bui501

Many congratulations, Blueman2. I’ve learned so much from your posts and from the replies from the other members. I built a KGSSHV with lots of advice from members on another thread in this forum, and I’m about to put iron to boards today on my Carbon build. Hopefully, your good vibes will rub off on my build. ) -Vinh Sent from my iPhone using Tapatalk

John, I found the Goldenreference7plus and goldenreference7minus boards--they look like just the LV version you've mentioned. Which ones of the boards is the GRHV board? Sent from my iPhone using Tapatalk

Thanks, John. I'll go with the GRLV. Much appreciate the tips.

So... Having completed by first KGSSHV build using boards from Spritzer, I'd like to move on to a KGSSHV Carbon build. I've already had the carbon amp boards fabricated using the gerber files on Dr. Gilmore's site. I'm puzzled as to which of the myriads of power supply boards I'll need to power the carbon amp boards, however. My KGSSHV build was an on-board version -- I'd like to go with an off-board version for the carbon build. Would some of the more experienced members give me some tips on which power supply boards I can use and any gotcha's to watch out for with a carbon build? -Vinh

Thanks! I love machining -- if only they'd let me wear my electrostatic headphones around the milling machine Aw! Thanks! :-)

George, This is the link for the case I purchased from eBay; the seller is located in China: http://www.ebay.com/itm/New-aluminum-amp-chassis-home-audio-amplifier-case-size-340-430-92MM-/322291438722?hash=item4b0a111482:g:zQ0AAOSwyLlXo3Qc The seller charged me a reasonable price for 3-day DHL shipping from China. I didn't like the plastic feet that came with the case, so I purchased these aluminum feet: http://www.ebay.com/itm/321374671507 And the handles on the front plate came from this seller on aliexpress (also located in China or Hong Kong): https://www.aliexpress.com/store/product/Breeze-audio-handle-for-chassis-82type/331129_32718799987.html For the etching, I simply used a laser engraver and etched directly on the anodized aluminum. I just used a low power (100mW) laser engraver; normal anodized aluminum (not the hard-anodized version) engraves really well with a laser. Any spot that's hit by the laser turns a white color.

Thanks, Chinsettawong. It was your DIY electrostatic headphones that got me rolling down this path. Sent from my iPhone using Tapatalk

Thanks, John. I've been following your work on head-case.org and that means a lot to me coming from you. -vinh

After almost 4 months of learning and building, an exciting spark from one of the amp boards, and lots and lots of advice from Spritzer, I finally finished up my KGSSHV last night. I've posted photos of my build below. I know the electrical build can't compare with those by other members here, but I'm rather proud of the case work. I purchased a generic aluminum case from an eBay seller in China and spent the last couple of months learning to use CAD CAM software along with some machine shop equipment to customize the case for my build. The red and black anodizing was done by a local shop (in Bangkok). I did all the customized mill work. I etched all the text on the front and back panels using a laser that burned the text directly onto the anodized aluminum. (I put the "BuiAudio" logo on the front just to impress my little sons. :-) The amp sounds wonderful -- no noise at all and dramatically better (and louder) than my STAX SRM-1/MK-2 with my stax SR-303 and SR-407. Now for the next phase... To build a pair of DIY electrostatic headphones like the ones inspired by chinsettawong on head-fi.org...

The white ones coming off the PSU are Molex power connectors; the green ones on the amp boards are Phoenix connectors, but to be honest, I looked up the specs, and the white molex connectors are rated for only 250 v at 5amps... I need to switch to higher voltage ones to be safe. They just happen to be what I had in my parts bin from a former project. Sent from my iPhone using Tapatalk

Wow! What a roller coaster ride of a day... I woke up early this morning to test the amp boards. Plugged them into the PSU, turned on the power, and all LEDs lit up. I thought I was golden... For about 2 seconds before there was a bright spark accompanied by a loud "POP" from one of the IXTP01s on one of the amp boards. The first pop was quickly followed by a second pop before I could yank the power cord from the wall. I was initially too embarrassed to post this in this forum: The sparks resulted in scorch marks on the IXTPs on the one board. Spritzer confirmed to me that I should have used aluminum oxide isolators instead of just plain heatsink paste between those high-power mosfets and their heatsinks. Fortunately, the damage was on only one of the boards. I created some space between the IXTPs and heatsinks and cleaned off the heatsink paste on the second board and plugged it in. The LEDs came on and stayed on with no sparking from the board, and everything was stable enough for me to adjust the balance and offset pots on the board. By the end of the day, I was able to hook up a phone as a source and my beat up pair of Stax 303s. The result was loud, distortion-free music from the one board. I screamed so loudly with joy, my wife got pissed off at me... Back in the dog house again. Hopefully, the only damage on the first amp board is only in the scorched IXTP01s and nothing else... I have some replacement IXTPs along with proper aluminum oxide isolators on order from Mouser... Damn these long waiting spells for replacement parts. At least the first board is working. Sent from my iPhone using Tapatalk

Spritzer will have to answer that one. The transformer I have was custom ordered by him for the kit he sells with the KGSSHV boards. The xformer looks really well made, and the output voltages are very stable. Sent from my iPhone using Tapatalk

Forgot about the voltage drops through the resistors... I need to go back to engineering school... ( Sent from my iPhone using Tapatalk

Awesome! Thanks everybody. I'll start testing the amp boards as soon as I get back home later this week... Sent from my iPhone using Tapatalk

I finished populating all the components on the three boards for my KGSSHV build late last night. I've tested the voltages from the mains line, transformer, and the PSU board and got the measurements below. Everything "seems" to be working correctly EXCEPT that I'm not sure if the differences between the actual and rated voltages coming off the PSU board for the +/-450V and the Bias output is OK or Not. The Bias TP on the PSU Board measures +580 VDC, but then the two terminals labeled "Bias" on the board both measure only 400 VDC or so. (It measures 385 VDC when I first turn on the power and then slowly rises to about 404 VDC after running for several minutes.) Can you guys help me? Are my voltage measuresments within acceptable specs for the PSU board? BTW, I decided to use Molex 2- and 3-pin connectors so I could connect and disconnect the various interconnections quickly and easily. If anybody sees a potential problem with that, let me know. The connectors are rated for lower voltages but much, much higher currents than I suspect would run through the power supply board. Mains Voltage directly from wall outlet: Rated at 220VAC, Measured Actual 230VAC on Fluke Multimeter Measurements from Transformer: AC420, AC420: both measured 470VAC Actual AC15, AC15: both measured 16VAC Actual Measurements from terminals coming off PSU Board: Terminal Name - Actual Measurement +450 +500 VDC -450 -500 VDC +15 +15 VDC (we seem to be Golden here) -15 -15 VDC Bias Terminal (two pins both seem to be tied together on the board): +404 VDC Actual Measurement on Fluke Multimeter Bias TP +580 VDC Actual measurement <photo deleted to offset attachment quota>

Good advise. I use those wooden coffee stirrers at Starbucks as spacers while soldering the resistors to the boards. When done, pull 'em out. Gives a nice uniform outcome. Thanks again for the great tips. I started populating the boards this morning. Took your advice to use pieces of coffee stirrers as spacers to get the resistors and diodes off the board... Sent from my iPhone using Tapatalk

Just wanted to thank everybody for the support and advice I've received in my short time in this forum. This is better than I had hoped for! Sent from my iPhone using Tapatalk

Hi, Wachara! Thank you for the help offer. I can use your advice on potential sources for case and hardware once the electronics work is done, especially if you know if local vendors. Ah... (Light bulb moment). When I took apart my Stax srm-1/mk2, the first thing that struck me was why the heck the resistors were so high off the board and taking up so much space, so I almost took them off to remount because they were making it difficult for me to mount the pro mod board I was trying to install! :-D I've done a lot of DIY, but this is my first time with high voltage circuitry. Sent from my iPhone using Tapatalk

DOH!!! Onboard = heatsinks ON the Board? (I thought all along it had meant the power supply board was separate from the amp boards.) I just finished individually testing each and every passive component from mouser except for the high-voltage caps that my multimeter can't handle... I'll definitely be building this weekend.

Thanks, John, It's an offboard -- I got the boards and transformer from Spritzer. I promise not to inundate you guys and will probably just put up several posts to show the start and result of my build (assuming I don't run into issues as I do this over the next few weeks). Vinh (bui501)

Hello, everybody. I just received my KGSSHV DIY Kit from Spritzer (and BOM from mouser) and am ready to start building my very first KGSSHV. Would it be appropriate for a newbie to document and post his first build here in this forum? It was because of all the discussions I saw here in this forum that inspired me to want to build my own electrostatic headphone amp. I just want to share my excitement (and pick up some tips and advice along the way). -bui501 (in Bangkok, Thailand)