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    VTA ST-120 and ohms

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    coolhandjjl

    Posts : 5
    Join date : 2012-12-28

    VTA ST-120 and ohms

    Post by coolhandjjl on Thu Feb 28, 2013 6:02 pm

    I was looking at the pics of the VTA ST-120, and it has just one pair binding posts per channel instead of the usual multiple output terminals where you attach your leads to the impedance of your actual speakers. Can the VTA ST-120 be configured with multiple impedance outputs, or do you have to internally wire it to handle 4 ohm speakers? Oh yeah, can it handle 4 ohm speakers?

    Thanks in advance!

    peterh

    Posts : 643
    Join date : 2012-12-25
    Location : gothenburg, sweden

    Re: VTA ST-120 and ohms

    Post by peterh on Thu Feb 28, 2013 6:15 pm

    coolhandjjl wrote:I was looking at the pics of the VTA ST-120, and it has just one pair binding posts per channel instead of the usual multiple output terminals where you attach your leads to the impedance of your actual speakers. Can the VTA ST-120 be configured with multiple impedance outputs, or do you have to internally wire it to handle 4 ohm speakers? Oh yeah, can it handle 4 ohm speakers?

    Thanks in advance!
    The classical 4 terminal posts will fit. I think you may order your vta-120 with them too.

    http://www.triodeelectronics.com/dyna-termstrip.html

    There is also industry "barrier-strip" one example :
    http://www.te.com/catalog/bin/TE.Connect?C=16676&M=PPROP&P=2323&BML=10576,17560,17844&LG=1&PG=1&IDS=232201,232309,145511,146804,145672,145788,145791,144379,144608,144609,144728,144823,144853,144932,147907,147916,146315,146353,146733,146772&N=1


    Bob Latino
    Admin

    Posts : 2378
    Join date : 2008-11-26
    Location : Massachusetts

    Re: VTA ST-120 and ohms

    Post by Bob Latino on Thu Feb 28, 2013 7:30 pm

    coolhandjjl wrote:I was looking at the pics of the VTA ST-120, and it has just one pair binding posts per channel instead of the usual multiple output terminals where you attach your leads to the impedance of your actual speakers. Can the VTA ST-120 be configured with multiple impedance outputs, or do you have to internally wire it to handle 4 ohm speakers? Oh yeah, can it handle 4 ohm speakers?

    Thanks in advance!

    The VTA ST-70 and VTA ST-120 may be set up for either 4, 8 or 16 ohm speakers. Both output transformers have a separate tap for each of the three impedances. You just connect the one that you want to the red binding post inside the amp. If you have TWO sets of speakers and one is say 4 and the other 8 ohm, we do have the the optional (at extra cost) VTA 3 post binding posts, which may be set up for any combination of TWO of the impedances like 4 and 8 ohms or 8 and 16 ohms or 4 and 16 ohms.

    Bob

    coolhandjjl

    Posts : 5
    Join date : 2012-12-28

    Re: VTA ST-120 and ohms

    Post by coolhandjjl on Thu Feb 28, 2013 8:52 pm

    Thanks Bob. The 3-way (8 & 4) seems ideal to make the amp flexible for future use.

    On another issue, (aside from drilling holes, adding wiring, et.) can the rca inputs be moved to the rear, and the power switch be moved to the front without affecting performance?

    Bob Latino
    Admin

    Posts : 2378
    Join date : 2008-11-26
    Location : Massachusetts

    Re: VTA ST-120 and ohms

    Post by Bob Latino on Thu Feb 28, 2013 9:01 pm

    I suppose you could do what you propose by altering the chassis and drilling holes in the rear face for two input jacks. Running two input lines to the back of the amp should be done using shielded cable so that input wiring does not pick up noise from the power transformer.

    Bob

    coolhandjjl

    Posts : 5
    Join date : 2012-12-28

    Re: VTA ST-120 and ohms

    Post by coolhandjjl on Thu Feb 28, 2013 11:50 pm

    So I could use shielded cable with two conductors. Would I connect the shield at each end to the chassis?

    Regarding the switch for power cord, would that create any noise by passing so close to the underside of the main board up front?

    peterh

    Posts : 643
    Join date : 2012-12-25
    Location : gothenburg, sweden

    Re: VTA ST-120 and ohms

    Post by peterh on Fri Mar 01, 2013 3:14 am

    Regarding power switch;
    i installed an SSR(solid state relay) at the back, and a connector for DC . To power on
    i tap my preamp for control voltage.( anywhere from 3 to 32V, one mA will do)


    Bob Latino
    Admin

    Posts : 2378
    Join date : 2008-11-26
    Location : Massachusetts

    Re: VTA ST-120 and ohms

    Post by Bob Latino on Fri Mar 01, 2013 9:05 am

    coolhandjjl wrote:So I could use shielded cable with two conductors. Would I connect the shield at each end to the chassis?

    Yes ...

    Regarding the switch for power cord, would that create any noise by passing so close to the underside of the main board up front?

    It is best to run the power cord wiring around the side of the amp so it does not pass over the driver board.

    Bob

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