Can you blow a tube amp? (not literally:-)

[kenratboy]

I am interested in a tube amp, however I have ANOTHER question. How or can you blow a tube amp. Let me be simple. I am listening to some music really loud, and the volume us turned up all the way. What CAN happen to the tubes/amp? Does excessive amplification kill them, or is it the resulting heat, or something else? Do tubes need to warm up before listening? I have heard people wait half an hour to listen to a tube amp, but they were snobs with $150,000 tube amps, how about the sub $1000 stuff? Any other words of wisdom?

THANKS!

[Thoriated_Tiger]

I've yet to blow up tube gear. Even with the volume past 11.

Belive it or not, tube gear is VERY tough. Ask any guitar player worth his salt. They treat their gear like crap. And any guiter player worth his salt relies on tubes for tone.

That's more than I can say about crap mid-fi gear form the 80's..killed a couple of Carvers and a couple of Technics. Boom. Dead. Smoke got out, no workie no more.

My amp is 50 years old or so, has had one upgrade, and will strip paint off walls

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Klipsch SF2

Thorens TD145 / AT440ML turntable

Dynaco Stereo 70 power

Sansui CA-2000 pre

Pioneer RT707 tapedeck

Pioneer 4100 cd player

[Al Klappenberger]

Kenratboy,

I wouldn't worry about running a tube amp hard. A vacuum tube goes bad in time all by itself, mainly from its own heat. To extend its life just keep it well ventilated. Heat is the enemy! Running it hard will casue more heat, but any good amp is designed to handle that! Enjoy!

Al K.

[kenratboy]

What do I need to know about tubes? How important is the quality? How much do decent tubes cost? I read that South East Asian tubes are trash and only to be used if they are the only ones available, and that Russian and ex-Soviet Bloc tubes are the best. You also get what you pay for, and old tubes are just as good as new ones? HOW LONG DO TUBES LAST? Thanks, I may have a date with eBay..

[mike stehr]

Ken,

I eventually want to go the Tube route too.

I'm as curious as everone else, MH is pretty good at pumpin' everybody up, Hell, It seems like he has listened to everything under the sun, he gives good sensible advice with a good sense of humor.

Like Tom mentioned, Horns will do fine with Solid State or Tubes.

If your really interested in thermionic devices, hit them Keywords and search engines.

Tons and Tons of information on the net. The Internet is one big reason why Tubes have picked up in popularity, some good reasons, some bad for vintage hunters.

Hit the AA board Archives, there is Tons and Tons of information there as well.

Read up about them, understand the various tube designs and the amplifier designs.

Take your time, I've been interested in Tube amps for two years, Mobile Homeless isn't the only one that has sparked my interest, It's been from reading audio forums and sites for all this time.

I'm still trying to figure this all out.

Take your time.

In the end, you will be happy.

THANX!

[Klipschguy]

Kenrat,

Due to the shorting of a filter capacitor (effectivly shorting the power supply) I literally blew-up a rectifier tube - it glowed red hot and then the glass shattered - not pretty. A glowing rectifier tube is often indicative of a shorted filter capacitor. BTW, a "hum" in an amp is often a leaky filter capacitor in the power supply - easy fix. Anyway the moral of the story is: if you see your rectifier tube glowing red hot, unplug the amp!

The previous mentioned tragedy usually occurs when firing up an old amp that hasn't been used in years. Regular use of your amp keeps the the caps formed and healthy. When firing up an old amp it's not a bad idea to use a Varivac and bring the voltage up slowly to reform the caps gently.

Warm Regards,

Andy

[lynnm]

Quote:

"What do I need to know about tubes? How important is the quality? How much do decent tubes cost? I read that South East Asian tubes are trash and only to be used if they are the only ones available, and that Russian and ex-Soviet Bloc tubes are the best. You also get what you pay for, and old tubes are just as good as new ones? HOW LONG DO TUBES LAST? Thanks, I may have a date with eBay."

1.) How much do decent tubes cost?

This depends on the make/model of the tube. FWIW I recently purchased a matched quad of EL 34's on Ebay for $21.50

2.)I read that South East Asian tubes are trash and only to be used if they are the only ones available, and that Russian and ex-Soviet Bloc tubes are the best.

That is an over generalisation. Some of the best tubes ever made are being produced in the Far East and are more musical than some of the Sovtechs,(which are decent sounding tubes in general),for example. The fact is that good sounding tubes are being produced all around the world.

3.)You also get what you pay for, and old tubes are just as good as new ones?

NOS are often superior to their modern counterparts.

4.)HOW LONG DO TUBES LAST?

This depends on a number of factors,(circuit design,amplifier condition etc.). My information suggests that out put tubes should be good for 2000 or more hours if treated properly. When I ran a second hand store I had a radio that I bought that was well in excess of 45 years old that had been used extensively and still used all of its original tubes and was still working beautifully when I sold it.

5.)Thanks, I may have a date with eBay."

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It is meet to recall that the Great Green Heron rarely flies upside down in the moonlight - (Foo Ling ca.1900)

[djk]

Easy ways to ruin your tube amp: A)play a PP amp for long periods of time with an output tube gone (bad).As long as you don't turn it up all the way it won't sound too bad, its running single ended.The output transformer will overheat and develop a short.B)run your amp without speakers, turn the volume up when you can't hear anything.The output transformer will arc from the high voltage fly-back and develop a short.