Fairchild Pre Amp and Amp

mike88max

New Member
I have just uncovered my old stereo system a Fairchild 245 Amp (the other is MIA) and 248 Dual Preamp with case and Controller. Any tips on replacing the tubes as far as what manufacturer to go with and where to buy on line? I am sure several are spent and don't want to risk destroying anything before I power them up. The caps look ok but I know old paper caps are also a risk.
 
Tubes may be fine as they last longer than most think. You can buy spares to swap in either NOS or new production, that way you don't need a tube tester.

Best to recap it fully as you risk any or all the transformers if a cap shorts out. Clean tube pins and sockets also. As you probably know don't run it without a load of speakers.

Tubes don't like to be short cycled (quick off then on) say when testing tubes, so it's best to let them cool fully before startup.
 
Welcome to AK!

Hopefully that other 255 turns up!

I wouldn't worry as much about the tubes as I would the capacitors. Ticking time bombs...

Put your location in your profile. Maybe someone local has a variac and would be willing to lend a hand.
 
The good thing is there are not many caps. go checking and replacing won' t be to bad. I was thinking of the variac voltage turn-up also. I might be able to dig up one at work.

thanks

Mike
 
Hi mike88max and welcome to audiokarma..that is a fine setup indeed and hope you find the other 255 amplifier as it isnt going to be cheap to find a mate if you have to go buy one.the good thing is the 255 isnt as hard to find as say the 260 or 275.i myself run a pair of 260 amplifiers and a 248 stereo preamp.if you did any searching here on ak there are a few of us with fairchild gear mostly amplifiers and turntables.thers a few with the 240 preamps and about the same for either a single 245 or a pair but as of know we are the only ones wit the 248 setupwhich is quite rare.i was wondering what colour are the face plates on your 245 amps and the 247 stereo control.the reason i ask is they were available in white or a cream colour.my preamps both have the white faceplate but the 247 has the cream colour
 
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As far as firing them up others gave you some good advice.get a variacand you should be fine for the preamp and even the amp after you replace the output tube ..if the el34 is cloudy (white)it meas it let the gas out and will need to be replaced.
 
OK, a few pictures. I would have taken off the bottom plate for another but I am to tired tonight. Anyone know where i can get a Face Plate for it?IMG_1379.JPG IMG_1380.JPG
 
Ok for starters the el 34 is bad.another thing is your amp is a 255a and not a 255.the 255 used a pair of 6l6gc with a 5v4 rectifier and the 255a used 6ca7/el34 with a gz34 rectifier.
 
I find it strange that the decal would be missing off a 255a as it was a factory built amplifier.the 255 on the other hand was available as a kit as well as factory built similar to the mcintosh mc30 at the time which was also available as a kit.both didnt go over to well as it was probally cheaper to sell them built then to put together a manual for step by step directions and then offer a send it in if it dont work and we'll fix it.
 
I found a pic online, edited it in paint, and brought the finished pic to a trophy shop, and cut it in brass. I can send you the pics to edit and change the 260 to 255.
View attachment 897719
I found a pic online, edited it in paint, and brought the finished pic to a trophy shop, and cut it in brass. I can send you the pics to edit and change the 260 to 255.
View attachment 897719
Scott ,he needs the foil design like on my 260 amps .the gesture was nice though
 
I got the 255 amps one MIA now and the 285 Pre-Amp from My Friends Father, I believe he was an Engineer for a time at Fairchild! His name was Norman J Anderson a very smart audio engineer. I will post some of his patents soon. I can't give out all my A material on the first day on the board.
 
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