Guitar Gear Forum

I got carried away after buying a bunch of switches and caps. The amp is a bit dark stock. Not anymore.

Straight in with a JB.

Pretty nice tones, that's actually super cool I wish I knew how amps worked and could mod them how I like

i dig it. i dig a lot of what ive heard from the big boy version as well, if i was in the market for a new amp that would be on my list

Mod sounds great! I found mine dark too. Found it worked well with an Nobels ODR as a boost and the presence high though.

I offed my MT15 this week. Traded it for a Friedman IR-J, which is great so far.

Maddnotez wrote: ↑Tue Jun 24, 2025 11:47 pm Pretty nice tones, that's actually super cool I wish I knew how amps worked and could mod them how I like

I wish I knew more and wish I learned sooner. I also wish more people were okay with modding. So much gear is the same or similar, you don't need to spend hundreds or thousands on the next thing. Capacitors and resistors are cheap.

Rob Robinette's site is chock full of information on tube amps. https://robrobinette.com/Amp_Stuff.htm
Electrosmash focuses on iconic pedals. https://www.electrosmash.com/

I liked mine a lot stock. Hard to tell what this mod did without a reference point. It sounds bright in the video but like it could be the camera mic doing that. But sounds good!

RaceU4her wrote: ↑Wed Jun 25, 2025 1:39 am i dig it. i dig a lot of what ive heard from the big boy version as well, if i was in the market for a new amp that would be on my list

The 100 was long anticipated, now seems like it's already forgotten. You'd think having a Dumble channel would get more attention. The MT15 V2 has a new overdrive channel though not foot switchable. I'd love to see the schematics to both. The V1 is a great fit for me still.

heath wrote: ↑Wed Jun 25, 2025 2:34 pm Mod sounds great! I found mine dark too. Found it worked well with an Nobels ODR as a boost and the presence high though.

I offed my MT15 this week. Traded it for a Friedman IR-J, which is great so far.

I'm a long time OD booster too. The clarity is really what I was going for, not so much the presence at least not the fizz. I like pick attack and upper mids. The MT15 is already tight enough in the low end, I modded my SD1 for more bass. Since dialing in the amp I don't need any extra tone shaping pedals.

ninjaraf wrote: ↑Thu Jun 26, 2025 1:32 am I liked mine a lot stock. Hard to tell what this mod did without a reference point. It sounds bright in the video but like it could be the camera mic doing that. But sounds good!

The beginning is basically stock. I should have listed the mods:

Switches, left to right. All are ON/OFF/ON. Most have 2 values to play with.

Negative feedback on or off, black NFB wire.
Presence cap, C35, not much change, didn't demo.
Pre tone stack high cut cap (parallel R32).
Pre gain treble peaker cap (parallel R6).
Gain pot bright cap (signal side of R7 & R9).
Coupling cap (parallel C2).

Lead master volume (500K) changed to audio taper.

Rear has
Depth pot (R66).
Depth cap switch (C35) (didn't demo).
Adjustable negative feedback pot (or increase R70).


Minimum mids jumpered (R58)

JSutter wrote: ↑Wed Jun 25, 2025 4:30 pm

Maddnotez wrote: ↑Tue Jun 24, 2025 11:47 pm Pretty nice tones, that's actually super cool I wish I knew how amps worked and could mod them how I like

I wish I knew more and wish I learned sooner. I also wish more people were okay with modding. So much gear is the same or similar, you don't need to spend hundreds or thousands on the next thing. Capacitors and resistors are cheap.

Rob Robinette's site is chock full of information on tube amps. https://robrobinette.com/Amp_Stuff.htm
Electrosmash focuses on iconic pedals. https://www.electrosmash.com/

Will look ty.

It's been on my mind for YEARS and used to consider Bruce Egnaters class. I can solder.....probably along the same skill set as Billy Blades.

l've bought and read books over the years, but a lot of these things teach concepts from simpler Fender circuits. I've never had one of those, so I never really was able to get my hands dirty.

I did a couple of mods on my old 5150 BL. Bias mod and something to try to tighten up the low end that was soldered onto one of the tube sockets, maybe? It's been over a decade. Relatively easy to do.

Psionic Audio YT channel has a TON of great info, but without the hands on piece, it's basically impossible to really learn this shit. Definitely a learn by doing kind of thing, IMO.

That'll do the job!!!