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    Dynaco VTA ST120/Magnapan 1.6 QR ?

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    scottlowe76

    Posts : 15
    Join date : 2017-06-15

    Dynaco VTA ST120/Magnapan 1.6 QR ?

    Post by scottlowe76 on Wed Oct 18, 2017 11:43 am

    I have a friend with a pair for sale . I want to know if any one has tried these with a VTA ST 120 ? would that be ok ? i know them to be power hungry . I just wonder if this combo would sound good ?
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    deepee99

    Posts : 1759
    Join date : 2012-05-23
    Location : Wallace, Idaho

    Re: Dynaco VTA ST120/Magnapan 1.6 QR ?

    Post by deepee99 on Wed Oct 18, 2017 12:40 pm

    86 dB would be stretching it for an ST-120.
    A workaround the Maggies would be adding a used Vandersteen 2W powered subwoof, with the requisite filter,
    https://www.ebay.com/itm/Vandersteen-V2W-Subwoofer-In-Near-MINT-shape-/202082444062?hash=item2f0d0d631e:g:RXYAAOSwFYxZ2pQW
    for example, takes a lot of the heavy lifting off the tubes and fills in the bass that all Maggies famously lack while preserving their nonpareil mids and highs.
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    wgallupe

    Posts : 114
    Join date : 2014-05-18
    Age : 63
    Location : Central Mass.

    Re: Dynaco VTA ST120/Magnapan 1.6 QR ?

    Post by wgallupe on Wed Oct 18, 2017 1:03 pm

    When I had an ST120 I tried it on a pair of MMGs (same efficiency rating as 1.6QR). To be honest the ST120 sounded good at lower volumes but struggled at anything above 'average' volume.  The same amp kicked a$$ on a pair of GR Research OB5s (91dB rating).

    Nowadays I have a pair of VTA/Mark III monoblocks that, interestingly enough work quite well and achieve high volume with the same MMGs. The two amps have the same output power rating, same KT120 output tubes and similar VTA driver board so I have to believe the difference in performance comes from the dual/independent power supplies.

    If I were in your shoes I would start with one ST120 and then when funds permit, add a second and wire one amp to each speaker (one channel to the low frequencies, the other to high frequencies). Of course the best approach would be to sell the ST120 and go with a pair of M125s Very Happy  

    Wayne

    scottlowe76

    Posts : 15
    Join date : 2017-06-15

    Re: Dynaco VTA ST120/Magnapan 1.6 QR ?

    Post by scottlowe76 on Wed Oct 18, 2017 1:30 pm

    I use a jbl 2245 h in a 12'cubic ft box tuned to 30 cycles . so would that help ?
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    deepee99

    Posts : 1759
    Join date : 2012-05-23
    Location : Wallace, Idaho

    Re: Dynaco VTA ST120/Magnapan 1.6 QR ?

    Post by deepee99 on Wed Oct 18, 2017 2:13 pm

    scottlowe76 wrote:I use a jbl 2245 h in a 12'cubic ft box tuned to 30 cycles . so would that help ?

    Doubt it, unless you're using a high-bypass filter in between the preamp and power amp(s). The Maggies are still going to be sucking on the tubes across the full spectrum without one.
    Here's Vandersteen's take on it:
    The Vandersteen subwoofer interface is unique. A first-order, passive high-pass filter is placed in front of the main amplifier. The subwoofer samples the output from the filtered main amplifier and corrects for the roll-off that has been introduced. This is the only way to provide a true, first-order blend between the subwoofer and the main speakers that is transparent and seamless.

    A passive high-pass filter is as transparent as the input coupling capacitor that is probably present in the amplifier already and may actually improve the sound of direct-coupled amplifiers that use servo circuits instead. Sampling the output of the main amplifier passes along to the subwoofer the sound and propagation speed of the amplifier that drives the main speakers for a seamless blend between the two.

    For additional explanation read the Audio Perfectionist review of the 2Wq. You can find it in the Reviews section of our website.

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    Peter W.

    Posts : 527
    Join date : 2016-08-07
    Location : Melrose Park, PA

    Re: Dynaco VTA ST120/Magnapan 1.6 QR ?

    Post by Peter W. on Wed Oct 18, 2017 2:14 pm

    scottlowe76 wrote:I have a friend with a pair for sale . I want to know if any one has tried these with a VTA ST 120 ? would that be ok ? i know them to be power hungry . I just wonder if this combo would sound good ?

    Somehow this did not get through the first time.  

    a) Maggies are gorgeous-sounding speakers. Sometimes awkward to place due to their size and stand-off requirements.
    b) Maggies are power-pigs. The ones you mention are 4-ohm fixed impedance, so the 8-ohm tap will do well.
    c) Maggies are not subject to electrodynamic braking (Damping Factor) - so there is no intrinsic disadvantage to a tube amp with a typically low DF.

    http://www.integracoustics.com/MUG/MUG/articles/speakers.html

    If you have a moderate room with moderate acoustics and listen at moderate levels, you will be fine with a 60-watt RMS amp. Truly. However, if you have ambitions of volume and near-live levels of reproduction for highly dynamic signal, not gonna happen.

    I keep MG-IIIa speakers - and a 200+ watt RMS amp is adequate in a large room. My 75-watt RMS tube amp simply failed at above-moderate volume.

    scottlowe76

    Posts : 15
    Join date : 2017-06-15

    Re: Dynaco VTA ST120/Magnapan 1.6 QR ?

    Post by scottlowe76 on Wed Oct 18, 2017 2:31 pm

    Peter W. I planned on an active x-over before the st-120 . I know the 2145 h is usable up to at least 200 cycles that should take alot of stress off of st-120 ? I would be using in a 12x12 fott room so ive read they can sound ok in a small room . thanks for your input .
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    Peter W.

    Posts : 527
    Join date : 2016-08-07
    Location : Melrose Park, PA

    Re: Dynaco VTA ST120/Magnapan 1.6 QR ?

    Post by Peter W. on Wed Oct 18, 2017 3:10 pm

    scottlowe76 wrote:Peter W. I planned on an active x-over before the st-120 . I know the 2145 h  is usable up to  at least 200 cycles  that should take alot of stress off of st-120 ? I would be using in a 12x12 fott room  so ive read they can sound ok in a small room . thanks for your input .

    12 x 12 is tiny for those Maggies.
    You will be fine with the 120!
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    j beede

    Posts : 412
    Join date : 2011-02-07
    Location : California

    Re: Dynaco VTA ST120/Magnapan 1.6 QR ?

    Post by j beede on Fri Oct 20, 2017 2:00 am

    I've owned ten pairs of Magneplanar speakers going back to 1977. The 1.6-QR sound unlike any other Magneplanar that I have owned or currently own. If you can audition them in your own listening room before purchasing them, I would strongly recommend you do so.

    Small room? I find a pair of MkIIIs driving SMGA or MMG to be a musical and enjoyable combination.

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