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    Interested in trying different driver tubes

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    Sutton

    Posts : 12
    Join date : 2011-04-30

    Interested in trying different driver tubes

    Post by Sutton on Thu Jun 30, 2011 1:12 pm

    I, too, would love to have a little more gain, and I think it could be accomplished with tubes, maybe. I just don't know what will work in the circuit and what won't as there are no direct substitutes for a 12BH7 tube. Will an ECC99 work in either position in the circuit, and would it give slightly more gain? Maybe as a compromise, a slightly higher gain version of the driver board could be offered. It might not take much, and I don't want to cast anything but praise for these wonderful amps, but I juest don't understand why I have to turn the volume on the preamp up almost full tilt to get the same volume I can get from an amp with half the power rating and the preamp at 10 o'clock position. And I'm running the KT-120's which should be able to throw some real juice at speakers.

    I love the M-125's. Never doubt that...I am just trying to get everything from them that I can, and maybe the headroom is a great thing to have, but I'd love to get some more gain. Please don't be offended at me for this, I've just never quite encountered anything like this before. I am trying to be constructive, and to try to speak for others who may have a similar itch, but remein silent on the subject...

    Westy56

    Posts : 58
    Join date : 2011-05-09
    Location : Albuquerque

    Re: Interested in trying different driver tubes

    Post by Westy56 on Thu Jun 30, 2011 1:17 pm

    A CV5042 should be close?
    Don't know if they are hard to find.


    Steve

    Sutton

    Posts : 12
    Join date : 2011-04-30

    Re: Interested in trying different driver tubes

    Post by Sutton on Sat Jul 02, 2011 2:10 pm

    I recently tried a 6189W in the first position on the M-125 driver board, and I think it is THE ONE for this position in this driver board. I loved the CV4003, which was a Mullard complete with the Mullard sheild and the M8136 designation on the other side from the CV4003 information. I have tried Amperex, Telefunken, Electro Harmonix, Ei, RCA, Mullard and about every 12AU7 I had in my stash, and really liked the CV4003 (which has the reputation as the best 12AU7 ever made), but when I placed this JAN Sylvania 6189W in the position, it just seems to be the perfect tube for the position. The bass appeared to become fuller and firmer, the mids became even more liquid, and the top end just sparkles and there is air everywhere. The 6189W is NOS and has a very high gm, and has perfectly matched sections, but it is the real deal. I am now very happy. I will leave the 6189W in first position, and the black plate RCA 12BH7A in the back position, and already have backup tubes ordered. I think I found the combination. I'd still like to try the 5814A, but I don't know if it could come close. But if I get my nerve up, I'll try it.

    Try the 6189W and see what you think..

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