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    My VTA ST120

    Analog Man
    Analog Man

    Posts : 56
    Join date : 2013-09-01
    Age : 56
    Location : St. Louis, MO - On The Hill

    My VTA ST120 - Page 2 Empty Re: My VTA ST120

    Post by Analog Man on Wed Mar 05, 2014 9:59 pm

    corndog71 wrote:
    arledgsc wrote:Gulp!   afro   Be sure and bleed those caps before working on the amp..

    Nice amp.  All this amp building creativity is giving me the itch to build a KT150 amp.

    If you can find suitable transformers let me know.  Sounds like fun!
    Edcor.com

    450-0-450 vac @ 300ma + 6.3 vac 6amps for power transformers, I got from Edcor.
    arledgsc
    arledgsc

    Posts : 493
    Join date : 2012-11-30
    Location : SF Bay CA

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    Post by arledgsc on Wed Mar 05, 2014 10:29 pm

    Edcor.com

    450-0-450 vac @ 300ma + 6.3 vac 6amps for power transformers, I got from Edcor.
     Shocked That should do it!
    corndog71
    corndog71

    Posts : 702
    Join date : 2013-03-19
    Location : It can get windy here

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    Post by corndog71 on Thu Mar 06, 2014 2:30 am

    I replaced the 12AU7 driver tubes I was using for a set of RAM Labs standard grade 12BH7 tubes. I don't know what the original makes of the tubes are. If I can ever get this amp out of my rack maybe I'll take a closer look. For the time being I'm too busy listening to music.

    My VTA ST120 - Page 2 IMG_8583_zps5e3104c0

    Noise went down and width, depth, and clarity improved.

    My VTA ST120 - Page 2 IMG_8588_zps2c1cbd85

    I really want to get KT120s but so far these 6550s sound really good. Someday...
    corndog71
    corndog71

    Posts : 702
    Join date : 2013-03-19
    Location : It can get windy here

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    Post by corndog71 on Sun Mar 23, 2014 12:02 pm

    I made a small change. I swapped the Clarity Cap ESA .1uF caps for Clarity MR series .1uF caps. It was sounding great as is but I know the MR caps are much more transparent than the ESA series particularly in the higher frequencies. I didn't notice a huge change although separation of instruments in the soundstage seems better. Plucked and strummed strings seem more dynamic. Or it could just be in my head.  Wink 

    My VTA ST120 - Page 2 IMG_8643_zps7a1384a1
    corndog71
    corndog71

    Posts : 702
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    Post by corndog71 on Sun Apr 06, 2014 2:01 pm

    I kinda feel like Skizo by posting yet another pic of my amp tongue but here goes.

    My VTA ST120 - Page 2 IMG_8721_zps40fd4f3e

    Notice anything different?
    arledgsc
    arledgsc

    Posts : 493
    Join date : 2012-11-30
    Location : SF Bay CA

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    Post by arledgsc on Sun Apr 06, 2014 2:14 pm

    Notice anything different?
    Just guessing triode/ ultralinear switches ??
    corndog71
    corndog71

    Posts : 702
    Join date : 2013-03-19
    Location : It can get windy here

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    Post by corndog71 on Sun Apr 06, 2014 2:29 pm

    arledgsc wrote:
    Notice anything different?
    Just guessing triode/ ultralinear switches ??

    We have a winner!  I forgot to take a pic after installing them so this is an under the hood shot.  Not the greatest but you get the gist.  I didn't even need the terminal strips.

    My VTA ST120 - Page 2 IMG_8709_zpsf779c670

    It's getting a bit crowded in here.

    My VTA ST120 - Page 2 IMG_8736_zps128a3b32

    My VTA ST120 - Page 2 IMG_8739_zps221ca503

    I have to admit that triode mode sounds way better than I anticipated. I had converted my first ST70 (with Curcio mods) around a decade ago and for whatever reason didn't care for it. The last few nights listening to Dave Brubeck, Mozart, Chopin, and Vivaldi have been quite glorious.  Shocked  Cool 

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