make sure you use 500v caps, and it will work at 400v. obviously change the zener string and transformer.

 

in other news, kgsshvcarbon boards by joamat posted.  mirror images for the truly insane.

Regarding the new kgsshvcarbon boards by joamat.

 

What is the value of the smd capacitor in pF between MPSA5 and HN4C51J?

 

It is not clear in the silk screen.

 

Thank you very much Kevin, James, Joachim and Kerry for the design.

Thanks! Do you recommend using larger heatsinks on the transistors along with the 500V capacitors?

Edited May 4, 201511 yr by gepardcv

The size of the heatsinks always reflects the difference between the raw DC off the rectifiers and the regulated voltage.  The 2" sinks should be fine though. 

/

 

Edited November 11, 201510 yr by JoaMat

there will be a new version of the boards posted when i get home.

 

difference is bigger mounting holes.

Regarding the new kgsshvcarbon boards by joamat.

 

What is the value of the smd capacitor in pF between MPSA5 and HN4C51J?

 

It is not clear in the silk screen.

 

Thank you very much Kevin, James, Joachim and Kerry for the design.

 

I haven't built this yet.  I'd guess nothing, 5pF or 220pF.  just looking to kill any oscillation if it exits.  in the spice models I used 5pF, but that's just a model.

/

Edited November 11, 201510 yr by JoaMat

Is there a circuit diagram of the kgbhultraminipsv4 somewhere? I couldn't figure out its file name based on the file listing on Kevin's site.

 

I'm trying to figure out how to change the zeners for 400V: the board has two strings of 100V+150V+150V. Do they both need to change to 150V+150V+150V? (Was hoping the circuit diagram would shed some light on this.)

 

For changing the 450V caps to 500V: I assume the resistors attached to them should also change to 430k (up from 330k)?

Look at the old Blue Hawaii article on Headwise, it's pretty much the same psu.  Zener string sets the output voltage and the board was designed for 400V use.  If you set it to the stock values then that is 400V. 

 

The resistors should be the same. 

Interesting, thanks! I read earlier on this thread (or the KGST thread) that the zener string should be set 50V above the target output voltage. The stock zener string values on the two rails add up to 400V on a board that's supposed to put out +/-350V. I figured that to put out +/-400V, I should have the two zener strings each add up to 450V. Is that wrong?

Yes, that is wrong for this PSU. 

That's the guideline for the lt1021 supply, http://tee8tee4388.blogspot.com/2013/07/kgsshv-amplifier.html

@nopants: Yup, thanks, I saw that page — I'm trying to use the much smaller BH power supply and just push it harder.

 

@spritzer: Then it looks like I just need to bump the two 450V caps to 500V, leave the zener strings alone, and that will give me 400V rails? For the transformer, would 2x 330VAC @150mA plus 1x32VCT (16-0-16) secondaries do the trick?

new to the board.  I am making the KGSSHV with power supply in a separate chassis. One single unit is  too big for desktop uses.  I have difficulties in getting an Umbilical cord of multi-conductors which is safe in high voltage  .  What are you guys using?

 

Many thanks in advance for your help

 

Sam

go to eBay and look for old amphenol connectors.

These site has some too but don't know about the quality:

http://www.vt4c.com/shop/program/main.php?group_id=3&cat_id=1015#1003

Amphenol military grade connectors.

I am planning to put my KGSSHV PSU in a separate chassis from the amp boards as well and have been looking at Amphenol military grade connectors at Mouser like John suggested. Some of the ones I looked at are rated at 600V and should be safe for this application.

I'll find the Mouser part number and post it here tomorrow.

I also have a question too - what's the reasonable length for the connecting cord? I like it to be long enough to have the flexibility with the PSU location but not too long to compromise the performance of the amp.

 

 

Edit: Here is a female, panel mount 6-pin connector from Amphenol's ML-C-26482 series. This one is rated at 600V, 7.5A. Mouser part number: 654-PT02E-10-6S. 

Edited May 6, 201511 yr by mwl168

Dear all, 

 

 

thanks for the prompt replies.  I have the connectors.  I am looking for the multi-conductors cord/cable.

 

I always use cable of 5 ft long (someone said it should not be more than 3).  I find this length to be adequate for placing the power supply on the floor.

 

Sam

Most of these connectors are rated to an AC voltage so the DC voltage will be much higher.  If you want to go a bit cheaper then the Chinese Y2 connectors on ebay are pretty nice.  Far from Amphenol quality but at a fraction of the price. 

 

For the Megatron's I'm planning it will be Fischer or other such insanity. 

 

Also, who says you can't build a KGSSHV which fits on a desk? 

 

@spritzer: Then it looks like I just need to bump the two 450V caps to 500V, leave the zener strings alone, and that will give me 400V rails? For the transformer, would 2x 330VAC @150mA plus 1x32VCT (16-0-16) secondaries do the trick?

 

Yes and yes. 

 

I bought a few sets of the  industrial connectors from a local shop a few years back.  They are good for 1000V AC.  only 30 dollars per set.  

 

I could not find multi-conductor wire/cable for the job.  Most multi-conductors cable are good for low voltage only.  Can I use a bundle of teflon hook-up wires, bind them together to create an umbilical cord?

 

though I much prefer to use multi-conductor cable.

 

 

Make your own multiwire cable. Thats what I did, using 600 V cables, all different colors to avoid errors.

600V multi conductor cable is very expensive and very hard to find unless you want to drop 2k$ on a whole roll. 

 

 

I bought a few sets of the  industrial connectors from a local shop a few years back.  They are good for 1000V AC.  only 30 dollars per set.  

 

I could not find multi-conductor wire/cable for the job.  Most multi-conductors cable are good for low voltage only.  Can I use a bundle of teflon hook-up wires, bind them together to create an umbilical cord?

 

though I much prefer to use multi-conductor cable.

 

Sure. Pick up some techflex and heatshrink (adhesive) of an appropriate size to dress up the bundle. Use teflon 600V wire as mentioned by others, and vary the color if you can to eliminate errors in wiring.

I did just as Pars suggests for an Aikido pre-amp I built a while back.  I used DB connectors instead of the Amphenols though.  Very happy with the results.

 

 

 

Me