Hello this is my first time posting on this forum. I have a protone haunted delay. In bypass everything is fine signal goes from guitar to amp. When engaged light goes on but no sound gets through. I took off the back cover and multimetered the dc in and it is getting 9 volts. I don’t have much in the way of trouble shooting chops and any assistance would be appreciated. I was multimetering all the components but don’t really know what I’m looking for.
Update and question: Protone haunted delay non-op Q
- Thread starter Nobigdeal
- Start date
DailyDovetails
Well-known member
Can you take a clearer picture here? It looks like something might not be right.
DailyDovetails
Well-known member
I think that part might actually be OK and just wired a little different than I am used to seeing. typically the small piece of bare wire only goes to 2 terminals and not 3 but I think it technically works this way also. I unfortunately don't have any info to help you with this particular pedal. I think this pedal https://www.pedalpcb.com/product/pcb026/ is likely very similar to what you have and it may help you somewhat to trouble shoot it. I think my best advice would be to take the pedal apart if you feel comfortable doing so. Then look for any solder connections that might be broken, components that looked damaged, wires or components touching the case that shouldn't. You could likely fix that pedal if you spend a bit of time learning the basics of pedal building but it would be up to you if that is an interest you have. Nothing else immediately jumps out at me about it.
update and bump for any advice: I reflowed some of the solder and now a signal goes through when pedal is engaged. But the volume is really dropped, and I think I am only getting the delay effect rather than the guitar attack. If the mix is all the way left there is hardly any sound and if all the way right the delay effect is more prominent. Any help appreciated I hope to rescue this pedal.
It sounds as if the main problem is the clean signal from after it goes to the delay chip but before it goes to the mix pot. You probably need to make an audio probe and probe the clean signal and see where it dies. You may need to trace out some of the traces to work that out.
I put together a crude but working audio probe. When in bypass all good, probed input and output jack hot lugs audio signal (looped guitar strum) passes through. When the foot switch is engaged audio signal does not pass at the lug pictured with word no drawn on it. Audio does pass at the lug pictured with the word yes drawn on. For the rest of the components the only ones where audio signal pass through are shown in the first pic, the ones not Xed out. Any advice greatly appreciated.
Attachments
The switch lug that you have marked yes is the lead running into the PCB, so that tells us the switch sees to be working. For the rest you will need to be able to see the traces on the board, so you might need to carefully take it out of the case. Before you do that though I want to clarify something that I have just noticed from earlier. Robert asked for the voltage on pin 8 of the TL072, and you reported back that there is 9.6V on pin 1. Can you confirm that was a mis-type? 9.6V is right for pin 8, but not for pin 1. Actually, can you give us all the voltages on the tl072? If you are not probing any audio on that chip then it is likely that you are losing signal quite early in the signal path. Let's measure all the voltages on that chip to make sure they are close to expected.
That looks like a problem. I would be expecting 9V on 8, 0 on 4, and about 4.5 or so on the rest. You will need to get those voltages sorted before moving on. Somewhere near where the power comes into the board I would normally expect a network of components to derive that 4.5V and some capacitors to filter it. Near where the power comes into the board you will be looking for 2 resistors of the same value that are connected together at one end (and I don't mean the 2 resistors that join in mid air 
. Locate those and measure and measure the voltages at the join, and also the other ends of those resistors.
. Locate those and measure and measure the voltages at the join, and also the other ends of those resistors.Thanks PJS can I do that measuring from the top or should I take the board out? It looks to be siliconed in. Here is a pic from the top.That looks like a problem. I would be expecting 9V on 8, 0 on 4, and about 4.5 or so on the rest. You will need to get those voltages sorted before moving on. Somewhere near where the power comes into the board I would normally expect a network of components to derive that 4.5V and some capacitors to filter it. Near where the power comes into the board you will be looking for 2 resistors of the same value that are connected together at one end (and I don't mean the 2 resistors that join in mid air
