JP6 - Piezo Circuit Question

[rarebit]

Has anyone ever experienced this?

I've got a very early JP6 with a piezo. Using the mono out with the magnetic PUs the output suddenly drops and gets very distorted. Not being on the shared or piezo only selection I wouldn't have thought the preamp/battery would be in the circuit, but after swapping the battery, it did improve alot. But it still seems to have a touch of unwanted dist.

Unless there is some underlying wiring issues shouldn't the magnetics be independent of the preamp circuit with the proper switch selection on the mono out?

Thanks in advance...

 

[beej]

No- the mono out sums the mags and piezos (both of which have to go through the preamp, to patch the different impedances). The stereo out will give you independent signals (or just the passive mags, with a mono cable into the stereo out).

The distorted output sounds like a power issue. I'd first check that you have a good battery, and that it's making contact. Sometimes the batteries don't fit in the box properly. In which case, you can either put a little bit of folded cardboard at the end of the battery to make sure it sits properly (with the lid closed), or use a little screwdriver to pry the metal battery contacts forward, if they're not making proper contact.

Hope that helps.

 

[rarebit]

Thanks for the clarification that really helps... looking at the JP6 control function diagram it wasn't clear. Now I can do a proper comparison.