It looks like you used the tube-voltage reference and skipped the zener chain. I would still go for the LED bias on the 12SN7. Floating the heaters 100V above ground is not a problem for the 6BX7, as the cathodes are quite high above ground, but it may stress the 12SN7 gain tubes. Good move...

The same thing could have been asked some 8 years ago when the DIYers who were around at the dawn of head-fi started to disappear. There have been threads like this before.   But then they taught themselves to design and build stuff. Then they built it. Most of it will suck but it is better to...

If you want "recipes" Koss Portapros or KSC-75 are your friend. They are quite affordable, have well documented modification path(s), don't look quite cool or expensive enough to steal, and they sound pretty much like what you describe yourself wanting.   In the meantime try adding small...

I'm curious if it can be bent multiple times - Mu-metal can not...    I cant wait to see how this will play into the cable wars. 

  subscribed. 

This is a terrible idea. First I will tell you why. Then I will tell you how to do it anyways.    The reason that this is a terrible idea is that at some time, the user set the system to play headphones, expect to hear speakers, and turn the headphones WAY WAY up before figuring out what is...

Have you measured DCR of all the resistors and inspected for solder bridges?    Have you tried a totally different tube?    Have you engaged the "mono" switch?    Do you have an "inverse RIAA" circuit to test?  http://www.hagtech.com/iriaa2.html http://sound.westhost.com/project80.htm...

No problem.    The driver heating up AFTER you plugged the headphones in is a problem.   This can happen because the cable is wired wrong, OR because the amp is toast. In either case, it is not good.   Measure resistance everywhere mentioned above. Does everything make sense?   If all of...

  +1

  Probably need new drivers. Possibly dont.  What does the multimeter say when you measure tip to sleeve, tip to ring, and ring to sleeve?    Whatever you do, I would figure out why the driver got hot.    Why not build an adapter to go from 1/4" to 1/8"?

  Its still rolling along same as it ever has... 

Mouser?

Pics or it didn't happen. 

  Through the hinges.  Isnt that why you wanted to take them apart? 

Why not just thread the wires through? 

Hope this link helps:   http://www.angelfire.com/electronic/funwithtubes/Amp-Bal.html   Try circuit "C" with modifications necessary to get low output impedance, and desired range.  *values as a starting point* Omit the 120Kohm resistor between input and pot Use a 5Kohm linear pot 10Kohm...

Good enough to get pwned by apple to the tune of 3bilion dollars. 

  I have a hard time reading this seriously.  HD-600 have been pretty much rock solid since they came out.  The LCD-2 were superceeded by the LCD2mk2 how quickly? How long before that before the LCD3 overthrew them? And then the LCD-X?  If you make your choices for "endgame" based on what...

Sounds fun. 

You may have better results with a lower stepdown ratio. If the transformer has a 16 or even 32ohm tap, for example, try that. You wont get as much voltage at the output, but you dont really need that. As much as the STAX mafia likes to talk about freakishly high voltage swing, nobody uses much...

  I like this line.    A DIY turned MOT who shall remain nameless told me he once sold an amp to a guy who liked fuses.  A few weeks later the guy called him up asking where he gets his fuses...  The builder asked why, and was told that his customer bought and tested alllll sorts of fuses...

  There are dozens of commercial options, only a bit larger (2^3 times) than you are looking for.    Building anything the size of the FIIO alpen is insanely hard. Or its just crap. Actually building anything in that form factor requires tons of design effort.     Buy the MIXAMP™ PRO...

Why not just ask ****? 

Probably best to find a mentor in this endeavor.    Or perhaps a shared workshop type space where you can just use the lathe for a few hours - and probably get hooked up with someone who can watch over your shoulder. 

Will they go loud enough - maybe. Define loud enough? High end sennheisers play loud enough to be clearly audible a good 20 ft down the hall.    Perhaps a more important question is "will they have reasonable bandwidth" To which the answer is almost certainly no.    You will probably have...