What's more important tone-wise? Pre-amp or power amp tubes?

Discussion in 'Amps and Cabs' started by sbreide, Feb 23, 2009.

  1. sbreide

    sbreide Member

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    Right now my amp is loaded with Sovtek 12ax7wa's in the preamp and Sovtek 5881's in the power section. I'm finding that the amp seems kind of "harsh" and thin when overdriven/distorted. Bias has been checked. I've only got the money to do one section right now.... So which do you think will make a bigger difference? Pre-amp or power?
     
  2. Luke

    Luke Senior Member

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    Preamp tubes.

    Your preamp tube is the beginning of your tone, if it is poor it is almost impossible to improve it.

    Also, power amp tubes need to be running near full blast for their differences to be be truly appreciated.

    Real NOS Mullard ECC83s
     
  3. rrhea

    rrhea Member

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    What amp are you playing?

    I agree that real NOS Mullards would do the trick. :) But if you find those too expensive an economical solution would be to try a Mullard reissue in V1 and keep the Sovteks in the rest of the positions. If it's still too harsh try another Mullard in the phase inverter (last preamp tube). That should smooth out your tone considerably.

    RR
     
  4. FrankieSixxxgun

    FrankieSixxxgun Member

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    Both! Slacking in either department will affect your tone.
     
  5. sbreide

    sbreide Member

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    Yes... I understand this. However, both is not an option right now. If I had the money I would go ahead and do both right now.

    I'm playing a Traynor Custom Special 90 (YCS-90). I play it mostly on the 25 watt setting so the power tubes do get a little bit of a workout.
     
  6. stratovarius

    stratovarius Supporting Member

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    A big plus about experimenting with preamp tubes is that matching and rebiasing are not necessary. They're a better investment too, because they last much longer than power tubes.
     
  7. freaksho

    freaksho Member

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    +1 on changing preamp tubes first. call Doug or Mike and tell them what you're looking to accomplish and your budget. they will steer you right.

    btw, if there's any chance you might end up getting multiple tubes in the near future you should try to bite the bullet and come to terms with that right away because it's better to get them all in one order and consolidate on shipping. (speaking from experience :))
     
  8. soldano16

    soldano16 Member

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    another vote for preamp tubes BUT BUT BUT

    that's only on the assumption that your power tubes are properly biased. The proper biasing of power tubes is the #1 factor to getting decent tone. If your bias is cold, the amp won't sound good at all.
     
  9. lpaine

    lpaine Opinions are like... Just don't become one. Gold Supporting Member

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    I just ordered some ANOS (lightly used) GE 12Ax7's from Mike at KCA. They are about half the priced of the NOS GE's, which I have, and LOVE. Might be a nice way to try a couple, and see if that is getting you closer to what you want, without breaking the bank. They are about $35 each.

    Just a thought.
     
  10. sbreide

    sbreide Member

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    I've made sure the amp is biased to spec.

    I figure ANYTHING has to sound better than the Sovtek 12ax7WA's that are in there now.
     
  11. Guitar Dave T

    Guitar Dave T Member

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    Unless you have V1 cascading into V2; V2 will probably not last that long. Also, if you slam the front end of your amp with OD, distortion, your preamp tubes will generally last no longer than your power tubes.
     
  12. FrankieSixxxgun

    FrankieSixxxgun Member

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    Truth! Get some Tung Sol RI tubes even, they sound leagues better than Sovteks and they're like $12 a piece.
     
  13. slider313

    slider313 Silver Supporting Member

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    +1 The Tung Sols are the best sounding new production 12ax7. If you can get up the coin, pick yourself up a few GE short grey plate 12ax7a/7025's.
     
  14. INX

    INX Member

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    To evaluate your form, we need to know it's aspects:

    Make and model of amp.

    Guitars used, pickups and electronics

    cables

    speakers, type of cab, wiring

    Sovteks pre and power are harsh beasts, period. JJ's or SED's will help out in the power section. If the plate voltage is under 500v, you have other options as well.

    One of my students got a Zinky Velveteen for Christmas, and we replaced the 12AX7EH (sovtek) and 5881 with a Sovtek Mullard 12AX7 and a JJ 6L6GC and the result went from harsh to usable.
     
  15. FrankieSixxxgun

    FrankieSixxxgun Member

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    We need to know all that to answer a simple question? I dunno, looks like it was answered a bunch already. :MMM

    Oh yeah, get some JJ 6L6's to replace those 5881's and you should be pretty tonally sound for a deal. They're not gonna sound like vintage glass, but they'll last a while and they sound pretty good. I just biased a set into a JCM 900 and put some Tung Sol RI's in the preamp. Sounded pretty good, even for a JCM 900!
     
  16. INX

    INX Member

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    I've fought an amp with the same compliment stock, and the heart of the issue is ICE-PICK.

    George L's, series speaker wiring, lack of batting in the cab, and 500k pots contributed icepick to the degree that each had to be changed in order to have a form that resulted in satisfaction. Ergo, he could change tubes and still be dissatisfied hence the inquiry. :)
     
  17. FrankieSixxxgun

    FrankieSixxxgun Member

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    That I can get down with. Sovteks are notorious for lacking top end.

    And actually, 500k pots and George L's seemed icepicky because they're working as advertised, sir. Using wires with more resistance and/or lower value pots is just about the same as turning your tone knob on the guitar or amp down a little. All my guitars (except my Strat) are loaded with 500k pots, and I use George L wires on my board. The only amp I have an issue with treble on is my Vox AC30, and that's kinda how an AC30 acts. Easily resolved by using the tone cut knob.
     

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