I have a '70 Traynor YBA-1 that I am converting to a JMP 50 and I am quite stumped at the moment. I have done tons of searches, I promise.
Background: I am using the Triode Electronics version of the 1987 layout and it has gone well up until when I have started to get voltages in step 1 of the testing instructions.
Here is what I have so far:
1)I am getting 114vac at the power switch.
2) Heaters are at 3.45vac each side (which is a little hot I know).
Turn the amp on to run (standby off).
I have implemented the Full Wave Bridge Rectifier per Hoffman's description. My PT has no center tap. That was my initial problem. However, I get 337 VAC across the two red HT lines. Rectified I only get 342 VDC. I know my diodes are fine. I test them and they are doing their job. But as soon as I flip the standby switch, the HT fuse blows.
I have also retained the separate bias tap from the Hammond PT and used it to feed the bias circuit. Those voltages aren't right quite yet but they are converted to DC Neg properly. This is no longer the case. I am using a leg of the HT like on most Plexi builds. I think I have a leaky coupling cap going to v5. Will test that later.
The biggest fish to fry as I see it is to get my HT rectification sorted out. I think I should be getting about 471.8 VDC after rectification.
Here are the pictures I have.


Pic removed for latest gut shots down below.
Pic removed for latest gut shots down below.
Pic removed for latest gut shots down below.
Pic removed for latest gut shots down below.
Paul