Lafayette (or Univox??) U-80A mystery amp

[jrcstudios]

Greetings all, any help with my current project would be appreciated.
It is a Lafayette U-80A Muscal amplifier... I've found out that "muscal" is a known typo on the circuit boards of Univox imported circuits.

Anyone got a schematic? It isn't listed as a Univox amp that I can find on The Univox Page

I've replaced all the caps in it and the pots to bring it (almost) back to life. It sounds really good. However, the tremolo is not working. I have found that activating the footswitch will make it tremolo one time, it just won't continue.
It's a circuit board amp, which make tracing it out a PITA.

I wonder if the capacitor types I used were wrong? I used electrolytics for everything above 1 uF, and metalized polyester for everything less.
All the caps I replaced were Atlas Oil capacitors or standard old-style electrolytic... and the oil was all over everything.

Tubes: 2 of 6AQ5, 2 of 12AX7 (solid state DC Rectifier)


Before cap change:


After cap change:

[Brad1]

That sure looks a lot like my '66 U45B Univox (on the amps page of the Univox Page, it's pics 6,7 and 8...not the earlier U45B), except that yours has two speakers to my one, and yours has four pots to my 3. I have volume, tone and tremolo. I can see the volume and tone label on yours. What's the other two on yours?

You may want to check out the U45B schematic to see if it is close at all. It's definitely the same vintage and style.

BTW, mine does a really nice smooth-grungy old early-Stones kind of thing cranked to 10.

Good luck,

Brad1

[jrcstudios]

That sure looks a lot like my '66 U45B Univox (on the amps page of the Univox Page, it's pics 6,7 and 8...not the earlier U45B), except that yours has two speakers to my one, and yours has four pots to my 3. I have volume, tone and tremolo. I can see the volume and tone label on yours. What's the other two on yours?

You may want to check out the U45B schematic to see if it is close at all. It's definitely the same vintage and style.

BTW, mine does a really nice smooth-grungy old early-Stones kind of thing cranked to 10.

Good luck,

Brad1

My knobs are: Volume, Tone, Speed, Intensity. The jacks are Guitar, ACC, Aux and footswitch. The U45 is a lot simpler looking, and different tubes.