Tube Radio
Super Member
I'm looking to build a preamp that will interface my Scott LK-72A amp to my computer so that I can use its phono preamp to transfer some vynl to the PC. According to the manual the record output jacks must have greater than 220 K load connected otherwise RIAA EQ will not be correct. I have made a schematic of a circuit using Windows Paint that I think will suit my needs. I'll post it here and see what you all think about it. I decided to use separate resistors and filter caps for each triode section so there would be better isolation between each stage. I will use variable resistors so I can adjust the voltages on the triodes to find the best sounding operating point. I have variable resistors between the first - second - third stages to permit adjusting for a gain of 1. I am using trimpots for all the variable resistors. I would like to have a circuit board made as that would make the project easier. I really don't know of anyone who makes circuit boards. I've used the TAD 12AX7 tube in my Scott LK-72A amp and like its balanced tone. I would like to use it in this project, but I'm not sure how that would work out given that I need to drive a low impedance load. Since I'm connecting this to a PC will a 10K impedance be ok for the output of the cathode follower?
Attachments
Last edited:
