ones the build doc says 312 and 318. The closest to those numbers I have is a BC183B that is about 317 and a BC018B that is about 228. So the only real difference I have is one of the silicon transistors is significantly lower than one in the original model. (Or is it significant? I also have ones even lower and ones higher. What would higher or lower gain values do?)
I biased to about 4.5 and it sounds good! Pretty much like the demos I think. I'll compare more later. And also adjust the bias and see what that does.
Then after I tightened all the nuts and put the knobs on, I realized I spelled "Aberration" wrong. So I have a "Aberraton" fuzz. It's been that kind of day today. But, I'm happy to have the pedal done and that it works!