British Style 45 Offset Amp Kit

2 Reviews
$642.26 to $875.00
SKU: G145O341
Weight: 30 lb
Sale Unit: Piece

Check our Resources page for current build times.

On Back Order

Kit Build Difficulty: 

**Shell is shown with Mojotone Logo installed. Please leave us a comment when you order if you would like a Mojotone logo installed.**

This kit has a lead time.  Check here for more information.

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

Modeled after an early '45 with it's timeless good looks and unmistakable "offset" chassis. This kit produces similar tones to a 1965-66 Marshall® JTM45. Class A/B All Tube Amplifier. Which was the first amplifier Marshall® ever built based off of the 5F6A circuit. Favored by blues and rock guitarists, this amp can produce a warm sustain and elegant clean tones, with a pronounced rectifier "sag." Played by guitar greats such as Angus Young and Gary Moore.
  • Class Type:AB All Tube Amplifier
  • Output:~45 Watts
  • Circuit:M45
  • Bias Type:Fixed Bias with an adjustable potentiometer
  • Build Time:~6 hours
  • Preamp Tubes:JJ ECC83/12AX7 (3)
  • Output Tube(s):JJ E34L (2)
  • Rectifier Tube:JJ 5AR4 / GZ34
  • Transformers:Power - 45 (7020300), Output - 45 (7021300), Choke - (MOJO777)
  • Speakers:None
  • Cabinet:British Head Box w/ Offset Chassis Cut Out Head Cabinet
  • Hardware:British 45 Offset Small Parts Kit, British 45 Offset 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 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 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 45 watt Offset Schematic

British 45 watt Offset Wiring Diagram

Ratings & Reviews

2 reviews

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  • 2 stars
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  • 1 star
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2/17/2021 1:33 pm


by J.B.

As the title states OMFG!!! Just wrapped it up last night and was playing it till 2 in the morning!!! Needed to work out a couple of issues. Who knew that OT primary leads phase is an issue, I do now. That and bumped up the bias range resistor and then magic!! Just killer tones till 2 ;0)

Not my first Mojotone kit nor will it be my last. Saving my ducats for a NC3015 kit. The long and short of it is the kit was well worth the time and money as the results are priceless.


2/17/2021 1:33 pm

can't wait to show it off

by anonymous

Just got my new offset kit in today! Thanks for the super fast service Mojo! The grill cloth on this offset head shell looks so cool, can't wait to show it off to my bandmates.