Anyone heard Underwood level1 3910 mod?

I can't speak to the Mods, but I've bought several pieces of equipment from Wally and can vouch for him as a great guy to deal with. Also, check out Six Moons.com, I think they have a number of reviews of Wally's modded products.

La45, yes, HRAM indeed uses APL Master Clock.

Regards,
Alex

I am currently evaluating the 3910 mod. I purchased the Ultimate and sent Parts Connexion my 3910. I have finally let the unit burn in for 200 hours as Wally recommended. So far I am disappointed. The upper bass is overly pronounced and the overall sound isn't open. Vocals never come alive - low level detail seems obscured maybe because of the overly warm upper bass. I am AB-ing the unit with a Benchmark DAC-1. I will say that I don't remember the Benchmark sounding as good as it does now. The mod replaces the clock which Wally claims improves the digital out. I believe that has made a large difference. I have ordered some NOS Mullard 6922 tubes which I'm going to try in the unit next week.

Just a suggestion...
I have a APL 3910.
Perhaps your modded 3910 requires a different interconnect and power cord .
Try a silver interconnect like AZ, Kimber Select,Ridgestreet Audio, Purist Dominus, etc.
It may tighten the bass and open the sound.
The Purist Dominus power cord is awesome with my APL 3910.

Kisisam, Up front - I know nothing about your 3910 modded Denon. I'm reacting to your proposed tube change and I'm speculating.

Arn't the Mullards noted for a warmth which might be contra-indicated, especially if you are finding the mod'd Denon overly warm in the upper bass and, presumably because of the 'vocals which never come alive', closed in in the upper mid's and highs and you are finding the Benchmark more appealing. I would have thought a tube like a Seimans or 'Tele' might have been more appropriate. Just a guess/thought.