Anybody familiar with the old JE-1200 midboost circuit?cainco

[Ricey]

I had my old Jackson restored with the vintage JE-1200 midboost and J50BC and J200 pickups. I had all the correct pot values installed-50k midboost, 250K tone and 50K master volume. The volume and midboost controls work perfectly, but I think there is an issue with the tone control. When the mid boost is all the way off, the tone control does nothing. When the mid boost is turned up, even a little, the tone knob works, but very subtly. It rolls off some of the highs, but not as much as any other guitar I have ever played-no "woman tone" to be had.

Anybody here with experience with this circuit? Is this normal or did it maybe get wired up incorrectly? The guy that did it is studying electrical engineering at college. I told him to install a treble bleed resistor on the volume pot if the guitar dumped any highs when the volume is ramped down because I like to be able to control the amount of overdrive I get from from my amp by ramping the volume down without losing high end. Instead, he said he wired it up with "50's wiring" in lieu of "modern wiring". Could this be why the tone control seems to be interactive with the mid boost or is that normal even when wired with "modern wiring"?

Any advice or guidance would be appreciated, as it has been so long since I had a guitar with this circuit, I cant really remember how it is supposed to work. Back in the day, I pretty much ran everything on 10 at all times and 95% of the time, it was all bridge pickup!

[pianoguyy]

Are you sure it is the 1200?
And are you sure it is a tone knob and not a frequency sweep knob?

Also, of course, it is possible that it was wired incorrectly, particularly when the treble bleed was added. Because, these preamps, most people don't know how to wire them. They assume that it is all one system - ie, active pickups. Whereas, these are actually separate. Passive pickups, with active electronics.

[ed]

Here is a couple of wiring diagrams

https://imgur.com/a/vuaXYvw

[Ricey]

Yes, it is definitely a JE-1200. I have had both-a JE1200 in an '88 Charvel Model 6 and a JE-1500 in a '90 Jackson Fusion. The midboost knob definitely does what I remember it doing in my Model 6 many, many years ago; i.e., fattens up the mids and cuts some highs, as opposed to the very pronounced wah-wah sweep produced by the JE-1500. I just can't remember what the tone knob did, because it was so long ago and also because I always kept the tone control full up back then.

[paranoid]

Sounds like incorrect wiring. Tone is wired just like any other guitar tone control. mid boost should not effect its function.

[pianoguyy]

I will just toss this out there:

In 2014, I changed my rig. I replaced my decades-old amp and rack with a modeler. One little floor board replaced everything between the guitar and the soundman.
I get some great tone and will never go back to the old ways. But for whatever reason, my Jackson pre-amp became useless.
The new tech didn't obey the commands of the 'holy shit' knob. I plug it back into the old rig, and I can make ears bleed on demand. But the new stuff... Frankenstein's Monster has been reduced to a child in a Halloween costume.

[Ricey]

That is an interesting experience Pianoguy! I have owned and used modelers in the past, but am currently playing into an amp with traditional pedals only (no modeling). Is your preamp the Jackson JE-1200? If so, does the tone knob roll off highs normally when the mid boost knob is turned all the way flat? When the midboost is off on my JE-1200, the tone control does nothing. When the mid boost is engaged, I get some treble roll off with the tone control, but not enough to do the "woman tone" thing.

[Ricey]

So, it turns out that he had wired it incorrectly. He said the tone and volume pots are wired in opposite order from a normal passive circuit and he did not realize that until he looked more closely at the wiring diagram. All good now-sounds GREAT!