British Style 18W TMB Amplifier Kit

5Reviews
$585.00

Cabinet and Speaker Sold Separately (Add Below)
SKU: G1TMH411
Weight: 20.29 lb
Sale Unit: Piece

In Stock

1 IN STOCK

Amp Kit Difficulty Level

Easy
 
Hard

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Please read our article 'Mojotone Amp Kit Building Primer' along with our amp kit disclaimer located in the Specs tab before buying this kit.

 

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!

  • Class Type: A All Tube Amplifier
  • Output:~18 Watts
  • Circuit:1974 / 2204
  • Bias Type: Cathode Bias
  • Build Time:~6 hours
  • Preamp Tubes: ECC83/12AX7 (3)
  • Output Tube(s): EL84 (2)
  • Rectifier Tube: EZ81
  • Transformers: Power - 18W (7000018), Output - 18W (7000118)
  • Hardware: British 18W Small Parts Kit, British 18W Chassis, Front & Rear Faceplates, 10' Removable Power Cord

 

Disclaimer: Some of the parts contained in this kit are subject to availability.

Mojotone reserves the right to change or substitute any and all of the parts contained in this amplifier kit without advertisement or notification to the buyer. Part substitutions made by Mojotone are guaranteed not to affect the integrity or operation of your amplifier kit. Time estimates listed are from start to finish. If you are new to tube amplifiers, additional time may need to be factored.

 

When purchasing a kit from Mojotone, you will receive the following documentation.

1. Schematic

2. Wiring Diagram / Layout

Our beginner level kits such as the tweed champ and tweed deluxe include a manual. If you purchase a kit from Mojotone and do not receive these documents, you can obtain copies by emailing tech@mojotone.com or calling 800-927-6656. The Mojotone staff is available Monday through Friday from 8:30 a.m. to 5:00 p.m. EST unless otherwise closed.

 

Mojotone kits include the best quality parts that are available at the time of purchase. If a substitution is required, our team will use parts that are of equal quality to ensure the integrity of the kit build remains the same.

 

Building a fully functional amplifier kit is not an easy task. Before building a kit, one should have the ability to properly solder as well as read and understand a schematic and wiring diagram. While we do our very best to ensure all documentation is current, the included documentation is meant to serve as an overall guide to building the amplifier. Simply following the schematic and wiring diagram does not guarantee you will have a fully functional amplifier. In fact, post build troubleshooting is a common issue across all builds.

 

Our staff is available to assist with basic troubleshooting needs. There are plenty of online videos available that are helpful with most post build issues. Technical staff is available via email by sending a message to tech@mojotone.com. You may also call our sales team to discuss build problems, dial 800-927-6656 and press 1 for sales.

 

Building a tube amplifier takes time, dedication, resources and most importantly... Skills! The experience of building an amp can come with some frustration, the reward of completing the build is definitely well worth your time. Please review the wiring diagram, schematic and manual (if applicable) prior to making your purchase. Mojotone will not accept any returns on amplifier kits and/or parts that have been assembled, soldered or modified.

This amp kit also comes with the following documents. Please feel free to view and/or download them:
British 18 Watt TMB Schematic
British 18 Watt TMB Wiring Diagram

Ratings & Reviews

5 reviews

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1/13/2024 3:44 pm

Sounds amazing.

by Dave -

Just finished this kit and just had to comment how amazing it sounds! I'm giving this a 4 star instead of 5 because it wasn't 100% perfect.
1/2 star shorted because: I was shorted 2 resistors from the kit, and I feel like an extra 6" to 1' of wire would be nice to have as I like to cut long and trim down. I had to get some tubes anyways, so I just ordered the resistors and extra wire from mojotone, no real big deal.
The other 1/2 star is for the chassis not being 100% for this project. I had to enlarge 1 hole, and drill a couple new ones to accommodate the filter caps. The filter cap on the side is a little closer to the transformer then I'd like.

The layout was updated as of November, and I feel like it was very well done as I've heard there were inconsistencies with that in the past, but I found none.
Quality components. I would like to so an option to upgrade certain things like the input/output jacks.
It sounds 10/10, dead quiet, great overdrive and great cleans!

1/7/2024 11:57 pm

As easy as it gets, works great, sounds great!

by Teddy -

Ordered and built this in December 2023. The parts are very well organized and labeled. I was coming from wiring guitars and building pedals as a hobby. I was able to build it from the attached layout with no problems. To make life easier for me, I got extra wire (20 awg) for each color. Order of operations is essential. I wired the turret board first. Then I added the tube sockets are wired those next. Then the pots, ground lugs, jacks, and switches. Added the transformers next. Wired as much as possible before placing the turret board in, and did the connections from the turret board last. It will make your life easier to get a good soldering iron, I use an old Hakko with Kester rosin core solder. Have desoldering braid ready for any mistakes. The main thing to be aware is that extra wire is generally a bad thing in this application. Lack of organization is a bad thing. It’s easy to make shorts, which will sink your battleship.