left channel suddenly out of balance [resolved]

[kill_surf_city]

Can I see what the D socket looks like with that board pulled out?  I do see one solder joint on one of the PN2907s that doesn't look 100%, but nothing else that's obvious.

sure thing. I'll reflow that PN2907 as well.

 

[Paul Birkeland]

Other than the wire leaving D5 being improperly routed, I don't see any issues.  At this point things like non-electronics solder and flux start to pop up as possibilities for creating the issues you're experiencing.

 

[kill_surf_city]

Other than the wire leaving D5 being improperly routed, I don't see any issues.  At this point things like non-electronics solder and flux start to pop up as possibilities for creating the issues you're experiencing.

okay, the one that goes through D5 and into D4?

 

[Paul Birkeland]

Yes.  This isn't going to be the cause of your problems, but rather something that may cause problems down the road.

 

[kill_surf_city]

Yes.  This isn't going to be the cause of your problems, but rather something that may cause problems down the road.

Oh okay. What do I need to change?  Also, as for the solder I'm using it is 60/40 rosin core. Made by Cookson Electronics. It is however a bit thicker than what I used on my crack, but to be honest that actually made the soldering easier for me.

 

[Paul Birkeland]

With one probe on each of the 6.3V terminals, what DC voltage do you see?  It occurs to me that it's possible that your 6.3V regulated DC supply may not be putting out sufficient voltage for proper tube emission, so that's worth looking into (or there's something in the heater circuit consuming extra current).

 

[kill_surf_city]

With one probe on each of the 6.3V terminals, what DC voltage do you see?  It occurs to me that it's possible that your 6.3V regulated DC supply may not be putting out sufficient voltage for proper tube emission, so that's worth looking into (or there's something in the heater circuit consuming extra current).

Okay, I'm getting 6.25v on the 6.3 V terminals on the PSU board.

 

[kill_surf_city]

With one probe on each of the 6.3V terminals, what DC voltage do you see?  It occurs to me that it's possible that your 6.3V regulated DC supply may not be putting out sufficient voltage for proper tube emission, so that's worth looking into (or there's something in the heater circuit consuming extra current).

Hey PB, I noticed that one of the screws that is supposed to secure the PSU board just wasn't there, found it and screwed it in. I decided to go ahead and connect everything and redo my voltage tests. Everything was well within range on all boards. The Kreg on the shunt regulator is still showing me ~1.9v  on both sides but I went ahead and turned it on and everything sounds perfect to me. No balance issue. No hum. Do I still need to worry about that Kreg value on the shunt regulator?

 

[Paul Birkeland]

If the front C4S board is hooked up and you still see 1.9V at each of the Kreg pads on the board above the D socket, what's the DC voltage at the +275V pad on the power supply board above the power transformer?

 

[kill_surf_city]

If the front C4S board is hooked up and you still see 1.9V at each of the Kreg pads on the board above the D socket, what's the DC voltage at the +275V pad on the power supply board above the power transformer?

With the C4S board connected I'm getting 5.94v on side A and 5.92v on side b. DC voltage on the +275 pad is 265v.

 

[kill_surf_city]

I do also have the step up transformers installed if that makes any difference.

 

[Paul Birkeland]

Those Kreg voltages are more reasonable and should be sufficient for the circuit to operate properly. 

 

[kill_surf_city]

Those Kreg voltages are more reasonable and should be sufficient for the circuit to operate properly.

Awesome. Thanks for you help Paul.