i'm on a roll... the kgsshv

[livewire]

Buttoned up, ready for the meet tomorrow.

Edited April 22, 2011 by livewire

[El_Doug]

the sticker is a nice touch now you just need to fabricate some gull-wing doors for it

[livewire]

Ha-Ha!!!

That thought actually crossed my mind.

Section the cover in the middle with a piano hinge running front to back.

Have some gas shocks to hold it in the up position.

[wink]

WOT? only 1.21 jigawatts. That's only 0.00000000000000000000000000334 Googlewatts.

Which is only 0.000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000.5 factorial...

Hope mine will look even half as good..!!

Edited April 23, 2011 by wink

[Kerry]

Nice build! Congrats.

Yeah. You'll want to hear some high-end Stax headphones with that.

Start saving

[livewire]

Thanks for the compliments guys.

I just wanted a clean "econo-build", nothing fancy to help keep the price down.

Kerry, you're right about the "start saving".

I heard an O2 Mk1 (I believe n3rdling's) through the KGSSHV at the meet last weekend.

All I can say is WOW!!!

His Blue Hawaii with the original Omegas trumped that experience. I AM IN AWE!

Now where am I gonna find $11K for a BHSE and a SR-009?

Aint gonna happen soon unless I were to win the lottery.

Think I'll stay content with what I got. It does sound nice.

[rille]

My power supply is still not working

Q8 and D1 were fried at first test and had a short. I changed them and also Q1/Q2. But Q1/Q2 were ok, no change. I get ~50V output voltage at the positive rail. The negative rail is working. The other transistors in the positive rail seem to be ok. A diode test was ok and there're also no shorts. The LM4040-10 has the desired 10V. What should I try next? My next idea is changing all the other transistors. Is there a schematic with operating points like AMB has?

[livewire]

No, nothing exists that shows test point voltages.

If you read back about seven pages, you will see that I asked similar questions and had similar findings.

When this happened to me, I also found the 100ohm resistors in the battery sub-circuit to be fried

as well as the 2SC3381 sand. Since I wasnt having any luck with understanding how the battery outputs work,

that coupled with the negative rail still bad and the positive rail working but not regulating under load,

I gave up and went to a simpler iteration of the power supply circuit sans battery, using a zener string instead.

FWIW, I started researching older psu designs on KG's HeadWize site, then tripped across his earlier psu design

in this thread. It all made perfect sense to me now. This I could understand and implement. Worked fine for me.

I would like to revert to the battery regulator design, but wont for now until those questions are answered

regarding it's function and input/output voltage test points.

So long story short, I left the crippled battery circuits in place and cut some traces

to disable current flow through them and soldered in the zener strings(3ea@150V-5W) as shown in the schematics below.

kgsshvps2.pdf

[rille]

Thanks for your reply. I will try changing the parts first.

[livewire]

KGSSHV at the San Diego HF Meet last Saturday.

Check out what's plugged into it.

We were standing off to the right side auditioning the O2 Mk1.

It was a big deal for me, I've never heard (ex)flagships before.

[kevin gilmore]

i cannot figure out why the power supply is blowing up, mine

still works great.

However a current limit is a good idea

and maybe a switch to doug's magic chip depending

on price and real availibility.

[livewire]

That's good to hear, so I guess the design of the battery circuit is a sound one.

Please remember that I initiated the trouble both times. (blew it up)

I suspect that rille's woes were from HV shorting to the heatsink, but i'm guessing here.

This battery sub-circuit is shrouded in mystery to me.

It seems that after things "went sideways" I could not get the battery circuits to function

properly no matter what I did. I got tired of shooting in the dark. Then I saw the (zener) light.

I know they are probably noisier and may not regulate down to the last nanoamp, but should be good enough.

You have used them in most of your previous psu's.

Without knowing the inner workings of the battery circuit I have a gut feeling concern about

the 2SC3381 sand and the two 100 ohm resistors sitting right on the -450 volt rail.

They do seem like a weak link and fried on me both times I shorted things out upstream.

I'm just a tech, not a design engineer. I dont have an understanding of exotic circuits such as current tunnels.

It would be nice to have a "blow by blow" on how this battery circuit functions.

That is one of the things that I appreciated while reading about your stat amp designs in your HeadWize site.

Though not detailed, the sub-circuits were explained in a way that a novice could grasp or at least research further.

Anyhow, blah-blah-blah. Please excuse my moaning.

I am really happy to have a functioning stat amp even if it was a little over my head to build.

There will not be a T2 in my future.

Next thing for me is to learn what I need to test the audio output on the KGSSHV for quality.

I may take it to a lab, cause I have no idea what is needed to test audio that has a 900 volt swing.

[Craig Sawyers]

This battery sub-circuit is shrouded in mystery to me.

Without knowing the inner workings of the battery circuit I have a gut feeling concern about

the 2SC3381 sand and the two 100 ohm resistors sitting right on the -450 volt rail.

They do seem like a weak link and fried on me both times I shorted things out upstream.

I'm just a tech, not a design engineer. I dont have an understanding of exotic circuits such as current tunnels.

It would be nice to have a "blow by blow" on how this battery circuit functions.

If you have a poke around on the T2 thread, I got under the skin of the battery while diagnosing multiple faults (caused by Chinese counterfeit 2SC3675's), including modelling it to work out the strategy for adjusting the original circuit's two pots.

KG has updated and upgraded the circuit to get rid of the LED chain and JFET, but the operating principle is the same.

In brief:

Q4/Q5 are a long tailed pair that compare 10V from the reference with the voltage set on RV2. Q6/Q7 are DC level shifters to keep Q4, Q5 and Q8 inside the VceBR voltage at which they blow up. Q8 is a Widlar current mirror. This has a very high impedance, and is there to increase the gain of the long tailed pair - standard practice in IC's and high quality discrete designs.

As you adjust RV1, the current through Q4 and Q5 is forced to be equal by the current mirror - so both increase in step. The output voltage is taken from Q8B - which is electrically equivalent to taking it from the collector of Q5 if we disregard the level shifter.

Edited April 29, 2011 by Craig Sawyers

[Lil Knight]

Craig,

Do you have a pic of those counterfeit 2sc3675s? I got a bunch of those and about 30% of them look different from the others.

[kevin gilmore]

Power supply board with either simple zener option, or

full regulator soon. Includes current limit to prevent

the fets from blowing upon application of dead short.

Edited April 30, 2011 by kevin gilmore

[livewire]

@ Craig Sawyers - Thanks for the explanation, I need to study current mirror theory.

@ KG - Thanks again for your continued efforts, cant wait to see it.

[kevin gilmore]

http://gilmore.chem.northwestern.edu/kgsshvpower4.pdf

http://gilmore.chem.northwestern.edu/kgsshvps7e.jpg

http://gilmore.chem.northwestern.edu/kgsshvps7e.zip

current limiters as suggested by doug,

place for add on board for doug's regulator chip

mounting hole size increased for #6-32

multiple build options including zeners only for

simple and cheaper. (well cheap is a relative term)

amplifier with on board heatsinks

http://gilmore.chem.northwestern.edu/kgsshvampv6.jpg

http://gilmore.chem.northwestern.edu/kgsshvampv6.zip

amplifier for mounting to wall of the pesante case

http://gilmore.chem.northwestern.edu/kgsshvampv7.jpg

http://gilmore.chem.northwestern.edu/kgsshvampv7.zip

Edited May 1, 2011 by kevin gilmore

[Kerry]

I love what you did with the current limiters.

Very slick

[Craig Sawyers]

Craig,

Do you have a pic of those counterfeit 2sc3675s? I got a bunch of those and about 30% of them look different from the others.

Check the T2 thread - chapter and verse in there. Counterfeit ones came via Dalbani in the UK. They replaced them without any quibble.

[Lil Knight]

I saw the link but it was dead...

[Craig Sawyers]

I saw the link but it was dead...

Thanks for the heads up - I changed ISP's when the one I used to be with (Hotchilli.com ) had a server crash and failed to recover the folder containg images. Staggering incompetence

I'll find the images and upload them again - and then post the link.

[charlo89]

Good evening,

I will launch the construction of a kgsshv. But I have some questions.

I made a drawing of the internal wiring (with only one channel), I do not know what is a "CT" and I'm not sure of the connections, especially at the RCA.

Thank you for completed my drawing.

And I would like to knows where buy my transfo for my voltage (220V)

http://imageshack.us/photo/my-images/220/cablageinternebeta.jpg/

Additionally I modeled an amp in a box Hifi2000, it costs about $ 220

Thank you

[DouglasQuaid]

http://img815.imageshack.us/img815/3715/kgsshvamp.png

http://img829.imageshack.us/img829/7848/kgsshvlogo.png

http://img859.imageshack.us/img859/1917/panelkgsshv.png

Only terrorists and pedophiles put the volume knob on the left.

CT = Center-tap.

[n3rdling]

Cool front panel design, reminds me of the Pass Labs stuff.

[kevin gilmore]

center tap is optional.

and i have an even newer and slightly simpler high voltage supply coming soon.

less parts, and the battery thing flipped upside down, and reference is now lt1021-10

because in fact it outperforms the lm4040-10 by a major amount.

Long story on the lm4040 part...