Most excellent Deepak! Should be something new coming to the 'different thread as I'm looking into improving the WES design. By improving I naturally mean throwing most of it away...
Nope, it comes from Sennheiser showing and auditioning a prototype at the international distributor meet last year. That event was meant to show the distributors what R&D were up to.
This is a curse, every time I say "ok, time to sell all this shit I never use" I'm up to the same number again in a couple of months. Hell, I just paid for a SRD-X Pro and a SR-Alpha Pro Excellent and I have no idea why I bid on them...
DIY is much worse. Those Mouser orders really add up...
The DRV134 is a POS and causes far more issues than the slight loss you get with the natural phase splitting in the HV. Just make a RCA-XLR cable with the - grounded.
My HV doesn't run quite that hot, about the same as the standard KGSS. To lazy to wire it up and test though but I did take a lot of care with cooling the amp boards.
The T2DIY is indeed 100% a Stax design on the amp side. Our version is miles better in terms of noise, stability and is actually run at full power (not 50% as Stax did) but the design is 100% theirs. What's in the PSU box is all Kevin's work.
The internal filaments you are referring to are the output tube filaments? They are referenced to the - power rail so a small trace will not cause any hum issues.
The tubes are rated to 1.5A but there is always some variation so I always overspec for at least 10%. I'm using 25VA transformers to drive them in this amp.
Each of the front end tubes draws 300mA at 6.3V so 1.3A would be good for the front end. I highly recommend DC for this role though.
My Megatron boxes just arrived but I'll probably not get to do any construction for a while. Other stuff to finish first...
I got some HD650 capsules as a gift from a certain headphone manufacturer (long story) which I've now turned into a HE60 with some reconditioned parts. Not easy by any means and holy hell they are bright off the B-10 amp. I just love how this amp draws out every small annoying characteristic and just pushes it to the front to really annoy you...
The potential on the filament is quite high so the transformer has to be close as it possible. Remember that the cathode of these tubes sits on top of the output tubes anode so there is a lot of voltage there.