[donlin]

Add the new Sennheiser HD800S to the list of phones that sound wonderful with microzotl2. I had owned the original HD800 twice in the past with some very expensive amps and was not a huge fan. This combo is great though, possibly the least glassy sounding piano I've heard.

 

[bazelio]

Interesting, donlin.  I don't think I'd have considered the unmodded HD800 a good match, and I have yet to hear the HD 800 S.  But Tyll's measurements and resulting EQ profile seem to indicate its quite a bit more tame with the 6k dampener. 

 

[jamato8]

 
Funny, because I'm more of a clarity and treble-head, but I really like what the RCA smoked glass tubes do. They do sacrifice some clarity and air, but they are so liquid and deep. And, well, smokey.
 
Like I said, I doubt I'll want them on all the time, but for now it's a really nice change. I have some Sylvannias coming too.
 
There are so many 12AT7 variants, but the 6SN7 choices really are much more limited.

The 6SN7 was one of the largest produced tubes there was. There are many, many varieties and variances in the tubes. 

 

[zachawry]

   
Curious, do your Mullards have the D shaped getter?

The getter is the wire at the very top, right? In this case, circular. 
 

 

[bazelio]

More progress here.  (Tired of me in this thread yet?  

)
 

 
 
1960 Mullard 12AT7 D Getter.  Certainly showing signs of use: the flashing is aged, the pins have some oxidation (will take care of that later).  But they test strong, and sound very good.
 
So far, I'm 2 for 2 on tube swaps.  Raytheon VT-231, now the Mullards.  More details on these tubes later.  For now, though, I can say my stock tubes have found a permanent resting spot on my shelf.  

 
I've got a few other tricks up my sleeves yet ... notably a 12V 2.5A LPS build is under way.  High hopes there, and more details later.  Approx 2 weeks out.  

 
Happy listening!! 

 

[RKML0007]

Go go ... bazelio-ooooooo !!!!

 

[jamato8]

 
The getter is the wire at the very top, right? In this case, circular. 
 

Actually the getter is the silver coating on the inside of the glass. It was on wire when the tube was made and then flashed, which causes to to adhere to the glass. But most people refer to the wire as a round getter, square, horseshoe, etc., out of convenience. 

 

[doctorjazz]

Don't stop the tube rolling...I'm on hiatus, back to stock, Bert still interested in what you folks find. I'll jump in again at some point.

 

[TomekZ]

Loving the microZOTL, esp. with a linear power supply. Bought a used older model Mojo Audio power supply. Made the upper mid - treble so much mellower & sweeter. This region really makes or breaks enjoyment of music/ audio equipment. I couldn't weight for Urban Audio to ready their own, but when it ships, I bet there will be a lot of positive comment. Also changing the 12at7 Tung-Sol for a Psvane pair made for an improvement: more open & full. Want to also say that Urban Audio stands behind this product: they quickly replaced my first one which had hum with my efficient Audioquest Nighthawk.

 

[bazelio]

@TomekZ
 
Yeah, I suspect a LPS is going to have a more significant effect than tubes - and tubes will become icing on the cake.  I'm looking forward to making that upgrade, myself.  In the meantime, however, I'm pleased with what my tube selections have done - they've helped reduce the treble glare and forwardness, created a fuller and warmer sound overall, and have even expanded the soundstage.  So we are moving in the right direction!

 

[nephilim]

Speaking of tube rolling... I thought this would be much easier with the tubes being placed where they belong: on top of the amp such that I can behold the beautiful glow
 

 

[svmusa]

  Speaking of tube rolling... I thought this would be much easier with the tubes being placed where they belong: on top of the amp such that I can behold the beautiful glow
 

Yes, I did request Mark from urban Audio and he said they will consider having top cover with tube sockets...waiting to see if they will get to this in their future upgrade list.

 

[nephilim]

Oh, so they are seriously considering this? Would have saved me a couple of DIY hours.

 

[bazelio]

What kind of connection did you make at the sockets on the board?

 

[zachawry]

That is awesome! How much for you to make me one?

It appears you're running four 6SN7's, though. How does that work?