The design presented here is copyrighted, including the schematics, or parts thereof and the PCBs. Use of these for commercial purposes is prohibited without proper written authorization from the authors. For questions regarding copyrights, or general questions regarding this design the authors can be reached at bruno@hypex.nl or ssassen@hardwareanalysis.com. PCBs for this design are available for purchase, please contact ssassen@hardwareanalysis.com for pricing and details.

Concept, design: Bruno Putzeys
Schematics, layout, prototyping: Sander Sassen
Article text: Sander Sassen, Bruno Putzeys

***Update 10-12-2014: Updated stuffing guide***

The silkscreen for the amplifier PCB contains an error where the labeling of L1/R6 is swapped.

If you've already built the amplifier, please swap L1/R6 around as the amplifier will see a large(r) DC offset and reduced performance due to this error.

***Update 01-12-2014: parts value change***

With a simple parts value change the ExtremA amplifier sees an improvement in slew-rate, step response and overall stability, so it is recommended making these changes. There's four capacitors that need to be changed:

C1/C2 = 68pF - COG or NPO - 5mm pitch (Vishay NP0 ceramic)
C4/C9 = 220pF - film capacitor, polypropylene or polyester - 5mm pitch (WIMA FKP2)