KGSSHV amplifier

An all solid-state electrostatic headamp design by Dr Kevin Gilmore.

Official thread: http://www.head-case.org/forums/topic/8327-im-on-a-roll-the-kgsshv/

There are 2 options for the KGSSHV. Onboard or offboard heatsinks.

Schematics:

Amplifier with Servo:
http://gilmore.chem.northwestern.edu/kgsshvproductiondual.pdf

Mini Power Supply:
http://gilmore.chem.northwestern.edu/kgsshvps8g.pdf

Latest silkscreen:

• Onboard:

Board dimensions(mm): 185 x 123

• Offboard: 

Board dimensions(mm): 183 x 99

• Power supply:

Board dimensions(mm): 176 x 167

Latest BOM:

https://docs.google.com/spreadsheet/ccc?key=0AoNVeoQi85GgdEFDQnc1aVZBdmNoc0o4WXczVGwxSVE#gid=0

Important notes:

There are 2 ways to build the KGSSHV. Either one with 450V or 500V power supply. 

For 450v version, these are the requirements:

• Power transformer specs: Pri: 110v/220v. Sec: 2x 420v/130mA, 16v-0-16v/500mA
• PSU board:  Use 4x 440K resistor ; Total zener diode string is 500V (150v-150v-200v) ; Populate ALL the parts, including the voltage multiplier.
• Amp board: Use either 2x 2SA1968 (recommended) or 2x IXTP01N100D.

For 500v version, these are the requirements:

• Power transformer specs: Pri: 110v/220v. Sec: 2x 450v/130mA, 16v-0-16v/500mA
• PSU board:  Use 4x 487K resistor ; Total zener diode string is 550V (150v-200v-200v) ; DON'T populate these parts in the voltage multiplier section: 0.22uf/1kv cap next to the bias output, 2x 4007 diodes, 15k and 787k resistors, jumper the 0.22uf/1kv cap next to the 300k resistor.
• Amp board: Use 2x IXTP01N100D only. The 2SA1968 is not up for 500V operation.

Power Supply build notes: 

• Fuse ratings: it is recommended to use fuses for both Live and Neutral. For 110-115v mains voltage, use Slo-Blo 2A. For 220-230v mains voltage, use Slo-Blo 3.15A.
• Power transformer can be custom ordered from either Sumr.com (Canada) or Toroidy.pl (Poland). Toroidy does offer 2 kinds of transformer, standard one or audio one with selected and measured core, electromagnetic shield. They do have more reasonable price and shipping charge.
• Use either 6x 2sa1486 with the 270v zeners unpopulated or 6x ksa1156 with the 270v zeners populated. Also, either 4x 2sc3840 or 4x ksc5026m.
• 10m90s devices need aluminum oxide isolator. Also, MUST use nylon screws.
• FQPF8N80C devices themselves have isolated tabs so no need to use anything with them. Just apply a bit of heatsink goot and whatever screws are fine.
• Elevate the high wattage resistors (15R/2w and 240k/2w) for better heat dissipation.

Amplifier build notes:

• Absolutely make sure you connect either Local or Global Feedback jumpers.
• Adjust the balance trimpot in middle.
• Adjust the offset trimpot to maximum.
• Use aluminum oxide and PEEK screws (recommended) wherever needed.
• Connect the Servo jumper, if needed.
• Measure everything for short.

Wiring Sheme:

Here is the wiring scheme, superbly drawn by johnwmclean (thanks, John!).
Make sure using 600v teflon wires here, except for signal path.

https://docs.google.com/file/d/0B4NVeoQi85GgOTdvOGpxc1hyRFU/edit?usp=sharing