I want to check voltage points for my Dynaco ST-70, since the bias value seems too high.
In the manual of the Dynaco ST-70, I found the attached voltage points for EL34, GZ-34, Capacitor lug, selenium rectifier (which I replaced with a diode) etc.
For example, EL34:
Pin 1 - 1.56v
Pin 2 - 6.4v ac
Pin 3 - 410v
Pin 4 - 415v
Pin 5 - 32**
Pin 6 - 32**
Pin 7 - 6.4v ac
Pin 8 - 1.56v
Pin 9 - --
The manual specify for ** "Measurements at these points can only be made with a vacuum tube voltmeter. The two tubes in a pair should have identical readings."
I am a newbie so few questions come to my mind:
Can I measure all these voltages with a common $10 digital multimeter?
I guess for each pin I'm testing the Red probe from the multimeter would plug into the pin. How about the Black probe? Should I always connect it to ground (which I suppose is the amplifier chassis)?
Your help understanding how to measure the pins will be very welcome and help me avoid being electrocuted
In the manual of the Dynaco ST-70, I found the attached voltage points for EL34, GZ-34, Capacitor lug, selenium rectifier (which I replaced with a diode) etc.
For example, EL34:
Pin 1 - 1.56v
Pin 2 - 6.4v ac
Pin 3 - 410v
Pin 4 - 415v
Pin 5 - 32**
Pin 6 - 32**
Pin 7 - 6.4v ac
Pin 8 - 1.56v
Pin 9 - --
The manual specify for ** "Measurements at these points can only be made with a vacuum tube voltmeter. The two tubes in a pair should have identical readings."
I am a newbie so few questions come to my mind:
Can I measure all these voltages with a common $10 digital multimeter?
I guess for each pin I'm testing the Red probe from the multimeter would plug into the pin. How about the Black probe? Should I always connect it to ground (which I suppose is the amplifier chassis)?
Your help understanding how to measure the pins will be very welcome and help me avoid being electrocuted
