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    VTA ST-120 channel separation specification?

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    eickmewg

    Posts : 43
    Join date : 2014-08-29

    VTA ST-120 channel separation specification?

    Post by eickmewg on Sat Dec 27, 2014 10:40 am

    I am wondering what the Latino VTA ST-120 amplifier channel separation specification might be. I can't find this specification in my assembly manual. The reason I ask is that I recently did some work to revitalize my old Hafler DH-200 amplifier that I built in 1982 and I wanted to see how it sounded with my recently built Transcendent Sound grounded grid preamplifier. I am using my old Polk SRS SDA 2.3 speakers which are designed to expand the sound stage beyond the speakers. To my surprise, the Hafler sound stage was noticeably wider, extending farther beyond the speakers, than that of the ST-120. The Hafler has typical channel separation of 60 to 66 dB, so says my assembly instruction manual. I was wondering how the single dual triode voltage amplifier tube on the VTA board might affect channel separation, or anything else in the amp causing the sound stage contraction with my Polks? Not a big deal, but it just got me to wondering. The Hafler is very nice with a strong bottom end but it lacks some of the mid-range warmth of the ST-120. Happy New Year!

    Bob Latino
    Admin

    Posts : 2414
    Join date : 2008-11-26
    Location : Massachusetts

    Re: VTA ST-120 channel separation specification?

    Post by Bob Latino on Sat Dec 27, 2014 11:11 am

    The VTA ST-120 channel separation has never been speced out .. It is, however, plenty wide enough to give very good channel separation. One thing to note > The VTA ST-120 does not invert phase. If you use the VTA ST-120 with a preamp that DOES INVERT PHASE then that inverted phase will be passed on to the ST-120. Inverted phase usually results in a narrower sound stage + loss of bass ..

    Bob

    eickmewg

    Posts : 43
    Join date : 2014-08-29

    Re: VTA ST-120 channel separation specification?

    Post by eickmewg on Sat Dec 27, 2014 11:53 am

    Interesting. So does anyone know if the Transcendent Sound grounded grid preamp inverts phase? If it does, can I just switch inputs at the speakers? Might the DH-200 invert phase? Thanks Bob for the information. I guess I need to fool with this stuff a little more.

    sKiZo

    Posts : 1312
    Join date : 2013-04-01
    Location : Michigan USA

    Re: VTA ST-120 channel separation specification?

    Post by sKiZo on Sat Dec 27, 2014 3:08 pm

    Interesting ...

    I suppose easiest way to tell would be to switch the speaker wires about and see what happens. Main indication of when it's wrong should be a cut in bass ...

    Not to forget ... the center driver tube can make a big difference in stage. Try swapping that and see if it opens up? I'm currently using an old production Telefunken 12AU7 there - second best would probably be an RCA clear top.

    PS ... don't ask me about what you should be hearing for separation and sound stage on the ST120. My system drives that with the front channels of a Sansui vario-matrix quad w/Carver holographic AND uses a Dynaco Quadraptor splitting the output on the rear channels. Meaning my stage is sort of ... unique.

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