The Dynaco Tube Audio Forum

Would you like to react to this message? Create an account in a few clicks or log in to continue.
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


    Voltage readings with ws1T vta st120 at 113v

    Njrob
    Njrob


    Posts : 50
    Join date : 2022-05-14
    Location : Nj

    vta st120 - Voltage readings with ws1T vta st120 at 113v Empty Voltage readings with ws1T vta st120 at 113v

    Post by Njrob Thu Feb 23, 2023 8:53 am

    Thoughts?

    Vta st 120 Tested at 113v
    Weber Copper Cap ws1T
    Pin 4 to ground - 400 - 425 volts AC (390)
    Pin 6 to ground - 400 - 425 volts AC (390)

    Any 6550/KT88
    Pin 1 to ground - approx .550 volts DC (depends on bias setting) (.470)
    Across pins 2 and 7 - 6.0-6.5 volts AC (6.4)
    (b+ startup peak at 520v )
    Pin 3 to ground - 470 - 500 volts DC (492)
    Pin 4 to ground - 470 - 500 volts DC (493)
    Pin 5 to ground - minus 50 to minus 60 volts DC (-49 )
    Pin 6 to ground – minus 50 to minus 60 volts DC (-50)
    Pin 8 to ground - approx .550 volts DC (.470)

    Quad cap - authenticap 550v/600peak
    (B+ startup peak at 520 settles at 499)
    (SQUARE) 480-505 volts DC (499)
    (HALF CIRCLE ) --- 470 - 500 volts DC (493)
    (FULL CIRCLE) 470 - 500 volts DC (492)
    (TRANGLE) ----400-430 volts DC (421)

    Central 12AT7 - Pin 1 or pin 6 to ground > 130 - 160 volts DC (155)
    Two outer 12AT7's – Pin 1 or pin 6 to ground > 255 – 285 volts DC (265)
    Any 12AT7 - across the two incoming heater wires > 6.0-6.5 volts AC (not measured)
    "-50 VAC" on driver board > 48-55 (52)
    "B+" on driver board > 400 - 430 (421)

      Current date/time is Tue Nov 26, 2024 3:25 am