New Jackson Rhoads RRXMG control knob confusion

Question

I just bought a New Jackson Rhoads RRXMG with EMG 85 Neck and EMG 81 Bridge pickups. I am having trouble with the control knobs. In theory I should have one master volume, one neck p/u tone and one bridge p/u tone control. There is no markings indicating what each one controls unlike my fender.

The problem is when I switch to the neck p/u, the knob nearest the neck seems to be the volume, middle nob does nothing and the "tail" knob Slightly tweaks the sound.

When I switch to the bridge p/u, the knob near neck does nothing. The middle knob seems to become the volume,and the tail knob again seems to change tone a little. I would think a master volume knob wouldn't change! The only one that stays the same is the tail knob that only slightly changes sound. How can I figure this thing out?

Bonus question, if I have the switch to Neck pickup, when I turn the knob nearest the neck pickup to adjust "Volume". I have a highly irritating "scrubbing/grinding" sound from the amp. Same when I switch to Bridge P/U. Is that just my setup or something to learn to deal with?

Answer 1

It's not unheard of to have NO master volume, and instead to have separate volume knobs for each pickup. When your P/U selector is in the middle position, this then allows you to dial in the exact mix that you want.

The third knob, then, sounds like it's a master tone for both pickups.

The grinding sound when you turn one of the knobs could just be a low-quality or dirty potentiometer (the part inside the knob that scrubs a wiper across a resistor). If you purchased the guitar at a local shop, this would be a good reason to bring it back to them--they may replace the pot for you.

Answer 2

From the direct neck to bridge the default for the 3 RR model knobs is:

1. Neck PU Volume
2. Bridge PU Volume
3. Master Tone

For your bonus question:

I have a highly irritating "scrubbing/grinding" sound from the amp

Just cheap electronics. The Jackson X series are made in indonesia and they are trying to keep the cost low, so they skimp where they can to achieve that goal. You can try cleaning the pots, maybe just dust/debris is causing the issue, or replace them with higher quality controls.

Some history I'm aware of still doesn't explain why the layout is like this for this model. From what I've read:

• Randy's original Jackson prototype was the "Concorde" nicknamed model (the white and gold pinstripe), which had the same 2 volume/2 tone control layout of Randy's earlier guitars (gibson les paul and his polka dot V)
• The second prototype (black and gold one) lost one of the control knobs, my understanding it was a 3 control: Master volume and 2 tone controls setup
• There were 2 other prototypes, but don't know more about them as he died before they came out--that's why the first 2 are the ones you always see Randy with in picture and generally only playing the white one.
• The future RR models that came out after his death based on the 2nd black protoype.

There are so many variants and models, but generally

• RR1 has Master/Tone/Tone
• Brief RR2 had single master volume, no tone
• The RRX24 end up with Volume/Volume/Tone
• RR3 had a bunch:
  • 1996-1997:1 Volume, 3-Way Toggle Switch
  • 1998-2011: 2 Volume + 1 Tone, 3-Way Toggle Switch
  • 2016-2017: 1 Volume + 1 Tone, 3-Way Toggle Switch
• and on and on...