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Lafayette 250a

brimat66

brimat66

How old is vintage??
Today I aquired a lafayette 250a from a guy I work with. He wanted somthing newer with a tuner and had seen a late 80s jvc amp and tuner I was using as a test amp. So he wanted to trade me even for mine. So I went and picked it up today. He said It worked when he put it up a year ago when his wife redid the basement
This being my first venture into tubes I will probably be asking a-lot of questions so I thought I would warn you fine folks and say thanks in advance and as soon as I figure out how to post pics I will do that as well:music:
 
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Hey, brimat66, welcome!

I still have the 250A that my father built in the early 60's. I've used it on an off for nearly my entire life.

I don't know how familiar you are with this stuff, so I strongly suggest that you take the time to have a tech look at it, and give it a clean bill of health before you use it. Those old caps in the power supply can do bad things.

In the late 70's I needed to replace a couple of resistors because they literally burned up (tube failure). I've used mine up until very recently, when I noticed some strange behavior that turned out to be the death of one of the multi caps in the PS. As it turned out, I was very lucky that the thing didn't catch on fire. I checked resistors and found several have drifted out of spec, so, I decided that I need to replace not only the caps, but also check all of the resistors and replace them as needed, too. The silicone diodes in the PS are prone to failure so they should be replaced, also.

I haven't gotten around to replacing anything in it yet, but maybe this year...:D

When they were manufactured, they could be bought assembled or as a kit. There are 2 versions of the units, AFAIK; the earlier model KT-250 (LA-250) and the later version, the KT-250A (Stereo 250A) so, make sure you have the correct schematic if you need one, as there were some changes made in the biasing circuit, IIRC.

It's not what many would consider a TOTL unit, but it has always sounded nice to me. :music:

Good luck with your first experience with tubes, it can be a lot of fun! :thmbsp:
 
Nice find there. You will need to check and replace all out of tolerance resistors. Also replace all paper capacitors and all electrolytic capacitors. Check and replace any weak or bad tubes. I've got some documents on my desktop PC at home about tubes and tube amps. PM me with your Email and I'll send the info if you would like to learn more about tubes. It will be tomorrow before I get to send the info though.
 
Wow I quess I didnt think about it catching fire. I thought this was maybe a project I could handle myself. I took the cover off and plugged it in and all the tubes lit up. I noticed that one of the paper caps had been changed and everything was pretty dirty. I work with electronics all the time in the heating and air field but not like this.

The guy I got it from bought it in 1960 when he first went to college and had it paired with a garrard type A which I also got from him some time ago and have already restored. I know the turntable was made about 57 but I have no clue when the amp was made any thoughts ?
 
Ok I got this pic thing I think. In the pics you can see where one of the caps has been replaced and zip tied to the other paper cap. Also 1 of the knobs is broken and one is missing. I really want to take this project on myself so where do I start ? lol
 

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First thing is to locate the schematic. I looked but could not locate it. You have a nice little amp there, should be a fun project. I'm sure someone here will be able to locate the schematic somewhere. Then I would replace all the electrolytic caps and check resistors, clean pots etc. Have fun and welcome to the tube forum. John
 
I'm a heating and air guy and the folks here talked me through this stuff, so I'm sure you could do it. Like Sloob said, track down a schematic and make a parts list. You'll want to replace all the electrolytics, coupling caps, out of spec resistors, etc.... You'll need to find someone to test the tubes for you too. I'd be happy to if you decide to tackle the project.:thmbsp:
 
Endspec said:
I do hvac too and jay has helped me alot on here too so we do pass along the helping hand of AK.
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Thanks for the hand I know what you mean about ak if it wasnt for the help I received here then I wouldnt have been able to restore my garrard type A TT
 
The Lafayette KT-250 is the same as the LA-250. The KT being the kit version.

It is in Sams #501 dated October 1960.

You should move that electrolytic capacitor below the chassis. It's a hazard. Also, it's most important to replace the .1 coupling capacitors. It's a good idea to replace most of the paper caps and the electrolytics.

Here is a picture of mine.
 
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