KGSSHV Carbon Build Thread

[Whitigir]

12 hours ago, Inu said:

Ugliest build....  

Aluminum sheets from e-bay.  

I like it a lot ! Unique looking build

Edited May 30, 2017 by Whitigir

[GeorgeP]

Has anyone use the Carbon amp board with ground plane (version .6G)? Wanted to know if people have had successful builds with these and there were no board errors. Have a couple sets, not sure from where with all the board ordering over the past year, and thinking of building one.

[johnwmclean]

I've built several amps with those boards with no issues.

[GeorgeP]

Great, thanks, John!

[GeorgeP]

Other quick question.

Was going to use 2 +400 PSU boards (cap off-board version), making one to output -400. From what I can tell looking at the schematic, all that I need to do is output one of the +400 boards to ground to get -400 out of the ground terminal. Don't think there are any other considerations to keep in mind. Using a GRLV and separate bias board as well.

And as an aside, there are two errors in the cap off-board psu - will post a picture later on.

[GeorgeP]

So answering my own question - there are no other considerations, and it works like a charm.

Regarding the off-board PSU PCBs, for anyone interested the errors are shown in the pics (also, various values have changed, but the circuit is the same):

 

Edited June 7, 2017 by GeorgeP

[kevin gilmore]

edit: found the output file, but no source file.  (or I named it something stupid) but from the dates, no matching source file

 

 

Edited June 8, 2017 by kevin gilmore

[GeorgeP]

kgsshvpssicfetnocap.zip

[kevin gilmore]

pretty sure i found the right source file, will have to look later

i got to get this crap under control somehow

edit: fixed board layout for future use if any

 

kgsshvpssicfetsingle2newstretch2 - CADCAM.ZIP

Edited June 8, 2017 by kevin gilmore

[P3t4]

First post here Where might I find the schematics and whatnot to get a project going? Does someone sell the boards already or do I get to order them from somewhere? Cheers!

[gepardcv]

@P3t4: The board and schematic archives are in a transitional period right now (read the stax mafia circuit boards thread). If you're after the solid-state Carbon, I think this post has links to the schematics of the Carbon amp and the GRHV power supply. As for boards, you can get your own made (links to recent Gerbers should be floating around here somewhere), or buy from someone who has extras. It'll help to review this entire thread, as I think it covers every tricky point of the build. Other things to read, and think about:

• The original KGSSHV thread has great info on the basics of building an electrostatic amp. It's old and long, but well worth reading.
• A few more basics are covered in the old DIY electrostatic amp thread.
• If you decide to build an off-board heatsink design (like all Carbon variants), I hope you have access to at least a drill press. A full metal shop would be better.

Depending on your experience with building high voltage circuits, starting with something non-electrostatic — like a Dynalo with GRLV — might be a good idea.

[mypasswordis]

I do everything by hand, and hand drilling and tapping heatsinks actually isn't too bad as long as you make sure all the holes line up. And with L brackets you just need 2 or 3 blind tapped holes to mount the bracket to the heatsink. That said, a drill press would be a lot more convenient for pretty much every other aspect of chassis work...

[P3t4]

I just found the google drive folder with the projects. Is kgsshvcarbonv5.zip the one I'm after, going for the solid state carbon? Does the zip file have all the files needed for my project? Thanks!

[Pars]

Not sure about version, but the .zip file is the Gerbers, which is what the board shop needs to make the board(s). It will not contain schematics or anything other than the Gerbers.

[gepardcv]

v5 works. I think that's the one most of us used through group buys. v6 is the same, except slightly smaller and needs slightly smaller L brackets. Compare them with a Gerber viewer (like circuitpeople.com).

Edit: Don't forget the power supplies. The one most people used for the Carbon is the GRHV, in either a split or single-board version. The files for the split PSU were kgsshvpssicfetsinglenewleftfat.zip and kgsshvpssicfetsinglenewrightfat.zip, but there are several others in the archive, with "s" and "sw" suffixes on the file names. I'm not sure what those are. A close look at the rendered Gerbers should prove enlightening.

Finally, some builders chose to bypass the GRHV's built-in low voltage power supply in favor of the dedicated GRLV. If you go down that road, the file is goldenreference6.zip (no clue what 6d is, and I guess the ones with minus and plus in the file names must be split versions).

Edited July 1, 2017 by gepardcv

[Laowei]

Pretty sure the GRHV files with .sw and .sws suffix are power supplies with an optocoupler controlled B+/B- delay. Useful only in circuits with vacuum tubes, to allow the heaters to fully warm up before blasting plate volts. Will help the tubes last longer. Not needed for an all SS Carbon. 

[P3t4]

How do you mount the boards in the case? Does the modushop case come with screws? Do they also do the holes and carvings? What kind of wires are preferred? I'm almost ready to start the project at the university

[P3t4]

Also, I'm interested in how to make an adjustable bias output for vintage stuff.

[Pars]

Hmmm, university student(?) and still spoon fed?

This thread is 45 pages. Read them. If the content of that doesn't answer your previous post, then there are other threads showing builds, etc.

Your previous post doesn't elicit confidence in you making a successful build

[gepardcv]

@P3t4: You generally mount boards on standoffs. You will need to drill the case, and heatsinks, to do this. Alternatively, make a CAD file and have a machine shop do that for you. Front Panel Express does this well and even provides a simple CAD program for doing this. Rather expensive, though. Modushop cases come only with the screws necessary to assemble them. You can also get a case at Cam Expert who I believe can also do customizations, but no idea about prices or heatsink availability.

McMaster-Carr carries a wide selection of mounting hardware (and a million other things).

For wire, I buy PTFE 600V-rated spools from Bulk Wire. Good for most builds.

On that subject, though, do you know how to safely work with high-voltage electricity? You must have a grasp of safety technique. If you short-circuit one of these power supplies while touching a rail, it can stop your heart. That's why I suggested you start with a Dynalo+GRLV. You'll have to solve similar construction and wiring problems, but the circuit is much safer to work with.

Edited July 9, 2017 by gepardcv

[P3t4]

No need for worry, I've got friends at the university who have studied electrical engineering for years. I'm merely managing the build not messing anything up myself. I am from the computer science department and while I do know how to solder the rest of the expertise I do not have. Thank you for the info. I'm about half way on this thread.

[mypasswordis]

Except everything you've said and asked so far causes a lot of worry. I know from personal experience that EE students can easily go through all 4 years without touching a soldering iron let alone messing around with almost a kilovolt, so that doesn't mean anything in terms of safety. I also know from personal experience that comp sci majors don't know how circuits work. You should listen to Pars and gepardcv and build a low voltage amp first while reading up on high voltage safety, because while we are not responsible for your injury or death we still don't want to end up on the news (for the wrong reasons)

[P3t4]

All I have asked relates to my utter and complete newbieness as you have pointed out cs majors don't deal with hardware. My friend is a stone cold professional, already graduated and working at the uni. He has also built all kinds of devices including amplifiers. I haven't showed the schematics to him yet but when I do I will ask him whether he has worked with such high voltage and if he knows the safety measures before I go further with the build. I appreciate your concern.

[P3t4]

Anybody got a spare TKD 4cp potentiometer for sale?

[nopants]

you can always use a courier service yourself and order them