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    Question about Dynaco ST -70 production



    Posts : 9
    Join date : 2011-06-23

    Question about Dynaco ST -70 production

    Post by metlmrk on Tue Oct 04, 2011 8:01 pm

    I picked up an additional ST-70 a few days ago. When I arrived at the sellers home, he had it playing some music and I thought it sounded just fine. I pulled the screws, three to a side, and took a quick look inside (cant be to careful) everything looked in order and I noted it had cloth transformer leads. Today I had it set up in my workshop and I noticed the transformers were both marked: 454326 and Z-326 the power transformer was marked: PA 060. So here is my question. I thought only the A-470 transformers had cloth leads and I thought the Chassis with three screws were newer moldels. Is it reasonable to assume that this was a transition piece where they ran out of the A-470 covers and just slapped Z-326 covers on the older cloth lead wound core?

    Can any of you hard core Dynaco historians shed some light on this ?

    As always thanks for your knowledge and support!!!!



    Posts : 181
    Join date : 2008-11-30

    Origin of Dynaco transformers

    Post by DynakitParts on Tue Oct 04, 2011 9:39 pm

    Hi Mark,
    It is my understanding that the 454326 (PA 060) and Z-326 (A-470) denotes these
    transformers were made in Japan. I have also seen the Z-326 outputs with a combination
    of both cloth & PVC leads. My thoughts on this:
    At some point PVC was the new preferred wire insulation and most likely a cost savings
    for manufacturers of electrical components. Towards the end years of Dynaco, all of
    their transformers were made overseas.
    The original Dynaco transformers were made by Tresco in Philadelpia, PA. David Hafler
    owned stock in this company during the heyday of Dynaco's early years.

    In my opinion, the perceived benefits of the cloth leads is greatly exaggerated.

    I know others may have differing opinions on this...Let's hear them.


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