Conrad-Johnson Premier Seven preamplifier Measurements
I only carried out a couple of measurements on the Premier Seven, more to satisfy my curiosity over its tonal balance than to give it a complete bill of health. Despite my feeling that the line stage was slightly bass-heavy, and Gordon's that it was slightly bass-light, it measured flat throughout the audio range, within ±0.05dB, being just 0.2dB at 20Hz. Likewise, the phono section was commendably flat within the tolerance of my inverse-RIAA network, being 0.2dB down at 12.5Hz and 25kHz.
The only other factor that could significantly affect tonal balance would be if the Premier Seven had a sufficiently high output impedance that it would lead to a premature bass roll-off with power amplifiers having a low input impedance. It measured as being 168 ohms, however, which is sufficiently low not to be too bothered by long cables or low amplifier input impedances. In fact, the only measured anomaly that I could find was the fact that switching from the "32dB" position to "30dB" on the left channel gave full output, this dropping again when the volume control was switched to "28dB."John Atkinson