[DarkAngel]

With all the info available on tubes trying to find answers to simple questions is very difficult, please help me with:

1)Do you wear gloves when changing tubes?

2)Do you turn power off for extended period before changing tubes, if so how long?

3)What is lifespan for small 12ax7 tube in low powered CDP, preamp, headphone amp if left on 24/7?
Do you turn off at night or leave power on 24/7?

 

[mrarroyo]

1. No
2. Yes, 5 minutes.
3. Thousands of hours. I turn my amps off when un-attended, regardless (SS or Tube).

 

[nc8000]

1. No, but I use a polishing cloth when handling the tubes.
2. About 15 minutes
3. I turn things on 15-20 minutes before listening and turn it of when finished. Goes for all equipment not just tubes. My "new" A2900 tubes are rated for 5-7000 burn hours.

 

[diego]

1- I wash my hands before handling my tubes but I don't take any additional measures.
2- Yes, until they are cool.
3- I turn it on at least 5 minutes before I start listening and turn it off when I'm finished. This also protects you from damaging your hearing if something goes wrong with the tubes at start up.

Regards,
Diego

 

[warubozu]

1. No, I too wash my hands prior to touching my tubes to make sure they aren't dirty.

2. I turn the amp off for about 15 to 20 minutes to let the tube cool.

3. I turn all my amps off when I won't be using them for a extended period of time. I turn them on an let them warm up for about 15 minutes.

 

[nikongod]

there are a few crap worthless tube amp hybrids that require many hours of "discharge" time, otherwise you are OK swapping tubes when they are cool to the touch.

a good designer will design the amp so that by the time the tubes are cool it is safe to swap them.

 

[ironbut]

1. No, I don't really do anything special unless there's a bunch of crap on my fingers, I just lick it off ( just kidding, but I have been known to wiping on my pants). I don't really care that much about the print on tubes but some people do and use linen gloves.
2.At least 10 minutes ( I did cook about 50 components in a preamp by not waiting long enough before turn on!)
3. For most small 9 pin triodes, the general figure given is 3000 hours give or take a 1000 ( it's all about how hard a vacuum is and can be maintained). Some higher quality variants are 10k hours (7308, 6h30dr,e80f etc.).

 

[donor]

When you turn the amp on 15 minutes prior to listening, do you just turn it on?
Or do you need to play music through it to "warm up"?

This has been bothering me.

 

[recstar24]

Quote:

Originally Posted by donor /img/forum/go_quote.gif When you turn the amp on 15 minutes prior to listening, do you just turn it on? Or do you need to play music through it to "warm up"? This has been bothering me.

Just turn it on, no need to run music. Make sure you keep a load plugged in though, just to be on the safe side.

 

[DarkAngel]

Regarding tube life, does everyone feel it is best to turn off tube CDP/Preamp/Headphone amp at night when you are done and turn on next morning when ready for music vs leaving on 24/7.......

I had heard that turn on/off is one of main factors to shorten tube life, and in applications where tube is not driven hard like CDP or preamp will tubes last longer just leaving power on with no music playing?

I am sure a large power amp with tube output would be best turned off but what about low power applications like CDP, Preamp?

 

[ironbut]

As far as warming up the tubes, this should be done without music, you're getting all the elements working correctly by warming them up so it will increase tube life. For the tubes to "sound their best, I warm it up for 30 min. and then it takes about 15-20 with music before they sound really good. It's usually the bass that seems a little loose, the soundstage tiny, and the imaging all over the place. It seems like the degree of gain becomes stable after complete warm up. The first time I fire up an NOS tube or large output, I give it 2-4 hours warm up without music. If it seems noisey on first listen, I give it more time.
As far as the turn on/off vs. on 24/7 I always turn my gear off for the night. If I'm home all day, after the first listen, I don't turn it off until I leave or go to bed. And if I just going to gone for an hour or so, I leave it on. I do this to avoid having to redo the whole warm up thing.
BTW have you guys read the tube facts sticky above. It's really excellent!