spritzer

The drivers are identical so I guess they all sound pretty much the same but there was indeed a 1977-1979 version with a round cable. Some of the phones (the two I've seen had a S/N around 5000) had a ribbon cable but instead of a solder connection it had crimp connectors which attached to the drivers. There was also more damping around the driver, basically they stuck some where ever it was possible. I've never owned a cloth cable Sigma so I'm not sure how the drivers are connected but it should be similar to the SR-X i.e. crimp connectors. That means there are at least 3 versions of the Sigma. Since all of my Sigmas are bought from Japan there might even be some local variations that were specially made for some distributors.

The ES-1 has been a joke from the beginning and that he's charging 20k+$ for the ES-2 is nothing short of a robbery. The amp in the pictures costs the same as DACT equipped BHSE or even more...

Sure but that's not given. There are quite a few versions of the Sigma and the crimp on connectors are hell to work with.

While those glue pads are pretty strong at room temp there is a reason for the hole in the middle...

Here is another one of the MPX. The fet has obviously been moved to the chassis as can be seen by the burn marks...

The short answer is no as it is so small you can't see it. It also requires a total disassembly of the drivers to get to the diaphragm which can be tricky or just impossible.

A buzz sound is usually due to some debris in the drivers shorting it out but the fart is more like a squeal generated by the diaphragms when air is pushed through them. That being said the baby Stax is very noisy due to the design.

Since the pictures are gone now I uploaded them to a more permanent location. Before: After:

Ditto. If this stuff isn't public then Mikhail can continue to blame it on anybody but him self. There are dozens of these stories and they drag on for years. To make matters even worse he's pushing the design even further now so it's no wonder those amps are breaking down.

The parts aren't cheap to make these so they run close to 1000$. Well worth it though IMO as they have many qualities in common with the Omega line and are much more linear then the other Sigma's.

Since I finished cleaning up and making some small mods to my SR-Sigma 404 I though a picture was in order. Considering that this is hands down the most filthy headphone I've ever had the misfortune of buying it did turn out great. I had to resort to some very strong cleaners to get the arc to look that good...

Yup.

I know that only a few of the electrostatic amps have been sent out with no issues and some of the new amps are just flat out broken. If there was any customer service then it could be remedied fast but there of course isn't so the owners are stuck with amps that can't hold bias for 5 minutes or have the jacks wired up the wrong way.

Ditto. HF is pretty much dead to me.

Same for me. I am interested in some variable filter though if it can be built cheaply into amps.

It acts as a diffuse field processor to alter the "perspective" of the headphones. It was a derivative of the binaural research that Stax was heavily into in the 80's and there are 3 versions of adapter boxes and one amp, ED-1, ED-1 Signature, ED-5 and the SRM-Monitor amp. I can't stand the effect but a more modern approach could be something to strive for.

Thanks for the pics and now I can bother Justin for a schematic. Those EQ adjustment pots could be fun to mess with....

Some pictures of the SR-Ω drivers. Here they are hooked up to an amp and playing some random test tracks. The electrical tape on the side serves two functions a) holds the assembly together and allows me to hold the drivers while powered up. I didn't notice any channel imbalance so I guess something outside of the drivers was the source. Now I have a spare set of SR-Ω drivers sealed in an airtight box if anything should ever go wrong with my set.

Just be very careful where you point the screwdriver and all driver damage is very unlikely. You could also choose not remove the earpad base plate and just plug port from there. This is untested but should work just fine. Speaking off blu-tack mods I've been torture testing the SR-Ω/SR-007 hybrid and the bass is still a bit loose but I'm not sure if the seal is broken somewhere or that the chassis just can't handle the SR-007 drivers. If I apply some pressure to the housing barrel the bass gets clearer so it might be time for some Dynamat... The SR-Ω housing is just a shell unlike the massive slabs of aluminum in the SR-007 so that has to have an effect. So you haven't noticed the midrange recess yet...

There is some black goo on the bottom of the chassis (vibration control?) and the caps scrape it off. The board is upside down in the chassis as you can see from the location of the jacks. Pretty damn good though I haven't compared it much against the APL in DAC mode as it's been sitting in my computer rig. I did get a Zero dac this week and it only took about 30 minutes to hear just how inferior the Zero is. Boomy bass, bright and nasty upper midrange, much less resolution and clarity and the soundstage just vanished. The DAC1 also isn't ruthlessly revealing so MP3's aren't a problem which isn't the case with the Zero. Two OcCon's next to the input. There are further two green Wima caps on the bottom and some resistors. It's a single TDA1543 dac chip with a CS8416 on the input, capacitor coupled output (bipolar Blackgates) with Riken resistors to ground. The transformers are all part of the PSU but this thing is so minimalistic that it doesn't have a fuse or any switches.

I did promise some internal pics a long time ago but here they finally are. I did manage to fuck up the shots of the other side of the board so only the top part shown. The SR-X Mk3 Pro used to show just how tiny this DAC is. Not that many parts used but the quality is very high indeed.

I know that feeling all too well...

I'm glad you didn't. The SR-Ω frame is by far my favorite of every headphone out there due to the great fit and having the better drivers is just a bonus. We have been expecting this. One can only wonder about where that He90 went...

There is one in Euro land but the price is a bit steep.

Must not buy a SACD Standard...