Solid State Preamp Reviews

In my own system, it was used with the following source components: the new Philips LHH1000 two-box CD player, its transport section also used to drive the Sony DAS-R1 D/A convertor; a 1975-vintage Revox A77 to play my own and others' 15ips master tapes; and a Linn Sondek/Ekos/Troika setup sitting on a Sound Organisation table to play LPs. Power amplification was provided by a Krell KSA-50 power amplifier, while loudspeakers were either Celestion SL700s or Vandersteen 2Cis, each pair sitting on their dedicated stands and bi-wired first with Monster M1, then with AudioQuest Clear loudspeaker cable. Interconnect was AudioQuest LiveWire Lapis between CD player and preamp and pre- and power amps, with Monster M1000 used for the other sources.

For comparison and bypass testing, I inserted the Iris set for unity gain in one of the tape loops of my reference Mod Squad Line Drive Deluxe AGT passive control center. Although I made some comparisons with the expensive Vendetta Research SCP2 phono preamp and the Conrad-Johnson PV9 tube preamp that had so impressed me in the May issue, most of the phono-section comparisons were made with the PS Audio 4.6 preamplifier, which in its $739 basic form is pretty much our reference preamplifier in the Iris's approximate price class (footnote 1) (though the M-500 power supply, which is what I used with the 4.6, does add a cool $470 to its price). The PS has a basically flat RIAA response, though very slightly rolled-off at the extremes when compared with the Iris (see December 1988, p.142), and was used mainly in its Straightwire position; levels were matched at 1kHz, and both input loadings were set to 100 ohms.—John Atkinson