SP100 is still one of the most neutral sounding, zero gain, zero feedback preamplifiers (buffers) available. This buffer does not have any capacitor in signal path. Instead of them, this circuit use trimmer and DC servo made with LF411 IC.
My kit consist of two SP100 boards which are already assembled + two empty PSU boards + all capacitors needed. PSU boards are not asembled, but kit already include all capacitors needed. You have to add few resisors and regulators which could be LM or LT. The PSU works as a cascode with two series regulators per rail. Recommended transformer should have around 30VA 2x18V per channel to obtain final +-15 Volts. All capacitors are from Panasonic...FM and FC ones for smaller value and TSHA for bigger 4700/35V ones.

Circuit is tested and it is in perfect working condition.
Price: 45 EUR + post costs
Email: moonaudio@gmail.com
My kit consist of two SP100 boards which are already assembled + two empty PSU boards + all capacitors needed. PSU boards are not asembled, but kit already include all capacitors needed. You have to add few resisors and regulators which could be LM or LT. The PSU works as a cascode with two series regulators per rail. Recommended transformer should have around 30VA 2x18V per channel to obtain final +-15 Volts. All capacitors are from Panasonic...FM and FC ones for smaller value and TSHA for bigger 4700/35V ones.

Circuit is tested and it is in perfect working condition.
Price: 45 EUR + post costs
Email: moonaudio@gmail.com
Here you can read some comments on this, one of the best Sten Warren (ex PS Audio) preamplifier designs:
http://www.positive-feedback.com/Issue23/superphon.htm
Kit include original schematic. Tranzistors are original ones and are matched.
http://www.positive-feedback.com/Issue23/superphon.htm
Kit include original schematic. Tranzistors are original ones and are matched.
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