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What makes tube bass amps different?

Discussion in 'Amps and Cabs [BG]' started by MichelD, May 21, 2020.


  1. MichelD

    MichelD

    May 19, 2014
    As the above query states; why does a Fender Bassman, an Ampeg B15, V4B or SVT, vintage Vox or Marshall bass tube amp sound different than the others?
     
  2. basscooker

    basscooker Commercial User

    Apr 11, 2010
    cincy ky
    Owner, ChopShopAmps
    It depends.
    If the question REALLY is "can I use a guitar amp for bass" then the answer is subjective.

    By design, there could be huge differences, depending on model and manufacturer. In general, a more robust power supply and different eq centers are two things that should be different. Power output is often higher on bass amps. Guitar doesn't need tons of power to seem really loud.
     
    Justinian likes this.
  3. MichelD

    MichelD

    May 19, 2014
    No, this quesiton is not about guitar amps or using bass amps for guitar or anything else. I'm curious what makes them tick.

    Full disclosure; I have an Ampeg V4B and a Roland Cube 60, plus oddly enough my main practice amp because it is right here in my office where I can play along with Youtube "no-bass" jam tracks, a Samick BA15 I found in an alley missing a power cable. I actually have another dumpster amp a friend rescued for me, it is a no-name solid state mini bass amp (proably 10 or 15 watts) with no on/off switch any more. It comes on when you plug it in.
     
    Slough Feg Bass likes this.
  4. Wasnex

    Wasnex

    Dec 25, 2011

    Designer intent. It's done on purpose for aesthetic reasons.
     
  5. D.M.N.

    D.M.N. (O)))) Supporting Member

    Oct 6, 2008
    Los Angeles, CA
    Pre-amp design, component values, power amp design, transformers. What makes a Bassman different from and SVT? The circuit design, in total. And that goes for any amp, tube or SS.
     
    dkelley likes this.
  6. JimmyM

    JimmyM Supporting Member

    Apr 11, 2005
    Apopka, FL
    Endorsing: Ampeg Amps, EMG Pickups
    There's just a beautiful thing that happens when you have an amp that's well designed and full of tubes vs an amp that's well designed and not full of tubes. I call it a 3d sound for lack of a better term.
     
  7. rickdog

    rickdog Gold Supporting Member

    Mar 27, 2010
    I have an intuition that there are a lot of different ways for tube circuits to be "imperfect" (in the sense of not perfectly reproducing a signal without distortion) that can change the sound in ways that we perceive as pleasing and musical. These various subtle characteristics give an amp designer greater creative freedom than I think is possible in solid-state circuits.

    Do you bias tubes (preamp or power amp) in a more linear part of their operating characteristics, or allow more distortion? Which of many phase-inverter circuits? What about negative feedback in the power amp? Plate voltages? Screen voltages (wasn't there a recent thread about this)? I've read that power supply capacitors can make a big difference in the sound (think sag), and that too stiff a power supply can take the life out of a tube amp's sound.

    I've dabbled a little in tube circuits, but hardly consider myself an expert... maybe some of the people here with more experience can suggest some of the other factors.
     
    LostJohnny, Bboopbennie and JimmyM like this.
  8. equalizin

    equalizin

    May 6, 2020
    A good tube amp just feels more organic. Its hard to describe. Play hard or soft and it comes through so good. It's something solid state is catching up to every year but IMO not quite there yet. But this really only happens at high volumes when you get the power tubes going with the natural compression. At lower volumes solid state/tubes dont matter much since you are mostly getting preamp tone. Solid states might have the edge at these volumes because the good ones can simulate the tube tone at lower volume. When I played guitar for many years I had orange, marshall, vox tube amps and nothing solid state comes close to the natural overdrive/gain of a tube amp. I stress the importance of having a tube amp cranked to get the goodness out of it. My favorite tone I've ever had recording/live was a mic'd 15 watt tiny terror with the volume dimed. One thing I've always found interested is how a lot of wattage claims are on tube amps. I've always been told they are rated at the clean wattage before break up. This expalins why some are so loud. My AC30 is "30" watts but at the shop was rated 45 watts and is insanely loud.
     
    Last edited: May 21, 2020
    Arthur U. Poon and JimmyM like this.
  9. better harmonics
     
    Mili, Scott Shaw, AstroSonic and 5 others like this.
  10. Jim C

    Jim C Is that what you meant to play or is this jazz? Supporting Member

    Nov 29, 2008
    Bethesda, MD
    The amps listed sound different because they are different in design and materials.
    Tube amps sound different because of the magic glass and fairy dust.
    Once we get that definition of "better" sorted out; well that will never happen so it pretty much a personal decision IMO.
     
    AGCurry, bassdude51, 2tonic and 2 others like this.
  11. Killing Floor

    Killing Floor Supporting Member

    Feb 7, 2020
    Austin, TX
    The tubes
     
  12. lowphatbass

    lowphatbass **** Supporting Member

    Feb 25, 2005
    west coast
    Tube amps are usually heavier.
     
  13. Wasnex

    Wasnex

    Dec 25, 2011
    The most obvious difference in the sound of different amps IMHO is how they are voiced. This comes down to the baked in EQ curve the designer chose. In my experience tube amps tend to have stronger baked in voicings, and their tone control circuits are often more limited and less powerful than many solid state or hybrid amps.

    Another important factor is how amps transition from clean to compression to distortion. This is a really key factor for most players who really consider themselves tube snobs.

    Unfortunately a lot of people can't really seem to put their finger on what they love about tube amps so they speak in essentially meaningless hyperbole the suggests all tubes amps are pretty much the same and equally awesome. In my experience tonal character and feel of tube amps can vary drastically from one model to the next. Hiwatts and Ampeg SVTs are both awesome amps, but they sound and feel drastically different. Also I have amps in my collection that sound pretty similar clean, but the way they transition into overdrive is drastically different. Despite what some people say, not every tube amp sounds great pushed into distortion.
     
    BassikBrad, D.M.N., AGCurry and 7 others like this.
  14. fourstringburn

    fourstringburn Supporting Member

    Jun 30, 2009
    New Mexico
    Well said!
     
    Novarocker, Loring and BOOG like this.
  15. Honkey tonk

    Honkey tonk Turn it up Supporting Member

    Feb 10, 2019
    Lower 48
    Tubes amps by looks, sound and dependability are rock and roll
     
    BassikBrad likes this.
  16. rufus.K

    rufus.K

    Oct 18, 2015
    SoCal
    20200521_142345.jpg
    I havent a clue.
     
    Mili, turcmic, Ace Of Bass and 2 others like this.
  17. Jim Carr

    Jim Carr Dr. Jim Gold Supporting Member

    Jan 21, 2006
    Denton, TX or Kailua, HI
    fEARful Kool-Aid dispensing liberal academic card-carrying union member Musicians Local 72-147
    Intentionally, the tube amps the on the OP's list, l presume, are vintage tube amps and mostly classics—though Vox was never widely regarded as a great bass tube amp maker, and except for the 200 watt Major (I had one) and the super bass—both quite rare—Marshall falls more or less in the same category.

    That leaves one fender and 3 ampegs. The blackface bassman—stand up if you ever gigged one (I did many times)—has its detractors. Remain standing if you enjoyed the experience. I am not standing. The 100 and 300 watt ampegs are useful, but I digress.

    I guess I am stuck trying to understand what the OP wants to know that TB can provide. If you are not an engineer or do not have a high level understanding of electronics, audio, and psychoacoustics, then I think one's best bet is to just go listen. Otherwise, the rest (opinions on tube amps) is noise, IMHO.

    A quick read of audio and tube amp articles from Wikipedia would be more factually useful than what likely will surface here, IMHO. I mean no disrespect, especially to the many engineers on the forum. I just think this outrageously broad, but very loaded question has no meaningful answer that can be formed into a TB post.
     
    Last edited: May 22, 2020
  18. Thumpin6string

    Thumpin6string Supporting Member

    Apr 25, 2013
    Redding CA
    The biggest reason that a tube amp sounds different from other amps is because....... wait for it .......................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................... it has tubes.
     
  19. mntngrown

    mntngrown Supporting Member

    Aug 18, 2007
    The lost Sierra
    True and appreciated and you only need to look at big concert venues and see the rigs. The best phat sound SVT and Bassman . Does the average concert or club patron care? YMMV
     
    Flabass likes this.
  20. JimmyM

    JimmyM Supporting Member

    Apr 11, 2005
    Apopka, FL
    Endorsing: Ampeg Amps, EMG Pickups
    That's how I look at it. Do I care if the average concert or club patron can tell the difference between an SVT and a cheap micro? Absolutely not. Gauging what you do by the lowest common denominator is a one way ticket to Palookaville. I'll definitely use a cheap micro at times :D but it's still very well chosen cheap!
     

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