What's the difference between tubes and ss?

Discussion in 'Amps and Cabs [BG]' started by SLiGhTLy_STooPiD, May 1, 2001.

  1. Pros and cons? the only kinds of amps i've ever owned are solid state because i don't know enough about tubes. help me out?
  2. yawnsie


    Apr 11, 2000
    Well, basically the difference between SS and tubes is that (Feel free to point out anything I get wrong here - it's the only way I'll learn. ;)) a solid state amp uses electronic circuitry, while tube amps use analogue valves to amplify the bass signal.

    Generally, SS amps tend to be cheaper, more reliable, less fragile, and don't need to be "warmed up" before use. This is all due to the fact that the electrics replace the often brittle valves, which could break and/or blow easily. (For example, a tube went in my guitarist's 2 month old Marshall today. :rolleyes: ) Tube amps are favoured by many traditionalists, due to their vintage tone - often far more warm, organic, and "real" than the proccessed sounds of a solid state amp.

    Basically, if you're looking to buy a tube amp, bear in mind that you won't be able to lug it around carefree like an SS one - as well as my guitarist's defective Marshall, I remember recording in a studio where the bass rig had a tube go. (not my fault, honest! :)) They'd only just got it replaced. And don't think that SS automatically = terrible tone, either. A lot of people (such as Andy Sumner from the Police) actually prefer the solid state tone to tubes - like most things, it's a matter of opinion.

    Hope that helps clarify things a little.
  3. cole


    Sep 14, 2000
    most of the pros and cons about tube/solid-state is subjective. the biggest "pro" of solid-state amps is that they're much lighter than tube amps, and you can have a lot more power in one package (try getting into the kilowatt range with tubes!). on the other hand, tube amps are meant to be operated at a higher volume level than solid-state amps, so a tube amp could be as loud as a solid-state amp with three or four times the power.

    either way, it's a trade-off.
  4. >on the other hand, tube amps are meant to be operated at a higher volume level than solid-state amps, so a tube amp could be as loud as a solid-state amp with three or four times the power.

    That's not quite the case. Solid state amps will be able to run at higher power / volume levels and for longer periods of time than tube amps.

    Tube amps, however, are favored by many who look for a vintage / warm bass tone. The downside is that they are beasts to lug around. Tube amps weighing 100 lbs or so are not uncommon...

    A good compromise, used by many bassists, is to have a tube stage in your pre-amp (Aguilar, Peavey Max, etc.) and send that signal into a solid state power amp. This is a "best of both worlds" situation - the power and reliability of solid state along with the warmth of tubes in the pre-amp.

    Hope this helps - John
  5. cassanova


    Sep 4, 2000
  6. RockFiend


    Aug 23, 2000
    from my experience, a 300 watt tube head can produce more 'power' to the human ear than a 500+SS amp,,, also when running SSamps at high volumes even if they are 1200 watts or whatever they make 'farting' distortion when the gain is turned up, I don't like SS that much due to it's tone and also the fact that my 200watt@8ohm head cut out frequently when I was running it hard,, I don't think, you'll find tube am,ps cutting out at any moment ,, from my experience again tubes are meant to be naturally distorted and pushed to the brinkl of the envelope whereas solid state will 'fart'(gross natural distortion sound form the SS circuitry) or they will over heat orcutout,,, I'm not a techie of any sort but from any exoperiences I have this is what I've noticed
  7. Here's my post from a couple of weeks ago on this topic:

    Tube Watts are equal to 2 Joules per second, whereas Solid state Watts are equal to the standard 1 Joule per second. :D Oh brother.....

    JUST KIDDING! (A Watt is a Watt no matter Watt.)

    If you have a tube amp rated at 300Watts clean, and a SS amp rated at 300Watts clean (which is how they are rated), the Tubes can put out more power than 300 Watts, if you can live with a little sweet-ass distortion that sounds slightly better than a fart from god's own restroom. The SS amp can put out more than 300 Watts too, but it will sound like the sounds eminating from the devil's outhouse after a 14 Taco binge at Taco Hell with some of that mad-cow beef from England. This is because of everything posted above.

    Restated in language fit for my grandma:

    The tube amp has just a tiny bit more distortion up to the point of clipping, pretty much negligible in the power measurement arena. Like 3% Total Harmonic Distortion at full power instead of 0.03% for the evil transistor amp. The big difference occurs beyond the full power point where power amp clipping occurs, where the tube distortion sounds good to lots of folks and does a good job of just compressing the signal without adding tons of high order harmonics, and the SS distortion sounds bad to a lot of folks since it is the outcome of hard-hitting the power supply rails and flat-topping (and flat-bottoming) the waveform. It has been said that SS amps with output transformers, like older McIntosh HiFi amps, still sound really good. So it could be just as much due to the output transformer as the tubes themselves.

    I dig the art of the tube fart.

  8. Further to Throb's post:

    The distortion above an SS amps clean power rating is also very dependant on the design of the amp. I don't know enough about this yet to pontificate for hours on the subject, but I do know for a fact that "higher end" SS amps clip differently than lower end amps.

    There is some company in australia that has developed a power amp that supposedly sounds incredibly tubelike at the limit.

    And, finally, A watt is a watt!


  9. Erich Zann

    Erich Zann

    Aug 14, 2000
    That wouldn't happen to have MOSFET's in it would it?
    And, how exactly would MOSFET's relate to this discussion?
  10. MOSFET's are just another type of transistor, as opposed to the standard BJT.

    MOSFET = Metal Oxide Semiconductor Field Effect Transistor

    BJT = Bipolar Junction Transistor

    FET's are cool because they use voltage to control current, whereas a BJT uses current to control current. A tube uses voltage (Field Effect) to control current like a FET, so they are kinda similar. But the tube is a high impedance device, and a transistor is a low impedance device. The FET's are still transistors, although they are the swankiest of the transistors.

  11. Erich Zann

    Erich Zann

    Aug 14, 2000
    The reason I asked is because MOSFET's always seem to be advertised as being as good(almost) as tubes, but as reliable as SS. So, they're not realy like tubes, they're just really good transistors?
  12. Note from mod: you were not supposed to publicly post that e-mail!
  13. My apologies.

    I hadn't condidered that.

  14. Yeah, that's about it, but they do have an Achille's heel. Static Discharge will punch a hole through the insulating layer. That's what all this "static sensitive components" stuff is all about on computer boards and such. Once they are in circuit, they are safe from the microscopic lightning bolts. :D

  15. Erich Zann

    Erich Zann

    Aug 14, 2000
  16. top028


    Dec 14, 1999
    Lancaster, PA
    One of the reasons for MOSFETSs to be advertised as better is the fact that they are most simmilar to tubes in operation...Just as throbbinut (hope I spelled that right) said about the fragile insulating layer, That layer is very high input impedance. almost infinite. Tubes are the same way. tubes work like a neon bulb. Tubes pull electons from across space (between the plates). This is why they operate at 300-500 volts. MOSFETs also can operate at larger voltages than BJTs THe reason they weigh so much is the input and output transformers, The input transformer in my Bassman is a 8" cube of solid iron and coper(this is what steps up the voltage from 120 to 300) The output transformer then has to bring that voltage down to a lower voltage at higher current for the speakers use. Transformers trade voltage for current in some strange way involving flux (and capacitors...hehe) My bassman head wieghs about 50lbs but it is worth it...for 100 watts of beautiful tone.

    Hope I didnt bore any one with my electronics lesson