Róisín – A little guitar amp.

Here is a little diversion from the woodworking posts I’ve been putting up.

This is a guitar amp I made a while back. Her name is “Róisín”, which is Irish for “Little Rose”. She was named as a companion for a larger amp I had called “Rosie”, named after an AC/DC song.

Researching cabinet design is one of the factors that sent me down the rabbit hole of woodworking.

roisin-1

For those interested in the woodworking it is made of solid maple dovetailed with (horrors!) a dovetail jig and router. The rear panels on the back and front of the speaker cab and the head cab are birch ply. The head cab has a maple panel. I have to make a face-plate for the amp but I held off as I have a tendency to keep modifying. Also both cabs have an off-white fabric cover.

roisin-2

The amp has one input a volume and tone with an on/off switch. Rear of the amp shows a 3-position impedance selector with speaker input, fuse and power cord.

The speaker cabinet houses a 12″ Celestion Greenback. Tee nuts in the front baffle hold it on tight.

The amp is based in part on the AX84 P1, except I used a 6v6 power tube with the 12AX7 pre-amp tube and just put in a simple volume/tone circuit. It puts out about 5Watts at full tilt. Definitely too loud for in the house unless I get the place to myself.

I designed the circuit first and then did the layout for the components in Autocad. I printed these out and used the layout as a guide for drilling out for the turrets.

 

 

roisin-7

roisin-6

roisin-5

The Heyboer transformers were from a PI kit I bought from Doberman Amps years ago and have been in a few variation of amp since.

roisin-3

I took pains to try and lay the components out so that each one has a dedicated pair of turrets it goes between so that it would be easier to swap them out if I wanted to tweak the sound.

 

roisin-4

It is a good little amp. It breaks up at about 5. Cranking all the way can make the walls rattle and can get little bit too bassy. Great though for playing something like The Who. At lower volumes and going easy on the guitar strings it can sound pleasantly clean. It takes pedals well. This is my go-to amp now and likely will stay in its present configuration unless I get the itch sometime soon to start soldering again. 🙂

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