I want to troubleshoot a possible probematic footswitch

[thermionix]

The tube screamer works with just about any DIP8 dual opamp.  Different people have different preferences, but most traditional is the 4558 type (JRC4558D aka NJM4558, or RC4558P).

[pfapin05]

The tube screamer works with just about any DIP8 dual opamp.  Different people have different preferences, but most traditional is the 4558 type (JRC4558D aka NJM4558, or RC4558P).

Thank you, I got like 20 of them for super cheap on ebay... $5 from a US seller too. I hope this 4558 chip will make this pedal sing again!

[pfapin05]

I also bought the stuff to make an audio probe today, just have to wait on it to ship. I need to buy a looper pedal for the signal right?

[Slowpoke101]

A looper pedal is a handy thing to have but you don't really need it to use an audio probe.
Just disconnect your amplifier from your guitar/pedalboard then use the amplifier and lead for the audio probe. You will need a signal source for testing and the guitar can be used for that. Just connect the guitar to the effect that you are testing, turn your amp on (low volume) and start probing. Make sure that the effect is also powered.

Have your tried a new IC in the effect yet?

[pfapin05]

A looper pedal is a handy thing to have but you don't really need it to use an audio probe.
Just disconnect your amplifier from your guitar/pedalboard then use the amplifier and lead for the audio probe. You will need a signal source for testing and the guitar can be used for that. Just connect the guitar to the effect that you are testing, turn your amp on (low volume) and start probing. Make sure that the effect is also powered.

Have your tried a new IC in the effect yet?

I ordered some new IC's today and am waiting on the shipping. If I hook it up through my amp like that, will I have to hit the guitar strings everytime I go probing around in the pedal to get sound? I think if thats the case then a looper will come in really handy.

[Slowpoke101]

Waiting for parts....One of life's little joys. Can't be avoided.

Anyway, using a looper as a signal source is a sensible idea.
And as good an excuse to buy one that I've ever heard 
I will use that excuse myself right now.

[pfapin05]

Waiting for parts....One of life's little joys. Can't be avoided.

Anyway, using a looper as a signal source is a sensible idea.
And as good an excuse to buy one that I've ever heard 
I will use that excuse myself right now.

The ammoon looper looks nice and cheap... I really want a TC electronics Ditto looper for better quality though.

[DIY Bass]

I just use an old MP3 player with a 3.5mm lead and then a 3.5mm to 6.5mm converter.  Cheap (I already had all the parts) and easy enough for a few hours worth of signal :-)

[pfapin05]

Great idea! I have to find my old zune and charge it up, I think it will work just fine. Thank you for the idea!

[pfapin05]

I just use an old MP3 player with a 3.5mm lead and then a 3.5mm to 6.5mm converter.  Cheap (I already had all the parts) and easy enough for a few hours worth of signal :-)

Question though, I see how you hook the MP3 player into the amp with a 3.5mm to 6.5mm converter, but how do you plug the audio probe into the MP3 player, this dosent add up to me.

[thermionix]

Mp3 player goes into the pedal you're testing.  Audio probe goes into the amp.

[pfapin05]

Mp3 player goes into the pedal you're testing.  Audio probe goes into the amp.

That setup doesnt quite add up to me for some reason though... for example here is the layout with a looper...

amp <====> looper <=====> test pedal <=====> audio probe

how would the mp3 be set up in a situation like this, the way you explain it looks like this...

amp <====> audio probe (?) test pedal <====> mp3 player

how does the audio probe hook up to the test pedal? This does not add up for me.

[Slowpoke101]

The audio probe is used to probe various circuit points within the faulty pedal.
The probe is connected to the amp. The probe's ground connection goes to the faulty pedal's ground.
An input signal is applied to the faulty pedal's input jack. This signal can be supplied by an MP3 player or a signal generator or a looper. The looper would require something connected to it that it could record (say a guitar) and then play back.
The faulty pedal's output can be tested with the audio probe.

[DIY Bass]

If you read up how to make an audio probe, most of the articles i have read also explain pretty well how to use it.

[pfapin05]

Waiting for parts....One of life's little joys. Can't be avoided.

Anyway, using a looper as a signal source is a sensible idea.
And as good an excuse to buy one that I've ever heard 
I will use that excuse myself right now.

Just got the chips in, never got around to even making an audio probe but didnt need to. I simply lifted the old chip out, and replaced it with one of the new ones and the pedal works just fine now. Now I have to find a way to protect that PCB from touching the chassis of the pedal when I put it back into place. The previous owner just used a glue gun to stick the bottom of the PCB to the chassis of the pedal, that might have been what caused the chip to go bad. Could I just hot glue a piece of a plastic folder onto the chassis to protect the underside of the pcb from touching the metal pedal chassis? Would the plastic folder piece generate static somehow and mess things up? I am open to any ideas on how to protect it from something making contact with that chassis, but I want to make sure to do it right. Thanks in advance!

[thermionix]

Also, that 1458 looks...suspicious.