Just when I thought I had this licked, I’ve got another strange issue.
I get a perfect signal on pin 7 of the TL072, as per the test points on the SMR4 Mk II build page, but following the 68r resistor, I get a very faint signal and not a lot else.
I’ve checked the soldering on this component, checked the bridge where the output gain pot can go, reflowed solder over all these connections etc etc. I measure resistance from the tip of the output Neutrik socket to pin 7 of the TL072 (so through the whole circuit which contains the 68r resistor) and I get 68.2 ohms, so I don’t think there’s any problem with this part.
I’m keen to know what this resistor does. Can I just jumper it and go without, since when I probe directly before it the signal sounds good and is at a decent level…?