PDA

View Full Version : Tubes for old Audio



USSEnterprise
August 26th, 2006, 09:35 PM
I recently dug out an old reel to reel portable player in my basement. Turns out its from the Late 50, and belonged to my grandfather. Made by Recordio. I plugged it in and set up an old tape (christmas music) and heard nothing. I hooked up a microphone and heard nothing. I knoticed an auxiliary input on it, so I take a line from my CD player and hook it up. I hear Aerosmith. I'm assuming the preamp is out. Now this is not solid state. Tubes. I open her up, and look up the various tubes. I think I find the pre-amp tube, a Mullard ECC83/12AX7. Cheapest I can find the thing is $150. Does the tube have to be the same brand, cause I can find other brands of the same model tube for $8. I don't want to put a lot of money in this, just enough to get it playing tapes again.

alexkerhead
August 26th, 2006, 09:36 PM
Curiousity: What size reels does it use?

You can use any compatible tube.

USSEnterprise
August 26th, 2006, 09:37 PM
I think they might be 7". They're about the same size at a 45

alexkerhead
August 26th, 2006, 09:43 PM
I think they might be 7". They're about the same size at a 45

cool beans.
Is it self amplified?

If not, then you have yourself something really nice there.

Self amplified means it was for just basic usage(cheapo all in one), non-amplified means it was for a integrated amplifier with monitor speakers or such.
If it is plastic, I would guess late 1950s to the late 1960s seeing as it uses tubes.

USSEnterprise
August 26th, 2006, 09:48 PM
nah, its got a built in mono amplifier. When connected to my CD player, it gets pretty loud. I'm being careful, though, not to blow the 40+ year old speaker seals. Its in a wooden case though, not plastic

alexkerhead
August 26th, 2006, 09:50 PM
nah, its got a built in mono amplifier. When connected to my CD player, it gets pretty loud. I'm being careful, though, not to blow the 40+ year old speaker seals. Its in a wooden case though, not plastic

Wood. Nice find even if it is mono.
If the built in amp works, then the head is probably shot, good luck finding one. Try getting it demagnetized first though.

USSEnterprise
August 26th, 2006, 09:57 PM
well, I need the preamp working before I can even test the head. Its all a matter of $. When I google the model (recordio r-602), I get all of 2 results. No chance of finding parts for this I think.

alexkerhead
August 26th, 2006, 10:07 PM
well, I need the preamp working before I can even test the head. Its all a matter of $. When I google the model (recordio r-602), I get all of 2 results. No chance of finding parts for this I think.

Yeah, your gonna have to find a specialist online to help you find a compatible tube.
I had that issue when I was looking for a set of tubes for an electrio 1939 tube radio. Never found any, but the unit looks hawt.:lol:

modem7
August 26th, 2006, 11:39 PM
I think I find the pre-amp tube, a Mullard ECC83/12AX7. Cheapest I can find the thing is $150. Does the tube have to be the same brand, cause I can find other brands of the same model tube for $8. I don't want to put a lot of money in this, just enough to get it playing tapes again.
Any particular reason why you suspect the 12AX7? Yes, those old tubes were short-lasting/unreliable (relatively speaking), but be aware that with an amp that old, the problem could be just as much a dry joint (bad solder joint), or a dried out capacitor. I appreciate that you may not have the tools and/or knowledge to determine which.

Re 12AX7. Interesting read at http://en.wikipedia.org/wiki/12AX7

A comparison of 12AX7's is at http://www.thetubestore.com/12ax7review.html
Based on that, I'd be going for the 'Electro-Harmonix 12AX7' ($9). I wonder what the survivability rate is for tubes sent in the mail?


Does the tube have to be the same brand
Might be worth finding a vintage radio/amp forum, or send an email to www.thetubestore.com

Terry Yager
August 27th, 2006, 12:17 AM
A 12AX7 may be hard to find, but if you can find the generic equal for eight bucks, it's prob'ly worth a try.

--T

atari2600a
August 27th, 2006, 03:53 PM
so...On the topic of Reel to Reel players, I have one, & it fast-forwards & rewinds, but doesn't play. (Well, if you FF or RW before trying to play, It'll spin a rev or two & slow to a stop...)

I'm not good with non-computer hardware from mid- '70's or earlier, & I don't have anything like a voltimeter at the moment, so I haven't bothered opening it, but can anyone here diagnose the problem? (I also have 3-4 antique radio's (& TV) I plan to replace all the tubes in *1337*)

(Sorry for going semi-off topic)

compu_85
August 27th, 2006, 03:54 PM
There are a lot of cheap tubes to be had. Brand doesn't matter for function, just get the same number tube.

The reason the Mullard tubes are expensive is that they're some of the best. The cheap Russian ones you can get new today aren't nearly as good for sound quyality, but they'll work just fine.

(I have a friend with several Hammond / other vintage tube audio devices. Mullard tubes are one of his favorites to load them with)

-Jason

ribbets
August 28th, 2006, 06:19 AM
try www.vacuumtubes.com/12ax7.html
gives the substitutes and the reasons why.

alexkerhead
August 28th, 2006, 09:55 AM
so...On the topic of Reel to Reel players, I have one, & it fast-forwards & rewinds, but doesn't play. (Well, if you FF or RW before trying to play, It'll spin a rev or two & slow to a stop...)


Open her up, I suspect a belt is dried up or just plain gone.
Measure the belt and buy an appropriate replacement.
Oil all moving metal joints and motors.
Use De-Oxit contact cleaner on all the switches, buttons, and knobs.
If those don't work, then you may have a bad actuator that controls the pichroller(roller may be dried up)

Those are pics of the mechanical insides of my main r2r, and then a pic of her back together.
The first is the mechanical part, with the actuators, pullies, pich rollers, etc.
THe second is the back of the mechanical part, the middle motor is a high torque play motor, the ones on the left and right are for tension and Rewinding and Fastforwarding.
This unit is a 3 head, so it plays what you record on it in real time.

alexkerhead
August 29th, 2006, 08:04 AM
Atari, did that help you any?
If not you can PM me about it.

USSEnterprise
August 29th, 2006, 09:10 AM
Got all the tubes the recorder has in it. Only cost $40 with shipping. My mom is paying, since it was her father's tape recorder. Suprisingly, all tubes were under $10. I wasn't expecting that.

atari2600a
August 29th, 2006, 04:15 PM
See, I didn't even know R2R players even had belts! Thanks alot Alexkerhead! :p

Terry Yager
January 5th, 2008, 11:12 AM
Does he have a catalog or webpage in English?

--T

Vlad
January 5th, 2008, 11:27 AM
It was Spam Terry, he pasted that in a few places and was not relevant to the discussion.

Mad-Mike
January 5th, 2008, 08:14 PM
I dunno if anyone has mentioned it, but 12AX7's are in VERY popular use right now in Guitar Amplifiers. Granted, I don't know much about tubes, but a LOT of tube guitar amps use 12AX7's in the power section. You might want to try Guitar Tube Amplifier tube outlets for replacements.

While tube radios have mostly gone the way of the dodo, there will ALWAYS be tube based guitar amplifiers, there's nothing that sounds like them, not even the emulation via amp modeling technology.