I've recently finished my third and fourth B1 boards (bought from the official source, with the JFETs). The two boards were built identically (for balanced operation, eventually), with extra-high quality parts (e.g., Z-Foil resistors in the signal path).
One of them is working perfectly, but the other is giving me problems. I'm guessing it is because, when first testing it, I hooked up the power supply backwards. Presumably, that could have damaged (or worse) the filter caps. Before I swap those out, though, I thought I'd ask here, and see if anyone had other ideas.
The symptom is bad distortion in both channels, and what seems like low volume, as well. I used to hear something similar when using batteries with my other B1, when they would start to die. But voltage measures OK at e.g. the gate of Q100.
I'll attach a photo of the board in my test enclosure, though I don't know if that will be much help.
One of them is working perfectly, but the other is giving me problems. I'm guessing it is because, when first testing it, I hooked up the power supply backwards. Presumably, that could have damaged (or worse) the filter caps. Before I swap those out, though, I thought I'd ask here, and see if anyone had other ideas.
The symptom is bad distortion in both channels, and what seems like low volume, as well. I used to hear something similar when using batteries with my other B1, when they would start to die. But voltage measures OK at e.g. the gate of Q100.
I'll attach a photo of the board in my test enclosure, though I don't know if that will be much help.