• WARNING: Tube/Valve amplifiers use potentially LETHAL HIGH VOLTAGES.
    Building, troubleshooting and testing of these amplifiers should only be
    performed by someone who is thoroughly familiar with
    the safety precautions around high voltages.

EL86: push-pull for home

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A low impedance source might be able to provide enough grid current for the ECC83. Alternatively, is this 'measurement' actually a simulation using valve models which omit grid current or perhaps naively assume that grid current starts from Vgk=0V?


Spice model for ECC83 tube is this:

******************
.SUBCKT ECC83 1 2 3
*ANODE G CAT
X1 1 2 3 TRIO2 G=1.02m MU=90.6 B=18 Vc=50.7 k=5
X2 2 3 Igrid ALPHA=.01m BETA=.1U
C1 1 2 1.7p
C2 2 3 1.6p
C3 1 3 .46p
RF1 1 3 200MEG
RF2 2 3 50MEG
.ENDS

******************
 
Sorry, as I am not a Spice model expert that doesn't tell me much. It appears to include grid current, but how accurately I don't know. I suspect it will not model the grid current which can appear from about -1V upwards.

Incidentally, can we limit the word 'measurement' to mean actually measuring something? You know, with a real meter or real 'scope on a real circuit; not virtual instruments in Spiceworld.
 
Sorry, as I am not a Spice model expert that doesn't tell me much. It appears to include grid current, but how accurately I don't know. I suspect it will not model the grid current which can appear from about -1V upwards.

Incidentally, can we limit the word 'measurement' to mean actually measuring something? You know, with a real meter or real 'scope on a real circuit; not virtual instruments in Spiceworld.

I know you're right and I understood from the beginning what you mean. I just wanted to analyze how this amplifier just pure curiosity.
Finding another PSF for ECC83, raising the voltage to + 550V, performances have improved radically.
Thanks and I hope I have not upset anyone!
 

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