Tube amps! Why use them?

nascarmannnascarmann Posts: 1,464
edited November 2002 in 2 Channel Audio
This is something I know very little or next to nothing about. What are the pros and cons with tube amps? How do power ratings compare? Is 50wpc tube the same as 50wpc SS? It would seem to me the 50 wpc tube must punch harder? Will it? Someone jump in here and tell me about tubes? (madmax, BDT, Russmann, hoosier21 and the rest)
Oh, the bottle has been to me, my closes friend, my worse enemy!
Post edited by nascarmann on
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Comments

  • phuzphuz Posts: 2,413
    edited June 2002
    From what I understand, tube amps have a warmer, richer sound. They also look cooler. :)
  • mantismantis Posts: 15,986
    edited July 2002
    I think tubes sound more natural on most speakers, not all of them but most.Tubes always sounded warmer to me as well.Good drive with lots of reserves.Also can calm down bright speakers.
    Tubes you have to maintain, buying new tubes about once a year depending on how much you run them.They also sound better after they have been on for awhile.They need to be hot inorder to sound fantastic.
    I wouldn't buy a amp just because it was tubes or not.Sound quality with your speakers"Mating"is how you buy an amp.
    Solid state and tubes today are very good.Not as many tube amps on the market as solid state.
    They do look cool don't they!
    Dan
    My personal quest is to save to world of bad audio, one thread at a time.
  • AaronAaron Posts: 1,853
    edited July 2002
    Disclaimer: I'm far from the expert here, but I have a bit of knowledge on the subject.
    What are the pros and cons with tube amps?
    pros:
    - the "tube sound" (warmer, smoother, etc.)
    - cool factor

    cons:
    - tubes wear out
    - amp has to warm up to get optimal sound quality
    How do power ratings compare? Is 50wpc tube the same as 50wpc SS?
    No. I'm not sure that there is a magic conversion number. It's pretty rare that you'll see any tube amps above 100W, and if you do, they'll cost you a bundle. It seems like decently powerful tube amps run in the 30-50W range.

    Aaron
  • gidrahgidrah Posts: 3,036
    edited July 2002
    Yes, tubes are warmer. Then again I've never heard an acoustical live show that I would characterize as "warm".

    Tubes have are known to be able to drive difficult loads (ie. 2 ohm loads) and produce a soft-clipping. This is usually not detrimental and can be treated as "oh well, it's just not there". SS usually hard-clip. They continue to send the full force of music and wind-up blowing a speaker. Most of us will agree that most speakers are blown by inadequate amplifiers (they clip before the sound wave is completed) that have no dynamic range. My 100wt (x)rcvr blew a 175w speaker, while a 30w speaker didn't even distort. I've never heard of anybody blowing a speaker on tubes.

    I've heard people say that X watts tubes is equal to 2 or 3 watts SS. This may be attributed to the extended dynamic range.

    All speakers have a continuously changing impedence. Damn that nominable BS. Some vary more or less than others. This degree of variance can dictate the benefits of a quality amp. The greater the variance the more a tube or expensive SS amp is needed to compensate. Theoretically a speaker with a straight impedence would sound identical with any amplifier able to drive it to it's full potential (shear watttage).

    Depending on your usage, some tubes can last a number of years. But I would suggest something that can be easily replaced. Don't buy something that can only be replaced with NOS. Electro-harmonix makes some splendid replacement tubes.
    Make it Funky! :)
  • RuSsMaNRuSsMaN Posts: 17,995
    edited July 2002
    Because we all know tubes are 'cool'

    -R
    Check your lips at the door woman. Shake your hips like battleships. Yeah, all the white girls trip when I sing at Sunday service.
  • Ron-PRon-P Spaceman Spiff Posts: 8,511
    edited July 2002
    The Tubes are cool. Remember such great songs as; "She's a Beauty" and "Talk to You Later"?


    Peace Out~:D
    If...
    Ron dislikes a film = go out and buy it.
    Ron loves a film = don't even rent.
  • RuSsMaNRuSsMaN Posts: 17,995
    edited July 2002
    I have the 45rpm single for each of those, pure GREATNESS.

    Cheers,
    Russ
    Check your lips at the door woman. Shake your hips like battleships. Yeah, all the white girls trip when I sing at Sunday service.
  • hoosier21hoosier21 Posts: 4,406
    edited July 2002
    I have the LP's, I have to get a turntable, I have 5 boxes of 12" wasting away.
    Dodd - Battery Preamp
    Monarchy Audio SE100 Delux - mono power amps
    Sony DVP-NS999ES - SACD player
    ADS 1230 - Polk SDA 2B
    DIY Stereo Subwoofer towers w/(4) 12 drivers each
    Crown K1 - Subwoofer amp
    Outlaw ICBM - crossover
    Beringher BFD - sub eq

    Where is the remote? Where is the $%#$% remote!

    "I've always been mad, I know I've been mad, like the most of us have...very hard to explain why you're mad, even if you're not mad..."
  • HBombTooHBombToo Posts: 5,335
    edited July 2002
    Nascarmann, I know a little about Tubes because my first job out of school was with Litton Industries as a Power Tube Engineer. What a tough,complicated and process oriented this OLD technology is... but proven and reliable if done right.

    The reason we hear cleaner, warmer and lower noise by the tube is that a tube requires no bias voltage to amplify, "It is always ready". In a transistor we dope the wafer with either plus or minus dopants and the Bias, or voltage potential across the junction is what causes electron flow. As the sine wave crosses through 0 Volts within the bias region the semiconductor shuts off. So in an AB type amp or Push/Pull there is a brief moment in which nothing happens. "Distortion of the signal". Without getting into some really cookie stuff, in short, "HATS OFF TO OLD TECHNOLOGY".

    HOPE THIS HELPS A LITTLE:)
    ***WAREMTAE***
  • RuSsMaNRuSsMaN Posts: 17,995
    edited July 2002
    Dopants, Bias. Well, I'm totally clear on tubes now....

    Dumb it up a little HBomb, peel the onion, break it on down....

    Cheers,
    Russ
    Check your lips at the door woman. Shake your hips like battleships. Yeah, all the white girls trip when I sing at Sunday service.
  • HBombTooHBombToo Posts: 5,335
    edited July 2002
    I have some meeting I have to go to but after work I'll drink a 6pack and jump back in...
    ***WAREMTAE***
  • TroyDTroyD Posts: 12,324
    edited July 2002
    Dopants and Bias......hey weren't they drafted by the Celtics a few years ago?

    BDT
    I plan for the future. - F1Nut
  • nascarmannnascarmann Posts: 1,464
    edited July 2002
    I have some meeting I have to go to but after work I'll drink a 6pack and jump back in...

    Yeah,

    You got sum splanin to do
    Oh, the bottle has been to me, my closes friend, my worse enemy!
  • madmaxmadmax Posts: 12,438
    edited July 2002
    Tubes?

    Pros:
    You can hear many more small sounds (detail) at the same time.
    They sound better when you look at them.
    They respond well to tweaks.
    They scare off the normal Best Buy audiophile.
    They warm the heart and the hands on a cold day.

    Cons:
    You have to wait 30 to 40 minutes before they really sound good.
    They should be replaced after about 3000 hours.
    The AC comes on more often.
    You can hear the SS distortion clearly after a good listening session with tubes.

    madmax
    Vinyl, the final frontier...

    Avantgarde horns, 300b tubes, thats the kinda crap I want... :D
  • AaronAaron Posts: 1,853
    edited July 2002
    You're bringing back memories of my EE classes. No!!!

    Aaron
  • jcautjcaut Posts: 1,863
    edited July 2002
    Hey! I had a few of those EE classes myself! Aside from a dopant here and a bias there, I thought that was a pretty good explanation. Hmm.. Maybe I DO need a tube amp....

    What about a class A, or non-switching SS amp? Is the purpose to emulate a "tube" sound? Don't tube amps generally have a low damping factor, making it difficult to produce tight, hard-hitting bass? Just curious. I could probably research that and come up with my own answer, but I'm lazy and figure it's easier to just ask.


    Jason
  • HBombTooHBombToo Posts: 5,335
    edited July 2002
    Do not turn your tubes OFF!!! Why? because thermal variations may cause a leak in the glass over time...
    Power cycling a tube is good for the manufacturer but bad for the user.
    A Tube has a cathode which becomes a source for electrons due to heat. Its called a thermionic emmitter. A substance such as Barium Oxide, to list only 1, on a sheet of say Nickle becomes a great cathode. As the potential from the grid, or multiple grids, is applied, from the input signal, electrons due to the EMF move in the direction of the +Plate. "High current low noise AMPS are a result." There are differences between quatrodes and pentodes as to the grid geometry but they all fundamentally work the same. The whole deal is... A tube is always ready when HOT, NO waite time, and the more we turn the tube on/off the more stress we put in the glass. If oxigen gets in the glass the tube is HISTORY or, say, the barium oxide is no longer an emmitter.

    I just got off my hall pass in which many BEERS were consumed so please excuse my rampage.

    Hbomb
    ***WAREMTAE***
  • LiquidSoundLiquidSound Posts: 1,273
    edited July 2002
    Yumm..beer.
    Yumm..tubes.
    Two Channel Main
    Receiver - VSX-54TX
    Mains - Csi40's
    Sub - Spiked Velodyne Cht-8 On Spiked Landscaping Stones

    "If you could put speakers in a needle, I'd never see him again..." - My Girlfriend
  • LiquidSoundLiquidSound Posts: 1,273
    edited July 2002
    No idea of the sound quality, but wow.
    Two Channel Main
    Receiver - VSX-54TX
    Mains - Csi40's
    Sub - Spiked Velodyne Cht-8 On Spiked Landscaping Stones

    "If you could put speakers in a needle, I'd never see him again..." - My Girlfriend
  • nascarmannnascarmann Posts: 1,464
    edited July 2002
    HBombToo

    Your knowledge is amazing in this area. Could you try explaining this as if you were talking to..........oh lets say a 7 year old so I can keep up!

    BDN
    Oh, the bottle has been to me, my closes friend, my worse enemy!
  • HBombTooHBombToo Posts: 5,335
    edited July 2002
    LiquidSound, That is a great link! Soon, I hope that the traveling will stop and I can buy a house with my OWN man cave. My man cave will be called the Pentagon, with raised ceilings so that no 90 angles are in the room.
    I will go with TUBES as long as the POOL don't bankrupt me.
    ***WAREMTAE***
  • madmaxmadmax Posts: 12,438
    edited July 2002
    So lets say the advertised life of my tubes is 3000 hours. If I leave them on continuousely vs turning them on for 6 hours a day how long will they last? Will there be any benifit from leaving them on? Lets say the 3000 hour value is considering they will always be powered. That would be 125 days. At 6 hours per day that would be 500 days. What do you think the rating is based on, always powered or intermittant use?
    madmax
    Vinyl, the final frontier...

    Avantgarde horns, 300b tubes, thats the kinda crap I want... :D
  • LiquidSoundLiquidSound Posts: 1,273
    edited July 2002
    I say the theater has priority. The pool can wait.
    When you say 'raised ceilings' to get rid of 90 deg. corners, exactly what do you plan on modifying structurally?? Or are you building a room from scratch?
    Two Channel Main
    Receiver - VSX-54TX
    Mains - Csi40's
    Sub - Spiked Velodyne Cht-8 On Spiked Landscaping Stones

    "If you could put speakers in a needle, I'd never see him again..." - My Girlfriend
  • HBombTooHBombToo Posts: 5,335
    edited July 2002
    Nascarmann... I don't know what to say because the last thing I intended was to write a useless post. I just wanted to share my experience... I guess the best thing that I could say about Tubes are in my opinion, for a PreAmps is, TUBES are the BEST. " No Distortion". (I was a tube engineer but that was a long time ago....)

    HBomb
    ***WAREMTAE***
  • nascarmannnascarmann Posts: 1,464
    edited July 2002
    Nascarmann... I don't know what to say because the last thing I intended was to write a useless post.

    Was not saying it was useless. Just hard for my big heed and little mind to follow.....:D
    Oh, the bottle has been to me, my closes friend, my worse enemy!
  • nascarmannnascarmann Posts: 1,464
    edited July 2002
    She-at! Have I offended someone esle?:(
    Oh, the bottle has been to me, my closes friend, my worse enemy!
  • ziplinziplin Posts: 36
    edited July 2002
    Had old Audio Research D-100 Tube Amp, 100 watts Per channel. Eight tubes that glowed warmly in the dark. Sounded warm and seductive. Then came time to think about replaceing the Tubes ( about a year and a half of continueous use) Andy's vintage tube service in MN. offered new old stock tubes of a price tag of $700.00 for all. Broken hearted I realized the maintence of the Amp was much more than I could continue to keep up with.
    Sure I miss the sound, beauty, and aura of the tubes, but to tell the truth I think a lot of todays solid state electronics have improved over the years to actually give tubes a bit of a run for the money.:)
  • HBombTooHBombToo Posts: 5,335
    edited July 2002
    Nascarmann, No offense taken here bud, I just want to help when I can.

    LiquidSound
    I would hope to build the room from scratch. "I Hope". The wife likes the idea so maybe:)

    A Tubes Life
    When we rated the life of a tube it was under maximum load. The 2 mechanisms that are responsible for a tubes demise is a leak or the cathode shoots craps. If we leave them on not under load then the cathode is in a quiescent state and no loss of cathode material. As we turn the tube on and off the expansion/contraction of the glass can leed to a leak.

    In our test units for some of the real high power stuff we never shut the modulators down, just let them glow nice and pretty like, and the tubes lasted for 4 or 5 times the rated life.


    I think that ziplin makes a great point regarding Tubes vrs Semiconductors. The relatively new mosfet technologies really, really good stuff.
    ***WAREMTAE***
  • mantismantis Posts: 15,986
    edited July 2002
    this is a effin good post........I love the **** out of it.
    Yeah man thats what I'm talking about!!!!!!!!!!!!!!!!!!!!
    HBombToo,
    Kepp it coming man ............I'm sucking it all up......my man!!
    Leave that alone you sick F%%%S
    Dan
    My personal quest is to save to world of bad audio, one thread at a time.
  • nascarmannnascarmann Posts: 1,464
    edited July 2002
    The relatively new mosfet technologies really, really good stuff.


    HBombToo

    The mosfet technology is good if you are not building a high powered amp.....and bipolar is still the technology used in most high end units. Cost is the biggest factor with the mosfet against bipolar....less engineering costs with the mosfet? Mosfet amps will not drive low impendence loads like bipolar amps will at high power levels......if you intend to drive speakers such as the SDA-SRS or 1.2's a mosfet amp would not be the right choice IMO.....they do not like low impendece loads......
    Oh, the bottle has been to me, my closes friend, my worse enemy!
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