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Tube watts

Discussion in 'Amps and Cabs [BG]' started by dalek, Oct 16, 2009.

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  1. dalek


    Apr 20, 2009
    You know what they say about tube watts being twice louder than solid state watts. I've noticed this in guitar amps, I tested a 45w tube amp against a 100w solid state and the tube amp seemed even louder (I know we don't perceive 100w not even nearly twice as loud as 50w) Both were quality amps.

    I assume this also happens when comparing tube bass amps to solid state ones. Am I right?
  2. anonymous02282011

    anonymous02282011 Guest

    Jun 27, 2007
  3. seamonkey


    Aug 6, 2004
    Perceived loudness is like perceived speed.
    You may perceive you're going faster in one car travling 30mph than another - but they're both going 30 mph.

    Tube usually add distortion - in the midrange where our ears are more sensitive, the midrang can actually be louder. A SS amp being clean, isn't going to add midrange distortion. Unless you turn up the midrange, or plug in a little distortion box to generate midrange distortion. This trick goes way back to all the legends of the 60's 70's using fuzz boxes to even increase distortion for tube amps.
  4. Rickett Customs

    Rickett Customs

    Jul 30, 2007
    Southern Maryland
    Luthier: Rickett Customs...........www.rickettcustomguitars.com
    The comparison of tube and SS watts are the same....watt for watt. From what i've read, an "all tube" amp possesses overtones (harmonics), that a solid state amp does not produce, due to no tubes in the power section. These overtones (harmonics), make an all tube amp seem louder, with less or equal power.
  5. unclejane

    unclejane Guest

    Jul 23, 2008
    I don't see how (this can be right). Power is just a function of voltage * current with both AC and DC so it is what it is.

    I'm more inclined to think it's not the power involved but the distortion of the waveform of the AC that gets fed into the speaker. If it favors a band of frequencies that the speaker is good at transducing, it's going to sound "louder".

    It's never really clear how accurate the power ratings of individual amps are or what they really represent. I.e. is it peak power capability? RMS? Average? or ?
    So who really knows what you're comparing.....

    I used to have to gig with those terrible junky tube amps (had to play through a Bassman for a while, holy smokes talk about terrible) and my arms are still sore from my efforts to be heard. Amazing these garbagy things are now worth thousands of bucks as collector's items and that folks still try to actually gig with them. Eeeeyikes....

    The clean and clear headroom of modern SS amps is heaven by comparison, cheaper, lighter, more reliable, everything. No more having to carry a can of tuner cleaner with you to clean the corrosion off the socket pins, wiggling the tubes to get the thing working again in the middle of a gig, the full power crackling and rasping when you do the wiggling, again in the middle of a gig.......
    Bleach: Just Say No to Tube Amps!

    Don't care what the power ratings are ;)

  6. unclejane

    unclejane Guest

    Jul 23, 2008
    One big difference is how tubes behave as they approach being overdriven. They become non-linear earlier (i.e. at lower input currents) and the plate current "maxes out" more gradually. Transistors (especially bipolar transistors), OTOH, remain linear or nearly so until max collector current is reached, then they abruptly stop responding to the input signal - they just conduct at max and that's it.

    So, the waveform of a clipping tube amp on an oscilloscope will look more like an inverted "U" with a mildly flattened top, but a clipping transistor amp will look more like a square wave - very sharp edges at max collector current.

    So the harmonic content of the distorted signal is actually richer with the transistor amp, but contains a lot more high frequency harmonics. That gives them that characteristic raspy "brraap!" when they go into clipping. Tubes, tho tend to have that muddier distortion when they clip because of the reduced high frequency harmonic content. This gives them the more chocolately sound when overdriven.

    Another difference is tube amps normally have to use an output transformer for impedance matching purposes - those big coils of wire aren't exactly wideband devices and in fact actually act like chokes. so you get a lot of filtering at the output from the transformer too that you can avoid with a SS amp that uses bipolar output transistors.

    Finally, tubes are just less linear devices in general than the typical transistor, so they always have a kind of coloring to their amplification all the time.

  7. Here we go again :scowl: I know we should have a sticky about this :rollno: Maybe a search function so stuff like this won't show up all the time? :eyebrow:
  8. EricF

    EricF Habitual User

    Sep 26, 2005
    Pasadena, CA
    Tubes pushed into distortion sound good. SS amps pushed to distortion sound like crap. If you're measuring wattage at (for example) 1%THD, you might get the same volume from each amp. However, a tube amp can be pushed much higher than 1%THD and still sound great.
  9. johnk_10

    johnk_10 vintage bass nut Supporting Member Commercial User

    Feb 16, 2008
    Thousand Oaks, CA
    John K Custom Basses
    all i can get out of your post is that its unfortunate that you decided to use an underpowered tube amp that was in need of a complete service to base your opinion of them.
  10. It comes down to compression. Tubes tend to softly compress initial transient peaks whereas solid state stuff will just plain clip. Since that hard-clipping sounds bad, you need a 1000 solid state Watt amp to handle that very short peak, even though your average power out may be nearer to 50 Watts. A 100 Watt tube amp will compress that 800 Watt peak down to 100+ watts or so of softly distorted goodness, and then handles the 50 Watts average stuff no problem. So people end up thinking the 100 Watt tube amp was just as loud as the 1000 watt solid state amp. I'm just picking numbers out of my butt, but hopefully you get my gyst.

    Plus tube amps just sound better. :D

  11. lomo

    lomo passionate hack Supporting Member

    Apr 15, 2006

    Sir, it has all, as John Lennon said, been done. Simply bypass threads that don't interest you. Problem solved. have a nice day.
  12. unclejane

    unclejane Guest

    Jul 23, 2008
    Well, no. These problems afflict all tube amps as those of us who had to gig with them know very well. These are just routine maintenance requirements of any tube amp not an exceptional "complete service" circumstance.

    The only difference today is the poor victims are going to pay thousands for them rather than hundreds. We only had to pay maybe 100 or 200 back in the day, but the misery of gigging with them and keeping them going is still the same.

    You'll see what I mean if you get one and use it for a while (be sure and stock up on tubes and tuner cleaner).

    We're truly in the Good Old Days of basses and amps now rather than 25 or more years ago, and it continues to get better and better. We have so much wider of a selection of far better basses, amps, electronics than we ever did back in the tube days. If you really need a tube sound you can get it without having to actually use tubes, DSP is getting better all the time.

    It absolutely boggles the mind that, for example, Markbass can come out with an all tube amp for $2500 and anyone would ever take it seriously.......

  13. johnk_10

    johnk_10 vintage bass nut Supporting Member Commercial User

    Feb 16, 2008
    Thousand Oaks, CA
    John K Custom Basses
    I've been gigging with tube bass amps since 1967 and I still am. is that long enough for you? I haven't experienced any more problems with my tube amps than with new or old SS ones.

    yes, there's a 'larger' selection, but in my opinion, definitely not 'better'. for me, my original '62 P bass (my avatar pic) thru a vintage '69 SVT has yet to be beat, especially with DSP modeling. for me, close is still okay for playing horeshoes, and using dynamite, but not for playing bass.
  14. anonymous02282011

    anonymous02282011 Guest

    Jun 27, 2007
    Glad you found what you like.

    Personally, I've been working with a 45 year old tube bass amp and a 40 year old bass guitar for the last 14 years with great enjoyment. I haven't purchased a new tube or any cleaner or anything in the last 10 years. I got the amps back from my tech last week who tested everything and the amp was still strong.

    To each his own. Whatever makes you happy you know?

    The fact that tube watts sound louder than solid state has been asked and answered all over this forum. A quick search will turn up some technical answers, some of which have been presented in this thread.

    Aside from the technical details, why bother coming on here and putting your dislikes on display? If you feel the need to take a ****, use a toilet.
  15. Jefenator

    Jefenator Supporting Member

    Aug 22, 2008
    The term "tube watts" might be misleading, since apparently a watt is a watt, regardless of what type of amp producing it.

    A watt may be a watt but IME a rating is not a rating! ;)

    That is to say, most stated power ratings do not tell the whole story of how the amp will perform on the gig. Some models are notoriously over-rated for power, some manufacturers are known for being very conservative with their spec's. (Thus 300 "Mesa watts" might blow away something rated at 500 by somebody else.)

    And of course the tube thing. FWIW IME/O my 180 watt Mesa tube head fills the room and punches it out way better than my 600 watt solid state power amp.
  16. scotch

    scotch It's not rocket science! Supporting Member

    Nov 12, 2006
    Albany, NY USA
    Please see Profile for Endorsement disclosures
    You're just trolling, right?
  17. i hope he is the problem hes describing sound more like the kind've problems you encounter with cheapo SS amps.
  18. Schecter4


    Oct 20, 2007
    The Dalles, OR
    Perhaps, solid state and tube watts are equal, and we should really be considering solid state vs tube logarithms. :)
  19. unclejane

    unclejane Guest

    Jul 23, 2008
    Heh. I was never more happy when I finally got my first SS amp even tho it was a Sunn. It was heaven compared to the Bassman and Kustoms I was borrowing. They actually worked for the entire gig without cutting out on me.....

    Yeah I wouldn't want to go to great lengths to emulate that sound either..... Just joking! ;)

  20. Greyvagabond

    Greyvagabond Supporting Member

    Aug 17, 2007
    Los Angeles
    Tube amps are louder than SS amps of equal to twice the rated wattage. That doesn't mean they put out more "watts" though; they're just louder. Which, after all, is what we're after, isn't it?

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