spritzer

I have an even better way, just swap one phase from left to right at the Stax plug. Instant crossfeed!!!

Going on what few internal pics of the Pawel stuff there are it does look like a clone of the Stax circuit adjusted for the newer sets. They also had some amps but who knows what's inside...

The TTVJ amp works well because Pete knows his stuff. The gimmick comment was aimed at ALO since it is bound to be badly built garbage. Just look at the Rx, sounds like shit and they are up to Mk3 now because they can't seem to fathom that li-ion batteries do not behave as alkaline's. You can't just wire them with a CT and expect it to work...

Get the SR-009 then...treble head...

There were plenty of tubes designed to work at low voltages and made super small but using tubes is just a marketing trick. "Hey this one is different!!!" Then you ALO to the mix and it's probably horrible in every way.

There is more to it than that and the exact choice in output devices matters here plus the topology of the amps. Now if we talking about electrostatic amps then the fets would be a bad idea of biblical proportions. BJT's are much better suited to this role.

I made two of these boxes on the behest of Victor, one for him and one for me to try out ultra high end transformer solutions. Both look identical except one uses small stuck on feet and the other the rubber cones from Justin. Both used Lundahl LL1627 transformers which were a good choice in some ways but not in others. Too many windings and all the issues one has with that but the only real improvement over these would be a McIntosh style bifilar wound transformer. Sound wise these are the best transformers I've ever heard and shockingly transparent but not perfect. Transformers really aren't my thing and this project was to settle that once and for all. Same reason I'll take an SS amp over badly made tubes...

I cobbled together a version of this circuit when the A-10 first came out so I have a good idea how this one will sound. Thick with distortion and no output power what so ever. There are some tricks here though to try and make the SRPP circuit behave as it should (it only really works into a fixed impedance) so there should be a marginal improvement. For me the enjoyment is building this stuff even if it will sound sucky and with these tube amps it's a lot of fun to dig through my castoff bins to find the parts I need. All the terminal strips in this amp are from the ES-1, the plate resistors for the ECC83's are the brilliant TKD CM2's pulled from a SRM-T1 and the coupling caps are from my first ES-1 repair attempts. I never throw anything away... Sure, I still have a pile of the Alpha pots left.

Time for an update on the B-10 as it is now called. I decided it was just best to stick with Rays fubar amp design but improve on it where possible so the volume control was moved to the front of the circuitry (not in the middle as on the A-10), grounded DC heaters used for the input tubes and AC heaters used for the output tubes (hungry at 4A). Now using a SRPP setup in a single tube is rather stupid since it means there is too much voltage on the cathodes for the cathode/heater gap. Best way to mitigate this is to use a center tapped heater winding and float it on +300V so this only becomes an issue with the amp swinging 500V or more. Other than that the amp is pretty much stock and here are a couple of pics: The psu will be in a same size chassis but 2U in height. I designed a new PCB for it loosely based on the old GES supply which should arrive soon.

It would be a welcome change if these fit my head... I may get a set since I'm eternally curious about this stuff. On a similar note, I was talking to a friend yesterday who had a huge collection of very nice cameras but sold a lot of it to pay for a Leica S2 system to compliment his M9. He was at the local Fuji dealer and didn't even look at the new cameras they had there, the Leica system just killed any curiosity to try anything different. I do wonder why this hasn't happened to me yet with not one headphone ever coming close to besting my old SR-007 over the last 10 years.

Happy Birthday buddy! I made you cake but I... ehhh.... ate it. Might try again tomorrow but I fear the result will not be favorable...

That's excessive but expected.

In case anybody missed it over there, the Floats are coming back: http://www.open-end-music.de/vb3/showthread.php?t=4455 I have some issues with the driver mounting but they do look interesting if rather fugly.

Fear of the Dark is pretty amazing and she lives in Iceland...

The 6CG7 is pretty much just a noval version of the 6SN7 so it should work just fine but do check the heater currents in the datasheets so that they are similar/same. The added benefit would be to use the rugged versions of the tube which can handle more voltage, GTA, GTB etc. The SRD-7's are as different as they are many but all but the very early units have a 100V "harmonic suppressor" (two 100V zeners back to back) on the input so the voltage the bias circuit sees is never higher than that. The chassis isn't connected to anything so the ground is the center tap on the transformers (two green wires). Your plans with the electret drivers are sound and the only tricky part is getting the bias connection. You also might have to tamper with the bias voltage since the diaphragm/stator gap on these is unknown. It's obviously geared to work well with the Stax electrostatic sets but that doesn't tell us a whole lot. I'd also try and sweep the diaphragm in the electrets with a grounded metal bit to try and dissipate the charge which is causing the imbalance. These drivers don't wear out so either it arced or a charge is sitting on it causing the imbalance.

That's not what I've found to be honest and the number back this up since the midrange is the most benign load for any amp. Over blown bass, check. Distant and rolled off highs, check. Very compromised sound stage, check, but the midrange always shines through. Could just be me and the small issue of me falling hard for the 007 even off my old SRM-313...

Bárðabunga does have a nice ring to it in Icelandic but I guess it doesn't translate well... Askja or Laki would perhaps be better for the international market. Both truly terrible eruptions though...

You could try some thin glass wool or anything similar at the local hardware store. Thin foam would also work but it won't sound the same.

Same thing for me. Most of my HD800 time has been spent with one of the very early sets (demo pair at the local distributor) and to me the LCD-2 is a superior transducer over all. Those that have owned numerous sets, is there any change in the production? Sennheiser is known for tampering with things such as there are 3 very different versions of the HEV90 but they never said anything...

Gotta love the inrush current. I think I used 3.15AT fuses up here (230V) but that is probably overkill. Mikhail used 6.3A in the ES-1 but those transformers dim the lights.

It's actually mineral wool and not glass wool. No idea what type they used though as the stuff made up here is much, much coarser.

Ohh that's what they were. Sorry but they were all sent here but thrown into the nearest lava pit as they didn't have a 5 pin headphone plug...

I've been poking around in my old 3GS and I bet one of the connectors just popped loose. Gentle push and it should work just fine. Be extra careful with the antenna connectors since they break very easily (small round coax units)

Mine is well on its way but I'm easily distracted...

I don't get that either. The BH has enough power on tap to burn up the headphones if they were introduced to it's full fury and the KGSS is damn close to that. WES isn't even close and DC offset and balance issues make it even worse. I've said it time and time again, gain means nothing and less of it is usually better.