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    VTA 'ultimate' PAS phono tubes

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    Dingojazz

    Posts : 71
    Join date : 2010-09-03

    VTA 'ultimate' PAS phono tubes Empty VTA 'ultimate' PAS phono tubes

    Post by Dingojazz on Thu Feb 07, 2019 10:13 pm

    Have the 'ultimate' PAS refurb that calls for 12AY7 tubes. Apparently the 12AT7 has same specs as the 'AY', but can handle a bit more voltage, and has higher 'mu' (like 60 vs the AY's 45".

    My question; can I sub in some of my larger collection of 12AT tubes without risk to the pre?

    Anyone who's tried it? Thanks in advance.

    Thanks,

    K.
    peterh
    peterh

    Posts : 1211
    Join date : 2012-12-25
    Location : gothenburg, sweden

    VTA 'ultimate' PAS phono tubes Empty Re: VTA 'ultimate' PAS phono tubes

    Post by peterh on Fri Feb 08, 2019 4:00 am

    Dingojazz wrote:Have the 'ultimate' PAS refurb that calls for 12AY7 tubes.  Apparently the 12AT7 has same specs as the 'AY', but can handle a bit more voltage, and has higher 'mu' (like 60 vs the AY's 45".

    My question; can I sub in some of my larger collection of 12AT tubes without risk to the pre?

    Anyone who's tried it?  Thanks in advance.

    Thanks,

    K.
    Neither 12 AY7 nor 12AT7 will harm your PAS. Neither will improve it's ability to
    reproduce sound either. PAS is designed for 12ax7 / ECC83 accept no other types
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    Dingojazz

    Posts : 71
    Join date : 2010-09-03

    VTA 'ultimate' PAS phono tubes Empty Yes, originally 12ax, but this is the VTA supplied board

    Post by Dingojazz on Fri Feb 08, 2019 12:56 pm


    -"ultimate upgrade" version, (now through Audio Nirvana) which is designed for/supplied with 12AY7.
    It sounds like you're indicating a 12AT7 wouldn't harm anything.
    Whether it actually SOUNDS better or worse would of course be another issue.

    Thanks,

    K.
    peterh
    peterh

    Posts : 1211
    Join date : 2012-12-25
    Location : gothenburg, sweden

    VTA 'ultimate' PAS phono tubes Empty Re: VTA 'ultimate' PAS phono tubes

    Post by peterh on Fri Feb 08, 2019 2:06 pm

    Dingojazz wrote:
    -"ultimate upgrade" version, (now through Audio Nirvana) which is designed for/supplied with 12AY7.
    It sounds like you're indicating a 12AT7 wouldn't harm anything.  
    Whether it actually SOUNDS better or worse would of course be another issue.

    Thanks,

    K.
    Sorry , i got the impression that it was a dynaco PAS that was discussed.
    A dynaco PAS uses 12ax7.
    tubes4hifi
    tubes4hifi
    Admin

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    VTA 'ultimate' PAS phono tubes Empty Re: VTA 'ultimate' PAS phono tubes

    Post by tubes4hifi on Wed Feb 13, 2019 6:34 pm

    DINGO,
    the 12AY7 tube you are referring to is I believe (since I'm the one that sold my PAS mod designs to TubeNirvana/Erhard-Audio)
    is in the PHONO stage, not the line stage. A 12AT7 (or any other 12XXX tube) is NOT a replacement for a 12AY7 in a PHONO circuit.
    The RIAA EQ in a phono circuit is very highly dependent on gain and impedance, both of which are totally different with different tube designations.
    Although other 12XXX tube will FUNCTION, they will not provide you with accurate phono equalization in that circuit design.
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    Guest
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    Post by Guest on Wed Feb 13, 2019 7:21 pm

    yes, as tubes4hifi indicated, our Z-PH10 phono preamp is designed around the 12AY7. Using any other model tube will have quite the negative effect on the reproduced sound!
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    Dingojazz

    Posts : 71
    Join date : 2010-09-03

    VTA 'ultimate' PAS phono tubes Empty Okay, great!

    Post by Dingojazz on Thu Feb 14, 2019 9:26 pm

    Thanks to all!

    K.

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