Pioneer A-757 specifications

Brand : Pioneer

Externally visible differences to Pioneer A-7 17 MKII:

General

connectors

Technical data

special features

number of inputs: 8
- DAT /TAPE 1, TAPE 2, ADAPTER1/ TAPE3, ADAPTER 2, CD (gold plated), TUNER, LINE, PHONO (gold plated)
number of outputs: 2
- TAPE 1/CD-R/MD, TAPE 2 MONITOR

DAT /TAPE 1, TAPE 2, ADAPTER1/ TAPE3, ADAPTER 2, CD (gold plated), TUNER, LINE, PHONO (gold plated)

the duration of the performance (total harmonic distortion)
- 8 Ohm : 2x 95 W / 0,003%
- 4 Ohm : 2x 140 W
- 2 Ohm : 2x 200 W
dynamic performance
- 8 Ohm : 2x 150 W
- 4 Ohm : 2x 200 W
- 2 Ohm : 2x 300 W
total harmonic distortion: 0,003% (20Hz - 20 kHz, 95W, 8 Ohm )
frequency response: 5 Hz - 70 kHz
stereo channel separation:
signal-to-noise ratio: 108 dB
damping factor: 200
sound-control: analog
- Bass: ±8 dB (100 Hz)
- height: ±8 dB (10 kHz)
Loudness: Yes, button
Subsonic: Yes, button
Mute: Yes
Direct/Line-Straight: Yes

recording selector switch
pairs of Speakers and headphones via Relay
metal front plate
Direct - switch to Bypass the tone control stage
Phono input with possibility to choose MM/MM subsonic Filter /MC/MC subsonic Filter
Switchable Phono pre-amplifier
auftrennbare in Front of switched - and power amplifier
connections for 2 pairs of Speakers A+B
shortened signal paths possible clean sound
separate levels: Reduced interference
resonance-absorbing construction: honeycomb-shaped reinforced frame, heat sink, and a damper to prevent microphonic effects
powerful, niedrigimpedantes power supply: 2 power transformers and ribbed solid cast housings ensure a high capacity
good resonance damping and clean magnetic shielding
"Non-Switching" type III: the elimination of the switching distortion and improved stability at low impedances
Phono equalizer (can be switched off) with a high amplification factor; suitable for MM and MC systems

Pioneer was launched at the time, starting from the A-717, a whole series of amplifiers of the same basic design: Solid design with consistently sized components, which was reflected in the weight low. The durability is enormous, so that most of the amplifiers that are still available used today work absolutely flawlessly. In particular, the typical scratching of old switches and potentiometers is rather rare here. From 7x7 the amplifiers have two transformers in the power supply. However, these do not serve as usual for the separate supply of the two stereo channels, but provide the positive and the negative operating voltage of the output stages.

Although the amplifiers have two connection pairs on the back, each connected by a wire bridge, they have none on separable pre- and power amplifiers. Rather, this so-called adapter connection is located in front of the volume control and tone control stage. That's why you can use the Pioneer amplifiers as power amplifiers for other preamps, but you can't connect the Pioneer preamps to other power amplifiers.

The sound of these amplifiers can be described as warm, powerful and precise compared to similar amplifiers from other manufacturers, although perhaps the last bit of precision is missing compared to devices that are several times more expensive. The devices must be certified as having an excellent price - performance ratio, especially with the used ones available today, which are technically always in new condition.

The amplifiers of the A-656 to A-757 series, possibly also later models, have only one real weak point: a capacitor in the protection and turn-on delay circuit breaks, after which the speaker relays turn on with a delay and then buzz for a while. The repair should cost about € 50 in a specialist company, plus 80 cents in material costs.

Pioneer A-757