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Closed - KGSSHV Carbon and GoldenReference HV PS Group Buy


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EDIT 8/4: attach updated GB details and remov outdated chart

EDIT 7/31: attach updated GB details and remov outdated chart

EDIT 7/27: attach GB details and remov outdated chart 

EDIT 7/23: attach PCB cost quotes and limit first time poster to 4 set of amp boards max.

EDIT 7/19: proposing use of HV Carbon V5 board to replace both V2 and V3 boards. See posting # 190.

EDIT 7/13: attach snapshot of final order entries and board count.

EDIT 7/12: This GB is officially closed as of 7/12/2015.

Due to the changes Kevin made to the PS boards, it'll take a few more days for these boards to be checked before I officially request quotes from the fab houses. I hope to have information on the cost of the various boards to share in a week or so. I will post an image of the spreadsheet here for all to review.

EDIT 7/9: Please double check and confirm or make any final updates to your record on the spreadsheet by end of day Saturday, July 11. On Sunday, July 12, I will officially close the GB, lock down the counts of the various boards, post a snap shot of the spreadsheet on this thread for your review and proceed to request final quotes from the fab houses.

As promised, I am planning a KGSSHV Carbon GB which includes both the amp boards and the PS boards. First I like to gauge the interest for the GB which will also help me estimate the cost of the PCB boards. My plan is to make 2mm thick PCB with 2oz copper. (EDIT 0731: HV PS boards are upgraded to 3oz copper)

For the amp board, we'll most likely use the latest board, kgsshvcarbonv2.zip and kgsshvcarbonv3.zip that Kevin posted on June 30 which has the cascode CCS and uses mostly current parts including the PZTA SMD parts. This board measures 5.45 x 4.05 inches according to Kevin. THIS BOARD HAS NOT BEEN CHECKED NOR TESTED AT TIME OF WRITING.

For the HV PS board, we have the following options (these HV boards contain built-in LV supply):

1. the GoldenReference dual HV (kgsshvpssicfetdual2new.zip that Kevin posted on June 27, 6 x 6.48 inches). I have checked this board by tracing the PCB visually and Kevin has corrected the issues I spotted and updated the schematic accordingly (see Kevin's post #4802 on the KGSSHV thread for the schematic). I cannot guarantee I did not miss something. THIS BOARD HAS NOT BEEN TESTED.

2. the split/single, "skinny" PS boards (one board for each rail), they are kgsshvpssicfetsinglenewleft.zip and kgsshvpssicfetsinglenewright.zip which were also posted on June 28 (3 x 6.48 inches). THESE SINGLE PS BOARDS HAVE NOT BEEN CHECKED NOR TESTED.

3. the split/single, "fat" PS boards (one board for each rail), they are kgsshvpssicfetsinglenewleftfat.zip and kgsshvpssicfetsinglenewrightfat.zip which were posted on June 28 (4.05 x 5.45 inches). THESE SINGLE PS BOARDS HAVE NOT BEEN CHECKED NOR TESTED.

For stand alone Golden Reference LV PS, two options (THESE PS BOARDS HAVE NOT BEEN CHECKED NOR TESTED):

1. the dual LV (goldenreferce3.zip)

2. the single LV (goldenrefernceplus4.zip and goldenreferenceminus4.zip)

We'll need to at least check these boards before proceeding to have them fabricated for the GB. I will try to find time to trace them but can really use others' help for double-checking.

To gauge the interest and to help get an idea of the volume in order to determine the cost, please respond with the following information (be specific) if you are interested in participating in this GB:

1. How many amp boards do you want. (one channel on each board, you need two amp boards for one complete amp.)

2. Which HV PS (dual, single skinny or single fat) and how many of them do you want. (you need at least one dual board or two single boards for one complete amp.) The HV PS has built in LV and bias sections. The separate LV PS and Bias boards are optional.

3. Please use this link to register your request: https://docs.google.com/spreadsheets/d/1GWDWwLfsIDtwn1HB-x76lS6WyWwLd5lwsORFKiUuuEQ/edit?usp=sharing

The chart below is for reference only and not up to date. The spreadsheet contains the up to date information. Please let me know if I missed anything.

It's advisable to read the the following posts at the minimal for relevant information to this GB: 16, 34, 42, 51, 68, 80, 89, 92, 113.

More to come.


EDIT 6/28: updated information due to the newly released "fat" single PSU and updated gerber files for PCBs

EDIT 7/3: added Golden Reference LV and Bias board options and start using sorenb's shared spreadsheet

EDIT 7/6: remove early spreadsheet image

Note: For the single PS boards, quantity of 2 indicates the participant will receive 1 left and 1 right boards (or 1 plus and 1 minus for the LV).



Edited by mwl168
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I'd be interested in a set of amp boards with the dual power supply and two sets of amp boards with the split power supply (both skinny and fat).  


6 V3 amp boards

1 dual PS board

1 skinny left PS board

1 skinny right PS board

1 fat left PS board

1 fat right PS board



EDIT: updated upon release of the fat PS boards

EDIT 2: updated to indicate all V3 boards

Edited by chiguy
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4 Amp boards, 1 dual psu board and 1 of each left/right psu board.




I have heard from sorenb that there were some quality issues with the kgst boards from the recent GB. I cannot comment on this, because I have not used my boards I got from this GB yet.

Therefore the question: Will you be using the same manufacturer or anonther? I think for an Amp such as the Carbon higher quality PCBs could really be justified, even if it adds a bit to the cost. 

Edited by insanity
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i will be updating the v2 amp board and dual power supply boards shortly.


increasing the distance on the heatsink to .8 inches so that the heatsink completely covers the metal

part of the fet and shrinking the amp board slightly.


here is the final stuff unless someone finds an error








single version boards updated


amp board 5.45 x 4.05 inches 211 holes


psdual board 6 x 6.48 inches 287 holes


ps single boards 3 x 6.48 inches

Edited by kevin gilmore
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the idea behind splitting the PSU into HV, LV and Bias board is that it is more versatile ...I asked Kevin to keep the width less than 80mm(2U) so you have the option of mounting upright rather than horisontal in order to cram the amp into less space ...

Also I asked Kevin to include option for NB on the Bias board ...

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