I have a Music Man 112-RD that I bought from Will Ray of the Hellcasters in the 90's. He had put into a "bright boost" toggle switch (above the input jack) on the clean channel side and had a very heavy speaker in it. It sounded huge but was really heavy.
I replaced the speaker with a Celestion that ripped and had to be replaced with a newer Celestion (see photo).
I have always found in spite of it's great portability and dependability it can sound very trebly and "ice pick-y." with Humbuckers/Single Coils and pedals.
Is this normal for this amp to have such limited eq?
My version has a "Bright" rocker switch on the clean side and a "Mid-Boost" on the distortion side. I never use these as I always trying to make this angry beast, warmer and rounder sounding.
Thanks for your feedback and keep your earplugs in.
Teetosh
Tone solution...
This may help you and it may not. First, I have a stock RD 112 50 from the early '80's. I usually do this routine at every gig/rehearsal because different rooms sound different. 1. Start with the tones all the way down and your pickup selector on the bridge PU. 2. Add bass until you get your desired amount of woof while playing the sixth string. 3. Add treble while playing the first string until it's a bit too bright then, back it off a hair. This seems to always work(at least, for me.) Also, it doesn't matter what amp you're using, it works well! If you're using an amp with a midrange control, strum the third and fourth strings together and add mid until you just begin to hear the difference. To be clear, I don't use any effects; not even reverb but, that's a tale for another day. After this routine with my Strat, the amp is usually on about 6 or 7 on the bass and 4 or so on the treble(that's the clean channel.) Also, with humbuckers, you'll find that a bit less bass and a good bit more treble is required. let your ears be your guide.
Anyway, I hope this helps you. Let me know, as I'm curious if it works for other folks as well as it does for me. Happy Holidays!
Another Option
First thing I would do is try a different speaker. The WGS Reaper HP and Eminence Patriot Cannabis Rex are both excellent choices to warm up your sound and tame the harsh top end.