Need Help Identifying Amp

What does it sound like? Just curious.

 

Can you fill us in on what all the small wording says if there is any? A lot of the clues are there.

 

Looks like it just says "Solid State Bass" and "Made in USA" on the front, then "105/125 volts", "50/60 Cycles", "35 amps", "Speaker 8 Ohms", and "Fuse rating 1/2 amp" on the back.

 

I was hoping it would say more than that, but the made in USA is a great thing! Mongomery Wards and Sears had similar amps in their catalogs when I was a kid. There are a lot of knowledgeable people here on Talkbass; I hope someone has a good answer for you.

 

Q4 stands for Transistor Number Four. I don't know why, but "Q" was chosen for numbering transistors in schematics.

With a single power transistor, it has to be a Class-A power amp. That's an oddity.

 

Hello, This is a Unicord amplifier manufactured in 1969 and sold through Lafayette Electronics. It came with the regular UB250 one fifteen cabinet.The following year Univox introduced this amp and cabinet as the UB250, with a redesigned face. This first one had a speaker input on the back. The redesigned models had the speaker line hard wired from the amp. The ub250 amplifiers sold under the Lafayette brand all featured the new look after the 1969 Lafayette catalog. You can get a copy of the schematic diagram at The Univox Page.

 

You got that? I asked about it yesterday and didn't get any answers. I was to busy to go and get it today. For $50 you can't go wrong if it works. Bring it to the next GTG.

 

I was tempted as well ... glad it went to one of 'us'

 

Do not use that amp any more until it has been recapped. The electrolytic caps (those big paper-covered thingies) have dried up. There are also two or three electrolytics on the circuit board. (if this is the U250-P, the schematic does indeed show the electrolytic coupling caps that are on the circuit board.)

If you can use a soldering iron, and can read a schematic, the caps are readily available from Mouser or Digikey for a few bucks.

 

You ask me how I know this.The short answer is I have devoted my life to the study, acquisition and restoration of the Univox UB250 amplifier.The amplifier you have was branded for Lafayette a full year before Univox featured it in their 1969 catalog. All the flat face, as I call them, amps I have owned have dated 1969. The oldest redesigned amps I have date to 1970. Yes even though they are shown in the 1969 catalog. I have never seen a redesigned made before 1970. I have never seen a flat face that dates after 1969. Having said that, I would say that production in Westbury had some pretty loose standards, Because I have '71 heads that came with '70 cabinets. By the same token I have blue face UBs with 71 cabinets. I know you're thinking that the speakers were laying around for a year before they put them in a cabinet, but you can't date the cabinet by the speaker code alone. You have to determine if the corners are chrome or nickel plated or black. Or are the corners screwed in or secured with push pins. Is the strap handle is smooth or ribbed. Are the rubber feet the 1/2 inch variety or the short rounded off type. And don't get me started on logo placement. It seems like the position or the nameplate was determined by whoever was working that day. I have cabinets with black corners, with the logo in the lower right of the baffle board and cabinets with tall feet with the logo in the upper left. The serial numbers are random numbers which are indecipherable. And the worse part of it is : Nobody wrote anything down. If it is possible, could you write down the numbers on one of the pots and let me know.To answer your question, yes I have used the Lafayette branded heads and they were good to use for both practice and recording, back in the day. I wouldn't use it now myself because it is an ungrounded amp ( in a manner of speaking ) and I have a morbid fear of electricity. You can have a grounded line installed but this might cost more than the amp is worth. Did I mention that Univox solid state amplifiers do not have a very high resale value? Hope this helps

 

laughing house, you are to Univox what JimmyM is to Ampeg. I knew when I posted that someone else would know something. And my guess is that you know a little more that just the history of Univox. Good job!

 

I would replace the volume and tone pots (when they're that old and drop out like that, they are likely past the point of using contact cleaner), and all the electrolytics. This would cost somewhere around $100 for a competent honest tech.

Now, here's the bad news. That amp is not quite like the U250 I saw in the schematics link that was posted. The schematic for the U250 version 1 shows a pair of output transistors in a quasi-complementary configuration which would likely be good for around 20 watts. But the amp you have has only a single output transistor which means its running in Class A and therefore is only good for maybe 5 watts.

Do you REALLY want to spend another $100 on an amp that's worth...maybe the $50 you paid for it? It's cool and all that, but still...it's a late 1960's low wattage solid state amp and I doubt it has any value even to a collector.

Now, if you could buy the parts and replace them yourself, that's only $20 or $25 and that would be quite reasonable. But paying for a tech to do this...well, hey it's your call.

 

... it would also be interesting just use the shell and put a simple 'modern' circuitry inside from maybe a small gutted combo amp ...