Tube Amp Compression

Discussion in 'Amps [BG]' started by kmon, Nov 20, 2012.


  1. kmon

    kmon Supporting Member

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    May 11, 2009
    Looking at a classic SVT, had a question about compression...

    I use an MXR Bass compressor with my shuttle 9 to even out levels between strings. I use 4:1, the lowest setting.

    Running an SVT, and I like some grit so I'd expect the gain to be up a bit, would the tubes give me a similar level of compression?

    Never rolled with an all-tube amp...I'm not looking for a ratio, just a sense of whether I'll want to hang on to my MXR or whether the tubes will balance out my string levels for me.
  2. dincz

    dincz

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    You'll be running different volume at different venues so the amount of compression contributed by the output stage will vary accordingly. For consistent compression, you might want to hang on to the M80.
  3. Tractorr

    Tractorr Supporting Member

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    Also, tube compression reacts in a slightly different manner than a solid state compressor pedal. If you get the SVT keep the MXR, try it out, and see what you think.
  4. Bassmec

    Bassmec

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    By the level that an un power soaked SVT starts producing much output transformer saturation and power supply sag, if you are using an efficient cab like the 8 X 10 you are going to be a bit loud for most places.:bassist:
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  6. Jim C

    Jim C Supporting Member

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    OTOH, I've tried a few different compressors with my SVT-CL and didn't like the results nearly as much as with some SS heads (normally prefer a touch at say 4:1)
    Perhaps psychosomatic, but the touch sensitivity and ability to maintain super consistent note to note volume does seem to be "built in" to an SVT even at lower power levels.
    Similar to how early non-transformer input stages on an MCI console seemed to make drum tracks jump out of a track and the transformer inputs on an older Neve console was smoother.
    IMO/IME
  7. jetbike

    jetbike

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  8. Bassmec

    Bassmec

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    I know exactly what you are talking about, yes it's far more dynamically
    controllable than any big transistor amp without any compression at all.
    My AMS Neve 33609JD would certainly make any transistor amp compressively fairly similar at any level but then it cost about as much as a whole big bass rig including a quality bass guitar.:D
  9. Calaverasgrande

    Calaverasgrande

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    Using a compressor with a tube head is kind of backasswards.
    Using both SVTs and Mesa Bass 400s I've always been able to get soem compression at lower levels than output stage overdriving.
    I think some of this has to do with how tube eq works. Some has to do with the built in voicing of the heads. The SVT has a very resonant midrange eq.
    The mesa does not really have a midrange eq, but its bass eq is very resonant indeed.
    And SVT, even clean and at low volume already sounds compressed to me.
    It doesn't have that VCA breathing of course. But the evening out of notes, and increased sustain are already there. When you get into output compression on an SVT or Mesa bass 400, it can get almost ludicrous.
    I actually end up playing with exaggerated dynamics. My soft notes are my fingers barely touching the strings, the loud ones I am beating the daylights out of the whole bass.
    The volume difference is negligible, but psychoacousticaly the louder notes have much more harmonic content. So they "seem" louder.
  10. rpsands

    rpsands

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    I didn't have a lot of luck coaxing good sounds out of my Hexavalve with my FEA, but I didn't spend a lot of time trying.
  11. kmon

    kmon Supporting Member

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    I'll give it a shot with and without. The MXR has been great with my shuttle head for evening out levels between strings, but I was hoping I might get some of that out of the box with an SVT. Sounds like I might...I just need a little so maybe the MXR can move on.
  12. fitz420

    fitz420 Knows Lows Supporting Member

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    i think the tube compression from an svt is pretty subtle and more apparent at louder volumes. i would also keep the mxr, at least until you see how the svt reacts. i just started rolling with an svt full time too. last few amps were a streamliner 900, little mark II, and an ashdown abm500. the svt actually took some time to get used to....way different than the others. i just bought a fdeck hpf-pre to help with some of the lows....its really helped out and highly recommend looking at one.
  13. kmon

    kmon Supporting Member

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    May 11, 2009
    ok so you're in my boat...looking to try out an SVT, last few were shuttle 9.0(current), TC RH450, streamliner 600.

    Was the SVT tough to dial in? What cab you using?
  14. Jim C

    Jim C Supporting Member

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    IMO, the SVT is the easiest bass amp to use; just plug and play
    Start flat and with the switches off and go from there
    Most don't use much EQ
    The downside is that if you want to add tons of EQ and like the sound of some of the SS amps filters who ring and honk like a siren, you will not be able to get that with an SVT
  15. steve_rolfeca

    steve_rolfeca Gold Supporting Member

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    You may find that you still like having a compressor pedal around as an effect.

    The smoothing effect of an all-tube head is easy on the ears, and most, including the SVT, already have some going on at low volume, well before you reach the point of power supply sag or transformer saturation.

    Still, it's a different sound and "feel", and more subtle than most compressor pedals.
  16. Jim C

    Jim C Supporting Member

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    I was hoping that I wasn't the only person that heard it this way. :) Each console can act as their own voice just like an instrument.
  17. fitz420

    fitz420 Knows Lows Supporting Member

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    i'm using a bergantino NV215. not tough, just different. the lows were a bit flabby for me....i just bought an old NOS GE 5-Star 5751 for the V1 position. it did wonders for the streamliner....really helped focus the lows a bit. i read people have had great results with a 5751 in v1, so i figured i'd give it a shot.
  18. kmon

    kmon Supporting Member

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    May 11, 2009
    nope, that's part of the appeal...I don't want 38 knobs, plug and play all the way
  19. Inconnu

    Inconnu

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    I've been using an SVT for the last 17 years and no, it won't even out your string levels like a compressor does. Keep the MXR, the result should be great.
  20. wcriley

    wcriley

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    Please excuse me for going off topic, but is this a problem many/most bass guitar players face?
    Just asking because I've never had a problem with string to string levels being unbalanced.
  21. Tractorr

    Tractorr Supporting Member

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    Do you by any chance play flatwounds?

    When I play flatwounds I feel that the sound from string to string is fairly consistent with a bit of EQ.

    When I play roundwounds I feel that a bit of compression helps. Though I should probably just focus on better technique ;)

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