DENON PRA-1100

Commentary

A control amplifier with excellent transmission characteristics and perfect interface characteristics.

It is equipped with a UGI (Unity Gain Interface) amplifier that emphasizes the output interface.
The output stage of the PRA 1100 is not just a buffer amplifier, but a UGI amplifier with FET full complimentary service push-pull circuit using Pch/Nch FET is adopted to realize signal sending with extremely low impedance of 10 Ω.
This eliminates the effects of high-frequency noise from digital devices and the degradation of high-frequency characteristics due to the longer connection code to the power amplifier.

Equipped with CD direct terminal.
This input uses a high-reliability gold-cracked terminal transfer relay between the output side of the flat amplifier and the UGI amplifier. The CD source is directly input to the 2nd volume and output only through the UGI amplifier. The CD signal is directly transmitted to the power amplifier.

The equalizer amplifier section contains DENON's own broadband super equalizer amplifier.
This circuit combines the equalizer characteristics of both CR and NF types. By adopting a 2-parallel differential amplifier configuration with four ultra-low noise Hi-gm FETs at the first stage of each channel, the SN ratio and distortion factor are improved and excellent wide-range characteristics are realized.

The flat amplifier section consists of a high-speed operational amplifier in which a cascode bootstrap circuit is added to a high-Gm type FET differential amplifier.
In addition, the SN ratio when the volume is reduced is improved by setting the volume at the front and rear stage of the flat amplifier by using the four connected volume, and matching the impedance attenuation of the volume at the front and rear stage to the severe.

The tone control circuit includes a real-time tone control with a defeat function.
In this circuit, a tone element is incorporated into a direct servo circuit to ensure a stable operation from low to high frequencies in spite of a wide range, and to suppress influence on dynamic characteristics such as high through rate.

The loudness circuit uses variable loudness control and can be freely adjusted, unlike the general fixed type.

The power supply section is equipped with a toroidal transformer and a block capacitor.
In addition, a constant current circuit using an FET and a constant voltage power supply circuit using a tracking method are constructed to improve the ripple removal rate and eliminate the influence of power supply fluctuations.

A chassis layout with electronic switches is used to ensure excellent input interface characteristics.
Each input terminal is mounted on a printed circuit board fixed to the rear panel of the amplifier to avoid unnecessary wiring inside the amplifier.

It uses a wooden cabinet cover.

Model Rating

Type	Control amplifier
<MC/MM Equalizer Amplifier Section (Phono in-Rec out)>
Input Sensitivity / Impedance	MM : 0.25mV/47k Ω MC : 02mV/100 Ω
Maximum allowable input (1 kHz, 0.1% THD)	MM:160mV MC:13mV
Gain (1 kHz)	MM:35.6dB MC:57.5dB
Maximum output voltage	10 V (1 kHz, 0.1% THD)
Rated output voltage	150mV
Total harmonic distortion rate (1 kHz)	0.001% (at 7 v output)
Equalizer deviation	MC : 20 Hz to 100 kHz ± 0.3 dB MM : 20 Hz to 20 kHz ± 0.2 dB
S / N ratio (input short, A-weight)	MM:90dB MC : 73 dB (at 025 mV input)
Input equivalent noise voltage (input short, A-weight)	MM:-142dB(V) MC:-147dB(V)
Flat Amplifier Section (CDin to Preout)
Input Sensitivity / Impedance	CD, Tuner, Aux, DAT, Tape PB1/2 : 150mV/50k Ω CDdirect : 1V/10k Ω
Gain	CD etc:16.5dB CD direct:0dB
Rated output voltage	Pre out:1V
Maximum output voltage	Pre out:10V
Output impedance	Pre-out : 10 Ω or less
Total harmonic distortion factor	0.003% (CD etc in ~ Pre out, 20 hz ~ 20 khz, output 5 v)
SN ratio (at 150 mv input)	CD etc:105dB
Line input frequency characteristic	1 Hz to 300 kHz + 0.2 -1.0 dB 10 Hz to 100 kHz ± 0.2 dB
Tone control	Bass : ± 8 dB (100 Hz) Treble : ± 8 dB (10 kHz)
Filter characteristic	Equalizer Subsonic Filter : 16 Hz, -12dB/oct.
Loudness property	100 Hz : 0 to + 8 dB 10 kHz : 0 to + 4 dB
Headphone port	With Dedicated Amplifier Vol Maximum Output : 440mW/8 Ω (8 Ω ~ 10k Ω Compatible)
Muting	Pre out off muting (LED blinking)
<Others>
AC outlet	Power switch interlock : 2 systems (total 100W) Power switch not linked : 1 system (250W)
Power supply voltage	100 VAC, 50Hz/60Hz
Power consumption	12W (Electrical Appliance and Material Control Law)
External dimensions	Width 466x Height 136x Depth 302 mm (Including Knobs and Feet)
Weight	6.3kg