The Dynaco Tube Audio Forum

Dedicated to the restoration and preservation of all original Dynaco tube audio equipment - Customer support for Dynaco VTA tube amp kits, all Tubes4hifi.com products and all Dynakitparts.com products


    Sutherland solid state driver board for the Dynaco ST-70

    Share

    Bob Latino
    Admin

    Posts : 2411
    Join date : 2008-11-26
    Location : Massachusetts

    Sutherland solid state driver board for the Dynaco ST-70

    Post by Bob Latino on Wed Jul 30, 2014 8:44 pm

    In the 1980's there was an all solid state driver board for the Dynaco ST-70. The Sutherland board used JFETs and MosFets in combination to drive the output tubes. Although the Sutherland board stopped production in 1990, a company called Nobis Technologies in Wisconsin produced an ST-70 like amp in the 1990's using the Sutherland solid state driver circuit. It was called the Nobis Cantabile and had solid state rectification, an under chassis cap board and an LED system to set the bias. Considering the $1700 price tag on the Nobis Cantabile, not too many were sold. Nobis Technologies ceased production of this amp in about 2004. Every now and then one will show up on Ebay ..

    Bob

    Below are a two photos of an original Dynaco ST-70 modified with a Sutherland board. The last photo is of a production model Nobis Cantabile.







    sKiZo

    Posts : 1310
    Join date : 2013-04-01
    Location : Michigan USA

    Re: Sutherland solid state driver board for the Dynaco ST-70

    Post by sKiZo on Wed Jul 30, 2014 10:06 pm

    The Nobis is a legitimate high-end tube amp, offering sound quality on a par with many of the better-known companies on the market. If your listening requirements don't include louder-than-hell levels and bass-bass-bass-all-over-the-place, the Nobis Cantabile deserves a serious audition.

    http://www.stereophile.com/tubepoweramps/992nobis/


    gooch

    Posts : 2
    Join date : 2016-03-05
    Location : Florida

    Re: Sutherland solid state driver board for the Dynaco ST-70

    Post by gooch on Sat Mar 19, 2016 11:32 am

    Anyone heard that amp? I know someone who has the original Sutherland board still in the box with all the instruction. I wondering if it is worth a try in a ST70. I have a ST70 with the Curcio PWB-3A CCDA DRIVER AMPLIFIER board I did some years back for the most part it sounds good but the bass is not a tight as I would like. Now maybe that just tubes I don't know seeing I don't have another tube amp to compare it to.


    Regards

    Dave

    tubes4hifi
    Admin

    Posts : 1286
    Join date : 2008-11-30

    Re: Sutherland solid state driver board for the Dynaco ST-70

    Post by tubes4hifi on Sat Mar 19, 2016 12:38 pm

    Dave,
    here's what I wrote back in 1989 when I compared every available ST70 mod . . .

    Sine wave frequency bandwidth was from 5 Hz to 6 KHz, not much better than the stock Dyna. Square waves remained fairly square from about 60 Hz to 3 KHz.
    This mod definitely changed the sound of the amplifier from being warm and rounded, to being more neutral. The music came thru very clean and detailed without being harsh.
    The sound was open without the veiling noted above, although the soundstage seemed to be more recessed. Cymbals and bells were reproduced with a clean airy sound around them. The bass reproduction was about the same as the stock Dyna, probably limited by the power supply. There was a noticeable lack of impact with too much smoothness.
    The dynamics of the music was better but still not as good as the three mods below.
    (VTA, Curcio, GSI)

    Here's a link to the original article . . . http://www.tubes4hifi.com/st70mods.htm

    gooch

    Posts : 2
    Join date : 2016-03-05
    Location : Florida

    Re: Sutherland solid state driver board for the Dynaco ST-70

    Post by gooch on Sat Mar 19, 2016 1:59 pm

    Thanks for the info you kinda summed it up as to what I was hearing with the Curcio dry sounding

    Sponsored content

    Re: Sutherland solid state driver board for the Dynaco ST-70

    Post by Sponsored content Today at 2:32 pm


      Current date/time is Mon Dec 05, 2016 2:32 pm