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    VTA Mk III triode mode fans?



    Posts : 64
    Join date : 2010-09-03

    VTA Mk III triode mode fans?

    Post by Dingojazz on Fri Apr 25, 2014 4:01 pm

    Anyone added this option for their Mk IIIs?  I recently completed octal VTA versions and am enjoying them a lot.  Just wondering if there are any reviews of triode mode for these?
    I  added triode option to  my ST 70, but I don't use it much, as it just sounds like somebody dropped a wet blanket over the speakers.  
    Just wondering if there are any Mk III users who have tried/like this mod.



    Posts : 1466
    Join date : 2013-04-01
    Location : Michigan USA

    Re: VTA Mk III triode mode fans?

    Post by sKiZo on Fri Apr 25, 2014 7:31 pm

    Triode mode will give more or less the same results on any push/pull amp. I think of it as more or less a quickie tube swap without swapping tubes. Gives you another tonal option with a flip of the switches. The sound tends to be more laid back and mellow - good for late night listening, and especially nice for jazz and female vocals. You DO lose a bit of power in triode mode as it's not as efficient as pentode, so that may factor in if you're already working it hard. That said ...

    My ST120 has triode mode, and I seldom use it anymore. Switched it in regularly when I first got the amp, but I've since voiced the room and gotten rid of the brightness that had made me want to use it in the first place. I find I can accomplish the same thing with tube selection. Currently running a 5963 in the center - that tends to be a bit dark. I compensate for that with a matched set of 1940's RCA foil getter cleartops - which tend to be bright. Together, they're close, and I fine tune that with my TubeMagic Dac using a tasty little Western Electric JW2C51.

    So anyway. It's all in the ear of the beholder. If this sounds like something you want or need, go for it. Be sure to report back with the results.

    PS ... worth mentioning - laid back ain't my style, and I'm in the middle of nowhere, so I don't get too worked up about turning it down for late night listening ...


    Posts : 64
    Join date : 2010-09-03


    Post by Dingojazz on Fri Apr 25, 2014 10:26 pm

    Well, this amp's different from my ST70 in that it's got octal drivers, and an SP14 pushing it, so there's a lot of potential for tube changes in the chain.  

    I like current combination of Sylvania to RCA redbase 6SN7 in the preamp driving another Sylvania / RCA 6SN7 combo to GL KT88 in the amp.  Produces plenty of mid range, bass and sparkle without glare.  

    I'm totally happy with this combo, just wondering if anyone had found audio nirvana with triode switching in the Mk IIIs.


    (You know the syndrome...- is someone maybe having more fun with their amp than me....Wink

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