Univox U80A

[Big chief]

Univox U 80 A no tremolo replaced all electrolyte caps and tubes
Voltages V1 p1 68.8 p2 0.2 p3 0.2 p4 p5 3.1 p6 113.1 p7 0.1 p8 1.3 p9 3.2
             V2 p1 168.1 p2 9.4 p3 67.1 p4 p5 3.1 p6 118.3 p7 0.1 p8 1.3 p9 3.2
             V3 p1 1.3 p2 2.8 p3 3.1 p4 3.2 p5 276.8 p6 263.4 p7 1.3
             V4 p1 3.7 p2 2.7 p3 3.2 p4 3.2 p5 279.1 p6 268.2 p7 3.7
Used foot switch and shorted jack cleaned all imput jacks and pots
Any help would be great could not locate schematic

[PRR]

http://www.prowessamplifiers.com/schematics/images/Lafayette_U80A.pdf  ?

V2 p8 p6-- does the voltage wobble?

Replace all the 0.02 and 0.01uFd caps at V2b-- they have a tough life, were bought cheap, and small leakage may stall the oscillator.

[Big chief]

Thanks will remove circuit board and replace all caps

[sluckey]

V2 p8 -- does the voltage wobble?

Probably meant V2 p6???

[Big chief]

Have replaced caps now no sound also replaced bad wires from circuit board to tubes

Any ideas

[shooter]

In my profession, it would be the last thing you did, since the OP indicates sound just no trem

[Big chief]

As you can see from the photo the wires going to tubes are Bredel and need to be replaced as I found one wire broken off circuit board now have roaring sound imput jacks not sending signal  will replace all wire from circuit board to tubes

Question I have cloth covered single wire or should I use stranded wire
Tremolo weak
Thanks

[astronomicum]

The 24 gage wire that Univox used is stranded but the problem is that when the wires are soldered, the solder wicks up the strands and essentially makes it solid up through the point it protrudes through the circuit board. A couple of bends right at the board and they break right off as you have discovered. You can see how almost all the wires coming off the board are bent at 90 degrees which weakens them substantially. What I have discovered works well is before I begin work on one of these Univox units, I will straighten each wire so it is perpendicular with the board and put a small amount of hot melt glue around each wire. This stabilizes the wire and will not allow it to bend at the board allowing you to lift the board to work underneath without breaking the wires. Since you need to unbolt the potentiometers to lift the board, bending at the solder joints of the potentiometers will also break the wires off after a few bends so I also put a small amount of hot melt glue around each solder joint of the potentiometers to stabilize them. As far as your original question, I would recommend stranded. You might make out ok with solid for all new work but if you ever have to lift the board again for additional work, you may find that the solid wire may make that task more difficult.

[Big chief]

Thank you so much for you instructions. I’ll use your idea