livewire

Ha! Thats knee slappin good! Gonna email it to my daughter. (who happens to know every-little-thang)

Yes it is the same pcb that I fried twice, and the only one I have left. I'm almost to that point in this build. Not ready to go there yet, I still think that if I glean a little more knowledge maybe I can localize the trouble spot.

Some observations and ramblings follow. I've been pouring over the datasheets to better understand the operation of the mosfets in this circuit. I see that the 10m90s that is ahead of the pass regulators is configured as a current source regulator. When switched on by the battery, the 2sc4686a transistor feeds the gate/kathode of the 10m90s as well as the gates of the paralleled fqpf8n80c series pass regulators. It seems that the pass regulator is not "turning on". My questions are: 1) what should the output voltage of the battery be to the base of the 2sc4686a? 2) what should the three mosfets gate voltages be? (as supplied by the 2sc4686a) 3) is there any way to bypass jumper parts of the circuit to get it to operate? 4) am I looking in all the wrong places? One last observation / question for now is the negative rail is only outputting -15 ~16VDC. Is this a intended minimum "leak-by" voltage to drive the battery? I'm really not getting how this battery thing works. The mirrored, cross-connected, cascaded transistors that comprise it are throwing me a curve ball. Thanks in advance for any suggestions, answers or insight that any of you gurus may have. kgsshvpower3(final).pdf

In a word, yes. I've replaced almost everything on the negative side Cross checking against the good +450 volt side is difficult due to the groundplane linking everything when hot. If there were two separate identical 1/2 psu boards instead that were linked like in the schematic, it would be more straightforward for newbie comparison testing. It was working originally, so my goofs created a hole that I must now crawl out of. Knowing some testpoint voltages at the regulators and battery for instance could shed some light on the trouble spot(s). I wanna say "I'm done, stick a fork in me", but i'm not there yet.

I'M SOFA KING WE TODD DID. CANT FINGER DIS TING OUT.

http://www.youtube.com/watch?v=gkIrZxN9pHk

FWIW ebay's got 50ca10 chinese tubes and sockets.

Words of wisdom! (regarding the caps) Can anybody here translate the japanese? I'm sure just viewing the schemos is all KG needs to see. Rest assured, I wont be messing with any of that HV tube stuff.

That is a good idea, keep in mind that if the psu does not utilize bleeder resistors, your DMM will act as one due to it's internal (high) impedance. The bleed-off time if noted, will only be valid for bleed down with that meter attached. At least you will know when it has become discharged and be safe to handle.

@DQ, Some may think this is excessive, when I work with high voltages like this I have a ground strap attached to each arm and the device under test and perform the work while using a nonconductive rubber mat underfoot & on the workbench. I make a lot of mistakes, like slipping with the test probes, some of which are chronicled here on HC. I dont want a multi-hundred volt charge crossing through my heart, if you get my drift. On the job as a maintenance electrician, I have been shocked many times. Using safety procedures like these has probably saved my bacon numerous times.

Also keep in mind that a power supply that does not utilize bleeder resistors that are connected across the filter capacitors can harbor a deadly charge for days even when unplugged. Think of the filter capacitors as high voltage batteries. Be very careful!

I can only speak regarding the KGSSHV board that I have built. I'm assuming that others would be similar depending on if they have bleeder resistors across the supplies filter capacitors. Also bleeddown time is governed by the cap's size (in mfd's) and the size of the bleeder resistor. I'm sure there is a mathematical formula that describes this, but I dont know it. The best way (for me) to be sure is to use a voltmeter to read the remaining voltage charge across the filter capactiors on the psu when switched off. For a given power supply, I use a stopwatch and check the caps multiple times until they bleed down to a "safe" voltage, say a couple of volts DC. Make sure that the thing is unplugged before starting and remember that the voltages encountered here are deadly! If you become part of the circuit, it can stop your heart, that is cause fibrillation that may result in death. My KGSSHV supply bleeds down to a safe level in about a minute. The specified bleeder resistors for this psu are 300K ohms to 400K ohm units. The intial voltage on each rail is 450 volts DC, so it has a total potential of double that, or 900 volts DC.

Yes, but not everone is tech saavy as you are, and handy with a soldering iron. Then there is the issue with violating the warranty, that is if one is given when buying from a japanese vendor. Also the newer units are not "voltage switched" on the backside like some of the older units are. Right?

Spritzer speaks the truth, power matters. (see post #62 above) Case in point, I have a low-end Stax setup. SR-202 Lambdas with a SRM-252II amplifier that has +/-280 volt output rails. The sound is incredible, but I have no headroom. The phones max out with SPL of ~85 to 90 dB depending on the source. I am currently building a KGSSHV with +/- 450 volt output rails. That should do the job (and then some). I really need MOAR POWER! I do plan on upgrading to the SR-507's in the near future as well. EDIT: I just saw your last post. I certainly do not claim to know everything as you do, but I do know that I need MOAR POWER! (and I want to keep it SS)

The SRM-323 ouputs +/- 400 volts to the rails, what is the rating on the SRM-006t? EDIT: Found the answer. SRM-006t = +/- 300 volt rails. Regarding the "S" thing, you are referring to the older stuff, right? As of late, it seems the "S" suffix relates to 120volt mains input. (States?-for the U.S. market) While the "A" suffix denotes 100 volt mains for the Asian (japanese?)market. I could be wrong here, as I see conflicting vendor info on ebay. Would probably be smart to buy the amp from an established vendor in the USA to avoid the stepdown transformer hassles needed for a 100 volt mains unit.

The Byrds - My Back Pages "I was so much older then, I'm younger than that now" Writer - Bob Dylan

Elton John - Funeral For A Friend / Love Lies Bleeding

Elton John - Madman Across The Water

Infected Mushroom - CD Vicious Delicious - "Becoming Insane"

Metallica - Nothing Else Matters

Going forward, you may be right. I'm happy to have gained some initial ideas from the group here.

Happy Birthday sir!

Monkey, I'm not sure that I understand "73", but thanks anyway. blessingx thanks for your input as well. Your mention of quality and bit perfect has me wondering. Might there be delays or drop-outs on this type of device versus a caable connection? Here again, I'm a total apple n00b so exscuze my estupidness.

Thanks Reks, thanks grawk! I'm looking into it, seems like just what I need.

Please excuse my ignorance but, How would this get pumped into my USB/optical DAC? Would I need some type of wireless adapter or <cringe> need to buy an Airplay enabled DAC? (if they even exist) I've seen Airplay enabled speaker setups and a few Sony and Denon amps that support this. I'm also seeking something that outputs music at least on par with flac files. Or is the realistic alternative a MacBook with optical out or a PC server like I have now?