This is another project I did a long time ago, I sold the machine to a nice man on the internet and never looked back. I have however been asked about it numerous times and feel I should put this info somewhere.
I bought this machine on reverb after years of wanting one, it came to me in pretty okay condition with the original 5 pin din trigger inputs upgraded to 1/4" jacks (yay). If I remember right the main output volume and its associated gain stage had been bypassed (okay).
Voices triggered but were inconsistent, some LED's didn't work, and there was an overwhelming 60hz hum coming from the power supply. Recapping the voice boards was a huge improvement but the hum was still there, real relief came from replacing the power supply
The voice boards are powered by +/- 9vdc so it was simple to use an off the shelf DC/DC converter IC (MORNSUN WRA1209ZP-3WR2) and a normal guitar pedal power supply. I opted to remove the power transformer and de-solder all the other components in the original power supply, then made a small daughter board for the DC/DC converter. Problem solved! The thing ran dead quiet and and sounded fantastic, This is a great solution to for any of these ancient devices that were made before modern switching power supplies. Theres no reason to have any AC power in a device like this in the year 2026
I decided to sell when doing a studio purge after the birth of my son, I hope its working well for the guy who picked it up.
-SAP
I got this amp for 60 dollars on marketplace about two years ago, I fixed it up bit by bit over that time and sold it just before writing this so I apologize for anything I may remember incorrectly.
When I picked it up, it had no back panel, a missing driver, and the press board speaker baffle had been broken from some sort of impact
Step one was to cut a new baffle out of 1/2" birch plywood. After that i painted it flat black and I stretched some new grill cloth over. I came close to getting it perfect but I burned a small hole into it right about where it meets the cabinet at the top. You can barely tell. The way these speaker baffles fasten into the cabinet just doesn't seem right to me, there are three small bolts (#10 screws if I remember correctly) on the top and bottom and that's it. It adds very little structural integrity to the cabinet but I guess that's how they did it on the old tweed fenders. Without the baffle installed this cabinet just feels bendy, and with the baffle loaded and installed it isn't much better under the weight of the speakers and amp chassis.
Next was to move on to the electronics. The missing speaker was replaced with a Jensen MOD. I replaced all electrolytic capacitors and a few other passives, but everything was largely okay.
It was at this point that I decided to park this amp in my studio and not touch it for over a year. I have a tendency to get 80% of the way through a project before setting it on a shelf and starting three more. This habit extends to every aspect of my life.
This summer I decided it was taking up too much space, I would finish the job and decide whether to play it or sell it. I made a quick backpanel out of some plywood underlayment I had laying around. They must have used some very thin stock on these originally, the 15/32" thickness was JUST thin enough to not sit proud of the tolex on the cabinet (yes, this is covered in that tweed patterned tolex, not the real thing). I had to glue a T brace of pine into the back to keep it from flexing. After a coat of lacquer I added a little section of wire cage to protect the 4 power tubes and it was pretty much done.
I played and enjoyed it but not enough to justify keeping it in my already cramped studio. Someone else would get far more joy out of it. Unfortunately the used gear market is not in the greatest shape and it sat on marketplace for over a month before I decided to trade it into to the local guitar shop as part of the payment towards a 6 string kit build pedal steel (more on that later).
-SAP
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