MT15 Lead Channel

LeeBob

New Member
Joined
Oct 19, 2019
Messages
3
I just recently acquired a used MT15 and I've been disappointed with the lead channel. I made a quick post in the main MT15 thread, but wanted to solicit some more specific feedback as to my issues/concerns.

First, I wanted to establish that the clean channel is beyond expectations. Beautiful cleans and takes drive pedals better than any Boogie I've owned in the past. Both my Strat and PRS Tremonti sound great.

My experience lead channel however has been disappointing and has lead me to believe there's an issue with the tubes or amp. I had viewed numerous videos online from various players with various guitars and the MT15 always sounded great. Aggressive and thick, but harmonically rich. The same was true when I heard Tremonti play it in person backstage at an Alter Bridge show 6 weeks ago. My amp doesn't sound like that. The gain is over the top and fizzy. There is almost no perceptible change in gain over the entire sweep of the lead channel gain knob. 8:00 sounds essentially the same as 3:00. Both of my guitars sound like ****. My initial experience was with my PRS 2x12 with V30s. To determine if it was just a cab/speaker "compatibility" issue, I plugged it in to my UAD Ox and have since played it through a variety of cabs and speakers. Same outcome. Overly fizzy and lifeless. Again, contrast this with the clean channel and overdrive via the Ox which sound glorious.

So, what is the most likely cause of my issue? I've read several threads of members replacing the V1-V3 preamp tubes with various 12AX7, 5751 and 12AT7 tubes stating success. Should I try that?

Thanks in advance.
 
Did you buy it used? I also have an MT15 that I bought new that’s all stock and my experience with the lead channel is completely opposite. There’s a huge difference it gain between 9 o’clock and 3 o’clock on the gain knob and it sounds super full and saturated, the word fizz has never entered my mind even playing it.

I don’t think changing tube types is going to solve your issue but maybe try swapping in all new tubes and see what happens? Either that or contact PRS customer service to see what they say.
 
When I buy a used amp I always put in new tubes, at least preamp, almost immediately. I want to start fresh and not wonder ‘what if?’, never know what happened before you got it, especially if it shipped. I expect tubes would likely fix your issue, but but would absolutely start there and see if it sorts itself out before calling in the cavalry (PTC or a local amp tech).
 
I had one and swapped out various tubes in the main spot that effects gain and tone - I forget which spot but it is well documented here. As long as you are going for a heavier more modern tone you should be able to get what you want.

I was trying to get it to be more Marshally which did not work out and I sold it.

Even though I sold it I would still say it is THE BEST AMP FOR THE MONEY OUT THERE BY FAR.
 
Yeah, I’m going to agree with the others about the tubes. If you got it used, I put a full set of pre-amp tubes in. If you got it new, I’d think about swapping it for another. Mine wasn’t like you describe yours, at all.
 
Thanks all who have replied.

So, consensus seems to be a wholesale replacement of preamp tubes. Shall I stick with the stock JJ 12AX7's?
 
Back
Top