Universal Guitar Amp with Vibrator and Reverberator

[tigerzilly]

I picked up another vintage amp. It's solid state but still pretty cool. Its called Universal Guitar Amp Model 50-A by Universal Amplifier Corp. Its has a vibrator and reverberator! Looks like maybe it doubles as a sex toy!

It also has two 1967 Jensen C12NA speakers, a retractable power cord, and removable dollie.

Anybody ever hear of these?

Having problems posting pics.

[J M Fahey]

Upload them to imgur , then paste picture links here.

[tigerzilly]

Here are pics

[tigerzilly]

I see the panel also says "Astro Amp". I found an Astro Amp Astrotone Fuzz box of the same vintage and same graphics. Must be the same company.

[J M Fahey]

Very cool vintage amp.

[52 Bill]

Agree^^^^^^^

Never seen one before. I really like the vacuum cleaner cord roller part.

[nevetslab]

Agree^^^^^^^

Never seen one before. I really like the vacuum cleaner cord roller part.

Agree too ^^^^^^. Is the cord roller spring loaded, so it winds it back up? Hopefully not so strong as to want to unplug it from the wall.

[tigerzilly]

Yes the cord recoil still works. It only recoils when you pull on it. I hope I can put a grounded plug on and still use the recoil.

[J M Fahey]

Please add some chassis guts pictures, we want to see how it was built, what kind components it used, etc.

It might be similar to Standel amplifiers, or some Vox Thomas ones, with driver transformers, even Germanium transistors.

Would also love to see how they cooled the transistors.

The cherry on top would be to hear some YT video or MP3

The speaker complement is very serious for the era and a 50W SS amp, so they were obviously trying to do the things right.

[tigerzilly]

Attached are pics of the chassis. I haven't powered it up yet.

[J M Fahey]

Thanks.
Tons of serious Mojo there,from mushroom Fairchild transistors , gold leg TO92 ones, to cloth covered wire to direct chassis mounted TO3 transistors, construction type not too far from Kustom or Standel , early Acoustic or Peavey.

No driver transformer which is good.

Suspect minimal or no short protection, so be careful if connecting external speakers.


No we must hear it

REMEMBER to build a lightbulb limiter and plugging it there until absolutely certain there are no nasty surprises lurking.

[tigerzilly]

No we must hear it

Thank you for giving this your experiences eyes! I do have a light bulb limiter. I just need to get two other amps off my bench so I can start working on it. Hopefully the mojo is truly there. I'll let you know when I get it going and post how it sounds.

Mark

[tigerzilly]

Cleaning up the Astor Amp

[J M Fahey]

Some serious cleaning there.

It deserved that.

[tigerzilly]

I cleaned all the pots and got them moving freely. Sprayed all the jackes and toggle switches. Pulled the fuse and found a blown 3 amp fuse in a 15amp fuse holder. Found another fuse inside the chassis. It also was a blown 3 amp fuse. I put in a 10 & 5 amp fuse and powered up through the light bulb limiter. The light bulb on the limiter was lit brightly with a noticable hum from the amp. Powered down and have four suspect capacitors to replace. Noticable bulging at ends. Two are 4000mf, and two are 300mf. I'll order the caps and a new footswitch Jack.

I see the power transistors are RCA. Is that good? It would be if it were and old rca tube.