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Tube vs non-tube

Discussion in 'Amps and Cabs [BG]' started by tom dicus, Jul 16, 2017 at 11:03 AM.


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  1. tom dicus

    tom dicus

    May 17, 2017
    i suck at bass but will never give up
    I have an Ampeg SVT7Pro running a Peavey 410TX and a Fender neo 410.

    I would like to get an all tube amp.

    Am I correct in understanding a tube amp has a much different power spectrum than the solid state?

    For example, the 300 watts from a Fender Super Bassman sounds more powerful than the 1000 watts from my SVT7PRO.

    Please advise.

    Thanks
     
  2. socialleper

    socialleper Supporting Member

    May 31, 2009
    Canyon Country, CA
    That is my understanding as well. I don't think there is a predictable ratio, and it also depends on how clean you like your tone.
    The other issue is that while we use "watts" for heads, it isn't a very useful or exact measure.
     
  3. tom dicus

    tom dicus

    May 17, 2017
    i suck at bass but will never give up
    Thanks for the quick reply.
    Would a 300 watt tube amp be able to push two 410 cabs?
     
  4. jazzbass_5

    jazzbass_5

    Sep 1, 2007
    NY, Albion
    Would a 300 watt tube amp be able to push two 410 cabs?[/QUOTE]

    Yes
    svt-vr-svt810-av.
     
  5. socialleper

    socialleper Supporting Member

    May 31, 2009
    Canyon Country, CA
    That is sort of a tough question as what is "loud enough" is relative. Will it make noise? Of course. The infamous class SVT is 300w and is generally considered to be super loud. A lot of people like pushing those into distortion territory, which makes them "louder." It isn't as loud if you want a purely clean signal.
    I could be wrong, but I think 300w is one of the higher ratings for tube bass amps. I think the types of tubes in the power and pre amp sections changes how "loud" that 300w is, but that is a little outside my knowledge base.
     
    monsterthompson likes this.
  6. two fingers

    two fingers Opinionated blowhard. But not mad about it. Gold Supporting Member

    Feb 7, 2005
    Eastern NC USA
    That SuperBassman will be plenty loud. We can debate the finer points....and the reasons why it will be loud enough.... until we are all blue in the face. But that's the short version.
     
  7. ljazz

    ljazz

    Dec 10, 2002
    Cookeville, TN
    My 150 watt Shaw Audio tube head drives my Heritage 810 beautifully!
     
    lowplaces likes this.
  8. monsterthompson

    monsterthompson The Eighth Note Wonder Of The World Supporting Member

    Nov 25, 2008
    Hollywood
    A watt is a watt. Yet mysteriously 100w tube amps are "louder" than many 100w class D amps. There has never been a satisfying, argument settling post as to how/why the ratings and topologies relate, though there have been some good ones. One of the bass magazines did an analysis on the ratings (someone please help me with a link, if you recall it).

    Also, keep in mind that doubling of wattage (all else equal) changes the output by 3 dB. So, going from 500w to 1,000w shouldn't theoretically be *significantly* louder.

    I think the 300w amp in question will certainly be loud by most users' standards. It should be able to push two 410 cabinets, assuming the impedance is within the amp's range. Two 4 ohm cabs (2 ohm load) will not work with a head with a 4 ohm minimum. It looks like the Bassman 300 supports 2 ohm operation.

    Edit - Not the article I was thinking of (I believe it was Bass Gear Mag) but I did unearth this, which might help add some/a perspective.
    Beef. It’s Watt’s for Dinner | Premier Guitar
     
    Last edited: Jul 16, 2017 at 10:36 PM
  9. Ampslut

    Ampslut

    May 15, 2017
    A 300 watt tube head and a 300 watt SS head are different in a big way. A 300 watt SS head sounds fine until it tries to produce 301 watts. Then it gets real ugly real fast. When you push a SS amp into distortion it jumps directly into square wave and produces a farting sound. Not very musical. When you push a 300 watt tube head past it's distortion break it produces what it called "soft clipping" and can produce (I'm guessing) another 6db of distorted but still musical sound. That is where the 300w tube = 1000 w SS probably comes from.
     
  10. seamonkey

    seamonkey

    Aug 6, 2004
    False. Name one or a brand that does this?
    SS amps are everywhere and every second of every day a SS amp somewhere is pushed past it's rating. And nobody is running off to to the hills. The harmonics of a class-ab amp driven into distortion has nothing to do with the output devices.
     
    Aqualung60, lomo and monsterthompson like this.
  11. JimmyM

    JimmyM Supporting Member

    Apr 11, 2005
    Apopka, FL
    Endorsing: Ampeg Amps, EMG Pickups
    Markbass LMII/III did it. I don't know about their other amps.

    But Seamonkey is right that most don't anymore. Some of them sound downright pleasing when you crank them. And then there's also pushing the preamp hard to get distortion at more manageable levels. I can't speak for all SS amps, but I've got several Ampeg SS amps that sound great doing it.
     
    RaggaDruida likes this.
  12. NEXUS TUBE

    BTA 400 - Ashdown Engineering

    Hadda do it!:roflmao:

    I think Marshall also makes a 400-watt all-tube monster. These are scary!
     
  13. Coolhandjjl

    Coolhandjjl Supporting Member

    Oct 13, 2010
    Appleton
    Just keep it simple. Get an SVT. It can push two 810s if needed!
     
    J-Bassomatic likes this.
  14. interp

    interp Supporting Member

    Apr 14, 2005
    Garmisch, Germany
    "...but still musical sound..." Unless you can provide an objective definition of 'musical' this phrase is meaningless.
     
  15. Ewo

    Ewo a/k/a Steve Cooper Supporting Member

    Apr 2, 2008
    Huntington WV
    Whelp, I figure that in context the thought was clear enough, even if the 300 W/301 W threshold is an exaggeration.

    Push a solid stage amp into progressively more distortion, and most people don't like the way it breaks up. Push a tube amp into distortion, and many people enjoy how it colors the tone--even when it's producing a good amount of distortion. That's a broad-brush generalization of the difference.

    My experience is consistent with @JimmyM 's comment. A lot of the modern SS amps have some kind of limiter built into the power amp to prevent them from clipping much. And some have design tricks such that overdriving the pre actually can sound good in a gritty way. I believe that's the case with my Mesa D-800. And a lot of people do like the sound of a GK RB series "hitting the rails."
     
    JimmyM likes this.
  16. DigitalMan

    DigitalMan Owner of seven basses - eligible for 44 TB Clubs Supporting Member

    Nov 30, 2011
    Unless people are allowed to use subjectivity when presenting their opinions, all forum threads would be meaningless.
     
    GregC and Loring like this.
  17. JimmyM

    JimmyM Supporting Member

    Apr 11, 2005
    Apopka, FL
    Endorsing: Ampeg Amps, EMG Pickups
    For purposes of a discussion, subjectivity is fine. But even subjectivity has to be defined when it comes to building gear, otherwise we can't duplicate it.

    Here's an example...I remember reading a long time ago how when Seymour Duncan was just starting his pickup rewinding business, a client came in and requested that Seymour make his pickups sound ultra-clean. So he wound them that way, and the guy hated them, saying, "I wanted these pickups to sound clean like Carlos Santana!"
     
    GregC and interp like this.
  18. jazzbass_5

    jazzbass_5

    Sep 1, 2007
    NY, Albion
    Googled it and came up with this explanation of tube power vs SS power. Seems pretty legit.

    "The answer I was taught in a class about power amplifier design is that the non linearity of tubes produces prominent first, second and third order harmonic distortion. That means if you put in a sine you get out the sine, two octaves up and the fifth above that. Audibly that sounds like a power chord, which to us sounds more powerful than just the straight sine wave. With complex waveforms like a guitar or vocal, it becomes more prominent or warmer in the mids in addition to the brighter presence.

    A better, more engineering way of putting it is while the peak power of both amplifiers is the same, the average power is higher with the tube amp. If you take a peak at the waveform, the transistor amp with low distortion looks just like a sine wave. The tube looks more like a test tube shape that's wider. The area under that curve is greater, showing that it has greater power on average".
     
  19. Ampslut

    Ampslut

    May 15, 2017
    If you don't know what musical is, what can I say?
    The combination of a bass amp and a bass guitar, together, is a musical instrument. Power tube distortion has been a part of this instrument since before "Grand Funk Railroad" (West Amps). I've never heard SS power amp distortion used in any musical way. It just sound like ugly noise.
     
    Last edited: Jul 17, 2017 at 5:04 PM
  20. Ampslut

    Ampslut

    May 15, 2017
    Any SS amp I've used and I use a bunch had 2 sounds Clean and when driven to distortion, ugly.
     
    Last edited: Jul 17, 2017 at 4:59 PM