The last used SAS Audio Labs Reference 11A that was for sale was some
5 years ago, in Europe.
The 11A was the reference preamplifier by both Bound for Sound editor/publisher Martin DeWulf and by BFS reviewer Dr. Richard Weiner. (No magazine advertisements accepted.)
The only preamplifier on the planet that has an adjustment to compensate for different amplifier input impedances (Z) on the fly, which affects the frequency response.
Six power supply filter stages. Specialized filtering to prevent any input contamination from AC, power cords, transformers etc.
Only the highest quality parts were utilized, such as Vampire all copper jacks, Military Grade non-inductive resistors, 6N pure copper wire, gold plated tube sockets etc. Parts tolerances were less than 0.5% and between channels.
Mute section to prevent thumps with both power on and off
Series vacuum tube regulation
An AC polarity switch (mute will function when flipped, ~45 seconds)
The 11A under went 6 years of specialized, proprietary listening tests for perfect, natural, total accuracy of your music.
The owner's personal reviews.
"Dr. Rich Weiner: "The SAS 10A/11A is the most musically truthful preamp I'm aware of, and I will expand that statement by listing some of the line stages I've had in my otherwise very stable system: Herron VTSP-1, VAC CPA III, VAC Standard LE, Audio Research 3A, ARC 8, ARC 10, Mark Levinson ML-1, Levinson ML-7, Levinson ML-10A, Original Aronov PS-100 and Musical Concepts modification, Nagra PL-P, Beveridge RM-1, Rappaport, Placette Passive - there are more, but you get the point. Until I got the 10A/11A, I struggled to make the other components live up to their potential."
(Rich owns upgraded $15,000 300B monoblock amplifiers.)
"Graham: "I took the B11A into a shop in Auckland. I know the owner fairly well, and we agree that Shindo make some wonderful pieces of kit. (I wasn't looking for a change!) Almost immediately we started listening, he said "That's really fast!" We also agreed that the B11A was much clearer, making the Shindo sound slow, muddy, and coloured."
"Bob: "Hey guys. . .if anyone's interested, I'm selling my Tram 2 preamp since my SAS B11A is so awesome...." (Tram 2 uses 45, 2A3s)
Specifications are given for those interested in such.
Notice the FR specification is not simply +/-0,1db from 20-20khz. This equates to tonal variations in the poor range of -54db.
Clearly perceived.
Frequency Response 20hz: < -0,015db, 25k load. (16db tighter than 0,1db spec)
Frequency Response 20khz: < -0,0015db at 20khz, 100pf load (36db tighter than 0,1db spec)
Gain: 20db
Total Harmonic Distortion at 2 vrms: 0.015%, Approximately -78db or less (Min 18db less than with any 6SN7 or variant)
Channel Separation at 10khz: 90db typical
Signal Polarity: Inverts
Input Impedance: 25k ohms
Output Impedance: 1.9K (1900) ohms
Min. Amplifier Input Impedance: 25k ohms (20k ohms but with slight loss of bass)
Volume Controls: 2
Tape Loops, HT bypass: Optional
Line Inputs: 3 Basic Version (5 Standard version)
Preamp. Outputs: 2
Line Cord Length: 6 feet standard
Power Consumption: 28 watts
Power Requirements: 120/240 Volts AC, 50/60hz (set for 120 volts, 0,25 amp slo-blo)
Dimensions: 19" front
4" high (with stock feet)
14 1/4" deep (counting knobs and jacks)
Condition good, gold knobs are little dingy from hands.
Contact me vis PM or stevesammet at omnilec.com
Cheers
steve