spritzer

Yeah, going without sleep can lead to very stupid stuff. Once I wired up a time delay circuit so that it shorted the neutral and live from the wall instead of passing it through. The gigantic spark did wake me up...

I've had something similar happen once. I thought I'd save a bit and not solder in terminal blocks in every spot on a Blue Hawaii PSU which lead to a lot of fireworks when I decided to use one of the unpopulated spots during testing. A short to the between the two supplies will do that. Now this PSU is current limited so it might have survived the ordeal...

Nice going Craig!! The 6.3A is also needed for amps like the ESX, massive inrush current FTW...

The resin piece won't fit in a Mk2 and even if it did, where would you get one? The Mk2 cable entry is different from the Mk1 and a welcome improvement in my book. The drivers look the same but they don't sound the same. The Mk2 is just a tad more forward even when fitted with all Mk1 parts but I still haven't been crazy enough to swap the drivers between the two different frames.

You don't need the CT to create ground but something is up with that AC. How is the transformer mounted? Toroidal's are picky when it comes to that...

Well the port should always be there, it was there on the Mk1 as well: The little resin piece to the left plugs the port. On the SR-007A's I've owned there was this black cover of the cable entry but it creates an airway to the outside instead of sealing it completely. Here is the first set I got: This appears to be sealed on the new Mk2's as both sets I heard were 100% stock. Clark had one and the other was in the Woo room. If somebody wants to try the port mod, then it looks like this:

The 303 was very similar to the 404 and both have the annoying midrange etch. On the whole they aren't bad headphones except for that... I sold them simply because I saw no need to keep them. I do like how they sound but the comfort is lacking for my gigantic head and my only reason for having a Lambda here is for testing amps. I already have a SR-404 that somehow sounds bloody great (could be a SR-SC1 with the stickers removed) and it was far, far cheaper than the 507. Selling it to a local friend only made the deal easier since I can always borrow them.

Thanks for that but I would have to know when they were originally bought to know when Stax changed them. I'm also not sure if the change applies to the 007A model so it wouldn't make a whole lot of sense to buy yet another 007A to modify. If you are up for removing the earpads and see what is going on then that would be great. I still have the pics of my first SR-007A so it would be easy to compare.

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...