Head-Fi.org › Forums › Misc.-Category Forums › DIY (Do-It-Yourself) Discussions › Does anyone here have a BOM for the KGSS?
New Posts  All Forums:Forum Nav:

Does anyone here have a BOM for the KGSS?

post #1 of 18
12/11/09 at 12:35am
Thread Starter 
I think I've found all the parts for a KGSS, but I want to double-check. Does anyone have the BOM for the amplifier (preferably sans PSU?)

EDIT:

For those interested, a replacement option for the unobtanium 2sk389 is sold by DJgardnener for $6/ea.
http://djgardner.com/headphone/gilmore/

The remainder can be found quite cheaply at Electronix Online for about $10/channel.

http://www.electronix.com/catalog/pr...ducts_id/15892

http://www.electronix.com/catalog/ad...sc2705&x=0&y=0

http://www.electronix.com/catalog/pr...oducts_id/2877

http://www.electronix.com/catalog/pr...ducts_id/15352

http://www.electronix.com/catalog/pr...oducts_id/3041

http://www.electronix.com/catalog/pr...oducts_id/3013

That's under $35 for a whole amp's worth of transistors!
Reply
post #2 of 18
12/11/09 at 3:10pm
I don't have a BOM (built one KGSS recently and I'm working on another) but if you have the Headamp PCB's then all the part values are printed on the PCB. The only "tricky parts" are the 1.7V LED's, getting the correct 3296 pots and making sure that the heatsinks aren't touching the PCB as the solder mask isn't a good insulator.

Here are a few pics of a finished KGSS (missing the volume control which I've since added):



Reply
post #3 of 18
12/11/09 at 5:56pm
Thread Starter 
Quote:
Originally Posted by spritzer View Post
I don't have a BOM (built one KGSS recently and I'm working on another) but if you have the Headamp PCB's then all the part values are printed on the PCB. The only "tricky parts" are the 1.7V LED's, getting the correct 3296 pots and making sure that the heatsinks aren't touching the PCB as the solder mask isn't a good insulator.
Where'd you get the PCBs? I was figuring I'd have to protoboard the whole mess.

I didn't notice the 1.7v LEDs - I'll have to find some of those.
Reply
post #4 of 18
12/11/09 at 8:56pm
From Headamp, scroll to the bottom of the list. You need one of each for the amp.
Reply
post #5 of 18
12/12/09 at 1:01am
Quote:
Originally Posted by spritzer View Post
From Headamp, scroll to the bottom of the list. You need one of each for the amp.
Spritzer, where did you get your Transfos at? What are the specs? Can you use the same transfo for the BH Boards as well as the KGSS?
Reply
post #6 of 18
12/12/09 at 7:48am
The large one is from Victoria Magnetics which I bought in 2003 (they've stopped making transformers now) when I built my first KGSS amps. They have a single 230 primary and 2*280V/140mA secondaries. They only have the HV windings since I was using a different +/-15V supply for those amps. The small transformer is a dual 0-18V unit I bought locally and use it as a 36VCT. I can't remember the exact specs for that one but it's way too big for the role. Kevin did spec the current draw of the LV supply in the KGSS article so double that and you will be fine.

For custom transformers you can't go wrong with SumR. Certainly the same quality as Plitron but without the silly prices.
Reply
post #7 of 18
12/12/09 at 8:49am
I second SumR!
Richard is awesome and very quick a quotes and communication =)
Reply
post #8 of 18
12/12/09 at 10:15am
Ebay has some interesting options...
At least if you have a decent wall voltage.
Reply
post #9 of 18
12/12/09 at 11:39am
Quote:
Originally Posted by spritzer View Post
The large one is from Victoria Magnetics which I bought in 2003 (they've stopped making transformers now) when I built my first KGSS amps. They have a single 230 primary and 2*280V/140mA secondaries. They only have the HV windings since I was using a different +/-15V supply for those amps. The small transformer is a dual 0-18V unit I bought locally and use it as a 36VCT. I can't remember the exact specs for that one but it's way too big for the role. Kevin did spec the current draw of the LV supply in the KGSS article so double that and you will be fine.

For custom transformers you can't go wrong with SumR. Certainly the same quality as Plitron but without the silly prices.
Quote:
Originally Posted by nattonrice View Post
I second SumR!
Richard is awesome and very quick a quotes and communication =)
Thanx, I think SumR it is then.

Quote:
Originally Posted by Dres View Post
Ebay has some interesting options...
At least if you have a decent wall voltage.
I've been looking at some of those R-cores as well.
Reply
post #10 of 18
12/12/09 at 11:47am
You absolutely can not use a CT HV winding with the stock KGSS PSU. You need two 0-280V windings or it won't work. When this PSU was designed there wasn't the option of matched high voltage N and P channel components so the PSU is really two PSU's glued together at the output. While we do have complimentary N and P components now, it has been confirmed that they will be discontinued soon with no replacement in sight.

As for the earlier question of using a BH transformer for a KGSS, I really don't see the point in doing so. It would be at least 2*0-330V/200mA plus the two filament windings so rather more expensive then a KGSS transformer. You would also need 500V caps which are expensive and with some of the usual candidates being discontinued making finding them harder.
Reply
post #11 of 18
12/12/09 at 11:51am
Electronix is an odd vendor. I've ordered from them a couple times and they seem to be oriented toward the repair industry.

I've received parts from them that had obviously been pulled from boards (clipped leads with solder still on them) and I've received batches where some of a single type of transistor are one manufacturer and some are another.
Reply
post #12 of 18
12/12/09 at 12:23pm
Quote:
Originally Posted by spritzer View Post
You absolutely can not use a CT HV winding with the stock KGSS PSU. You need two 0-280V windings or it won't work. When this PSU was designed there wasn't the option of matched high voltage N and P channel components so the PSU is really two PSU's glued together at the output. While we do have complimentary N and P components now, it has been confirmed that they will be discontinued soon with no replacement in sight.

As for the earlier question of using a BH transformer for a KGSS, I really don't see the point in doing so. It would be at least 2*0-330V/200mA plus the two filament windings so rather more expensive then a KGSS transformer. You would also need 500V caps which are expensive and with some of the usual candidates being discontinued making finding them harder.
Hmmm, I thought the KGSS Power Supply board would do the KGSS or BH?
Reply
post #13 of 18
12/12/09 at 12:34pm
The board will work for both amps but they have different voltages, 350 and 400v respectively. Different transformers, caps and zener diodes are thus needed.
Reply
post #14 of 18
12/12/09 at 12:37pm
Quote:
Originally Posted by spritzer View Post
The board will work for both amps but they have different voltages, 350 and 400v respectively. Different transformers, caps and zener diodes are all you need to change.
Thanx, that's what I was wondering! I didn't know about the caps needed changing.
Reply
post #15 of 18
12/12/09 at 12:39pm
If you feed a 450V cap rectified 330VAC then bad things could happen happen. 330VAC*1.41=467VDC (minus a few volts due to diode loss) so 500V caps are the minimum.
Reply
New Posts  All Forums:Forum Nav:
  Return Home
Head-Fi.org › Forums › Misc.-Category Forums › DIY (Do-It-Yourself) Discussions › Does anyone here have a BOM for the KGSS?