spritzer

I've seen that a few times. Do they say "Professional" on top of the cups? Ohh and the resistors are actually silistors.

The diaphragm being stuck to a stator doesn't sit right with me for a few reasons. First of all, a diaphragm shouldn't be able to do that in the first place. The diaphragm is stretched tighter than the skin of a drum and there is no force inside those drivers strong enough to move it. It also stands to reason that if the diaphragm were to move from its center point between the stators at any point then the distortion would rise dramatically. It's a common misconception that electrostatics arc by the film touching the stator. The film doesn't have to touch the stator for it to arc, it just needs to break down the natural insulation of the air. That is ca. 100V/mill so certainly possible to do. Second would be how the "broken" driver sounded. I've heard drivers which have stuck to one stator a few times but all of them have been severely damaged and the distortion was easy to spot. This one was just lower in volume but it played just fine. Lastly how the bias supply in the KGST would have responded to diaphragm shorting out like that. Being a simple voltage doubler it can't (nor should it) maintain anything close to full output for the working channel. Granted it was a bit down in volume but it was one click on the DAC attenuator so not a major difference. Running Pro phones off normal bias can't do any damage what so ever.

Exactly the point, the 6+ has a huge battery for an iphone so use an ipad charger for it.

The 007 driver is held together in a resin frame and the 009 as well which is then encased in the alu shell so a lot of things would have to be loose on a lot of sets. I suspect the connection into the driver as the most plausible point of failure. The bias is indeed attached with a screw...

Ok.... something weird just happened. The SR-009 has seen heavy use recently off the KGST and today the right channel was suddenly quieter than the left one. No idea why but I've been wanting this to happen so I can study what the fuck is up with these things. First thing I did was to unplug and try grounding the stators and diaphragms at various combinations. Listening carefully when you do that gives an idea how the charge on the film is working. Nothing concrete to be gained from that so I just grounded all 5 pins. No change at all but when listening so some highly localized tracks I noticed the channels were drifting a tiny bit. Before ripping them apart I thought I'd at least try tapping them on the side of the housing as one does when there is some dust stuck in a driver causing it to buzz. Well here is the weird bit, one sharp knock to the side of the offending channel and it sprung back to life. WHAT THE ACTUAL FUCK!!??!! One thing I did observe is that the volume level of the "working" channel is lower than it should have been. As soon as the "broken" channel kicked into full gear the volume of the "working" channel rose by 2dB or so. Maybe a bit more. No other conclusion can be drawn from the info at hand than the imbalance issue is not caused by a charge sitting on the diaphragm but rather some build anomaly in the driver.

It should meet the 75ohm standard but they never really claim it does. Use something like this instead: http://www.bluejeanscable.com/store/digital-audio/index.htm

While Belkin makes excellent stuff (love the USB cables, better than any audiophile BS brand) I doubt the subwoofer cable is 75ohm. More likely is that it is 50ohm which will fuck up the digital signal. Get some nice Belden 75ohm coax with BNC's.

This thread took a different turn... Anyway, my only KGST is in use right now so I just grabbed the nearest plate to my desk, a mini HV: A few of the holes are crooked but they are all there for airflow so I'm not that bothered.

What ever sustains them is good for us. More stuff to hunt... A 007 being harsh isn't something which springs to mind... ever. They are one of the most forgiving transducers out there so even the crappiest of recordings are just fine with them. Something is up and it could be something basic as the digital cable used. My one time being a reviewer (not really but the guy pleaded with me until I caved in) was to test a digital coax cable. It fucked the sound up so badly in the high frequencies that I offered to send him my normal 75ohm coax cables which cost 1$ per meter so he would know how it was supposed to sound...

I suspect there is a simpler explanation, one of the wires which goes from the cable to the drivers is broken. Those are fiddly to say the least and can be easily broken. If enough load was put on the bias supply to reveal the AC frequency then the phones would drop in sensitivity as well, especially on the Stax amp which uses on 10nf caps in the bias supply.

Yup, the 6SN7 is a low power tube so I wouldn't worry about it.

The servo takes a while to catch up but if your offset adjustment is right on the limit of the pot then the servo can't make up for that.

The GS-1 wasn't cool or had insane fanboys shilling it so it wasn't selling. Goes to show that people in general are idiots...

What do you mean by 0V? As in it was at 15V and then got down to 0VDC after an hour or that it hit the magical 0V from 0.3V after an hour?

It nulls the DC offset

For the servo you can leave the opamps in with the jumper open and adjust the amp for 0VDC when it has warmed up. Then you turn off the amp and put in the jumper.

The 03 and 05 are the same except the 05 is slightly smaller since I needed that.

I drill a 9mm hole for the Alpha, then I enlarge it 2/3's of the way from the outside with an 18mm drill, essentially carving a hole into the panel for the nut.

It's obvious from the schematic.

I wouldn't touch this Shuguang crap with a 10 foot pole. In a normal tube amp them burning up and shorting would be bad but in the BHSE it would be catastrophic.

I'm sure Stax would sell you new drivers for (knowing Stax) 6k$ or so outside of Japan. No way to retrofit something like this as there are no spacers in that sense. Then we have the issue of actually opening up the drivers compromises them in terms of dust. The end result for me though is that the 009 sounds good off the KGST which means the KGSSHV Carbon will be even better when we get around to it.

I think that most of us just don't care in any way...

If the reverb is prominent then absolutely but if it is only occasional and thus tied to certain forces acting on the diaphragm then it wouldn't show up. Nice to hear that I'm not alone. I can't be sure about the sensitivity without a set for direct A-B as my source has a volume control and people keep messing with it...

We've had portable electrostatic headphones for 20 years so why not high efficiency magnetoplanars.

Nate is right that tube matching is essentially a fruitless exercise. If we leave aside the drift of the circuit in general then the tubes will wear out at different rates so any matching will not last.