VTL Deluxe tube mystery

[DParker]

Hey tube gurus,

I have a mystery for you. The VTL Deluxe calls for a pair of 12AU7's and a 12AT7 in the line stage. What's there now is a Mullard CV4024, which is cool; the weirdity is a pair of Russian 6H23n-EB, which crosses to 6922, which I have learned is not a 12AU7 equivalent. Or is it?
Because the preamp operates fine with no distortion or other anomaly. It's very quiet, can hardly hear it operating; it sounds very good also. Lots of space and depth to orchestral recordings. Soprano vocals are reproduced exceptionally.
So should I continue to use the 6H23n-EB's or look to replace them with 12AU7 or equivalent, or even 6922 when it's time to replace the pair?

Thanks,
David

 

[Zen Mod]

if circuit is not altered , using 6DJ8 in place of 12AU7 is wakoo thing

post some close-up pictures , so we can maybe see more

 

[DF96]

As a minimum the heater wiring would have needed a change.

 

[DParker]

Thanks for your replies.

Well apparently I have a wakoo, mystery preamp. (o:
I bought the Deluxe used and the 6H23n-EB tubes were in the line stage. I'm happy with them; it's just I want to be sure to use the correct replacements when necessary.
Since the Deluxe is working well with 6922 equivalent, I'll just use that as replacement. Lets me choose from some nice vintage like Amperex, Siemens or Valvo. Of course I can't afford the coveted ones. Or just look for same Russian tubes; they are very well made.

I would post pics but my old PC is the real wakoo; constantly getting DNS error and freezing.

Regards,
David

 

[atmasphere]

The preamp apparently was modified so 12AU7s won't work in it any more.