6550 tubes in a Jubilee?

Discussion in 'The Workbench' started by JacksonCharvelAddict, Aug 19, 2019.

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  1. JacksonCharvelAddict

    JacksonCharvelAddict Well-Known Member

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    I was wondering if anyone here has ever tried running 6550s in a 2555x or oryer model Jubilee. I know that they have a lot more headroom than el34s but I have also heard that they allow a wider frequency range. I thought maybe with the versatile EQ of the Jube it could benefit from this. I have some 6v6s I have been tempted to try as well.
     
  2. scozz

    scozz Well-Known Member

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    I was thinking about those tubes as well in my Jcm800 Studio, but when I heard about the more headroom part I moved on. I’m not interested in getting more headroom, I like the balance I have now.

    I’m completely happy with the EL34s I’ve got in there now. Although I must say I’m very interested in Tong-Sol EL34B. :hmm:
     
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  3. JacksonCharvelAddict

    JacksonCharvelAddict Well-Known Member

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    There are so many tubes to choose from for different purposes. I think the increased headroom would be handy for anyone that uses the Jubilee as a power amp. I frequently use my Kemper through the loop return and the increased headroom may help that at higher volumes.
     
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  4. Adrian R

    Adrian R Well-Known Member

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    Duuuudde! I never thought of that before...holy crap...got gas now..damn... That's what's great about the new Jube...the ability to run any power tube. I will have to try some out...


    Thanks man...
     
  5. RickyLee

    RickyLee Well-Known Member VIP Member

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    I have 6550 in my Jubilee Clone. My Clone has much beefier/higher power rated transformers though. Getting increased headroom in an EL34 spec'ed 50W/100W amp might not be fully attained to a 35W 6550, but be careful biasing them up regardless.

    As for the new Jubilee? I am not sure what the power supply is spec'ed for.
     
  6. DonP

    DonP Member

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    You can't just stuff whatever tubes in an amp unless the amp allows for them.

    6550's require a more negative bias. In order to use them in older JCM800's, you would have to modify the bias circuit. I don't know if the 2555X requires the same mods.

    On the other hand, my Randall RM100LB is designed to allow any power tube to run in it, and even mixed tubes. Each tube has it's own bias circuit.

    6V6's can only take so much B+ voltage. Sticking them into an amp with too much B+ will make them pop.
     
  7. Gunner64

    Gunner64 Well-Known Member Premium Member

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    The 2555x can use 6550s, and others. There's a tag next to the bias points that has a chart for settings. 2939fb1f-ae8c-4800-b226-5e53578a0ab5-jpeg.jpg
     
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  8. MarshallDog

    MarshallDog Well-Known Member Premium Member

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    Now that’s a great feature!
     
  9. Gunner64

    Gunner64 Well-Known Member Premium Member

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    Yea, it's pretty cool. All Amps should have this set up.
     
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