The output stage in the prototype was supposed to be DC coupled i.e. tubes to the headphones with nothing in between. They had issues with that so could have reverted back to the basic design of that circuit, i.e. the 2uf caps.
There are always Rudistor and RSA but overpriced and crap "engineering" springs to mind... This is being made to custom order in Japan and I know there are talks about offering a 117v/230v version. Nothing set in stone yet though.
If it were the speakers in the cellphones which were the problem then it might be but that's clearly not the case. A cellphone is a powerful transmitter and it can't be good to have it next to the head all day.
SR-007/313 as an entry level setup FTW!!!
Better caps matter but I'd rather spend the money on better topology, PSU etc. especially at these prices. What's strange is that the WES wasn't supposed to have output caps...
That's the worst of the lot IMO, it's just bland which strange given how well the same drivers perform in a Lambda chassis. I believe the had a KGSS, big black thing with no tubes?
Btw. it's O2 as in Omega2...
What Sigma did you listen to and off what amp? The Sigma 404 isn't like the other ones and you need a serious amp to drive them, even the normal bias unit needs a BH.
I almost entirely listen to rock, metal etc.