Byzantium rebuild from scratch

[mybud]

Ok, so I managed to detach the upside down footswitch from my first build (here). Getting sound but no hint of flange at present.

Planning to hand wire to a new footswitch but I just wanted to double-check the offboard wiring in case the problem lies there. I'm assuming that it goes BI, EI, Ground, Switch, EO, BO from left to right with the audio board uppermost. I'd be glad to have this confirmed if possible.

TIA.

 

[falco_femoralis]

Yes, when you are looking at the pedal with the back off, viewing the lugs of the switch, from left to right the board and switch daughterboard leads are audio in, IN, GND, SW, OUT, audio out. The main PCB has audio in/out pads at the top that connect to the audio jacks so all you have to think about is making the wires from the main PCB to the switch board go straight across from each other. If you're not using a daughterboard then it's wired just like a normal switch diagram, just pretend the solder pad on the far left (of the 6 we're talking about) is the signal coming from the audio in jack, and the pad on the far right is the signal going to the audio out jack.

 

[mybud]

Yes, when you are looking at the pedal with the back off, viewing the lugs of the switch, from left to right the board and switch daughterboard leads are audio in, IN, GND, SW, OUT, audio out. The main PCB has audio in/out pads at the top that connect to the audio jacks so all you have to think about is making the wires from the main PCB to the switch board go straight across from each other. If you're not using a daughterboard then it's wired just like a normal switch diagram, just pretend the solder pad on the far left (of the 6 we're talking about) is the signal coming from the audio in jack, and the pad on the far right is the signal going to the audio out jack.

Thanks, that makes sense. It's baffling that it worked before and no longer does. Also, the voltage on the regulator (since replaced) reads 2.2V or thereabouts, so it's certainly possible that my removing the footswitch has caused some upstream damage to the boards.

 

[Robert]

Ahh dang, if I had known this a couple days ago I would have sent you another breakout board with your shipment.

 

[mybud]

Ahh dang, if I had known this a couple days ago I would have sent you another breakout board with your shipment.

Thanks Robert, much appreciated.

Question is whether what I'm attempting is feasible without it: IOW wired straight to the footswitch as per the usual setup. If the breakout board has some special connection, that might explain why I'm getting audio but no flangery flangery.

I was quite careful removing the original and don't see any evidence of broken traces but that doesn't mean much given my eyesight

 

[Robert]

No, there's nothing special about the breakout board, it's exactly the same as the standard 3PDT breakout board.

I can't think of anything in that specific location that would cause you to lose the wet signal but still have a dry signal. Any trace or pad damage would more likely cause no audio whatsoever, or LED issues. The wet/dry is already mixed before it heads down to the footswitch area.

The bottom opamp (on the upper board) is where the wet/dry signals are mixed, maybe look for a solder splash or something around there?

Is it possible the trimpots got bumped out of alignment?

 

[mybud]

No, there's nothing special about the breakout board, it's exactly the same as the standard 3PDT breakout board.

I can't think of anything in that specific location that would cause you to lose the wet signal but still have a dry signal. Any trace or pad damage would more likely cause no audio whatsoever, or LED issues. The wet/dry is already mixed before it heads down to the footswitch area.

The bottom opamp (on the upper board) is where the wet/dry signals are mixed, maybe look for a solder splash or something around there?

Is it possible the trimpots got bumped out of alignment?

If they were aligned originally on the working version they’re certainly no longer so, since I’ve been trimming away like it’s out of fashion…

Let me check your suggestion regarding the bottom opamp but while we’re here, is that 2.2V reading on the regulator correct? I see it’s going to a voltage divider afterwards, so maybe so.

I might give this a day or two’s break to collect myself and find the cloth-brained thing that I’ve most likely done.

 

[Robert]

No, that's a 5V regulator so the output should be near 5V.

Check to see that you have 9V on the input, if not, we'll need to figure out why.

If you DO have 9V on the input of the regulator we'll need to check for shorts (assuming the regulator is good and oriented correctly).

Remove the upper board, remove any socketed ICs from the lower board (except the regulator), then apply power and measure the 5V supply again with the top board disconnected.

The 5V supply doesn't go to the upper board so we can eliminate it for now.

 

[mybud]

Thanks again to our esteemed constituent @Robert for these pointers. While measuring the board for voltages as he suggested, I noticed some less than perfect soldering on the IC sockets, retouched these, et voilà! the resuscitated flanger flanges as before.

Really grateful for the support and stoked that I can recycle these components (lots of expensive WIMA caps, not to mention the BBDs) for a working flangery device. It really does sound fab and is actually less daunting a build than it might appear.