The Daniels Audio phase compensated RIAA equalization stage enables the record to retain most of the phase information of the original master tape. Since the phase and the amplitude of the original master tape are maintained, the music will be virtually identical to that of the original analog master.

The equalization process used during the cutting of a record introduces a known phase and amplitude compensation at each frequency. An accurate conventional RIAA playback equalization introduces the inverse amplitude compensation but does not attempt to correct for the phase shifts introduced by the recording process. The end result is a signal which maintains the amplitude accuracy of the original master, but whose phase response shows little similarity to the original signal. The resulting sound loses much of the energy and coherency of the original performance. The phase compensated RIAA equalization introduces, in addition to the inverse amplitude compensation, a phase shift which is roughly the opposite of that introduced during the recording process. Hence the sound of the original master is more faithfully reproduced. The end result is music which is virtually indistinguishable from the original performance. When compared to the conventional RIAA equalization, the soundstage, dynamics, and image specificity are markedly improved. Simply put, the music comes alive; the instruments shrink back to their original size and spatial position.

The Nightingale phase compensated phono preamplifier spots a conventional single-ended input stage. Optimal choice of feedback resistor values ensures very good common mode rejection as well as a high signal to noise ratio at all gain settings. A servo amplifier insures that any DC offset resulting from the fully DC coupled amplifier is < .1 mV. Gain is adjustable from 36 to 66 dB, with a single resistor. Frequency response is £ ± 0.1 dB, 20 Hz- 20 kHz. Signal to Noise ratio for MC is > 81 dB (0.5 mV @ 60 dB gain) and > 91 dB for MM (5 mV, 40 dB gain). Not upgradable to Vireo.

In addition to the Phase compensated RIAA circuit mentioned above, the Vireo also uses other technology never used before by other phono preamplifiers. The Vireo’s input stage uses an ultra low noise (e_{n input} = 40 nV rms., 0.1 Hz -100 kHz), ultra high common mode rejection instrumentation amplifier at the input stage. The use of a balanced differential amplifier with high common mode rejection (100 dB @ 20 kHz), allows for the use of unshielded balanced cable with little noise penalty. To further minimize noise pickup a shield driver is used to allow for the use of shielded balanced interconnect (the suggested and recommended connection) without degradation to the common mode rejection due to the shield’s capacitance. The gain of the input stage is adjustable to allow for MC or MM cartridges. This allows for matching the cartridge's resistance precisely to the input amplifiers and thus allows for near theoretical noise matching. Additionally, output gain can be adjusted to allow for L/R cartridge tracking and/or matching the gains of CD player’s, etc. Compared to the Nightingale, frequency response is £ ± 0.06 dB 20 Hz-20 kHz, and signal to noise ratio improves by > 10 dB. Price ~$2550.00. Available Spring 1999

Daniels Audio Corporation
1001 N. Humphrey Avenue
Oak Park, IL 60302

Phone (708) 383-3319
FAX: (708) 383-3230