i'm on a roll... the kgsshv

[Victor Chew]

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

[n3rdling]

That's pretty cool, reminds me of Lite Brite

[morphsci]

That's pretty cool, reminds me of Lite Brite

Heh. I was thinking the same thing. Nice job!

[spritzer]

You need a CNC machine Victor...

[TMoney]

Beautiful work, Victor!

[swt61]

Really beautiful amp and PS.

[Kerry]

Nice work Victor!

Yeah, a CNC

[Victor Chew]

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.

Edited April 1, 2012 by Victor Chew

[jezz]

I really want to see a picture of that top on with the glow of the amp's LEDs behind it.

[cobra_kai]

Congrats on the successful amp Victor it looks great! All those holes must have taken a ton of patience but the result is really nice. Happy listening!

Edited April 2, 2012 by cobra_kai

[n_maher]

Pictures of my build

[Dreadhead]

Very nice build!

[guzziguy]

Excellent build. I'd never have the concentration to drill all those hole. Good job.

[Emooze]

That is utterly fantastic. What did you use as the cases?

If you rated the exstata as the worst out of 7, I suppose I should order parts for my KGSSHV...

Edited April 3, 2012 by Emooze

[Nebby]

That's a beautiful build, great job!

[Victor Chew]

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.

[Pars]

I'll echo the very nice job!

[Victor Chew]

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.

Edited April 3, 2012 by Victor Chew

[chinsettawong]

Very nice looking amp, Victor. Congratulations!

Wachara C.

[mikeymad]

Very well done... enjoy

[kevin gilmore]

I don't think i was capable of doing work that nice with a hand drill even 35 years ago, i always

found a way to get to a mill, but without a nc readout, it would still have been a pain.

It needs a wood knob! Making an ebony knob that big without cracking could be quite a challenge.

[johnwmclean]

Just noticed Lil Knights BOM for the +/-15 regulators should be 7915 and 7815 not 7912 and 7812.

[kevin gilmore]

Probably makes no difference, but should be 15v

[johnwmclean]

Thanks Kevin,

I was going to replace my installed parts - but if a 12v supply is ok, I’ll leave them in.

-John

[kevin gilmore]

Should be enough offset range to handle this