New Amp Day - StewMac Mojotone '65 P-Reverb Princeton Reverb Assembly & Review

[jonfields45]

20% off at StewMac this week. I have absolutely no need as a true believer in my UA Dream 65 and various Positive Grid Sparks. I look at it as a future piece of furniture for my living room.

I built several tube ham radio Heathkits (HW101, HR10B) in the early 70s while in junior high, so it will be looking back at old good times for me. I can also use tin-lead solder for its assembly which will give it a reliability step up from a modern Fender point-to-point assembled version.

[jonfields45]

[Glennwillow]

Well, that will be a very cool project, Jon! I will love to see and hear this when you have it all together!

- Glenn

[jonfields45]

[rmp]

this gives "Some assembly required" a whole new slant.

Good luck with the build!

[bleedingfingers]

My girls got me a 5F1 (Tweed Champ) kit for Christmas. Went with a bigger cabinet and a 10” speaker for a little less boxy tone. Debating if I build the circuit stock initially, or mod it. Should be a fun project either way. Super excited to build it with them and then to have it to play!

[PineMarten]

Hope it goes smoothly for you! A Princeton Reverb clone is a fun amp, but from my own scratch build a few years ago, I recall it can be quite involved troubleshooting compared to a simpler amp if there are any little errors or noises.

[Joe Garfield]

Excellent choice, and thanks for sharing! I built a few headphone tube amps during the Covid lockdowns, and was very close to getting one of these Mojotone kits. I enjoyed the process and this kind of thing ends up being an incredible value. I ended up buying my dream amp, but whenever I decide I want another amp I'll build one of these kits.

Keep us posted and enjoy the build!

[jonfields45]

Getting a little ahead of myself with this Etsy purchase...

At the pace I'm going it will take months to finish.

[Bluside]

Should be aa fun project. Take lots of pictures along the way and keep us posted.

I built one of their 57 Champ amps a couple years ago and put it in a custom tweed cabinet with a 12" speaker. I use it all the time at home.

[jonfields45]

Another weight penalty. You won't find 3.5+ pounds of steel in a modern design :~). Between this chassis and the transformers you nearly have enough weight to equal a nice Fender Mustang LT 25.

[Jeff Scott]

Stuff a good 12" speaker in it.

I used to have an early '70s PR that someone back in the last century installed a Celestion G12M-70 into. Loved it, until going strictly acoustic (except for bass).

[jonfields45]

All the bolt it to the chassis stuff is complete. It's a lot of slow going hand work that I can easily see motivates the current $2,799.99 MAP for a Fender 1964 Princeton Reverb. What I can't figure out, back in the days of 40% off list price retail, that the amp listed for only $229.50 in 1973 (my sophomore year of high school).

[clintj]

Just a heads up, both StewMac and Mojotone's power cord wiring is incorrect. The incoming black should go to the end lug of the fuse holder. Then from the side lug of the fuse holder to the switch. Switch to one of the transformer primary leads.

Neutral of the cord should be spliced directly to the other transformer primary lead.

Ground should be left longer than black and white, and bolted down to a dedicated fastener. That terminal strip bolted to the transformer bolt is illegal per current code for mains safety grounding. People have called them out on it and got the answer of they decided to leave it "vintage correct" for some incomprehensible reason. Rob Robinette has updated layouts on his website that actually meet modern regulations.

[Bluside]

Keep the pictures coming. I like the wooden holder you have for the chassis.