TravisM
Active member
I wanted a MIAB pedal so I decided on the M800 for my first build. It took 4 days to get everything soldered and wired together. The offboard wiring gave me a bit of trouble with polarity of the input/output jacks, the DC jack I was using was grounding out the ring to the enclosure and had to be replaced, and I wired the switch wrong the first go. After I found and fixed all those issues, the pedal turned on and the effect worked! It sounded fine, but was more low to medium gain with just a bit of high gain. I suspected something wasn't quite right when I couldn't get Q5 to bias as expected. A post in the troubleshoot forum and a few hours later, the culprit was spotted as the wrong value resistor in the circuit. Replacing that netted a much different animal, but I still wasn't sure it was what I wanted. So, I built another one.
The second try went together much quicker with all the offboard wiring and values correct the first time. The two effects sound the same so I guess this pedal isn't quite what I was looking for, but that's okay.
Other lessons learned:
1) Use multiturn trimpots - biasing the JFETS with single turn trimmers takes a finer touch than what I can provide. I can get them close, but they are extremely touch sensitive when dialing in.
2) When I was testing components, I checked the value against the order sheet and not against the build sheet. This let the wrong value resistor sneak by.
3) I used a soldering tip that was very small for the first build and in order to get enough heat into the board and parts, I had to crank up the temp and hold the tip in place longer than what is typical. I used a larger chisel tip instead of the fine conical tip when I made the second build and it was much easier with a lower temp and less time heating.
All in all, I learned a lot. The second build went together in 3 hours instead of 4 days and worked as expected the first time so even though the pedal(s) are not quite what I was looking for, I still consider this a success.
The second try went together much quicker with all the offboard wiring and values correct the first time. The two effects sound the same so I guess this pedal isn't quite what I was looking for, but that's okay.
Other lessons learned:
1) Use multiturn trimpots - biasing the JFETS with single turn trimmers takes a finer touch than what I can provide. I can get them close, but they are extremely touch sensitive when dialing in.
2) When I was testing components, I checked the value against the order sheet and not against the build sheet. This let the wrong value resistor sneak by.
3) I used a soldering tip that was very small for the first build and in order to get enough heat into the board and parts, I had to crank up the temp and hold the tip in place longer than what is typical. I used a larger chisel tip instead of the fine conical tip when I made the second build and it was much easier with a lower temp and less time heating.
All in all, I learned a lot. The second build went together in 3 hours instead of 4 days and worked as expected the first time so even though the pedal(s) are not quite what I was looking for, I still consider this a success.
