spritzer

The voltage divider is off the B+ so you need to lower it from +640V down to +580V. The resistors do that but remember to add the ballast resistor and a filter cap before the divider. No idea what parts you are talking about there though. UF4007's will work perfectly for that.

All products go through constant evolution so why would Stax be any different? Those of us who have opened up a lot of the stuff Stax have built over the years know just how frequently things are changed with zero notification of that change. There are at least 4 very different versions of the SR-007Mk1 but they never changed the name. The SR-Omega came in three versions and that was with Stax on their last legs. The T2 came in at least two versions and the SRM-T1 versions are probably about a dozen or so with the W and S variants. The SRM-1 Mk2 takes the cake though, it was in constant design mode with part changes, design revisions and new circuit boards. Ditto for the small Stax amps, three very different versions of the SRM-Xh exist out there, they aren't even closely related. It has also been confirmed why Stax altered the headphones.

All the SR-303/404 drivers had the red rings, no matter what headphones they were used in. 4070, SR-SC1 and 404LE As for the 007Mk2.9, they still sound awesome and easily trump the 009 with just the ports plugged. I just prefer the meatier sound of the 007's as the 009 can be a bit thin at times, even the new ones. The 007mk2.9 isn't quite as smooth as the Mk1 but it just gets out of the way better than the 009. Equal or even better detail retrieval than the 009 and the bass is the best anywhere, it's just perfect - tight yet tuneful. The 009 can't compete here as it's bass is... well how to be diplomatic here... lacking. Yeah... let's go with lacking. I've been spending a lot of time on the KGST lately and here the 007Mk2.9 just fits perfectly. Really shows off what circuit can do and why it's such a favorite of mine.

The advantage is that the 2SA1486 is out of production and the 9360 isn't... At 350V rails the A1156 works perfectly. At 400V I'd use the 600V parts just in case.

It will work pefectly fine with a normal bias phone with 230VDC bias.

I have some spare KGST boards on my site. I have only the mini KGSSHV psu for them as that's what I use.

No problem using the MPSA parts. The newest boards have had their labels updated As for the KGDT, it's pretty much a KGST that you can tuberoll. It was designed around the ECC99/12BH7A and 6N6pi with selectable current levels but I'll probably scrap that idea when I finalize the boards. It is bound to cause problems... Anyway, it is a cracking little amp. Reposting this for anybody who might not have seen it: Finished... The heatsinks have to be grounded, always.

If you have access to raw AC then you can do what ever you want. With just DC things get... complicated.

Nothing new to report, they continue to be great and I honestly have no desire to break out the 009 to compare. Too much shit going on and all that...

The KGDT is completely current production.. Off the shelf too...

The pot at max would take it out of the loop. The problem with most integrated amps is that the volume control used is pure crap. Alps RK27 or some cheap chip solution. Something like this would work but who knows if they have fixed their QC issues... http://www.khozmo.com/balanced_stereo.html

I've bought from them in the past and they were good. I just bought another lot so we'll see.

This is DIY, you can do what ever the fuck you want. I for one am tired of people coming up with stupid crap and then asking me to fix their fuckups when it inevitably comes crashing down on them. Overkill is well and good but it's often thrown around as an excuse for stupidity, using a 400VA transformer for a 50W circuit and stuff like that. I for one have tried the KGST with every PSU I have here and I'm sticking with my KGSSHV mini unit.

Yeah, that was for using it on a BHSE. I will draw up a new psu just for the BHSE when I can find some time. For the KGST I just can't see any reason to use the HV psu. Why use a PSU which was setup to run +/-500V at 350?

I have no interest in rugby but it reminded me of the beginning here for some reason... https://www.youtube.com/watch?v=NKbxuE07Xlo

He does have a nice vintage McIntosh setup. Not sure what the speakers are, could be old AMT or something like that.

Doing the same, it is very good.

The reason I gave above and the Pro output is 580V, not 480V. How else would you wire them? They are capacitors after all.

Tru dat. For a 350V B+ and a 270K resistor to ground you need a 141K series resistor.

Just for the record, there have never been any 2SA1968's with exposed tabs. Every last one ever made (i.e. real ones) had fully enclosed packages. The 2SA1967 on the other hand has an exposed tab but they are pretty rare.

I placed the filter cap before the divider and used 270K to ground but it really doesn't matter.

It is already a divider so it's better to use the regulated B+.

You only need to alter the bias supply for the amp to work with normal bias phones. See here: That is the bias supply for the normal bias on the right hand side panel of the amp, just behind the front panel. Just a voltage divider off the B+ with a small filter cap, two resistors to form the divider and a 4M7 ballast resistor.

If the sound comes and goes then it is probably the cable, not the drivers. That's exactly how a broken bias wire works... Edit: Normal bias has separate bias for each driver unlike the pro stuff.

Yeah, schematics are for the weak.