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    5V4 G in a VTA ST70

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    Dave_in_Va

    Posts : 172
    Join date : 2013-04-02

    5V4 G in a VTA ST70

    Post by Dave_in_Va on Wed Jan 04, 2017 10:11 pm

    I found a cool looking NOS RCA 5V4 G in my batch of tubes. Is this a good rectifier for my (pre-built) VTA ST 70? Right now I'm using a JJ 5AR4 (installed after a NOS? Sylvania went south).

    I searched around for that handy rectifier list Bob posted but couldn't find it.

    Thanks.

    (EDIT: According to eBay listings the 5V4 G is a GZ37 so I guess it's okay for the amp.)
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    j beede

    Posts : 375
    Join date : 2011-02-07
    Location : California

    Re: 5V4 G in a VTA ST70

    Post by j beede on Wed Jan 04, 2017 10:55 pm

    Have you done the "yellow sheet" update?
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    Dave_in_Va

    Posts : 172
    Join date : 2013-04-02

    Re: 5V4 G in a VTA ST70

    Post by Dave_in_Va on Wed Jan 04, 2017 10:56 pm

    If that's the mod involving diodes on the rectifier socket, no.
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    Tubes4ever

    Posts : 73
    Join date : 2015-07-14
    Location : Star, Idaho

    Re: 5V4 G in a VTA ST70

    Post by Tubes4ever on Thu Jan 05, 2017 1:26 am

    No. The 5v4 is not suitable for an ST70. The 5v4 is rated at 175mA. If you set the output tubes to 40mA then that is 160mA. You have to keep in mind the draw of the VTA board which is about 25mA. This equals 185mA. Since most tubes were rated a bit conservatively, it would probably work, but you would be running it on the hairy edge.


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