spritzer

Any Sigma can be fixed or fitted with new drivers but not everybody is up for that.

You know you can always come to us for advise.

The specs are just fine as I have SumR units here which worked just fine with that spec. Richard just did something wrong somewhere and we are paying the price. The units I have that actually work were after I got rather cross with him... The BHSE units I was having trouble with got very warm on the Blue Hawaii so we'll see soon how they are on the KGST. The transformers I had made in Hong Kong were designed from the point of keeping max temp rise low so they run cool and very few have any noise at all. Not cheap but as if I care.

No SMD here...

Going to watch some Bottom now. Damn shame...

Just so people know this version of the amp boards has been proved working. Pretty much the same as my sets except I fixed some minor labeling issues. Power supply is a variation of the Blue Hawaii design and a slightly different version to the one I used.

Yup, they often do that. The first 313's had the PCB mounted sideways which was then changed to a normal bottom mounted layout. Ususally goes hand in hand with part changes.

The UK service center will do it no questions asked. They also reply to emails which is always a welcome thing... The port needs to be filled and the spring inside the earpads expanded in size and flattened so that the pads can be used as if on the Mk1. Then you adjust the arcs over the head, bending them into the right position for the most comfortable setting. The right amount of pressure and angle.

Best move is to use an extension. Less tug on the cable that way.

Give it time...

All of them.

Hehe....

I'll be doing something like that. I'll probably rewire the front end filaments to run on 25VDC too.

The only Stax amp to have a major change to the circuitry over the production run is the SRM-1 Mk2. There were naturally revisions as at that point in time electronic components really came of age as we moved from 10% resistors to solid 1% units. Major development in transistors too but then again the amp was in production for 12 years so things will change. As for the headphones, the SR-Omega saw some refinement of the design as they tried to address issues. The outer grill rattled so a pad was installed to dampen it. The stator support was too fragile in worst case scenarios so they tried to improve that. Same for the Mk1 007, they were trying to address issues and to make production cheaper. The faux leather on the headband turned nasty so it was replaced, the drivers were hard to install (you do it blind) so they changed that and that meant they had to alter the support frame a bit. While there are some sonic issues involved it was all done from the point of improvement. Also the 007 Mk1 was made for 9 years and most of that time they are the same. Some QC issues but shit happens. The HD650 stuff is just ludicrous as nobody bothered to check what Sennheiser was doing. Improvement by using a sturdier material than the cloth they used earlier. What I do have a problem with is Stax releasing the SZ3 version of the 007A/Mk2 without telling anybody as that's a major change. Sure it is an improvement in many ways but it totally changes the sound of the unit. Same goes for the whole HEV90 debacle, shipping out basically broken amps and then trying to deny it.

Yup, all Mk1 cables will die at some point. The problem is the strain relief or rather that it is purely there for decoration. On the SR-Omega it bends and that is also the case with the 007Mk2/009 but on the Mk1 it's just too stiff. Stax never clean drivers or attempt any repairs. They are simply replaced with what ever is in current production at the time.

I would also run the raw mains on a separate umbilical. For safety and all that something like the Neutrik Powerkon would be perfect.

The filament transformer for the CCS tubes have to be close to the amplifier board.

Assuming the transformers behave then a bracket isn't an issue. Supporting the weight and all that goes without saying and it would be a good idea to allow for some holes to cool the transformers.

My front panels are laser cut but for the silver they put some material on it that the laser burns into the front panel. They are done by a place that normally makes small signs and the cost varies on a number of factors. Around 100$ or more for a panel is the norm.

That's true but unspecified upgrades aren't helpful to anybody and make the forum lemmings run wild. Remember the whole "white driver HD650" BS?

The SR-Omega prices are reaching into the "are you nuts!!!" spectrum so the Mk1 should be on the rise too. Personally I'll just be happy with a SZ2...

I think they do what Stax does and simply replace with what ever is in current production.

Yup and it's a mosfet that actually doesn't suck for this role.

I decided to try something new for the next round of HV's: I like the "black line" look and it will fit with the next batch of amps using some exciting transistors.

These are very hard to work on so I wouldn't attempt a DIY repair and have Stax do it. The cable might still work but it's a very old Mk1 so the cable is doomed regardless... Also check for dust in the drivers as that's one of the reasons the housing was changed. All the early Mk1 drivers I have here were removed due to dust issues.