DENON PMA-S10IIIL

Commentary

This pre-main amplifier is a limited model released in commemoration of the name change from DENON to DENON (Denon) in October 2001.

It uses the high-current amplifier UHC-MOS used in DENON's top-of-the-line monaural amplifier POA-S1. It further enhances the UHC single push-pull circuit to obtain high power while giving expressive power.

A toroidal transformer with a large magnetic circuit is used for the power transformer of the power supply circuit. It is designed to have a wide dynamic range for the magnetic saturation region to improve the tracking performance to music signals. In addition, in order to suppress the influence of the vibration of the toroidal transformer, an S. B. (Stable Based) fixing method using an aluminum sand mold case is used. In addition, the power windings of the power amplifier stage and the phono equalizer are independent to suppress the mutual interference between the circuits.

A newly developed block capacitor is used, and it is fixed with a stabilizer made of aluminum sand mold to reduce the effect of vibration.
The rectifier circuit that converts the AC power output from the power transformer into a DC power supply and supplies it to the amplifier section is equipped with a Schottky barrier diode developed for high-frequency rectification in parallel connection. The low-noise and high-current characteristics of high-speed operation enable low-noise, low-loss and high-speed power supply circuit.
In addition, by combining a high-capacity electrolytic capacitor using a low-impedance electrode foil with a capacitor with different frequency characteristics, the characteristics are improved and a stable power supply is achieved over the entire reproduction frequency band.
OFC wiring materials are used for wiring from the output of the power transformer to the output stage of the power amplifier to minimize energy loss.

By adopting a twin monaural configuration in which the power amplifier blocks are independent on the left and right, and by adopting a 6-block structure in which circuits with different signal levels are separated and shielded, sound quality degradation due to interference between circuits and inflow of noise is suppressed. In addition, the power amplifier circuit / power radiator is separated from the power transformer and mechanically shielded.
To reduce noise caused by vibration, the chassis is made of 1.6 mm thick steel plate coated with black paint to ensure rigidity and uniform temperature inside the chassis.

The insulator is made of newly developed cast iron and has a hybrid structure with a new material with high vibration absorption to enhance the vibration absorption effect.

By reviewing each of the volume circuit, tone circuit and power amplifier circuit, the upper limit of frequency characteristics in actual use has been improved to 100 kHz. Furthermore, by improving the volume circuit, noise generated in the amplifier in actual use is suppressed, and resolution is improved so that the wide frequency characteristics and dynamic range of the next generation media can be accommodated.

Equipped with a Precision Signal Ground circuit, it reduces the inflow of noise current such as a constant current circuit to the ground circuit which is the reference point of signal amplification.

The speaker terminal is made of brass machined parts plated with gold to reduce transmission loss.
In addition, the hole diameter of the clamp section has been enlarged to φ 6 mm to accommodate very thick speaker cables.

The phono equalizer is equipped with a discrete first stage circuit that uses a low-noise FET. Tuning power supply for the phono equalizer improves the sound quality.
In addition, a changeover switch is provided for each cartridge of MM/MC.

We have reviewed all the parts used in the PMA-S10III, including the 40-inch 4-channel volume, large machined gold-plated pin jacks, OFC internal wiring materials, inert gas-filled relays, high-sound film capacitors, high-sound electrolytic capacitors, and detachable OFC power cables, and have adopted newly developed parts.

Model Rating

Type	Pre-main amplifier
Power Amplifier Unit
Rated output (Both channel drive, CD → SP out)	100W + 100W (8 Ω, 20 Hz to 20 kHz, THD 0.07%) 200W + 200W (4 ω, 1 khz, 0.7% THD)
Total harmonic distortion factor	0.01% (8 Ω at -3dB rated output, 1 kHz)
Speaker output terminal	AORb : 4 Ω ~ 16 Ω A + B : 8 Ω ~ 16 Ω
Preamplifier Section
Input Sensitivity / Impedance	Line : 150mV/47k Ω (source direct off) 150mV/15k Ω (Source Direct On) Phono MM : 2.5mV/47k Ω Phono MC : 0.2mV/100 Ω
Equalizer amplifier output	150mV
RIAA deviation	20 Hz to 20 kHz ± 0.5 dB
<General>
Frequency characteristic	5 hz to 100 khz -3dB
Signal-to-noise ratio (A network, input short circuit)	Line:110dB Phono MM : 91 dB (at 5 mV input signal) Phono MC : 76 dB (at 0.5 mV input signal)
Tone control	Bass : 100 Hz ± 8 dB Treble : 10 kHz ± 8 dB
Power outlet	Switched : 2 systems, total 120W Unswitched : 1 line, 240W
Power supply voltage	100 VAC, 50Hz/60Hz
Power consumption	300W
External dimensions	Width 434x Height 181x Depth 485 mm
Weight	29kg