Old tube amp question.

Killerdoom14

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Hey, I have a Tub Amp lying around I would love to use in a Dac/Amp set up with my headphones from a PC.

My question is this, how long is it safe to use a tube amp before you run the risk of damaging it? I know when not in use it should be turned off to preserve the life of the tubes, but if I am listening to this amp for 12+ hours a day 365 days a year, will it damage just from that?

if your wondering the amp, it is a old Luxman 103.
http://www.hifiengine.com/manual_library/luxman/lv-103.shtml

I am still wondering which Dac/Amp to get, so if this is a bad idea to use it constantly I will be switching from this to a SS amp, or maybe a 2-1 combo. Something that doesn't involve tubes even though they sound so good.

Thanks!
 
Solution
no, a tube has two "parts". first part is the heater (filament) which is USUALLY either 6V-based or 12V-based, and it doesn't change between "flavours" in a family of tubes. for example, all 12A_7 tubes are 12V heaters. the "gain" of the tube would change, but it'll just change how it behaves and not cause anything to blow up.

figure out what tube you do have, and then you can find a list of "pin-compatible" alternatives. usually only 1 or 2 digits of the part number will change, but the main part (ECC8_, or 12A_7, or 6__) stays constant.

RunLuke

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I don't think it would cause any problems, you should be able to have it running 24/7 - but find a dedicated tube amp-forum and ask there to make sure that your specific model is well enough designed for it not to be an issue.

Also, I bought a used Pro-Ject Audio DAC and I'm very pleased with it, the treble is a bit off compared to the one coming out of my cd-player (yeah yeah, I still listen to CDs), but that may be because of the spotify quality (I used it in connection with a homebuilt Airplay / wireless streaming thing I've built with a raspberry pi) but both my amp, CD-player and speakers are very unforgiving, so that might make it a lot worse.
 
The Luxman is a hybrid integrated amplifier which means that it does have a tube preamp stage but the rest of it is solid state. You should have no problems using it for many hours. You will run through the life of the tubes faster than usual but they are available. If you don't know the how many hours the tubes have already you might want to get a set to put aside if you need them. There is degradation of sound as the tubes age.
If it had a tube power amp then you might have issues with heat and tube life on the much more expensive output tubes.
 

Killerdoom14

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Cool, do you know what websites have specific tube forums? I am not sure where to start. Should I get a transparent Dac or one with a bit of colour? You make it sound like yours changes the sound a bit, is that prefered by you?

 

Killerdoom14

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The amp does have a standby mode aswell, so a preamp is less demanding then a power amp? Nifty! Thanks for the input. Glad I dont have to spend another 200 on a amp :D

 

Killerdoom14

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May I ask how to know which tubes they are? Im stumped on the type and model, I have a online downloaded service manual but Im not sure what part it says the kind.

 

giantbucket

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the most common types are 12AX7, 12AT7, 12AU7, 12AV7, and 6DJ8. they could also be called ECC82, ECC83, or similar (those are Euro equivalents to the American 12A_7 types)

typical symbol is like this (or any variant that resembles it)

03006.png



i've bought tubes (for guitar amps) from TubeDepot.com and TheTubeStore.com and they should have the right type, and usually can grade them as well. sometimes you can find an equivalent that has the same pinout and main specs, but can be higher or lower power, which might let you alter the "character" a bit - sometimes nicer, sometimes not.
 

Killerdoom14

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Thank you for the help :) Do I have to worry about putting in a different tube? Will it explode or something if the power is higher or lower?

 

giantbucket

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no, a tube has two "parts". first part is the heater (filament) which is USUALLY either 6V-based or 12V-based, and it doesn't change between "flavours" in a family of tubes. for example, all 12A_7 tubes are 12V heaters. the "gain" of the tube would change, but it'll just change how it behaves and not cause anything to blow up.

figure out what tube you do have, and then you can find a list of "pin-compatible" alternatives. usually only 1 or 2 digits of the part number will change, but the main part (ECC8_, or 12A_7, or 6__) stays constant.
 
Solution