Originally Posted by gibosi
Would you be willing to provide a primer on how to make these measurements? My system, with a breadboard 9-pin socket and 7-pin Vectors, certainly provides full access. However, I have no good idea how to make these measurements.
Also, in case it makes a difference, I have an LD 1+, which is a hybrid amp, and it is my understanding that the tube stage is configured as a cathode follower.....
Are these AC Volt measurements? or the DC?
If I put the one of the meter's probes on Vector pin 3, one of the heater pins, where do I put the other probe? Pin 4? Somewhere else?
In the same vein, if I put one of the meter's probes on Vector pin 5, the plate, where do I put the other probe?
And the same question for the grid?
Further, is there anything else you think a rank amateur should know?
Heater Voltage - Set your meter to Volts AC , put one probe on pin 3 , the other on pin 4.
Plate Voltage - Set your meter to Volts DC , put the red probe on pin 5, the black probe to Ground. On the MK111 the best place for ground is the case screw next to the right hand driver tube. Not sure about the LD 1+ but a convenient place on the case should be fine.
Grid Voltage - Set your meter on Volts DC , put the red probe on pin 2 , the black probe to Ground. This is actually measuring the cathode bias voltage but at idle the grid is 0 volts so this amounts to the same thing.
Be very careful when taking measurements not to short out adjacent pins and normal disclaimers of at your own risk applies of course.
The output stage of the LD 1+ is different as you say, so I don't know what effect a plate voltage greatly different from the norm will have on the sound.