Quick question regarding the Piezo circuit in JP6

[Random Hero]

Is there a noise reduction circuit? The reason I ask is because I was just giving a lesson, and I was using a very noisy cable. It was buzzing like crazy with no guitar plugged in, like absolute crazy, and when I plugged into the mono jack it was buzzing when the volume was up on the guitar, but silent when turned down. However, it was silent with the volume up when I plugged into the piezo jack, using the magnetics.

Didn't really make any sense?

I used it with my main rig about an hour before an it was absolutely fine, and I just put it in the case, and took it out at the place I teach. I can't try it again until I get home tomorrow morning so I was just curious about the piezo circuit.

I opened the guitar up and couldn't see anything abnormal, and the jacks felt fine when I was putting a lead in.

I suppose I'll know better when I get home tomorrow, but if it is the case that the magnetic only jack has become buzzy, what could it be and what could be the fix?

 

[chrisallen]

I don't think there's any noise reduction circuit in the piezo... sounds like just a bad cable and maybe you bent the solder point in the cable when you plugged in and out a few times, thus eliminating the noise temporarily...

i'd say, get a new cable.

 

[Random Hero]

I don't think there's any noise reduction circuit in the piezo... sounds like just a bad cable and maybe you bent the solder point in the cable when you plugged in and out a few times, thus eliminating the noise temporarily...

i'd say, get a new cable.

Well I was using a cable the studio provided, which was exceedingly noisy. I got home this morning, tried it with my rig, and no problems. Means it was the dodgy cable.

What a relief!

I'm still a little perplexed that it was dead silent when using the piezo jack, literally every time. I must have switched between the jacks 15-20 times and it was the same every single time.

 

[SteveB]

Well, if I recall correctly (without consulting the diagram) the piezo jack outputs a 'buffered' signal if you use a mono cable in that jack.

Perhaps the 'buffering' just happened to clean up the signal in your situation? Who knows..

 

[Random Hero]

Well, if I recall correctly (without consulting the diagram) the piezo jack outputs a 'buffered' signal if you use a mono cable in that jack.

Perhaps the 'buffering' just happened to clean up the signal in your situation? Who knows..

Possible, but the amount of cleaning up the buffer did is quite astonishing if that's the case.