"All Tube" and the question of rectification

Discussion in 'Amps and Cabs [BG]' started by SolarMan, Nov 29, 2013.

  1. No. All tube is all tube.

  2. Yes. All tube refers to the amplification stages, not the diode stage.

  1. I have an "All Tube" amp.

    It was pointed out to me that no, I don't. It has a solid state rectifier.

    Well, excuse me!

    So; is my all tube amp (Bassman 20) "All Tube"


  2. Mr. Foxen

    Mr. Foxen Commercial User

    Jul 24, 2009
    Bristol, UK
    Amp tinkerer at Ampstack
    Signal path is the important bit. Tube rectification is fail.

    Edit: but bear in mind if the biggest boast something has is being 'all tube' whilst making concessions that it actually isn't all tube, then they must have even bigger problems with boasting stuff along the lines of being 'actually good'.
  3. ?

    Confused a bit by your edit. Nobody was boasting - just trying to figure out if calling a tube amp with ss rectifier "All Tube" is incorrect.

    Personally I'm heading back to 100% solid state.
  4. chaosMK


    May 26, 2005
    Albuquerque, NM
    Hi-fi into an old tube amp
    I can't think of any bass amps with a tube rectification stage. I think it's more of a guitar thing for people who want that "saggy" kind of tone. It doesnt seem like a desirable feature for a bass amp.
  5. slade


    Apr 5, 2001
    sounds like you have yourself a tube amp you don't like...
  6. headband


    Oct 18, 2013
    I always think of a tube amp as one that has no solid stated devices in the signal path. Tube rectification is not terribly reliable for bass amps with high output, which is why most manufacturers switched over when the wattage went up in the 60's (Marshall, Fender, and others).
    Interesting though, I have a tube rectified 1960 Blonde Bassman and it is the best sounding guitar amp I own. Not the best for bass, however.
  7. Joebarnes


    Oct 4, 2011
    Surrey, BC
    To me (and to most people) "All Tube" doesn't require a tube rectifier. If the Pre and Power amp are tube powered, that's an all tube amp to me. Tube pre? Hybrid. SS Pre and Tube Power? Its a Music Man or one of those Weird '80's Fenders. No Tubes? Probably Solid State.

    The Bassman 20 is a fairly coveted amp for guitar, I know there are a few guys on here that use and love them. Haven't heard it, but would like to play one, just to try it.
  8. Bassmec


    May 9, 2008
    Ipswich UK
    Proprietor Springvale Studios
    I agree that the signal path is what defines all tube but, I have a very old 4xEL34 Matamp with a pair of 5u4g rectifiers that sounds rather good power soaked in studio.
    I thought it would sag a heck of a lot more than it does, it's quite punchy really.
    The old Mesa Single, Dual and Triple rectifier solo heads are also surprisingly punchy on tube rectification.
    I also like playing bass through a little 5 watt single ended Elpico amp which is like the old RCA 6sl7 + 6v6 with 5y3 rectifier also copied by the old Fender c1 Champ.
    Now that does sag lots but sounds great round, smooth and compressed doing it.:bassist:
  9. headband


    Oct 18, 2013
    Tube rectifier circuits can be quite good, they are usually just a bit more complicated and thus a bit more expensive. Hifi audio circuits have provided good stable DC voltages for years.
  10. JimmyM


    Apr 11, 2005
    Apopka, FL
    Endorsing: Ampeg Amps, EMG Pickups
    Most B-15's have tube rectification. Personally, I couldn't give a crap how it's rectified. Either it sounds good or it doesn't.
  11. Bassnoise


    Jul 24, 2013
    Off track sorry but why are you going ss? I use ss so not ripping it just curious as I kinda want a tube amp...
  12. Mr. Foxen

    Mr. Foxen Commercial User

    Jul 24, 2009
    Bristol, UK
    Amp tinkerer at Ampstack
    Tones of amp manufacturers marketing departments do it. "All tube signal path" is more correct.

    You can do sag with a resistor, the old Simms Watts did it, the big resistor on top of the chassis, more reliable than a valve rectifier, much cheaper to replace if it goes (doesn't really wear out like a valve though). Dynamic might be a bit different.
  13. +1
  14. beans-on-toast

    beans-on-toast Supporting Member

    Aug 7, 2008
    A tube amp has tubes in the signal path. In the early days, all tube amps had tube rectifiers.

    All tube amps are not created equal. When pushed, a tube rectifier can add a desirable distortion caused by sag. Amps with solid state rectifiers can't do this in the same way. Sag affects the tubes and how they operate so in that respect, a tube amp with a tube rectifier performs differently than one with a solid state rectifier.

    But sag isn't limited to amps with tube rectifiers. To a lesser extent, power transformers can sag. The power supply design determines how much sag there is due to the resistors and capacitors.
  15. Ya know I smile quietly at most of my guitar customers with their "all tube" channel switching amps. Techs know what I am talking about :D
  16. beans-on-toast

    beans-on-toast Supporting Member

    Aug 7, 2008
    That's true. But the tubes still impart a lot of goodness.

    The all tube also goes out the window with amps that have a built in DI which uses operational amplifiers to pass the signal out. And what about those new fangled solid state mixing boards.
  17. Let's not forget the guitarists who insist they must have an all-tube amp for "that sound"...then promptly plug a Tubescreamer pedal into the input.
  18. lowend1


    Feb 15, 2005
    Not the same thing. A OD pedal in front of the amp is merely a method of overdriving the signal coming out of the guitar. What most guitar players are looking for (whether they realize it or not) is power tube grind. Depending on the amp, this is not always practical, so you do the best you can with an outboard device, be it pedal or attenuator. Ask anybody who owns an older Hiwatt.
  19. Anyone who wants to go for the zero tolerance approach to silicon in their "all tube" amp, where do you draw the line? Most fixed bias amps with valve rectifiers still use a silicon diode for the bias supply.
  20. So......you are looking for "all tube" amplification of your SS sound? ;)