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Help Cleaning Up SVT CL Tone

Discussion in 'Amps and Cabs [BG]' started by leemelone, May 24, 2011.


  1. leemelone

    leemelone

    May 24, 2011
    ATL
    I just picked up a very clean Korean made SVT Classic at a pawn shop for a great price and I need some suggestions to help clean up the tone. It's very fat sounding but the mids and highs are muddy sounding when connected to an older SVT 810. Is this a characteristic of the Classic? I've owned two other SVTs in past, a 70's and an 80's model and I'm not expecting this to sound as good. The bias lights on the back seem to indicate the amp is functioning properly. Would changing the preamp tubes to JJ or Rubys help clean up the mid and higher frequencies significantly ? What about the power tubes? Or do the the Classics just suck? ;)
     
  2. What year is your cab? There is an era of 810E's that are "muddy" thanks to the speakers that were used.
     
  3. leemelone

    leemelone

    May 24, 2011
    ATL
    It's not the cab. I've played numerous other amps through it and they all sounded fine.
     
  4. You could try changing the pramp tubes. I wouldn't touch the power section though. The stock power tubes should be sovteks, atleast mine are. I set my master up pretty high and use the gain to control the over all volume. I'm sure jimmym will step in here and drop some knowledge bombs soon lol
     
  5. Selta

    Selta

    Feb 6, 2002
    Pacific Northwet
    Total fanboi of: Fractal Audio, AudiKinesis Cabs, Dingwall basses
    First, let's start by asking what settings you have on the CL, and on any other equipment you have hooked up to it. I never noticed mine to be exceptionally muddy, except for when I ran it with certain ported cabs.
     
  6. okcrum

    okcrum in your chest

    Oct 5, 2009
    Verde Valley, AZ
    RIP Dark Horse strings
    My CL sounds clean on the mids and highs. I use a GE 1st preamp tube, Sovtek for the other 12AX7s, TungSol 6550s with RCA 12BH7s or 12AU7s for the drivers. Either driver tube sounds clean.

    Maybe the amp has a problem other than tubes? You might want to make sure you don't have an actual bad tube before proceeding further.
     
  7. Bassoballs

    Bassoballs

    Nov 14, 2009
    Mid Michigan
    Winged C 6550s and a better output transformer. Turns them into new amps.
     
  8. Selta

    Selta

    Feb 6, 2002
    Pacific Northwet
    Total fanboi of: Fractal Audio, AudiKinesis Cabs, Dingwall basses
    What's wrong with the factory OT? Which do you recommend replacing it with? I've gigged with a CL so much that the last thing I'd worry about changing is the OT, especially given the cost for the OT alone, plus the tech time to do it if you can't yourself. The output tubes I can see why some may do it, but I never had an issue with any set I ran in mine.
     
  9. leemelone

    leemelone

    May 24, 2011
    ATL
    At first I set all the tone controls to 12 o'clock, master on full, gain to 9 o'clock, ultra high and low off. I played my Jazz bass w/flats and my P bass w/round wounds plugged straight in. The Jazz was very muddy with very little midrange. The mid selector switch didn't add much even set at full in the 3, 4 & 5 position. I was able to clear it up a good bit by reducing the bass knob to zero. I've been using a Peavey VB-2 with the same cabinet and basses and it's much clearer. I don't think there is anything actually wrong with the amp but I've owned two other tube SVTs in the past and they were cleaner sounding. I'm not sure how old this head is but it looks fairly new. It's an SVT Classic (not CL) made in Korea by LOUD Technology. Anyone know how long this version has been made?
     
  10. Selta

    Selta

    Feb 6, 2002
    Pacific Northwet
    Total fanboi of: Fractal Audio, AudiKinesis Cabs, Dingwall basses
    I always ran my mid switch in position 3, but never had to crank it to get some serious results from it (usually ran it around 2 o'clock). That concerns me that you're not hearing much change having it dimed out. Otherwise, our settings are about the same (all other knobs at noon, ish, and no ultra lo/high). Did you check bias with those lights, or have it actually checked properly?
     
  11. okcrum

    okcrum in your chest

    Oct 5, 2009
    Verde Valley, AZ
    RIP Dark Horse strings
    Same here w/mids. He might have a bad tube or other problem in the preamp.
     
  12. Bassoballs

    Bassoballs

    Nov 14, 2009
    Mid Michigan
    The stock OT's work fine, but upgrading the OT will have a dramatic effect on the overall tone of the Amp. George Metropolous has been modding these for some time, and that seems to be the single biggest improvement in the quality of tone. The OT's he had made were from Hayboer.
     
  13. Selta

    Selta

    Feb 6, 2002
    Pacific Northwet
    Total fanboi of: Fractal Audio, AudiKinesis Cabs, Dingwall basses
    Huh, I can't find anything about him doing any work on SVT output trannies, so I'm very curious as to what he does with them. So you're not advocating having them replaced, but rather "modded" in some sense?

    Edit: Actually, the only thing I found on quick google search is George recommending getting the OEM transformer for a person who was looking to buy one for a blown SVT.
     
  14. leemelone

    leemelone

    May 24, 2011
    ATL
    I checked it with the lights on the back. I just bought it today and I haven't had it checked out by a shop. It's really loud and full. I just want more clarity in the mids and highs. The mid selector seemed to work better with the bass rolled completely off.
     
  15. Bassoballs

    Bassoballs

    Nov 14, 2009
    Mid Michigan
    The mod I was referring to, is actually replacing the OT.
     
  16. Selta

    Selta

    Feb 6, 2002
    Pacific Northwet
    Total fanboi of: Fractal Audio, AudiKinesis Cabs, Dingwall basses
    With which one?
     
  17. Bassoballs

    Bassoballs

    Nov 14, 2009
    Mid Michigan
    The OT's he had made are from Hayboer.
     
  18. With the exception of some obsessive companies, transformers are often less than stellar. Mind you, in some cases the "tone" is because of the less than stellar transformers be they power or output. Heyboer and Mercury Magnetics offer replacement transformers for SVT's IIRC. With Mercury Magnetics, one set is optomized oem and the other gets it done in a less hernia fashion which is possible with proper techniques and materials.
     
  19. heyboer.

    Personally though i'd try swapping the preamp valves, if that doesn't help then i'd take it to a tech.
     
  20. Big +1 on valve swap as you can pretty much retube the whole amp for what it costs to get one transformer. Preamp tubes can make a large difference. 6550 change can make a dramatic difference, particularly if the current ones are not wonderful. Make sure output tubes are installed and biased properly as that makes an enormous difference in tone and reliability.
     

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