Drip EQ1 build wrong voltage

Admiral-dk · Feb 19, 2023

Pin 2 & 7 are OK - BUT Pin 3 & 8 @ 3.7V is Not ...!!!!
I would say that either the two 360 Ohm resistors or the 1K Ohm on the Transformer values are wrong (higher than in the Schematic) or something wrong with the Transformer windings.
All this would result in a much lower current in the 12AX7 => much higher voltage on the Anodes etc.

Per

Martan · Feb 19, 2023

"All the transformer wires are all colour coded on the board. So it's pretty hard to mess up. That's really the only wiring on it."

Don't assume it is labelled correctly. I found errors on the Dual-Sta transformer labelling. Make sure the connection points are leading to the right place on the circuit board.

cameron spinks · Feb 19, 2023

Martan said:
"All the transformer wires are all colour coded on the board. So it's pretty hard to mess up. That's really the only wiring on it."

Don't assume it is labelled correctly. I found errors on the Dual-Sta transformer labelling. Make sure the connection points are leading to the right place on the circuit board.

OK, that's good to know. Will do, thanks!

cameron spinks · Feb 19, 2023

Admiral-dk said:
Pin 2 & 7 are OK - BUT Pin 3 & 8 @ 3.7V is Not ...!!!!
I would say that either the two 360 Ohm resistors or the 1K Ohm on the Transformer values are wrong (higher than in the Schematic) or something wrong with the Transformer windings.
All this would result in a much lower current in the 12AX7 => much higher voltage on the Anodes etc.

Per

Thank you, this helps alot. Appreciate. I'll pull the resistors and measure just to make sure and then trace the windings.
Thanks for everyones patience

cameron spinks · Mar 15, 2023

Alright, I was able to go through this with someone and figured out I had mistakenly put 360k resistors in R8 and R9 instead of 360R

You were right!
Thank's for everyones time and help, really appreciate it!

Admiral-dk said:
Pin 2 & 7 are OK - BUT Pin 3 & 8 @ 3.7V is Not ...!!!!
I would say that either the two 360 Ohm resistors or the 1K Ohm on the Transformer values are wrong (higher than in the Schematic) or something wrong with the Transformer windings.
All this would result in a much lower current in the 12AX7 => much higher voltage on the Anodes etc.

Per