original 2tube DI, need help: critique and optimize (on shoulders of REDDI)

[ruffrecords]

I usually lurk & absorb info (hence my username, haha ) but have a question. I'm wondering if this design could be modded to use a 12au7, and still have enough gain to be useful?

Edit: physical implementation looks great!

Should be straightforward. You will save on heater current for sure. 12AU7 plate resistance is higher than a 6N1P but that will just add more tone. A 12AU7 has plenty enough gain to make up the loss in the EQ stage.

Cheers

Ian

 

[capacitorless]

Thanks! Looking forward to building a pair, and seeing how the circuit performs as a summing amp (near/at the end of an analog mixing chain). I have a variety of gently used 12au7 and similar tubes with which to roll.

 

[damianschwartz]

Next step is to execute an intuitive and tidy build in this enclosure. I plan to complete it and document it in the preamp section.
I will go over how to orient your transformers for "ZERO" 60hz hum in a tight enclosure and wire it in a way that would make the 1940s lead dress scientists proud.

You can see that i have the power transformer safely prepared to apply voltage on the primary directly from the wall and listen for hum on the output transformer secondary.

Thanks for watching

Hey Andy!
Did you ever documented this ? can't seem to find it.