The D 'Agostino Progression Preamplifier adds new features that were previously not included in a D'Agostino preamp. Most notably, the progression preamp features an optional digital module. The digital module adds coaxial, Toslink and USB capability to the analog base model. A fully differential DAC handles PCM signals up to 24-bit / 384 KHz and DSD signals up to 4xDSD (11.2 MHz). This digital module feeds a fully complementary and balanced discrete analog signal path from input to output. Negative feedback is not used anywhere in the progression preamp, nor is it necessary. The open loop distortion is less than <0.006% and the open loop bandwidth extends to more than 100KHz.

Also new is the Bluetooth technology that is included in the remote control. The Bluetooth backbone extends the range of the remote control by a factor of five and eliminates the line-of-sight limitations inherent in infrared remote controls.

Volume control is performed with a balanced stepped resistor ladder, using high linearity solid state relays and discrete precision resistors. The bandwidth and transient response of the preamp circuitry are not affected by the volume setting. The progression preamp has two independent outputs that can be operated individually or used simultaneously to drive a second amplifier in a subwoofer-based system.

The power supply, housed in a separate chassis, uses extensive electrical and magnetic shielding to keep radiated interference away from critical preamp circuitry. Internal circuitry filters out RF noise on AC power and compensates for asymmetric power waveforms and DC on the network. A second DC output is included to power future progression source components.

Two analog meters, inspired by Swiss watch dials, function as VU meters during music playback. When the volume is adjusted, the meter hands change to volume adjustment indicators. After making adjustments, the meters return to function as VU meters. The meters also function as balance indicators when adjusting the balance.

Technical characteristics:

Frequency response 0.1 Hz to 1 MHz, -3dB / 20 Hz to 80 kHz, +/- 0.5dB

Distortion <0.018% THD + N, 20Hz to 20kHz

Gain +8 or +14 dB, switchable

Signal-to-noise ratio -95 dB, unweighted Standby power consumption <40W

Analog inputs 4 balanced XLR stereo pairs 2 single ended RCA stereo pairs

Digital inputs (with DAC module installed) 1 USB Type A 1 Optical Toslink 1 SPDIF Coaxial

Balanced XLR 2-pair stereo output

RS-232 control, 2 12V trigger outputs