Victor Chew

Congratulations John. Very nice build. The encapsulated transformer looks really neat. What attenuator are you using?

Eggil, you might want to twist/braid your ac, dc and input wires together or more tightly with each other to reduce noise. This is a electrostatic amp with very high gain and more susceptible to noise pickup. Output wires I believe are less prone.

I believe Kevin also said that the O+ and O- ought to be flipped as well to ensure that the phasing is correct. But this will be for the later stage when signal wires are being dealt with.

The wires should in the first place never be near the solder points. Even if the heat doesn't get them the sharp exposed leads might. Teflon sleeve wires are recommended. I would run them along the side of the boards. If you must, use higher stands offs and secure the wires to zip ties to anchors the wires http://www.amazon.com/Zip-Tie-Mount-25-Pack/dp/B000BSJHLE I use the 3m ones. Quite a lot more expensive as compared to the normal ones but they don't come off unless you literally use a screwdrive or penknife to cut them out.

Nice work Spritzer. "Balanced all triode".....Interesting! I have always loved the sound from the triodes in particular the 300B in SE mode. Though not much of power, but when matched with efficient speakers they sound nice with plenty of dynamics to my old ears. Please let us know how these perform.

Don't quite understand what you are saying.

Very Nice Birgir. What volume pot is it that you are using. Tiny little thing. Any expectation of te sound?

I wrote to Khozmo asking for some detais. This is their reply: "This weekend I will update my home page with new pics and dimensions. There will be also remote controll available. Best regards Arek Kallas"

Is it for balanced? Forgot to mention that I needed the balanced dimension. Apologies.

Anyone got the dimensions of the round type Khozmo attenuators? Infomation on their website is both sparce and not up dated.

Congratulations eggil.

Yes, interesting. Fake parts are real nuisance and trouble causer. Have a look at this video clip For those of us who don't have full facilities to check the parts including myself, can only hope that, even if all effort is put in to make sure that the build is good, can only pray that when the switch is flipped everything works. Also hopefully, it continues to work properly for a long time to come. I only have the vbr tester which is insufficient to check other important perimeters.

Electrostatic and dynamicin one build?

I will try with wood block pictured. Don't know what wood it is but is's so hard that when I cut it at the carpenter's shop smoke started appearing between the blades and the wood even though I was not pulling hard at the cutter travel. Don't know if I will succeed.

Nice work Vortex. Any further progress with the casings? Any suggestions, on implementation of a switch between high and low impedance cans?

Having a nice looking amp is one thing, but really to me, the sound it brings gives me even more pleasure. And for this pleasure, many thanks to Kevin for bringing such high quality music enjoyment to our ears.

Thank you all for your kind words guys. Some have asked how I built the casings. I used solid core 1/2 inch aluminium square section for the bones. 3mm thick Aluminium plates - 4 inch plates for the sides, 5 inch for the top, bottom, front and back panels. They come in length of 20 ft. I used the circular saw at the shop I bought them from to cut them to size. After that I drilled (using a cordless hand drill) and hand tapped the holes to put the bones and plates together. Precession was important for some parts so I had to be carefull to get the alignment correct. I was fortunate to get things correct first time. No wasted materials. I think patience is the key. Next, I drilled the necessary holes for the front and back plates for the audio sockets (XLR, Stax, Volume shaft, umbilical cord, and the iec input). I had to do some manual sanding filing of the holes as some of the sockets(stax, volume shaft and iec input) had funny shapes and sizes. The power socket was more challenging. I had to drill small holes to to get a rough shape of the socket. Knock out the unnecessary then file it down in size to take the iec input. After that I drilled the holes for the circuit board stand offs, ground connection terminals, dc splitter terminal and transformer secure hole. Finally, I drilled the holes for the ventilation. I glued graph paper onto the plates to use as a guide. Drew the designs I wanted, which is what you see in the pictures. The wooden board you see in the picture was the base I used to secure the plates followed by the drilling. Ever single hole was drilled using a cordless hand drill. Spent many back breaking hours bending over and doing it. All paint work was using can spray - for the top and side plates I used heat resistant enamel paint. I didnt paint the bottom plates. For the front and back plates I use motorcycle exhaust pipe paint. Then got the decals (US$25 for all) cut at a nearby shop. After the decals were pasted spray coated the plates with lacquer.

Thank you all so much for your kind comments. Spritzer you are correct about the dact causing the hum. All sorted it out by leaving the dact ground totally ungrounded. The body is grounded being tied to th chasis. The amp is dead quiet from voulme zero to max. Balance and Offset sits nicely at zero as well. Been playing it for hours and she doesnt run too hot, so that I can even touch the heat sinks with my bare hands. Yeah CNC next. Wonder how my Minister of "Home Affairs" will react.. As promised, here is my mini review. I will compare it to the equipment(717, Border Patrol pre/power with esc 1001 transformers/SRD 7mk 2/SRD 7SB and the exstata) that I used to have. Fortunately, they have been sold to my neighbour who is only 5 minutes drive away, so I have easy excess to them for comparison. Please take what I say with a pinch of salt as its only my view. The Koala tube CD player and Omega 2 Mk1 are used as the unchanged constant. The 717 has the most laid back sound. It has everything but on a smaller scale. Its like I am sitting futher away from the music. Pretty clear and neutral sounding I would say. All the transformers are greatly affected by what's driving them. I have used many other amps to drive them and like the Border patrol pre/power 300B SE best. On it own it produces a nice 300B sound which is euphoric and sweet sounding. Although only has 9w, its can produce pretty powerful music with strong tight bass when paired with efficient speakers. With the SRD7SB, music presentation is more forward than the 717 and I find the sound somewhat slow and slightly lacking in live, possibly because the bias is not independantly driven. Soundstage is wide but a little muffled and bass is lumpy. As with well designed 300B amps they produce a nice soothing midrange. Coloured is what I would term it as and preference or addiction to it much depends on the individual's taste. I love them. The SRD 7mk2 is also forward sounding but sounds much livelier than the SRD7SB possibly because the bias circuit is independantly driven. Sounds more powerful with a wide soundstage and does everything better than the SRD 7SB and with much better clarity. I find the the esc 1001 is a notch above the SRD7mk2 in everyway. They do not come with fixed input cables to the poweramp, unlike the stax transformers, so one is free to play with after market cables and match them to your liking, if you so believe in the differenced they can make. I happen to be able to hear the differences. If you like the audionote cables and they will be guaranteed to blow a hole in your pocket. The exstata is slow and sounds thin. Now for the KGSShv. A power beast. Music is more forward than the 717 but not as forward as the transformer boxes. I am particular about this as I like my music leave me alone. I get tired quickly when I am too close to the impulses. Wow the bass is wow. The attack and decay leaves me speechless. Its like audionote stage 5 bass. Really tight and detalied and you can feel the texture. I must say that I have owned many systems that can produce the attack but when it comes to decay, they roll off. I am also surprised that a transistor amp can produce such nice midrange. Not as euphoric as the 300B, which is coloured but not as detalied. With the KGSShv I can literally hear the singer breathing and so clearly. Clarity is unmatched by all of the other contenders and therefore the treble quality needs no comments. It's also nice that though clear it does not attack me. Instrument placements are also unmatched by the above contenders. Pin point accurancy. My rankings: 1. KGSShv 2. Esc 1001 3. SRD 7mk2 4. 717 5. SRD 7SB 6. Exstata.

OOps! Forgot to post pictures of the top, but here it is. Many more holes at the bottom as well.

Pictures of my build Spent most of the building time on building the casing. PSU has about 800 holes and Amp has more than 1200 holes for ventilation. All hand drilled. My wife thinks I am crazy. Fortunately it was done in the common area so I did not get any beating from her dirtying the place. Also had to wait 10 day for the lacquer to dry before implanting the boards into them.

EL_Doug I am sure things will turn out ok in the end. I am a bit luckier, I have found music after 3 months of hard work. However, my transformer has a slight buzz and I have hum when the voulme is at zero although I followed the suggested grounding plan. Any suggestions to cure them? I am using the dact potentiometer on a 2 box psu/amp build. I will have to thank Ben, Kevin and Birgir for helping me along with the build when I had questions and problems. Kevin thank you very much for designing the KGSShv. For the moment I am really tired spending more than 5 hours of intensive wiring earlier today. I will post a mini review of the sound later on, but for now all I can say is that I can feel the raw power of this amp extracting unbelieveable details, thick sound and big powerfully controlled bass. It is miles ahead of the exStata which I have infront of me on loan. I would also post pictures of the build later, but my quota has run out.

I am also pretty afraid of future shorts that may be caused by whatever reasons. As a precautionary measure, I cleaned the boards to deflux them. Infact after I did mine and I checked all the joints, I found a few cold solder joints and also a couple of unsoldered ones. I also wanted to remove potential shortings due to bridges caused by small pieces of solder. I use acetone (nail polish remover), followed by denatured alcohol to clean off the stickyness caused by the acetone.

As far as I understand, he is using the pc psu contained in the silver box to power the 5 fans with the intention of cooling the psu and amp. 2 on top of each amp board and one, not shown, inside the slver box to cool the PC power supply. He doesnt realise the amp and the transformer readings will stabilise when a certain temperature is reached. Callibration of the DC offset and balance as we know is achieved more accurately when the amp has warmed up. Currently 80mm fans but he wants to use 120mm for more cooling. The whole thing looks like a big computer box. Further I dont know how he is going to adjust the pots with the fans running.

I think the KGSShv deserves a lot better casing than that. What a shame. If the amp runs into problems, he will have a tough time getting the boards out. I am not talking about future problems but problems with the build at start up.

Some infomation about my build. Powered up the psu just now. Voltages were sitting as per spec. both at the +ve and -ve 500vdc and 15vdc. Then power up the amps. Balancing was perfect. However, I was not able to get the dc offset down to 0v Max I got was about +60vdc and was out of turns. Kevin suggested to either decrease the value of R26 or increase the value of R12 and R19, citing that the IXYS part was pulling too much current and is out of spec. Can't understand why the IXYS which is from mouser would do that. Anyway, Kevin said to change R26 from 2k to 1.5k. Didn't have that in hand so used a 1.2k. Hurray! Was able to balance and get the DC offset to roughly zero. What fuse rating would be good for this amp? The KGSShv pulls 5.5ma x 4. http://www.head-fi.org/t/582518/electrostatic-amplifiers-voltage-ratings