Mojotone's 18-Watt TMB Amplifier Kit addresses a common mod made to a classic circuit, but with a few new flavors of our own. The TMB is based on the circuit used in vintage Marshall models 1958, 1973, and 1974 (more affectionately known as the '18-watters'). Marshalls were only produced between the years 1965 and 1967, but were highly sought-after for having massive sounding JTM-45-like tones in a smaller, more manageable package. Because they were produced in comparatively low quantities, these amps still remain a 'lost ark' today.
18-watters became popular studio amps for many players and were used, at times, by everyone from Gary Moore, to The Pretenders, to AC/DC. Over the years, some players have reported having no use for the amp's original tremolo channel and have opted to replace the tremolo controls with a 3-band EQ, since the original amps were only equipped with a single tone control for each channel. In the Mojotone version, we have done just this, only we have integrated the preamp from our British 800 kit (based on the original Marshall JCM 800 circuit) for a lean and mean, hot-rodded gain sound. We have also integrated a master volume control so this monstrous sound can be harnessed and used in any size room.
Two EL84s give the amp's normal channel a warm and round character which, when volume is pushed higher, begins to break up into a smooth grind perfect for blues rock and classic rock rhythm sounds. On the dirty channel, one can access screaming lead tones perfect for everything from dim dirty grunge all the way to saturated hair metal sustain!
With our TMB mod in place, this take on a classic beast now has a normal channel with high sensitivity and low sensitivity inputs as well as a single volume and single tone control; the second channel has a single input with volume, treble, middle, and bass controls. And don't forget about the master volume!
For those players who are a little more "hands-on," we also offer the amplifier as a kit with a variety of options including small parts only, full kit (both head and combo configurations), export specs, and more.
Model: 1966-68 18 Watt Class A/B All Tube Amplifier - Normal Channel, British 800 TMB Channel Output: ~18 Watt Circuit/Model: 1974 / 2204 Bias Type: Cathode Biased Build Time: 6 hours Difficulty: 3.5 out of 5
The "Complete" version of this amp kit comes with the following items:
Awesome! I just picked up a assembled version of the 18 Watt TMB 1X12 combo at the Dallas International Guitar Festival. It sounded good at the show. When I got it home, it really came to life! It takes pedals well too. This might be the best sounding tube combo that I have ever played on. It is well worth the money!
Name: Shane B. Rating: 5
Low volume, High Power! This is my third Mojotone kit, and it amazes me every time that the MJT crew includes every part, not a single part missing out of a thousand+ components in my experience. Well done!
I was thinking about building the 1974x kit, but I didn't have a use for the tremolo channel, like the TMB ad says. The lure of having an 18 watt JTM channel with a JCM800 TMB channel, instead of the tremolo, made the 18 watt TMB an easy choice for me.
I'm fairly new to building still, so when I saw the new instructions and realistic wiring diagram layout, the sale MJT had on this model was all it took. I bought the combo version, with 1x12".
There are some errors on the wiring diagram layout, pin 4 and 5 of socket V1, should have a jumper between those pins.
Also, the input jacks of the JTM channel, the top jack, the green wire should be connected to the top most lug, not to the lower 68K resistor connection.
I got a 3-lug ground strip instead of the pictured 4-lug terminal strip for the PT ground point, had to do my own thing, but it turned out great.
Aside from that, I couldn't have built this kit without the new-friendly instructions and wiring diagram. I also couldn't have found the errors without the forum at TheGearPage.c.m, those guys are an incredible resource if you get stuck, or have questions.
The important part: how does it sound? Huge, in small way. Barely enormous. It sounds like a JTM and a JCM800 to my ears, and at a comfortable volume, but without the wall pounding thump of a 45W/50W and 4X10's/12's. It's very studio and bedroom friendly. Even at low volumes it gets raw on the JCM channel, gritty and spitty. The JTM channel has a nice clean tone, pedals are insane! Throw an OD at it, and it can scorch in either channel.
I really thought it was going to be much louder than a 15 watt 10" Princeton I built, but it's not. The raw and gritty tone can be had from the JCM channel at very low volume, thanks to the Master Volume. It can get loud of course, if you crank it.
The tones, and the response that can be coaxed out of this amp, are exactly what I was hoping for, and I had a lot of fun building it. Get one!
Name: Brad Myers Rating: 5
null I'll have to say that this kit was THE most straightforward build I've ever done! Steve, Andy and the crew did a GREAT job collectively marketing this kit. The tones are amazing! I did alter the kit by incorporating their channel switching board (the relay-bashed one) and inserted an FX loop ALA Matchless Lightning style. (That passive FX loop works well with this amps level at the PI. You can insert the loop just after the channel switcher and have your time-based effects there for both channels. You will want to use shielded cable when inserting the loop and to-from the channel switcher. I picked up too much noise using unshielded wire.) I will build this kit again!!!