There's a lengthy thread B1 Buffer Preamp at diyaudio and an explanation of the circuit The First Watt B1 Buffer Preamp Article Written By Nelson Pass at the below link.I have fairly long, 20 foot, lengths of interconnects to my amplifiers and relatively high, 97dB, efficiency speakers so I was intrigued by the circuit. I built it as much as an excercise as something that could realistically surpass my present preamp. Imagine my shock, as a diehard Tube Head when I auditioned the finished product and found it to be nearly a match for my far more expensive (parts cost) 76 Line Stage. It's so amazingly neutral and tonally balanced from bottom to top with the ability to convey authoritative bass and delicate treble. My 76 Line Stage is still slightly better and this little wonder is better off with someone who will use it daily. Keep in mind it is totally passive, just a volume control, a switch for the two inputs, and the low voltage elctronic buffer that makes the magic. It is not recommended for those with less than highly efficient or difficult to drive speakers. The build includes Clarity CSA output capacitors, PTFE insulated wiring, Vampire CmHex RCA's, and a 100k PEC KKA series pot. Included is the way above average Meanwell 24 Volt SMPS power supply and a custom high frequency filter for it (the small PCB shown). I'm considered an above average builder :), you can check my profile system listing here for the details of my all DIY system. My cost of parts is $330 including the nice but not lovely Hammond box and I would like to get $325 including shipping to the lower 48. Payment is by US Postal Money Order only.
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