Need help on DIY Toneland Delay build

[rdhj]

I bought a DIY delay kit from China and assembled it and there is no guitar signal when the footswitch is activated.  I have sound in bypass mod and it has power.  When I hit the switch all I get is alot of noise.  When you trun the volume, dealy, and speed nobs, the noise changes like the knobs are doing there jobs.  I try to show in the pics in the moddle of the board where there may be a solder bridge.  I removed most of the solder but there is still a shiny spot on the board between the two joints.   One is the plus side of a capacitor and one is one side of a resistor.  Can it be that shiny sport isnt actually solder.  I tested the ICs and other areas and they are getting 9volts.  Based on the systems, what should I look at?

[garcho]

Quite the rats' nest

It will be hard to diagnose without more info. Do you have a schematic you can post?

Do you know what an audio probe is? Now is the time to make one if you haven't.

Look through the troubleshooting guide here, more info = more help

Double check all grounds are connected.

Oh yeah, welcome to the forum!

[rdhj]

Here is a pic of the schematic they sent, but its only the component locations.  I didnt cut the wires to make sure they were long enough...I will check out the audio probe thing...


Is it correct that the board is ground to the case by way of the in and out jacks being attached to the  case...was wondering if there was something else I was supposed to do to ground it

[garcho]

Is it correct that the board is ground to the case by way of the in and out jacks being attached to the  case...was wondering if there was something else I was supposed to do to ground it

As long as your input and output jacks' sleeve is making bare metal contact with the enclosure, that usually works just fine. What's important at first is just to make sure every thing or spot marked ground is in contact. Of course, they don't need to physically touch, but there has to be conductive metal connecting all of it.

Just to start, try connecting the ground at your DC jack with a bare metal part of the enclosure, while you have the pedal turned on and hooked up to an amp (on low volume!). Poke around and see if you get a bunch of noise from touching it, that is a big clue about the ground.

The right way to do it is measuring stuff. You mentioned measuring voltage so I assume you have a DMM or multimeter or voltmeter. Read the troubleshooting guide (or follow it this time) and post all your voltages. Test every pin of the ICs, etc. Test everything marked ground against something you know for absolute certain is the return, like the power supply jack ground.

The picture you posted isn't really what we call a schematic around here. It's a word with a broad definition but usually we mean something that has the standard electronics schematics symbols, diagramming the actual electronic circuit.

Long runs of wire can make for really big problems with digital stuff (the PT2399 is digital) but that's probably not what's going on here. They can also be a problem when it comes to noise, hum, etc.

An audio probe sounds like something expensive you buy, but it's just an instrument jack wired up with the sleeve to ground of the thing you're testing, and then another wire to poke around and hear what's going on between the in and out jacks, "inside" the circuit. Plug it in to your amp and follow the audio signal path within the circuitry (again, super low volume, and of course, don't touch the power supply or anything but the audio signal path!). Very helpful, and very easy.

[rdhj]

Before I tried  the pedal on my  mustang amp, which is a digital modeling amp and that made all the noise.  I tried it again on a steady state amp and there is no noise, but also no guitar signal if that tells you anything.  When I connected the ground at your DC jack with a bare metal part of the enclosure, there was still no noise at all.  I am going to have to order a capacitor on ebay to make the audio tool...took voltages on the IC pins and they are all around 2.77 volts.

[rdhj]

I took some ohm readings of the footswitch and some of them were 102 and according to what I read they should be zero or close to it to be good.

[garcho]

please read and follow the debugging guide linked here

[rdhj]

I've messed with it today and found that i do have voltage going to the 9V connection and i get voltage readings on  all the IC pins......been reading alot on the faqs but still kinda confused how to go about finding the issue...not to savy on this kind of thing

[DIY Bass]

A lot of your solder connections look like they are either cold joints or do not have enough solder.  I would check and reflow any joints that need it.

[rdhj]

I was kind of wondering about that I've been touching them up as I've been going along but massage skills aren't that good yet. Is there a way to tell which ones are called joints

[rdhj]

I've been reading the debugging page that ask you to find the voltage of certain things and post it on the forum so I did that please see the picture and see if anybody knows if these voltage readings tell you anything

[Ripthorn]

The pt2399 voltages all look good. The opamp voltage look suspect. Your image was not a schematic, but typically the input and output buffers have a Vref input on them, and your voltage are way too low. Audio probe the output of the input buffer and see if you hear anything.

[rdhj]

I dont know what you mean by input and output buffers.  I havent been able to build an audio probe yet

[garcho]

^ The voltages on the non-power supply pins (pins 2-7) of the TL072 should be around half of the power supply. In your case it looks like they should be somewhere around 4V , or 4.5V but they're not, they're too low. Your power supply pins look like they're probably just fine. The TL072 is an "op amp", the way it's being used in this circuit is what we call a "buffer", something that basically allows the signal from your guitar's pickups to play nicely with the electronics inside the delay pedal. There is something wrong causing those voltage levels to be off, it's a clue where to find the problem. Double check everything soldered around the TL072 is nice and clean.

[antonis]

A lot of your solder connections look like they are either cold joints or do not have enough solder.  I would check and reflow any joints that need it.

THAT..!!! 

[rdhj]

i fixed the cold joints yesterday and it didnt help