EH Scott Radio Enthusiasts

The Fine Things are Always Hand Made

Question about the 800B Tone Control Modification

Norman;

I looked at the drawings and comments about the tone control modifications for the 800B. One thing that I am wondering about is the grounding of the shields for the added audio cables to/from the tone controls. Did you ground both ends of each audio cable or only one end? Or did you ground them all at one ground point on the chassis?

Scott's implementation of the tone control circuitry was spread across the front of the chassis with rather long wires that were not shielded. Along with the high cathode impedance of the V10 6J5 triode it was almost guaranteed to hum.

I am currently making the tone control modifications and want to plan ahead for any possible changes needed if I make a grounding error.

Joe

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Joe:
Thanks for your inquiry. Going from recollection I only grounded one end of the shielded wires at a the ground lug on the terminal strip. The capacitor on the output end of the tone control circuit is not needed.
Norman

Norman;

Thanks for that clarification. Now I can proceed.

Joe

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