Volmne Pot Limit

[GodWentPUNK]

I just purchased a Music Man JP, and must I say, what a great guitar. Great detail was put into this instrument. Anyway, I brought it to practice last night and I guess my only issue is going back and forth from the piezo and the regular magnetic pickups. The piezo and the magnetic pickups each have their own volume knobs however, with both pots at full, volume difference between the 2 is significant. I can roll the volume back on the magnetic pots but it then is limiting that signal which then cleans up the pickup. I was wondering if a capacitor could be put on the magnetic volume pot I can limit its volume so it's equal between the two. It's like a want a volume put that when opened all the way up, only produces 75% of it's original volume.



thanks,

joe...

[Grandturk]

So I'm clear - the piezo is lower in volume than the magnetic pickups?

If so - lower the magnetic pickups until you've reached a balance.

[GodWentPUNK]

So I'm clear - the piezo is lower in volume than the magnetic pickups?

If so - lower the magnetic pickups until you've reached a balance.

yes, the Piezo is lower is volume.

I know on a few other guitars, when I lowered the pickups, they lost their edge and sounded not as nice. I'll give that a try to see how they react on this guitar.

thanks for the suggestion!

joe...

[Grandturk]

Why not just lower the volume on the piezo? When you roll the volume down on a magnetic pickup, the tone changes, so that's not desireable - but why not just figure out where the piezo's volume should be to match the magnetic and set it from there?

Also - is it a stereo out? Do you have the piezo going to an acoustic amp?

[Hellbat]

There should be a mix trimpot (as well as bass and treble controls for the piezo) on the back of the guitar near the output jacks for adjusting the gain on the piezo system.

There is a set of diagrams for the controls here...

http://www.music-man.com/pdf/JP6.zip

[DonP]

If the piezo has a pre-amp (most do), check the battery.

If this doesn't work, get a stronger pre-amp.



If the piezo doesn't have a preamp, get one.

[GodWentPUNK]

1. Checked battery, it's OK.

2. I did adjust trim pots on back when I first got it but I'll take a look to make sure I set them correctly.

3. The piezo does have a pre-amp but I'm not sure if/how it can be replaced.

4. I'm not running in stereo.

joe...

[Hellbat]

Yeah I don't know if they label the trim pots on the guitar or not or if they are reversed on a lefty model or not.

[Newc]

What's Petrucci's setup? Stereo out to two amps - one for the piezos? If that's the case.....

[Hellbat]

If you run it stereo on output is mag and one is piezo, but if you run mono out it mixes them based on the setting of the mix trimpot on the back of the guitar.

This is according to the diagrams I posted above. I have never actually seen a Petrucci model.

[GodWentPUNK]

If you run it stereo on output is mag and one is piezo, but if you run mono out it mixes them based on the setting of the mix trimpot on the back of the guitar.

This is according to the diagrams I posted above. I have never actually seen a Petrucci model.

The MIX pot sets the level of the pickups so when you are using them together, you can define what level you want for each. However, if you go from mixed/straight piezo to only magnetic, I get an increase in output.

The setup I'm using is MONO, one cable, one amp.

joe...

[Hellbat]

Well I'm at a loss if the mix control doesn't do it. :dunno:

Basically it sounds like the piezos need more gain. I wonder if there is an additional gain control internally? I wonder if it's just something typical to the model. Seems odd though that you cant at least get within a couple of DB.

The part that keeps sticking in my head is the text of the diagram says "Note : When only the piezo/mono jack is connected, the mix pot controls the maximumum level of the piezo signal. When the Magnetic/Stereo jack is connected the mix pot is disabled." Is it possible there is a short in the Mag/St jack causing the mix pot to have no effect? Can you notice a difference when you adjust it?

What also isn't clear from the diagram is if the mix control only works when the mag/piezo selector is set to Both or not.