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Power tubes

Discussion in 'Technical Side of Things' started by Stefan, Dec 22, 2016.

  1. Stefan

    Stefan Country Gent

    Jan 20, 2016
    Germany
    Hmmm- I've swapped the GZ34 in my cathode biased SWART for a 5Y3 (curious about the tonal influence) and the amp lost remarkable volume and power. Back to the GZ34 and everything is okay again. Is it possible, that the power tubes (6V6) are too old?
     
  2. Tinman46

    Tinman46 Country Gent

    Age:
    48
    Dec 19, 2011
    Kitchener, Ontario, Canada
    From my limited understanding a 5Y3 drops voltage going through it by 50-60 volts and the GZ34 series only drops voltage around 17 volts or so. That may be the cause of volume and power loss.
     
    Michiel likes this.
  3. Stefan

    Stefan Country Gent

    Jan 20, 2016
    Germany
    Thanks, I didn't expected that much loss of power.
     
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  5. rcboals

    rcboals Country Gent

    Nov 21, 2008
    Springfield Oregon
    Loved my little Swart not sure why I sold it.
    Been there done that yup!
    Stay with the GZ34 your power tubes are most likely just fine. The best thing you can do to improve your amps tone is go practice for an hour. :) Have a Merry Christmas only if you want to.
     
  6. loudnlousy

    loudnlousy Country Gent

    Age:
    51
    Oct 18, 2015
    Hildesheim, Germany
    The 5y3 is simply the wrong rectifier-tube.
    If you swap the values of other components randomly you will will experience malfunction, Stefan. It has nothing to do with your powertubes.
     
    wabash slim likes this.
  7. Stefan

    Stefan Country Gent

    Jan 20, 2016
    Germany
    ZackyDog likes this.
  8. benjwri

    benjwri Country Gent

    Age:
    79
    Oct 27, 2011
    Central ON Can
    Check with the manufacturer.
     
  9. loudnlousy

    loudnlousy Country Gent

    Age:
    51
    Oct 18, 2015
    Hildesheim, Germany
    O.K: Maybe "by design" by this special circuit. ( if you want to reduce output, maybe.). Your tubes should be o.k. still.
     
  10. loudnlousy

    loudnlousy Country Gent

    Age:
    51
    Oct 18, 2015
    Hildesheim, Germany
    Stefan: If you got a working sound on that beautiful amp you should not experiment on it anymore, You wrote, that you love it. Whayfix something that is not broke?
     
  11. Sid Nitzerglobin

    Sid Nitzerglobin Synchromatic

    816
    Jun 8, 2015
    fROMOHIO
    My Pro dropped a bit in output (which was somewhat welcome) and got a good bit looser and saggy and tweed-ier/brown-er sounding w/ a NOS Tung Sol 5Y3 (which is very cool for some sounds but ultimately not exactly super flexible w/ pedals). I usually have a New Sensor Tung Sol 5AR4 in there now.

    Edit: in the interest of clarity, the above is w/ NOS Tung Sol 6V6 power tubes. I tried New Sensor Tung Sol 5881s and the amp really didn't want to run them for more than 5 minutes or so w/ either the NOS 5Y3 or RI 5AR4 or the stock GZ34. Was a little bummed as I liked the sound of them over the RI Tung Sol 6V6s, but oh well...
     
    Last edited: Dec 24, 2016
  12. wildeman

    wildeman Friend of Fred

    May 10, 2015
    norcal
    I think the 5y3 swap should be done when you go to 6v6's, bringing your 35 watt 2x 6l6, 1x gz34 amp down to around 10 watts. My Masco is a 10 watter 6v6, 5y3 amp and sounds rad.
     
  13. wildeman

    wildeman Friend of Fred

    May 10, 2015
    norcal
  14. Stefan

    Stefan Country Gent

    Jan 20, 2016
    Germany
    ^ Thanks, but I always thought a 5Y3 reduces Power?
     
  15. drrohle

    drrohle Synchromatic

    552
    Jan 3, 2014
    Hays, KS
    rcboals is right, stick with the GZ34, it's a superior rectifier tube to the 5Y3.
     
  16. wildeman

    wildeman Friend of Fred

    May 10, 2015
    norcal
    Correct. In Fenders with 6v6's you usually find 5y3, in 6l6 amps its a gz34.
    Like champ, Princeton, deluxe or pro,super, twin. There are guys here that know a whole lot more about the workings of an amp than me and hopefully one will be able to 'splain it better.
     
  17. MatchlessMan

    MatchlessMan Country Gent

    Nov 29, 2010
    Swindon UK
    My Swart STR runs with either a 6V6 or a 6L6 tube, and the 6L6 sounds bigger and more open to me. This is with a 5Y3 rectifier, and I've only just realised by reading this page that I could fit a GZ34. Now I'm going to have to try that out - d'oh!

    EDIT: Scrub that, just checked and it's a GZ34, it's staying!
     
    Last edited: Dec 24, 2016
  18. Stefan

    Stefan Country Gent

    Jan 20, 2016
    Germany
    Yes, all those STR and AST circuits are stocked with the 6V6/GZ34 combination and that works great (and hot!). I like it a lot but it makes me wonder that the 5Y3 eats so much power and volume.
     
  19. hcsterg

    hcsterg Country Gent

    Feb 13, 2012
    France
    5Y3GT = 125mA, direct heating
    5Y3GB = 125mA, cathode heating, lower Ri than 5Y3GT
    5U4G/GT = 225mA, direct heating, lower Ri than 5Y3
    5AR4/GZ34 = 225mA, cathode heating, lower Ri than 5U4

    Sorry, I don't remember instantly the other specs...

    Higher Ri = more sag, more voltage drop, varying with current drawing.

    A+!
     
  20. Stefan

    Stefan Country Gent

    Jan 20, 2016
    Germany
    Sorry, but I'm a lot more musician than technician...am I right that the GZ34 got more power and more headroom than the other tubes above?
     
  21. hcsterg

    hcsterg Country Gent

    Feb 13, 2012
    France
    Yes, Stefan. But a simple swap is not always possible, depending on the amp's design.

    A+!