My bandmate recently bought a guitar second-hand, an Ibanez RGA32, with a beautiful natural mahogany finish and active Ibanez LZ3 pickups.
The problem is the sound of it : it sounds like a starved fuzz, if at all !
It happened right after the replacement of the batteries (2 x 1.5V AA), and at some point he was receiving radio as well !
The sound is actually very weak, and when you attack the strings harder a loud, badly gated fuzz tone appears.
I did not find the exact schematic, but it's like the RGA42 without the EQ board and with a normal tone control :
https://img697.imageshack.us/img697/484 ... ga42fm.jpg
or like an ART300 with a single volume and a 3-way blade switch :
http://circuitwiringdiagram.com/wp-cont ... iagram.png
The preamps are inside the pickups, and totally enclosed in epoxy :
https://imageshack.us/photo/my-images/714/lz3k.jpg/
According to the RGA42 diagram, it seems that the white wires from the pickups carry -3V supply voltage.
I suppose this comes from an voltage inverter/charge pump inside the pickups, and the preamp is actually working with 6V rail-to-rail.
With 3.23V at the batteries (fresh alkalines), i measure about 1.1V at these white wires. When the strings are hit hard enough, and fuzz is heard, it jumps at about 1.3V.
I tried separating the white wires, that changes nothing. I tried lowering the voltage (just one AA battery), it just halves the voltage at the white wires and set the fuzz
I suppose that the charge pumps are fried, maybe because of some over-voltage or wrong polarity (that would be a shame for Ibanez to forget adding protection diodes ...)
The preamps would then be under-powered and/or badly biased, and give a badly distorted and gated sound.
Does this diagnostic seem correct ?
Then, what should i do ?
- Redo the whole wiring, just in case ?
- Try and degoop these things and fix the charge pump (if that's really the problem) ?
- Increase the supply voltage to 6V or even 9V to get some headroom back (hoping this will not destroy the preamps further) ?
- Add an external charge pump (or more batteries) to supply -3V into the white wires (hoping this will not destroy the preamps further) ?
- Ditch the pickups and tell him to buy EMGs ?