Archived from groups: rec.audio.tubes,rec.audio.marketplace,rec.audio.tech (More info?
I'm selling pairs of nice replacement PCBs for the Harman Kardon Citation II
Tube Amplifier for $70/pair. I've posted a picture of the board on ABSE.
This is a drop-in (unpopulated) replacement PC board. It could also be used
to build a custom amplifier as well. The quality of this circuit board is
outstanding, exceeding the original phenolic PCB (which was subject to heat
damage and degradation).
The board could also be used to construct a custom high quality tube
amplifier. A Citation ³clone² was built using a 3" chassis available from
Yaeger Audio (www.yaegeraudio.com) and transformers bought through eBay
(I've got pictures of the prototype if anyone is interested).
The dual layer PC board has a ground plane built into the design to reduce
noise. This helps shield the high gain preamp section from spurious
signals. It also improves the amplifiers grounding structure and gives
several common points to ground critical components. The silk screen shows
the actual part values on the top of circuit board. The bottom holds some
of the larger capacitors and follows the Citation layout.
More Board specs below:
€ Boards are manufactured double-sided with all holes plated-through.
€ Our laminate is 0.062" FR-4 epoxy glass with 1/2-ounce copper.
€ We plate an additional 3/4-ounce of copper (totaling 1 1/4 ounce),
resulting in a copper thickness of 0.0017".
€ The top and bottom solder mask layers are green LPI.
€ Pads on the solder mask layers are grown by a minimum of 0.004" on all
€ A white silkscreen is applied to the top side of the board.
€ The board finish is the industry standard of SMOBC.
€ Component outlines are printed on the silkscreen layer.
€ The dielectric constant of our FR-4 laminate ranges from 4.2 to 5.0.
€ The maximum operating temperature is 125 degrees C.
Contact me if you're interested.