Audio Research's first 21stcentury, audiophilequality linestage preamplifier combines retrotech vacuumtube amplification and powersupply circuitry with innovative, remotecontrolled gain, balance, tape monitoring, and signal routing The price is also 21stcentury $9995 As in ARC's Reference phono section, the Reference Two's pair ofHigh End Audio Repair (Hear LLC) specializes in Audio Research factory authorized repairs and custom upgrades Expert service by Ben Jacoby includes repairs and modifications for Audio Research amps, preamps, CD players, CD transports and D/A convertersA Tuneup for the Audio Research SP4/4A Preamp Introduction The ARC SP4 preamp was ARCs first solid state preamp It was controversial at the time and some say it almost destroyed the company Opinions about the sound quality are all over the map but based on dealer comments and my listening, it wasn't exactly world class Audio Research Sp 14 Polk Audio Audio research sp-14 mods ...