Peavey classic 30 phase inverter tube

Discussion in 'Amps and Cabs' started by aic7575, Apr 5, 2015.

  1. aic7575

    aic7575 Member

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    I am researching tubes because I'm going to change my preamp tubes for tonal reasons. I read in lots of forums that the sovtek LPs tube is a popular tube in v3 phase inverter position. What does this tube do in v3 and what does it do for tone? How would this tube affect my tone different than a jjecc83 in v3?
     
  2. kbgear

    kbgear Member

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    The PI takes the final output from the preamp, splits it into two out-of-phase signals, and passes each signal to each of the two sides of the push-pull power amp. Technically its only job is to create an inverted signal, ideally with some gain as well. But because it's the interface between the pre-amp and power-amp it's important to have a very solid tube for a PI.

    I think the LPS gets praise as a PI because it's a strong, high gain tube with some mid emphasis. (To my ears)

    Generally, people feel that the JJ ECC83 is a "meh" tube without a lot of gain or character. I tend to agree, though I don't think it's bad per se.

    Putting aside NOS tubes (and the potential endless comparisons there), I generally look at new-make tubes as PIs this way:

    * Tung Sol RI if you want a little more brightness and clarity.
    * JJ ECC803s if you want a little more midrange character -- IME it has a little more gain and character than the regular JJ ECC83s. I've noticed this especially in EL-84 amps, FWIW.
    * Sovtek LPS if you want slightly higher output with midrange emphasis.

    IME the effects are noticeable but not night and day -- tubes can fine-tune the sound but circuits, cabinets, and speakers would have much more profound influences. I generally default to the TS, and fall back to ECC803s or NOS if it's a little too bright for the job. From what I remember of my 90s Classic 50, the amp could stand a little more clarity, but it was probably a pretty different beast.

    HIH?
     
  3. CitizenCain

    CitizenCain Member

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    Whatever you decide, a C30 has a cathodyne PI so don't spend extra on a balanced tube.
     
  4. Jimmy MAck

    Jimmy MAck Member

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    Nice explanation there kbgear. Appreciate the tube critique too.
     
  5. aic7575

    aic7575 Member

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    That was a great explanation kbgear, in the peavey forum a tube set I will name them. V1- tung Sol v2 JJ ecc803s v3 sovtek 12ax7lps is highly recommended. the explanation and this tube recommendation all makes sense. Lots of people love this tube set and I have nothing to lose by trying it out because if its not as good as the previous I just change back. Also in my quest for tone I'm super confused with speakers. Speakers to me is like politcs. What's good in someone's eyes is not to another. I have narrowed down a selection of speakers to a wgs reaper 55 or HP, an expensive celestion heritage g 12 65, wgs et 65 or the et 90 for the headroom. And also my blue marvel is starting to sound like its settling in and is sounding great cleans and drive. I put a dimarzio x2n on my start and it completely changed my opinion of the blue marvel. So now I'm debating do I want to put the new speaker in my amp or in an ext cab which I am thinking in a 112 cab. Just a simple pickup change did a massive tonal change for the better. From reading I hear that an ext cab on the classic 30 is its magic mojo. It brings the amp to life and the harsh treble of the blue marvel lays off. The quest for tone is a journey all must endure.
     

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