5E3M micro amp

Tube Amp Projects   -   5E3M 'Deluxe Micro'   1 Watt mini-amp

Harmonica/ guitar player Greg Baker asked me if I could build a low power tube head, small and light enough to carry on a plane in hand luggage. His intention was to use this at festivals, where he could plug in a speaker for a stage monitor, and also run a line to the front of house PA. Commercial 1 or 2 watt mini-amps are available, but most have exposed tubes, or need an external power supply, and besides, Greg didn't want to spend THAT much.

Fortunately someone had already done the R&D work. I found this circuit at robrobinette.com - Rob based his circuit on the Fender tweed 5E3 Deluxe, and calls it the 5E3M Deluxe Micro.



 


I used salvaged/ recycled parts where possible, including the case from a 1960s AWA transistor amp.

It was a VERY tight build, as you can see, and there is a bit of hum because of this, but the result is very satisfying. This makes an excellent bedroom/practice amp for harp or guitar, going from clean to creamy overdrive. It can also be used as a compact gigging option, provided your sound engineer is compliant.

The 12AY7 is wired as a traditional preamp. The two triodes in the 12AU7 are run in parallel for an output of about 1 1/2 watts. They are biased at about 80% dissipation. Here are the photos and a short video.

 

 

 

Here's the You Tube video of me playing harp thru the amp.

https://youtu.be/L_5wPQz7aUA

If you want to have a go at building one of these, there is a layout diagram plus notes at www.robrobinette.com