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The Dynaco Tube Audio Forum

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


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Bob Latino
Westy56
dynacophil
7 posters

    want another mod and have 3 original ST70

    dynacophil
    dynacophil


    Posts : 35
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    Age : 67
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    want another mod and have 3 original ST70  Empty want another mod and have 3 original ST70

    Post by dynacophil Mon May 30, 2011 6:17 am

    Hi

    is it pc to ask about another mod made by another maker?

    If, I have an early VTA-mod ST70, I have a Sutherland-Mod ST-70 and a pile of 3 original ST70s, one already with aftermarket original layout board and replaced caps and rectifier.

    So 2 are left to be done something.... I also already have Dynakitpart-stainless chassis' waiting for a new project.

    I somehow read about that Welbourne Labs mu stage-Mod http://www.welbornelabs.com/st70.htm
    that seems interesting to me and wanted to know what others think about this design....

    Also (I can't find now, but have a link somewhere at home) I got the adress of some other modder that looked weird to me, becaause the used board was way bigger and was to mount outside what made the amp look like an oil-rig... If I find I'll ask about that too...

    best, Helge



    Westy56
    Westy56


    Posts : 58
    Join date : 2011-05-09
    Location : Albuquerque

    want another mod and have 3 original ST70  Empty Re: want another mod and have 3 original ST70

    Post by Westy56 Mon May 30, 2011 10:35 am

    dynacophil wrote:Hi

    is it pc to ask about another mod made by another maker?

    Also (I can't find now, but have a link somewhere at home) I got the adress of some other modder that looked weird to me, becaause the used board was way bigger and was to mount outside what made the amp look like an oil-rig... If I find I'll ask about that too...

    best, Helge




    Is that board yellow?


    Steve
    Bob Latino
    Bob Latino
    Admin


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    Join date : 2008-11-26
    Location : Massachusetts

    want another mod and have 3 original ST70  Empty Re: want another mod and have 3 original ST70

    Post by Bob Latino Mon May 30, 2011 11:25 am

    Hi,

    I don't know much about the Sutherland mod but beware of Welborne Labs. The Better Business Bureau of Denver,CO took away their BBB acreditation dues to numerous complaints of non-delivery of items over the past few years. Check some of the links below.

    http://www.bbb.org/denver/business-reviews/internet-selling-services/welborne-labs-in-littleton-co-90014438

    http://www.diyaudio.com/forums/everything-else/115516-welbourne-labs.html

    The Welborne driver board and parts set for the ST-70 is usually sold for $320. I see now that it is "on sale" for 20% off. ($256) (Hmmmm ... I wonder why? - It probably didn't sell well at $320?). In comparison, the VTA driver board and parts set is $90 year round.

    As to the Sutherland board ... I don't believe it is offered any more by Sutherland. If it is the board I am thinking of, it is a total SOLID STATE driver board with no tubes.

    Bob
    dynacophil
    dynacophil


    Posts : 35
    Join date : 2010-10-26
    Age : 67
    Location : Berlin/Germany

    want another mod and have 3 original ST70  Empty Re: want another mod and have 3 original ST70

    Post by dynacophil Mon May 30, 2011 12:12 pm

    Thx for the warning Smile i read about in a AK-Thread yesterday and somebody was writing very (maybe a bit too) enthusiastic about this...

    http://www.audiokarma.org/forums/showpost.php?p=4692944&postcount=7

    The Sutherland-Mod is the one I have running in one of the amps (right - very solid state), as the VTA Board in a second.
    avatar
    aliveatfive


    Posts : 7
    Join date : 2009-03-21

    want another mod and have 3 original ST70  Empty Re: want another mod and have 3 original ST70

    Post by aliveatfive Mon May 30, 2011 3:11 pm

    I would not buy from Welborne. I had to wait many months for delivery of the board + kit + transformer. They were delivered weeks apart from each other. When everything was finally here, there was no manual to go along with all the assorted parts. All I had was a schematic, which I used to assemble the parts. The thing never biased properly and a loud humming noise came from the power transformer. By doing research, I found that the zener diodes that they use in the bias circuit are a really unapproved method of regulating bias current. Buyer beware!
    dynacophil
    dynacophil


    Posts : 35
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    want another mod and have 3 original ST70  Empty Re: want another mod and have 3 original ST70

    Post by dynacophil Mon May 30, 2011 3:28 pm

    Ok... was just an idea...
    mantha3
    mantha3


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    want another mod and have 3 original ST70  Empty Re: want another mod and have 3 original ST70

    Post by mantha3 Mon May 30, 2011 9:37 pm

    If you have a VTA mod st70 then cool... Ya got to have one ST70 modded with a VTA.

    For other ideas... Maple Tree Audio is a nice place to check. I just got Loyd (Mapletree owner) to build me a passive pre amp. I think he sells his board. Looks nice!..

    No idea how it sounds... Loyd is a nice guy to do business with... Like the dudes of tubes4hifi

    Report on what ya do.

    mantha3
    mantha3


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    want another mod and have 3 original ST70  Empty Re: want another mod and have 3 original ST70

    Post by mantha3 Mon May 30, 2011 9:38 pm

    PS - Google "mapletree Audio" and then check his site for products... He has a version of board he sells for ST70s. Again, no idea if it is any good. I think you just wanted ideas here.. So ya have it.

    dynacophil
    dynacophil


    Posts : 35
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    want another mod and have 3 original ST70  Empty Re: want another mod and have 3 original ST70

    Post by dynacophil Tue May 31, 2011 4:19 am

    Hi
    The VTA u see in my Avatar...

    can't find any prices on Mapletree Audio Site...
    best, Helge
    mantha3
    mantha3


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    want another mod and have 3 original ST70  Empty Re: want another mod and have 3 original ST70

    Post by mantha3 Tue May 31, 2011 8:43 am

    You can call him at - (613) 387-3830

    Here is the board he has and I think you can pick the color -


    want another mod and have 3 original ST70  Special%20red%20ST70%20top%20small
    want another mod and have 3 original ST70  Special%20red%20ST70%20chassis%20small

    I hope I'm not ticking off anyone for mentioning this other company product... PS, You may want to have two VTA ST70s and use them as mono blocks...

    Here is his site -

    Mapletree[img]
    dynacophil
    dynacophil


    Posts : 35
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    want another mod and have 3 original ST70  Empty Re: want another mod and have 3 original ST70

    Post by dynacophil Tue May 31, 2011 4:59 pm

    mmmh
    the subject wire monoblocks out of st-70 has been discussed a lot and leads always to the same result: nope, no good idea.
    Sorry, sure I could call, but I guess I'am ±8 hours ahead, can't call US from job...
    mantha3
    mantha3


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    want another mod and have 3 original ST70  Empty Re: want another mod and have 3 original ST70

    Post by mantha3 Tue May 31, 2011 9:02 pm

    Sure, no biggie. If ya never call Lloyd it won't bum me out. Just ideas for ya. I think you were just looking for some ideas on things to tinker with..

    Assuming I'm right.. I found this one a few months ago and it was interesting... Read this link:

    The Ultimeate Dynaco ST-70 Mod - Remote Sensing Feedback

    Not an expensive tweek. Again, just tossing ideas out.

    Have fun and post pics/report on what works and what may not.

    Adios
    baddog1946
    baddog1946


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    Location : Costa Rica

    want another mod and have 3 original ST70  Empty Re: want another mod and have 3 original ST70

    Post by baddog1946 Tue May 31, 2011 9:43 pm

    Check out the dynamutt and KTA driver boards they are usually for sale on eBay.
    avatar
    j4570


    Posts : 150
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    want another mod and have 3 original ST70  Empty Re: want another mod and have 3 original ST70

    Post by j4570 Tue May 31, 2011 10:55 pm

    I don't think you can the ST70 in mono with a VTA board, as you only put the switch in there as a place holder.

    Anyway, I agree, nearly every briding amp I ever heard sounded better in stereo. Most of that experience comes from car stereo, and it was popular at one time. Now running two mono channels for bass is different than briding the amp. Most bridged amps heat up a lot (though I wouldn't think a tube amp would care).

    JW

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    want another mod and have 3 original ST70  Empty Re: want another mod and have 3 original ST70

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