OK, here's a preliminary schematic. A few things:
1. The gain triodes are a 6N1P tube. The WCF will most likely be a 12BH7A.
2. I want to bias the WCF with the 185V coming from the previous stage and save us a cap in the audio path. Tube CAD gives me some not-so-good results, but I haven't built anything yet. I might end up just modifying the second gain stage to run the tube at a lower plate voltage......
3. .....or I may shove a pot before the WCF for level control and will be stuck with a cap. Two of them, actually.
4. I calculated the feedback resistors and approximated them to Mouser's stock Xicon 1/4W 1% resistors. They're sized for 3dB steps, but tube circuits being what they are, they may need some readjusting before the final version.
5. COMMENTS PLEASE!!! Last time PRR and CJ saved me hours of pointless prototyping!
Peace,
Al.
1. The gain triodes are a 6N1P tube. The WCF will most likely be a 12BH7A.
2. I want to bias the WCF with the 185V coming from the previous stage and save us a cap in the audio path. Tube CAD gives me some not-so-good results, but I haven't built anything yet. I might end up just modifying the second gain stage to run the tube at a lower plate voltage......
3. .....or I may shove a pot before the WCF for level control and will be stuck with a cap. Two of them, actually.
4. I calculated the feedback resistors and approximated them to Mouser's stock Xicon 1/4W 1% resistors. They're sized for 3dB steps, but tube circuits being what they are, they may need some readjusting before the final version.
5. COMMENTS PLEASE!!! Last time PRR and CJ saved me hours of pointless prototyping!
Peace,
Al.