PAS visists the naughty side of town (red lit)
So, I said, what the heck, I don't have any 5842's, EC8010 or WE417's hanging around, why not use Morgan Jones preamp avec LED and pop an inexpensive LED instead of the cathode resistor in my PAS modded amp.
Here are the trace identifications -- The GREEN trace is the first stage 300k/1.8k per the Vorhis mod. The BLUE trace substitutes a cheap read LED for the 1.8K -- very little current is flowing through the LED.
The RED trace substitutes 157K for the plate resistor and utilizes the LED while the MAGENTA trace just used the 1.8K.
I used a very ancient LED --
[IMGHTTPDEAD]http://www.tech-diy.com/RIAA/PAS_RedLit.gif[/IMGHTTPDEAD]
So, I said, what the heck, I don't have any 5842's, EC8010 or WE417's hanging around, why not use Morgan Jones preamp avec LED and pop an inexpensive LED instead of the cathode resistor in my PAS modded amp.
Here are the trace identifications -- The GREEN trace is the first stage 300k/1.8k per the Vorhis mod. The BLUE trace substitutes a cheap read LED for the 1.8K -- very little current is flowing through the LED.
The RED trace substitutes 157K for the plate resistor and utilizes the LED while the MAGENTA trace just used the 1.8K.
I used a very ancient LED --
[IMGHTTPDEAD]http://www.tech-diy.com/RIAA/PAS_RedLit.gif[/IMGHTTPDEAD]