Shiva 20th, KT88 --> EL34

Discussion in 'Amps and Cabs' started by JeKo, Feb 11, 2012.

  1. JeKo

    JeKo Member

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    Hi! Seems that many people have swapped the power tubes and I'm interested as well. I talked to Charlie at Bogner and he said that no mods are needed, just biasing. I just got a couple of questions:

    - Will EL34s tame the highs of the KT88s?
    - Does the overdrive channel still retain that Marshally flavor?
    - Do EL34s work well for quiet playing at small gigs?
    - What brand of EL34s do you recommend?

    I love the 20th already but I'd like to take it to the next step if possible :) Thanks guys!
     
  2. Gnarlly

    Gnarlly Member

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    - Will EL34s tame the highs of the KT88s?
    KT88's produce a wider spectrum of frequencies; EL34s should produce less highs (but you could just play with the amp's treble and presence controls)

    - Does the overdrive channel still retain that Marshally flavor?
    Probably more of a "Marshall" flavor; more mid emphasis and compression.

    - Do EL34s work well for quiet playing at small gigs?
    You wouldn't notice the difference (trust me). Whether with EL34s or KT-88s, that amp might not be the best choice for "quiet" "small" gigs.

    - What brand of EL34s do you recommend?
    Bogner usually recommends old Svetlana/current "Winged C" SED EL34s. I've also used EH EL34s in a Shiva before and liked them.
     
  3. rdodson

    rdodson Supporting Member

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    I've had both, 20th with EL34s and with KT88s. I'm a huge EL34 fan, and they sound great, but since the bias drifts so much in this design the KTs are more forgiving of that. In other words, if you bias the 34s to sound good at lower volumes you are going to cook them if you crank it. If you bias them at 28-29 ma as recommended, they will sound quite cold when the amp isn't being pushed.

    I have vids on my YouTube channel of both flavors. Search my name "Ron Dodson" and Shiva 20th.
     
  4. JeKo

    JeKo Member

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    Thanks guys! Great videos rdodson. So there isn't a nice compromise between the cold and hotter bias setting with EL34s? Playing live, I've not needed to set the master volume higher than 9 'o clock so I guess I don't crank the amp that much (channel volumes around 12 'o clock max).
     
  5. rdodson

    rdodson Supporting Member

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    If you don't crank it AND you aren't using the depth too much (or resonance or whatever it is called) then you can bias up at 32ma or so and it sounds MUCH warmer. If you crank it with that setting the output tubes won't last as long, and the amp will run a little hot.

    I've heard of some biasing upwards of 34ma and I bet that sounds awesome. But you will go through tubes.
     
  6. RSRD

    RSRD Member

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    bumpin to see if anyone prefers one to the other.
     
  7. joafink2

    joafink2 Supporting Member

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    I'm curious as well... Anyone?
     
  8. RSRD

    RSRD Member

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    I made the switch and will give back a report soon.
     
  9. rdodson

    rdodson Supporting Member

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    Big Country, post back soon. What bias setting did you go with? Clips! :)
     
  10. RockStarNick

    RockStarNick Supporting Member

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    I made the switch from KT88's to EL34's as well.

    THE MOD: My "mod" involved having to clip a piggybacked resistor by the gain pot. Super easy, not a big deal. I clipped one end, and wrapped it in shrink tubing, so that i could easily solder back if I wanted to.

    - Will EL34s tame the highs of the KT88s?
    Yes. It totally did for me. I just don't dig KT88s. They're hard and glassy sounding. The EL34s are much more warm, and classic sounding. More vocal, less brootalz.

    - Does the overdrive channel still retain that Marshally flavor?
    Yes. Even more so than the KT88s

    - Do EL34s work well for quiet playing at small gigs?
    Yup.

    - What brand of EL34s do you recommend?
    Winged C.

    In a nutshell, EL34's make it sound classic. KT88s make it sound modern and hard.

    +1 on everything Ron said about the Biasing. Shiva's have bias drift at higher volumes. Bias them on the cool side so you don't blow tubes when cranked.
     
  11. gearDude

    gearDude Member

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    I’ve considered switching the tubes in my 20th Shiva from KT88 to EL34. But, the 20th Shiva seems to really get its gain from the preamp section, so I didn’t think switching power tubes would make a significant difference (particularly since I don’t play the amp loud enough to clip the power section).


    Am I correct about this? Does the amp need to be LOUD in order to hear the difference in power tubes or will the difference in power tubes be apparent even at "pre-break-up" volumes?


    Thanks!
     
  12. JeKo

    JeKo Member

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    Hey again,

    Just wanted to ask one more thing related to this topic... Many people here seem to prefer EL34s so I was just wondering how big a difference does it really make to switch from KT88s. Is it as audible as changing speakers for example? You're now talking to a guy who can tell the difference between different speakers but not for example cables :)

    I've still got some life left in my KT88s but I'm seriously considering EL34s when the power tubes need to be changed.

    Thanks!
     
  13. JeKo

    JeKo Member

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  14. TNJ

    TNJ Gold Supporting Member

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    I havent switched from KT88's to EL34's in the same Shiva.
    I just went from the 20th Annie to the classic EL34 combo.
    I owned a 20th Annie Shiva head...KT88 power section.
    The cleans were phenomenal! The OD was too "modern" or "gainy" to my taste. I did a swap deal with a friend who had an EL34 112 Shiva combo.
    Immediately I got back those Shiva tones I always preferred.
    Cleans that are fabulous...a cross between BF Fender and Plexi, but a bit different from the KT88 cleans.
    And OD tones that are really close to a good JCM800 Marshall.

    Hope this helps...

    S.
    j
     
  15. JeKo

    JeKo Member

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    Thanks! Seems that El34s are the way to go, no doubt. Still just curious as to how much they will affect the overall sound. But I guess I'll need to do the switch and find out myself!
     

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