i'm on a roll... the kgsshv

[kevin gilmore]

So for whatever reason a number of different projects are coming together at the same time.

This is the latest.

http://gilmore.chem.northwestern.edu/kgsshv.jpg

Its the high voltage version of the kgss with higher voltage pnp transistors, a cascode current

source for the 3rd stage, the lsk389 part (or singles) and much higher voltage output transistors.

The result is something that runs on +/-500 volt power supplies, and is as close as i know how

to do to the T2. (except fully solid state, and easy to build)

The transistors that go on the heatsinks are already insulated, which makes that part easy.

Not a lot more money than an exstata, and much better sound.

So do i make it a single box, Do i make it a two box affair with the power supply in a seperate

box... What are people interested in??

[Hopstretch]

I'm extremely interested in hearing one!

[spritzer]

Dual box but then you already knew that...

[Dusty Chalk]

Dual box would be easier to ship, I would think. They could go in separate boxes if they got too overengineered.

[kevin gilmore]

So krell style matched pair with heatsink on the left side for the amp, and on the right side for the power supply ??

[boomana]

What would be the advantage of one box over two or visa versa? Also, I'm with Stretch in that I'd just love to hear it. CanJam preview?

[kevin gilmore]

No way CJ preview. No box for the amp. NO BOX FOR THE POWER SUPPLY.

1 killovolt flying around with enough energy storage to kill.

Sort of like the BHSE prototype i have, only much more dangerous.

I'm not going to even supply pictures because i do not want to encourage

this kind of behaviour.

The company supplying insurance for the meet would probably go non-linear.

Overengineered? I would never do such a thing.

Headphone amps are supposed to weigh at least 50 lbs right?

Edited May 20, 2010 by kevin gilmore

[Dusty Chalk]

They don't gotta know. And who insures at RMAF? There's some insane things going on at that show, if I'm thinking of the right one.

And couldn't you rewire it (I.E. add resistors in crucial places) so that it travels effectively discharged, and then take the resistors out when you get there?

[spritzer]

Running it open would be the main issue here. "No touching of the pretty LEDs!!!!!!!!!!!"

Having the heatsinks on either side is a neat idea and would look great with the amp placed on a single shelf instead of being stacked.

[nattonrice]

Your house must look like a production line atm =)

My half finished kgss is having serious confidence issues...

[kevin gilmore]

2 boxes it is

http://gilmore.chem.northwestern.edu/kgsshvamp.jpg

board is 11.0 x 6.975 inches designed to fit in a box 11.2 x 7.0 inches inside with

.25 thick front and rear panels.

i have the dact in there as the pot because the rk50 would cost more than the rest

of it combined.

power supply hopefully the same exact size.

What other pot should i add...

I have actually cleaned up the house a serious amount...

All i have left is 30 of the heatsinks. Soon i will be taking those to

work. All the T2 chassis parts will be packaged and leave from work.

So no more 600+ lbs of aluminum stashed everywhere.

You can swap out the parts on your KGSS to turn it into the high voltage version.

You can leave the resistors at the top of the 3rd stage, or build the current sources

on addin boards... The original kgss design is TEN years old... maybe a bit more.

Edited May 21, 2010 by kevin gilmore

[luvdunhill]

Are all 30 heatsinks taken? If not... Either way, I'd be up for stuffing one whenever you're ready.

[kevin gilmore]

The heatsinks are the rest of the heatsinks for the T2's. All gone.

Because this thing is going to be less than 12 inches, standard heatsinks should be available, and without

all the extra machining...

[Currawong]

You can swap out the parts on your KGSS to turn it into the high voltage version.

You can leave the resistors at the top of the 3rd stage, or build the current sources

on addin boards... The original kgss design is TEN years old... maybe a bit more.

So I could build one of these with the set of boards from Justin I have on order?

[Dusty Chalk]

What other pot should i add...

Output impedance to fine tune impedance matching?

[kevin gilmore]

Yes you can certainly change the part values and add the current sources as outboard devices on justin's board.

In fact that is exactly what my prototype is. Power supply is obviously different.

The pot i was talking about was the input pot. Something that is available. Like the rk25, or some such, because

evidently the rk50 is soon to be discontinued.

Starting on the schematic now.

[n_maher]

Even if all the devices on the heat sinks are on one side only I'd still do a symmetric chassis with heat sinks on both sides.

[kevin gilmore]

first cut at the schematic

http://gilmore.chem.northwestern.edu/kgsshv.pdf

The boards definitely will fit together in one chassis

http://gilmore.chem.northwestern.edu/kgsshvamp.jpg

http://gilmore.chem.northwestern.edu/kgsshvps.jpg

depending on the thickness of the transformer which will mount to the back panel

i'm pretty sure that if you do it as one box, it sends up 14 across by 11 deep with

1 inch between the 2 boards.

I might have to make it a bit longer to accomidate the transformer.

[spritzer]

The RK27 is a dreadful pot so either those pots which you should receive soon or the TKD 4CP-601. The TKD is tiny so perhaps better for a tiny balanced desktop amp?

Edited May 21, 2010 by spritzer

[kevin gilmore]

Need the layout diagrams for any/all pots...

[spritzer]

Here is the TKD and here is the Alpha.

[nattonrice]

I like the layout. It's going to make for a very neat single box layout.

Bah I already have all the stuff plus traffo for the kgssbv (boring voltage).

[spritzer]

+/-350V being considdered boring just shows how utterly bonkers we really are...

[Currawong]

spritzer: Did you end up getting the Japanese pots?

[spritzer]

Yup, but they won't work in my KGSS chassis. The problem is the thick aluminum I used for the front panel (10mm+4mm spacer) so the pots just aren't long enough to mount a knob to them. I might modify the front panel by cutting out a 45mm hole in the front panel but with such a thick panel it isn't an easy thing to do (plus the center hole is too large for the center drill of the cutting bit). I did fit one of the Alpha pots instead of the RK27 and it was a pleasant upgrade.

One of the smaller TKD's has been fitted in the Stax SRM-Xh as I'm making the amp fully balanced and I'm upgrading the PSU. Tiny, fully balanced, fully discrete electrostatic amp FTMFW!!

Edited May 22, 2010 by spritzer