Any opinions or suggestions about this hybrid tube preamp ?

[gaetan8888]

Hello

Any opinions or suggestions about this hybrid tube preamp ?

Thank

Bye

Gaetan

 

[mashaffer]

Trying to figure out why the mosfets are needed and why the way too small anode resistors. I would delete the transistors and either use a properly biased 12AX7 with feedback or a nice low mu triode running open loop.

 

[BinaryMike]

The design looks plausible enough. The feedback should keep output impedance pretty dang low. I tend to solder up one channel of stuff like this on a breadboard and test it first, before committing any effort to a chassis build.

 

[gaetan8888]

Hello

I have done a Ltspice simulation using 12AU7 tube and with differents values for somes parts.

The thd spectrum look good.

Any thought or suggestions about it ?

Thank

Bye

Gaetan

 

[Lavane]

I have a headphone amp something like that. One dual triode per channel front end, single ended SS output. It also has a set of line stage out jacks. It can be used as a preamp as well. Its quiet and sounds pretty good after swapping the tubes for a pair of GE JAN's.

 

[Dr. Ears]

Hello

Any opinions or suggestions about this hybrid tube preamp ?

Thank

Bye

Gaetan

This Nobsound features a vacuum tube buffer. I rolled in 6J5-GT's and a pair of 6AQ5's using readily available adapters, it sounds great for the money!

 

[Dr. Ears]

Trying to figure out why the mosfets are needed and why the way too small anode resistors. I would delete the transistors and either use a properly biased 12AX7 with feedback or a nice low mu triode running open loop.

In almost all cases, I prefer the 5751's, which feature 70% of the gain of a 12AX7.