Mapletree Ear HD tube advice

Lloyd generally uses widely available and/or cheap NOS tubes for his amps.  You should have no trouble sourcing replacements.  I highly recommend ordering tubes from Jim McShane http://pages.prodigy.net/jimmcshane/ from whom I have bought literally dozens of tubes over the past 4-5 years.  Jim goes through the trouble of testing/matching and standing behind all of his tubes.  I have only had a couple failures and he's replaced tubes for me without cost.  Jim is a great guy and cares about the hobbyist.

Other good sources include Doug's Tubes http://www.dougstubes.com/ and Tube World https://www.tubeworld.com/.

If you want the high-flying super NOS tubes from the 40's, 50's and 60's, the supplies and prices limit availability.  Generally I don't recommend starting with old NOS tubes.  But if you go that route, then talk to Andy at Vintage Tube services, or Brent Jesse or Tubemonger.  Be prepared to pay big bucks, but you'll get guaranteed tubes not fakes, and tested tubes. 

Ebay is a crapshoot, and there are many famous tubes being replaced with re-labeled Chinese fakes, and other scams (no testing, bad testing, bad shipping, etc.).  Buyer beware.

Actually, the tubes that MAD amps come with these days are pretty good new production.  My MAD Ear+ HD Super II came with repro Tung-Sols which are quite nice.  I've replaced the driver tubes with Amperex Bugle Boy 12AX7's, but substituting NOS EL84's for the output tubes didn't make enough difference for me to burn up valuable old tubes where I can't hear much improvement.  For Grados, I use some GE triple-mica black plate 5751's.  But frankly, in your shoes I would stick with the stock tubes for a long time (6 mos at least) before experimenting.

Hope this helps!

Frank

One more thing.  Tubes in headphone amps generally last thousands of hours.  So don't worry that you're going to have to run out and replace tubes all the time.  It's useful to experiment with some new production tubes so you have a spare set hanging around.  But the MAD amps sound really great without having to spring for the most expensive possible tubes, and in fact you might be happier with the stock tubes -- which is disappointing if you have just spent $150 for a pair of Mullard Blackburn ECC83/12AX7's just cuz you gotta try 'em.  And yes, everything you've heard about their goodness with Grados is true...

HTH

Depends on what headphones you want to drive.  My first one was a kit (standard), but an older design from about 10 yrs ago.  My current one is a transition model before the current spec HD Super II.  It shares the two EL84 output tubes, and has 2 12AX7 input tubes, but has a solid state power supply unlike the HD 250? special edition which may have been Lloyd's best-sounding headphone amp.  I find that it actually does a credible job of driving the Audeze LCD-2, which likes a lot of power.  But it really is lovely with Grados.  I've used an older Grado RS-1 with it and the guitar tones are right-on + it really rocks.  I don't remember the standard edition rocking quite that hard.  Plenty of deep bass (especially with the LCD-2's).  It also sounds quite good with my Sennheiser HD-580's/HD-600's, although it doesn't really lift the Senn veil very much.

Frankly I think you'd be happy with the standard, but I'm happy with the Super and you might be too if you're looking for anything harder to drive than Grados.  Maybe I should be asking what kinds of music you listen to.  I listen to about 70% classical, but a lot of that is via speakers.  Most of my headphone listening is rock, world, blues, and the like for which it is quite good.  Where the MAD amps tend to err, it is on the side of being slightly romantic (some say more "musical") which is a big plus for crappy recordings, but doesn't deliver the incredible detail of something like the new Shiit models.  I guess it all depends on what floats your boat.  YMMV

HTH

Missed the build quality question.  These are definitely small-shop manufacture.  Everything is point-to-point wiring, cleanly done and neatly loomed.  You may or may not like to see parts glued to the chassis rather than using clamps and screws.  The paint is easily chipped, and shows a bit of orange peel.  In other words, nice, but not spectacular.  You could certainly pay a lot more for 1/4" aluminum casework, but the essential goodness of the amp is in the circuit design and component selection, both of which seem top-notch.  Think of it as "old school" build.  I dabble with a lot of vintage equipment and I feel right at home with the MAD stuff.

HTH

Until recently, I owned both the Ear+ HD and the Super II. The two amps are much more similar than they are different, IMO. The Super II does have somewhat more power, and was more effective at driving stubborn cans like the HD650 and T1, but the difference was not night and day for me. In fact, the biggest benefit of the Super II for me was that it uses the easy to find EL84 tubes in the rear, instead of the more obscure 12B4A tubes used by the Ear+ HD.

As far as tube rolling goes, I'd suggest getting a decent set of EL84/12B4As and forgetting about them. I never found a big sonic difference between good power tubes in this amp's configuration. I've read that some have, but I spent big on nice tubes and found the sonics to change very little.

For the preamp tubes, IMO you should have at least one good set of both 5751s and 12AX7s. The lower-gain 5751 (or its relative, the 7025) is perfect for relatively easy-to-drive cans like Grados. I preferred NOS Sylvania triple mica black plates from the 1950s. You'll want the increased gain of 12AX7s for pickier headphones, like LCD-2s or T1s. There are many, many 12AX7s to choose from, but I must admit that I got great results for relatively little $$$ using new production Gold Lion 12AX7s.

Lloyd's amps sound great and have a fun, DIY-type aesthetic about them. Build quality is simple and excellent, and Lloyd is great to work with.