I made the changes that you suggested and tested with sine wave signal input to the tube buffer and the results seemed ok. The phase is inverted which is correct for a plate follower and the gain is just a little over 1.
I built the chipamp using the pcb from Peter Daniel and I have the pcb setup like Peter suggests in his schematic. I have an input resistor of 220 ohm. Should I use the 22k from the Vin+ pin to the ground on the LM3875 or should I use a higher value, as my schematic has an input resistor of 10K? Also I don't have much space on the board and have no connections to ground, so how do you suggest inserting the resistor from the Vin+ pin to ground?
I am going to try the two circuits together later today when I am able to go to the lab again. Thanks again for all your help.
I built the chipamp using the pcb from Peter Daniel and I have the pcb setup like Peter suggests in his schematic. I have an input resistor of 220 ohm. Should I use the 22k from the Vin+ pin to the ground on the LM3875 or should I use a higher value, as my schematic has an input resistor of 10K? Also I don't have much space on the board and have no connections to ground, so how do you suggest inserting the resistor from the Vin+ pin to ground?
I am going to try the two circuits together later today when I am able to go to the lab again. Thanks again for all your help.
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