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    New tube combos help on VTA70 mod

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    Bigron865

    Posts : 45
    Join date : 2013-03-15
    Age : 48
    Location : Birmingham Alabama

    Re: New tube combos help on VTA70 mod

    Post by Bigron865 on Fri Mar 29, 2013 6:51 am

    I'm using 2 jj ecc82 on the sides and a GE 5814 in the center and it seems to mellow the upper mids. I like it.

    peterh

    Posts : 641
    Join date : 2012-12-25
    Location : gothenburg, sweden

    Re: New tube combos help on VTA70 mod

    Post by peterh on Fri Mar 29, 2013 7:14 am

    Bigron865 wrote:I'm using 2 jj ecc82 on the sides and a GE 5814 in the center and it seems to mellow the upper mids. I like it.
    Yes i use jj ecc82 on all 3. Much better !
    In addition i also use jj 6550.



    Bigron865

    Posts : 45
    Join date : 2013-03-15
    Age : 48
    Location : Birmingham Alabama

    Re: New tube combos help on VTA70 mod

    Post by Bigron865 on Wed Apr 03, 2013 8:59 am

    I ordered a trio of EH12AU7's that should be here tomorrow. I seem to be looking for more lower/mid tones on my system. Could it be that I'm still using a NAD ss preamp? The Klipsch RB61II speakers have horns and can be a bit harsh sometimes. Great bass and sizzle but mids are either bright or distant depending on the record. If I'm still having these issues after I roll in the EH tubes, what would you reccomend gor a much warmer center tube with the VTA board?

    Ron

    Bigron865

    Posts : 45
    Join date : 2013-03-15
    Age : 48
    Location : Birmingham Alabama

    Re: New tube combos help on VTA70 mod

    Post by Bigron865 on Sat Apr 06, 2013 8:57 am

    Received a new matched trio of EH 12AU7's yesterday. I have to say that I immediately noticed sonic characteristics "Lining-Up" I'm not sure how else to put it? It seemed that the soundstage widened a bit, vocals and lead instruments became more centered and a tad sweeter. Played the first pressing of Aja, Donald Fagen Nightfly and the new vinyl pressing of Diana Krall's Glad Rag Doll. All very well recorded material. These usually sound great on just about anything but I noticed much more sizzle and controlled attack on vocals. Three some CDs on later and the sweetness continued from Lou Rawls to Madlyn Peroux. I'm very pleased with the EH tubes. Now I have the vta70 running all Electro Harmonix 6CA7's and 12AU7's. My upgraded quad cap, PIO caps and new binding posts will be here next week. Read Bobs posts about Triode mode and considering giving that a try. What do you think?

    pjp3

    Posts : 39
    Join date : 2013-03-19
    Age : 54
    Location : Pelham, AL

    Re: New tube combos help on VTA70 mod

    Post by pjp3 on Sat Apr 06, 2013 11:44 am

    That sounds awesome Ron. I need to check that out sometime,

    nerpissad

    Posts : 58
    Join date : 2012-09-16
    Age : 43
    Location : amsterdam

    Re: New tube combos help on VTA70 mod

    Post by nerpissad on Mon Apr 08, 2013 7:56 am

    well, I went from sylvania (which I ordered together with my ST70 kit) to one telefunken 12AU7 (center) and two mullard cv4003's (left and right).
    I find it hard to really distinguish the difference between these two sets of tubes. I was told the sylvania's themselves were not bad tubes at all. but I expected a greater difference between these tubes.
    the driver tubes are supposed to have the biggest sonic impact, so I think I'll be leaving the EL34's alone for a while Wink

    Bigron865

    Posts : 45
    Join date : 2013-03-15
    Age : 48
    Location : Birmingham Alabama

    Re: New tube combos help on VTA70 mod

    Post by Bigron865 on Mon Apr 08, 2013 8:39 pm

    The quest continues... If you remember my previous post. I have been listening with the matched trio of EH12AU7's. well they sound great but for some reason I swapped the middle tube with an RCA 5814A Clear Top this afternoon. Wow! is this is a fantastic combo!!!. It's much smoother and tons of air and smooth mids. It seemed to really tame the horn harshness of my Klipsch but left the upper sparkle. I really like what I heard tonight! The PIO's are on their way too. Looks like a fun upcoming weekend.

    Ron

    corndog71

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    Join date : 2013-03-19
    Location : It can get windy here

    Re: New tube combos help on VTA70 mod

    Post by corndog71 on Mon Apr 08, 2013 10:39 pm

    I'm a big fan of Valve Art tubes from Antique Electronics. In my old ST70 and now in my MkIVs they sound very musical and detailed. It's been a while but I found EH tubes to be kind of boring sounding. I haven't tried JJ EL34s but I had a bad run of JJ 5AR4 tubes. I've had good results with Ruby 5AR4s. I do use JJ 6922 tubes in my Curcio driver circuit and they seem decent. Since I changed my ST35 tubes to all Genalex I've been blown away by them! If I wasn't trying to sell my MkIVs I'd probably get some Genalex KT77s for them. Another good source would be RAM Labs for selected tubes.

    pjp3

    Posts : 39
    Join date : 2013-03-19
    Age : 54
    Location : Pelham, AL

    Re: New tube combos help on VTA70 mod

    Post by pjp3 on Tue Apr 09, 2013 10:03 am

    I'm running two NOS Raytheon blackplate 1950's 12AU7 with a NOS Mullard longplate 12AU7. This seems to be a match made in heaven,
    at least for my system. Smooth mid tones with with a 3D soundstage and just the right amount of sparkle up top and tight solid bass.
    I tried a matched quad of Golden Lion KT66 tubes this weekend, the sound wasn't as pleasing to ears or my system as the GT EL34's I run.
    I really like this combo.

    Bigron865

    Posts : 45
    Join date : 2013-03-15
    Age : 48
    Location : Birmingham Alabama

    Re: New tube combos help on VTA70 mod

    Post by Bigron865 on Sat Apr 13, 2013 9:37 pm

    OK. Very productive Saturday! I installed the PIO caps, upgraded quad cap, new binding posts and the triode/pentode switches. The VTA 70 is sounding pretty good now. I think I need the break in/burn in time to get things settled down a bit. I did some Triode mode comparisons today too. Definately much warmer to me and will hopefully get better. Popped a fuse last night when I turned off the amp after several hours listening, to roll a new center tube. Did the swap pretty quick and turned it back on...pop! The 3a fuse blew. Not sure why but it worked fine today with a new fuse. The amp still seems bright with the Klipsch but hoping it will settle down soon. Soundstage is still great and I'm noticing a little more bass with the upgraded quad cap. Keep in mind that I'm still using a solid state pre and a solid state phono stage. Got my hopes up for a tube preamp project next. Thanks to Bob and Roy for the help with questions.

    Ron

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