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    VTA Amp For 85db Speakers

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    Jeff V.

    Posts : 34
    Join date : 2014-08-02

    VTA Amp For 85db Speakers

    Post by Jeff V. on Sun Sep 21, 2014 11:16 am

    I am wondering if the ST-120 would be sufficient to drive a pair of Selah Tempesta? Impedance: 5 ohms/nominal, 4 ohms/minimum, Sensitivity: 85.5dB. Or would the M-125 mono's be a better fit? I'm currently running a pair of Ncore 400 mono amps. They do sound wonderful, but after building the SP14 preamp I'm thinking about trying one of the VTA amps. Thanks!

    -Jeff


    PeterCapo

    Posts : 380
    Join date : 2008-12-05

    Re: VTA Amp For 85db Speakers

    Post by PeterCapo on Sun Sep 21, 2014 11:38 am

    Depends on the size of your room and how loud you like to listen.

    We don't listen loudly and have speakers with efficiencies in the low 80s in a 12x17 room, and we run them with a Stereo 35 or a Stereo 70 just fine.

    Jeff V.

    Posts : 34
    Join date : 2014-08-02

    Re: VTA Amp For 85db Speakers

    Post by Jeff V. on Sun Sep 21, 2014 2:43 pm

    Thanks Peter!  My room is 15'x18' with my listening position 10' from speakers.  I don't listen excessively loud but will crank it up at times.  

    -Cheers


    Last edited by Jeff V. on Sun Sep 21, 2014 3:25 pm; edited 1 time in total

    mazeeff

    Posts : 115
    Join date : 2014-01-06
    Age : 61
    Location : Grand Rapids, Michigan, USA

    Re: VTA Amp For 85db Speakers

    Post by mazeeff on Sun Sep 21, 2014 3:17 pm

    Based on this calculator previously posted by audiobill, the VTA-120 would be able to drive those speakers to about 88-90 dBSPL.

    http://www.crownaudio.com/elect-pwr-req.htm

    Mike

    sKiZo

    Posts : 1285
    Join date : 2013-04-01
    Location : Michigan USA

    Re: VTA Amp For 85db Speakers

    Post by sKiZo on Sun Sep 21, 2014 3:19 pm

    Ten inches from the speakers? I think that would qualify as "near field listening" ...

    I drive an ST120 to ridiculous levels with plenty to spare - 100+ SPL on the crescendos with a 6db cut on the preamp signal and a couple notches left on amp gain. KT120 tubes and 89db McIntosh XR16 big box speakers. Room hovering bass with exceptional air. The amp is the front half of a quad system and I've got two sets of speakers via a Dynaco Quadraptor in hafler mode to fill in the ambiance. Primary seating position is around six feet, so room size isn't really an issue here.

    Your call, but I'm sure you'd be happy with the ST120 using the four ohm taps. That setup isn't very well documented, but I'm sure Bob can fill in the details ...

    Bob? Oh Bob ... wherefore art thou?

    Bob Latino
    Admin

    Posts : 2374
    Join date : 2008-11-26
    Location : Massachusetts

    Re: VTA Amp For 85db Speakers

    Post by Bob Latino on Sun Sep 21, 2014 3:24 pm

    Hi Jeff,

    The VTA ST-120 is conservatively rated at 60 WPC but will put out more power than advertised. A 15 X 18 room is not terribly large. The VTA ST-120 would drive your 85+ dB speakers to volume levels that would satisfy you ..

    Bob

    Jeff V.

    Posts : 34
    Join date : 2014-08-02

    Re: VTA Amp For 85db Speakers

    Post by Jeff V. on Sun Sep 21, 2014 3:28 pm

    sKiZo wrote:Ten inches from the speakers? I think that would qualify as "near field listening" ...

    Good catch!  Also my room is bigger than 15"x18" lol! . I corrected the earlier post.  Listening position is 10 feet.  Thanks!!!

    Jeff V.

    Posts : 34
    Join date : 2014-08-02

    Re: VTA Amp For 85db Speakers

    Post by Jeff V. on Sun Sep 21, 2014 3:29 pm

    Bob Latino wrote:Hi Jeff,

    The VTA ST-120 is conservatively rated at 60 WPC but will put out more power than advertised. A 15 X 18 room is not terribly large. The VTA ST-120 would drive your 85+ dB speakers to volume levels that would satisfy you ..

    Bob

    Good to know Bob. Much appreciated!

    -Jeff

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