Tubes with different gain for Moscode 401HR

6922 have higher gain than 12AU7.

If I recall correctly, the 401HR manual or the Moscode website has specific info about tube gain.

Not sure if mixing the two types will result in a satisfactory sound since they create different presentations in the 401HR.

I am currently using 6922s (6DJ8 - Amperex orange logo) for LFs and stock 6GUYs (+ 12AU7s next to them, so insides are 12s and outsides 6)for HFs and the sound is better than matching the 6922s for HF & LF.

You are not bi-amping, are you, Tvad?

The outside position has a more obvious affect on gain. If you swap the 12AU7 to the outer position in the HF amp, you will notice a difference, IMO.

12AU7 tubes produce a wider, yet shallower image than 6922. It's also a touch softer in the top end and upper mids. This was a more musical sound, IMO, and it would explain why you find the sound better in the HF amp using 12AU7.

I am not bi-amping, and I no longer own a 401HR.