FWIW, my low hours mint unit with the transformer upgrade is up for sale, as I'm no longer working in an office and am using speakers now. https://www.head-fi.org/threads/fs-price-drop-dennis-had-designed-dragon-inspire-iha-1-amplifier-in-mint-condition-w-lundahl-transformers-tubes.879866/

Thanks, great video! One of my favorite rectifiers with an old amp of mine was the Mullard GZ32/CV593 fat bottle like this: http://www.ebay.com/itm/GZ32-CV593-MULLARD-NOS-BOXED-VALVE-TUBE-/262293544641?epid=1789059112&hash=item3d11e9dec1:g:YO8AAOSwll1Wwzjr I'd love to hear your thoughts on...

@Aornic did you ever get a chance to try the Mullard rectifier? I'm curious what you found.

Nothing to be sorry for! My first time making that mistake I quoted a post almost 2500 lines long :), suffice to say, I made some new friends that day.

Hey reddog, Just a tip, but it's usually appreciated if you snip or spoiler tag the content of a really long quote like that so we don't all have to scroll through it to read your reply!

I'd pick T90 over HD700 all day long, but either way your source could use some love. I have the DF 1.2, and it's a decent source, but a little colored. You'll want a proper DAC/Amp combo before long once you own some nicer cans :)

Harsh, but accurate. Speaking as someone who has reviewed gear for years and spend time with 50,000 dollar hi-fi systems in my home, the T90 signature is MUCH closer to reality than the DT-990. Maybe some folks are conditioned to like a darker signature?

I review audio equipment semi-professionally and have been doing so for about 6 years. I try to test extensively and A/B as best I can. All my impressions are based on SPL calibrated listening levels (as levels change with diff. driver tubes) and a 20 minute warm-up, on a reference set of FLACs...

IMHO - it's about 80% rectifier, 20% driver in terms of noticeable change in the sound.

I bought mine from another seller,  vacuumtubes.net

I have a pair of the fat bottle RCA 6FD7 from the 50's that I've been using instead lately. I do like them, but I haven't quite decided yet. The 6GL7's may still be my real favorites.

Exactly. The point being this is likely a good thing for us, and our hobby as a whole. If Harman profits from it - great, as it will enforce similar research throughout the industry.

Your thread was the reason I chose it - can't thank you enough for that. It's a tremendous improvement.

I have some 6FD7's on the way just for comparison - will let everyone know.

Well finally got a chance to listen to the WA6 with the Mullard GZ32/CV593 and RCA 6GL7's. Ironically had a hum in the right channel that i traced back to my cordless phone! Removed that from the desk and now it's dead silent.   The new tubes have made a massive difference, bass now has some...

My T90 is definitely at a whole new level through a WA6. I'm running a Mullard GZ32/CV593 rectifier and RCA fat bottle 6GL7 driver tubes. Love love love!

http://www.modmic.com/

6FD7 seems easy to get. Have you tried various brands?

I only chose the 6GL7 due to it's strong recommendation on here. What have you paired the GZ32 with in terms of driver tubes?

Even though it's for their own benefit, Harman has a history of developing solid research methodologies that eventually get industry adoption. Ultimately, if they develop more tools like How to Listen and foster a culture of music appreciation, i've no complains.

Well - my first replacement of tubes will be a pair of NOS RCA 6GL7's and a NOS Mullard GZ32. Here's hoping it sounds good with my T90.

There's actually a lot of psycho-acoustic research about this. It's largely how Bose was able to capture the market early on, they were quick to emphasize frequencies we preferentially hear (mid-range) and compensate for our poor low frequency hearing. Now companies everywhere including Dolby...

http://seanolive.blogspot.com/2014/01/the-perception-and-measurement-of.html   Pretty interesting findings and a worthwhile goal. NRC/Harman are the reason we have effective measurements of loudspeakers and equipment, this could be a bell-weather moment for the future of our hobby.

I am using the uPower with it, yes and a KingRex uCraft USB cable. Not sure how much of that affects things, but that's the current setup.

Regarding DAC pairing with the Vali on my T90's, I've found incredibly synergy with my KingRex UD384. Absolutely fantastic, comparing to ODAC, AQ DragonFly - this thing is just a great pairing. Soundstage opened up fairly dramatically and I notice much more impact in the bass. More listening to...