spritzer

I for one think the extra money went into the earpads, cable and arc assembly so the 407 should have the same driver. I sold my 507 to a friend here so if I ever get one of the other sets comparisons will be easy.

The way I see it is that this is just a normal speaker amp which is stable into the very low impedance of ESL's but it isn't used to drive them directly. It's just a factor of the 20 output devices and a gigantic transformer but there is simply not enough voltage at hand here to drive 'stats directly.

The problem with any Mk2/A comparisons is that we don't know what Stax have done to those particular sets. It was quite clear at CanJam that Stax have modified the new models to suck less than the first ones but I'm not sure what they did. Anybody know about any cheap Mk2's for me to buy?

I'm not aware of anybody that has opened up any of the other new models. If I spot a good deal on any of the new models then I'll take them apart as well but with the Yen still strong this isn't likely to happen. We also shouldn't assume that these all have identical drivers as the SR-404, SR-404LE and SR-SC1 all should have identical drivers yet don't sound the same.

Can't wait to try this against the SR-007 and SR-Omega off the big bad amps.

Happy Birthday!!

The reason why all the mounting holes are isolated is to control the ground paths and stop any loops from emerging. High voltage or not, ground is just that but the aim here is to control how it is connected. I for one star ground everything so the amp boards, chassis earth connection and input ground are all connected to the PSU board at one spot.

Happy Birthday!!

A shitload of fireworks.

Happy Birthday!!!

Happy Birthday Jacob!! I baked you a cake but then I ate it...

The ESP9 has a lot of circuitry in the cups so you can't run them of a Stax amp without fashioning an external box for the circuit boards and wiring up a 6 core cable directly to the drivers.

For earpads I think the Pro AAA or something like that is the modern equivalent. These headphones used a grounded back stator to diminish the back wave output so you need to start cutting up the drivers. I never had any issues since I never bothered with the original fittings.

Could be quite a few things... As for the the stock tubes, they were all Golden Aero which was an early 90's rebrand. I did some digging and they appear to have been matched Amperex tubes.

MOV would be a good idea or you can just add a CL60 thermistor to the transformer which is what Pass does on his amps.

About as easy as working with high voltage can be. We could always have missed something though...

Arcy-sparky is an optional extra...

Happy Birthday x2!!!

That sucks... The circuit is pretty robust but I'd check everything, especially the 450/550. Did you burn both boards?

Merry Christmas y'all!!! Only 40 minutes until go time here...

Happy Birthday Ken!!!

I'd guess an Egmont from the tubes used...

That was the Koss way of "improving" its models, make them ever more complex. The ESP9 is so bloody complex that it is just absurd. It also took them two major revisions (i.e. ESP9B) and countless minor ones to stop using a shared return path for the speaker input. Bye, bye bridged amps...

Nahh, I need moar powah. I'm going to build another F5 just because I have all the parts (integrated this time with a buffer and some gain) but the next large project will be what ever power amp KG comes up with.

It drives my Spendor S3/5SE's with ease but almost imploded when driving a Stax transformer box. I clearly need to build a bridged unit...