27-11-2019, 06:59 AM
I worked on a Dominator Mk2 a few weeks back. I replaced the main reservoir/smoothing with a F&T 50/50u 500v, the axial electrolytics with Vishay's. All the resistors were in spec and the Mullard mustards checked out for leakage so were left. I took load of pics before removing the board.
One big change I made was to put a separate on/off SW in where the mains voltage selector is because there was serious hum on the normal/tremelo channel. Putting 240v/50hz right next to a volume control that feeds a grid is a bl**dy daft idea.
I found all the valve bases to be loose with the valves hanging on by the skin of their teeth, I tried tightening the pins which improved things a bit but if I'd kept the amp I'd have replaced the lot.
I also had to replace the mains tfmr, mine was getting very hot and dripping wax. These amps are running right at the max, I would replace the EL84 cathode resistors so they are running at less dissapation.
I also put a SW on the back panel to SW in the tremelo so you don't need a FS, a SPST is all that's needed.
When I put the board back I didn't use the holes, just soldered onto the traces, there's enough wire to cut off the ends and then strip back to form a new soldered wire. The wire in mine melted if you looked at them the wrong way, careful with the heat.
That's about all I can remember at present, good luck with the restoration, Andy.
One big change I made was to put a separate on/off SW in where the mains voltage selector is because there was serious hum on the normal/tremelo channel. Putting 240v/50hz right next to a volume control that feeds a grid is a bl**dy daft idea.
I found all the valve bases to be loose with the valves hanging on by the skin of their teeth, I tried tightening the pins which improved things a bit but if I'd kept the amp I'd have replaced the lot.
I also had to replace the mains tfmr, mine was getting very hot and dripping wax. These amps are running right at the max, I would replace the EL84 cathode resistors so they are running at less dissapation.
I also put a SW on the back panel to SW in the tremelo so you don't need a FS, a SPST is all that's needed.
When I put the board back I didn't use the holes, just soldered onto the traces, there's enough wire to cut off the ends and then strip back to form a new soldered wire. The wire in mine melted if you looked at them the wrong way, careful with the heat.
That's about all I can remember at present, good luck with the restoration, Andy.