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Tube rectifier change affect tone?

Discussion in 'Amp Tech Center' started by JDRNoPro, Nov 21, 2020.

  1. JDRNoPro

    JDRNoPro Friend of Leo's

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    I recently replaced the new production JJ 5Y3 rectifier tube in my Tweed Champ with a NOS 5Y3. Did this for reliability reasons. I may be crazy, but I think the amp sounds a little different - like it lost a little clarity. I mostly play cleanish/slight OD at around 5 to 6 vol with single coils.

    My question is whether a different rectifier tube can influence tone......or is this all in my head? Thanks!
     
    Last edited: Nov 21, 2020
  2. jman72

    jman72 Tele-Afflicted

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    I think the big difference would probably be voltages. I know the old 5Y3 tubes might give a slightly lower B+ than the new JJ 5Y3 tubes, so this could result in a change in tone. You could check the voltages with both tubes to see if this is the case.
     
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  3. uriah1

    uriah1 Telefied Gold Supporter

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    I have noticed variability in diff types both nos and new production. Imho
     
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  4. JDRNoPro

    JDRNoPro Friend of Leo's

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    Thanks for the quick replies jman72 and uriah1! I generally like and use all NOS tubes in all my other amps, but not so sure on this one.........
     
  5. Ricky D.

    Ricky D. Doctor of Teleocity

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    From thirteen years ago when I built my 5e3.....

    You need a NOS 5y3 to get the right B+ voltage, iir 360 volts. New ones are much higher. Makes a difference according to Bruce Collins at Mission Amps.

    I've only ever had the NOS.
     
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  6. JDRNoPro

    JDRNoPro Friend of Leo's

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    The amp is a new 57 Custom Champ. Wonder if its circuitry is tweaked for new production rectifier B+. I don't believe there are any circuit diagrams available for this current production 5F1 version....at least I haven't been able to find one. Really like the sound of this little amp - better than my 5F1 clone.......and think I like it better with the rectifier tube it came with....
     
  7. Bob Womack

    Bob Womack Tele-Afflicted

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    I commissioned a 5E3 build. The builder preferred to deliver it with new JJ tubes so that there would be no performance unknowns as it went out his door. Once I got the amp in my hands, a friend asked me to go through several boxes of used and NOS tubes and evaluate their veracity in my amp. He gave me my choice of the tubes for my trouble. I went through several 5Y3 examples and discovered differences between them. You know how between the negative feedback and rectification schemes the 5R3 is already a saggy amp. Basically the differences between the tubes showed up in feel. Some offered a softer and more pillowy feel than others. I went in an agnostic and ended up a believer.

    Bob
     
  8. Wally

    Wally Telefied Ad Free Member

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    I always take voltage measurements before and after changing a rectifier. A change in voltage rebiases every tube in the amp.
     
  9. FenderLover

    FenderLover Poster Extraordinaire

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    This is what I've always felt. I read the thread because there is sometimes a broad misuse of the word 'tone' to the point where it looses meaning. The slight change in voltage gives a difference in 'feel' as a primary and fundamental change. The effect on a circuit from a voltage change as a difference in tone is small, if not imagined. YMMV.
     
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  10. Wulf

    Wulf Tele-Afflicted

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    the sound will change...even if you had 2 "identical" valves..there is always a slight difference in them.
    stick 2 "identical" amps on a bench and try each and they will have different nuances and response ..and may sound similar but never the same.
    thats the great thing about "old tech"...nothing really like it
     
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  11. Wally

    Wally Telefied Ad Free Member

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    Ime, with rectifiers as long as the voltage output is the same the differences....if there are any...would be very minor and maybe not perceptible. If the voltages are different for two 5Y3s, then the response from the circuit changes. I wou”d agree that ifntwomr3ctifiers yielded the same voltages but due to the difference in the structure of the two tubes might yield a different result when the amp is pushed hard and the demand on the rectifier to meet voltage demand is challenged.
     
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  12. schmee

    schmee Doctor of Teleocity Silver Supporter

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    Generally I say no, but just the variation in rectifier voltage can adjust the bias setting.... ... but the Champ is cathode bias... hmmmm
     
  13. Wally

    Wally Telefied Ad Free Member

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    Schmee, yes, that circuit is cathode biased. All of then12A-7s in all of our amps are cathode biased, too. That does not mean that voltage changes do not rebias those tubes. Whether fixed or cathode biased, a tube’s current draw is affected by a voltage change...just as when one changes those bias resistors the current draw changes...and the plate voltage moves a bit as well.
     
  14. JDRNoPro

    JDRNoPro Friend of Leo's

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    Really appreciate everyone's responses and info. To clarify a bit more, the difference I think I am hearing is less clarity.....ie, the notes seem to run together more with the NOS rectifier, whereas with the new production 5Y3 it seems like I hear individual notes more distinctly and separated.......if that is possible.
     
  15. Wally

    Wally Telefied Ad Free Member

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    I am thinking the bias has changed because of a voltage change causing earlier distortion. If you take measurements on live circuits, comparisons of such numbers as plate and cathode voltages would be interesting.
     
  16. slider313

    slider313 Tele-Afflicted Silver Supporter

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    It could be the bias voltage has shifted or it could simply be the construction of the tube. I have found that same tube types with different construction (plates, spacers, support rods, etc) can change the sound. The RCA 5Y3GT's I've used seem to sag and compress (earlier break up and less defined) the sound more so than the GE or Sylvania's I've used. The Bendix 6106 has the least amount of sag of any 5Y3 variant I've used.
     
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  17. King Fan

    King Fan Poster Extraordinaire

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    Great info from smart folks here. I'm not the smart guy to sort all the pieces and string 'em together. But first things first. @JDRNoPro , do you feel comfortable measuring a simple B+ voltage? As noted above, different rectifiers may drop voltage differently; and NOS often more than new issue. (JJ 5Y3s, IIRC, aren't like Sovtek, which are well-known to drop a lot less voltage than a 'real' 5Y3). At any rate, again as above, *if* what you're describing is less clean headroom at the same volume, that might easily follow from a bigger drop in voltage, which could easily happen with NOS.

    *If* your measured B+ was pretty much the same, *then* you could start to figure out how much other 5Y3 factors (NOS v. new, brand, age, construction) changed the sound of an amp in some more subtle way. Opinions vary, and that's 100% typical of tube <-> sound topics.

    In a perfect world, now, you'd also try more than one NOS tube. Could it be the one you got isn't in perfect health? I know rectifiers die, but I have no idea if they get sick and sound worse before they do.
     
  18. ThermionicScott

    ThermionicScott Poster Extraordinaire

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    That sounds right. The Bendix 6106 was indirectly heated, so it would act a bit more like a 5AR4, or what Electro-Harmonix/Sovtek sells as a "5Y3" these days.
     
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  19. slider313

    slider313 Tele-Afflicted Silver Supporter

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    The GE 5Y3WGTB /6087 is indirectly heated also. The Bendix is built like a tank and takes 50 seconds to a minute to warm up where the GE 6087 takes about 5 seconds.
     
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  20. radiocaster

    radiocaster Poster Extraordinaire

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    I tried that Wangs amp that has a switchable solid-state or tube rectifier, and the difference was huge.

    To me the tube sounded cleaner, more bassy, and less volume. The solid-state rectifier was brighter and more distorted at the same volume knob position.
     
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