2nd Gen Build Started (that didn’t take long…)

[martin manning]

I really appreciate your patience and mentorship...

You're welcome, and thank you, this is entertainment for me, and I've certainly learned a few things about the 2nd Gen circuit. We probably could have spotted that missing coax run by staring at it long enough, but this way you got to try some signal tracing.

[Raoul Duke]

Thank you guys! Can’t always go as smoothly as my first build. Text book beginner’s luck I guess.

Erwin, I’ll definitely give what you say some thought. I was trying to find a way to keep heat away from the relay - although I’m not sure it was me who broke it.

Tim, I’ll definitely try testing it out of circuit and post results.

Martin, that co-ax run totally eluded me. When you pointed it out - I wanted to go hide under a rock, lol. I actually took note of it in some of the gut shot research I did - then totally forgot to ask about it.

[timrobertson100]

I think you may have your diode the wrong way round on your relay board.

[Raoul Duke]

Tim,
I have the white band on the positive side - same as my 102 relay boards. Should it be different for the way this relay is wired?

[martin manning]

That's correct, otherwise the diode would essentially short out the coil and the relay power supply (in Manual).

[timrobertson100]

Good. I couldn’t see the power wires on the pic I was looking at, but noticed it flipped from the PCB silkscreen.

[Raoul Duke]

Ok, today’s update:

While waiting for parts - I went back through all the controls’ connections and neatened everything up, checked continuity, re-flowed some dull solder joints, fixed some coax terminations, etc. What I’m saying is I checked everything to make certain connections, routing, insulation, component values et al were proper and correct.

My parts got here about an hour ago and I painstakingly installed the new relay and made the connections. Started it up, checked voltages, bias, etc. Plugged in the guitar and fantastic clean channel; beautiful! Switched to Manual mode and… still clean.

Wow. I’m completely deflated. Back to the drawing board I guess… Still not switching. I don’t know what to do - the only two things I can think of are the switch itself is bad (but passes continuity check for both poles/throws) or the cap I used in place of the 630v Mallory in the layout somehow is the culprit. The 12v is getting to the coil, the relay is brand new, the board was cleaned and checked for trace continuity before installation. The DC- has continuity with the blue wire on pin 2 of the DIN in pedal, then switches continuity to pin 3 when in Manual - which I think is right… I just don’t know…

The FET channel has more distortion (which sounds pretty cool BTW).

HELLLLLPPPPPP!

[martin manning]

In standby, Pedal mode, measure resistance across Com 1 and NC 1, and Com 2 and NC 2. Should bee zero ohms. Switch to Manual and measure resistance across Com 1 and NO 1, Com 2 and NO 2. Should be zero ohms. As unlikely as it sounds, it could be that you have another bad relay.

[Raoul Duke]

Pedal
-NC1: 1M
COM2-NC2: 1M

Manual
COM1-NO1: 2m
COM2-NO2: 1M

Wow, these are brand new Omron G5V-2-DC12.

[Raoul Duke]

Just tried the second relay - same result.

I opted for the socket just for this reason - could I have created a new problem? The pins were pretty tight - I checked them all with a small pick.

[martin manning]

And in Pedal you should have ~0V across the relay coil, in Manual it should be the full 12V. Does that check out?

[Raoul Duke]

Ok this is weird,

When I measure DC+ grounded to chassis I get 12v.
When I measure across the coil I get 0v.

[Raoul Duke]

Just tried again:

Manual: 2.5v across the coil
Pedal: 0v across the coil

Chassis grounded in pedal, 12v to both sides of coil

Chassis grounded in Manual, 2.5v to DC+, 0v to DC-

Strange, huh?

[martin manning]

Hmm. Seems like the 12V supply is not able to maintain 12V when loaded by the coil.

[Raoul Duke]

Also, in Manual I have 12v coming out of the bottom filter cap where it meets the brown wire headed to the DIN, but only 2.5 coming out of the regulator. When I switch to Pedal, it jumps up to 12v.

Bad regulator?