In the last few years I discovered a new passion - vacuum tube guitar amplifiers! I don’t remember where I first saw the idea of building an amp from a kit, but I thought it might be a fun project to do with my son. As it turns out, he wasn’t really interested so I let a year go by. The next year, around Christmas, I got the itch again and decided to order one – of course during the first year of the pandemic when most things were backordered.
While I waited for my first amp kit (a Mojotone Princeton Reverb ) I started doing all sorts of research and binge-watching YouTube videos on how vacuum tubes and amplifiers work. I was fascinated! Before the Princeton Reverb ever made it to my door I had already picked out what flavor of amp I wanted to build next (always N+1).
Next, I wanted to build a Mojotone 18-watt TMB amp, but I didn’t want it to be in a 24” wide amp head so … that’s right, I decided to build my own cab for it! The Mojotone 18w Power Transformer was backordered for months so with some help from kind people on the tdpri.com web forum, I used a toroid power transformer in the meantime (an Antek AS-1T300). I’m actually thinking of putting the toroid back in because it was a lot quieter (less hum) than the Mojotone PT. Did I mention this amp is INSANELY LOUD!?
While waiting for that 18w power transformer, I became enamoured with Rob Robinette’s 5F6A-M Bassman Micro project. Of course, since I was already building the 18W TMB cabinet, I had enough extra wood to build a small head for the micro amp.
With the Bassman Micro, I sourced all the parts myself, including designing the front and back faceplates. It uses a single 12BH7 as the output power tube and is about a 2-watt amp — surprisingly loud for a small bedroom. It takes pedals extremely well. I built it with a number of options and run a 12AX7 in V1 so it’s actually more like a micro Marshall JTM-45 amp.
While building the 18w and Bassman Micro amp heads, of course I needed speaker cabs to go with them. So I built two 1x12 speaker extension cabs in the styling of an old Marshall speaker cab. One cab is loaded with a Mojotone British Vintage BV-30H 8 Ohm (30W) and the other one a Mojotone Greyhound 8 Ohm (70W). Both of those speakers are pretty incredible and very efficient. My favorite is the Greyhound.
During this journey I actually bought (and sold) a Fender Princeton Reverb Reissue and a Fender Deluxe Reverb Reissue amplifier and did a couple of modifications to them to make them more reliable (like moving the screen grid resistors off the board and onto the tube sockets on the DRRI). These were great reference amps to compare with as I build my amps.
Next up, I wanted to build completely from scratch. I dunno why, but it did turn out to be an incredibly hard challenge. I loved the Deluxe Reverb Reissue but man, that thing is heavy! So, I decided to build a single-channel Deluxe Reverb-style amp using both Rob Robinette’s Blackvibe 6V6 and Hoffman’s 1 Channel AB763 projects as guides. I built one as a combo amp and one as an amp head. I won’t go into the hairy details on the build process, but they both turned out really well and I feel are my best amp accomplishments so far!
I’ve learned a TON of new things along the way! I would definitely do a few things different if I could do it again, like never make a stainless steel chassis or use vinyl flooring adhesive to apply tolex (I used water-based contact cement on my B-Verb amps and that worked SO much better).
Any of these amps are “For Sale” though a couple of them you’d really have to pry away from me. I don’t need all of them so if you are interested, please reach out: boyd at boydtimothy dot com
Mojotone Princeton Reverb 1x10 Combo
| Class | AB, All tube |
| Output | ~12 - 15 Watts |
| Circuit | AA1164 |
| Bias | Fixed Biased, adjustable |
| Preamp Tubes | ECC83/12AX7 (3), ECC81/12AT7 (1) |
| Output Tube(s) | JJ 6V6S (2) |
| Rectifier Tube | 5AR4 / GZ34 |
| Transformers | Power - BF Princeton Reverb (MOJO760EX), Output - BF Princeton Reverb (MOJO772), Reverb Driver - (MOJO776) |
| Cabinet | by Mojotone |
| Reverb Tank | Mojotone 4AB3C1B |
Mojotone 18 Watt TMB
This is a Marshall-style 18 Watt amp with two channels. The first channel is a standard 18-watt amp with massive-sounding JTM-45-like tones. The second channel has the preamp of a Marshall JCM 800 with Treble, Mid, Bass, and Master Volume controls.
| Class | AB, All tube |
| Output | ~18 Watts |
| Circuit | Marshall 1974 & Marshall 2204 (JCM 800) |
| Bias | Cathode Biased |
| Preamp Tubes | ECC83/12AX7 (3) |
| Output Tube(s) | EL84 (2) |
| Rectifier Tube | EZ81 |
| Transformers | Power - 18W (MOJO 7000018), Output - 18W (MOJO 7000118) |
| Cabinet | Hand made by Boyd Timothy, 19.75” wide |
Molinello JTM 45 ML (Bassman Micro LTP)
This little amp produces some incredible tone with all sorts of knobs and switches to tweak your sound.
| Class | AB, All tube |
| Output | ~2 Watts |
| Circuit | Fender 5F6A Bassman / Marshall JTM 45 |
| Bias | Cathode Biased |
| Preamp Tubes | ECC83/12AX7 (3) |
| Output Tube(s) | 12BH7 (1) |
| Rectifier Tube | EZ81 |
| Transformers | Power - Hammond 270AX, Choke - Hammond 155H, Output - Hammond 125B |
| Cabinet | Hand made by Boyd Timothy |
B-Verb 22W 1x12 Combo
1-channel Fender Blackface-style with bias tremolo, master volume, mid-raw control, bright switch, and reverb dwell control
Read the full write-up on this amp…
This is probably the most versatile amp I have built and one that I’m probably the most proud of. It’s all build from scratch, including the chassis – from the front panel of an old tankless water heater (it’s stainless steel and I will never intentionally build a chassis out of stainless steel again).
| Class | AB, All tube |
| Output | ~22 Watts |
| Circuit | Fender AB763 with 6G16-style bias tremolo |
| Bias | Fixed Biased, adjustable |
| Preamp Tubes | ECC83/12AX7 (3), ECC81/12AT7 (2) |
| Output Tube(s) | JJ 6V6S (2) |
| Rectifier Tube | GZ34 |
| Transformers | Power - 125P23B (MOJO761EX), Choke - Musical Power Supplies L4M50, Reverb Driver - 125A20B (MOJO776), Output - Musical Power Supplies OT20PP Vertical |
| Speaker | Celestion Creamback Neo 12”, 8 Ohm, 60W Neodymium – makes the whole amp lighter! |
| Cabinet | Hand made by Boyd Timothy, 19.75” wide |
| Reverb Tank | Mojotone 4AB2C1B |
B-Verb 22W Head
1-channel Fender Blackface-style with bias tremolo, master volume, mid-raw control, bright switch, and reverb dwell control
Read the full write-up on this amp…
This is the exact same amp as the B-Verb 1x12 Combo, but as an amp head. I built the chassis from scratch as well, but this time used 5052 aluminum (.090” thick) which was much better than stainless steel. I went all out with this build and used high-quality tone capacitors, Dale resistors, mostly all CTS potentiometers, and high-quality preamp tubes.
| Class | AB, All tube |
| Output | ~22 Watts |
| Circuit | Fender AB763 with 6G16-style bias tremolo |
| Bias | Fixed Biased, adjustable |
| Preamp Tubes | ECC83/12AX7 (3), ECC81/12AT7 (2) |
| Output Tube(s) | JJ 6V6S (2) |
| Rectifier Tube | GZ34 |
| Transformers | Power - 125P23B (MOJO761EX), Choke - 125C3A (MOJO778), Reverb Driver - 125A20B (MOJO776), Output - Musical Power Supplies OT20PP Horizontal |
| Cabinet | Hand made by Boyd Timothy, 19.75” wide |
| Reverb Tank | Mojotone 4AB2C1B |
