HS-PX30

WML ID #173

Manufacturer: Aiwa

Model: HS-PX30

Gang: Dolby C

Year: 1989

Made in: Japan

Technical details, specifications

Battery: gumstick2 EXT2AAA

Colors: yellow/gold

Window: no

Frame: plastic

Case: plastic

Carry: pouch

Expandable: no

External compartment: no

Head: Amorphous HX narrow gap

Tape selector: Manual switch

Waterproof: no

Speaker: no

Frequency range: 63-8000 (+-3.5dB)@1, 63-10000 (+-4dB)@2,@4 Hz

FMax output: 2x10 mW

Functions

DC in: yes

Record by input: no

Record by int mic: no

Hotline mode: no

Cue: no

Balance (L/R): no

Phone type: 3

Equalizer: no

Auto volume no

Auto reverse: yes

Anti rolling: no

AMS no

Blank skip no

Logic control: yes

Hold lock: no

Bass: DSL

Noise reduction: Dolby BC NR

Radio: no

Remote control: yes

Wireless headphone: no

Indicator: led

Description

Feature packed Dolby C player with amorphous head and bi-azimuth adjustment for best frequency response in both playback directions.

This was a high-end audiophile design where the electronic and mechanical engineering are extremely elaborate and advanced for the time. In this design they use a pair of integrated circuits (ICs) for the Dolby B/C function, hence there is a NJM2065AM IC for each channel. They also use the CXA1249M IC to provide the parametric DSL function, which was quite a feat of engineering during that time. For the tape transport functions, they used a system control and logic IC TC9311F-014, which also controls the solenoid (SOL1). The motor driver design is also elaborate with a 3-phase motor driven by NJM2613 IC, providing extremely smooth speed. The remote control design is a resistive ladder network type decoded by the BA3818F IC, which contains operational amplifier comparator blocks. Finally, the preamplifier and power amplifier functions, including channel switching, are achieved by the TA8115F IC manufactured by the Toshiba Corporation. The SMD version (F) had power dissipation of just 400 mW and typical quiescent current of 9 mA making it very efficient at 3 V operation. In these early ICs the power amplifier stages had fixed closed-loop voltage gains of 27 dB to keep THD to minimum, but still it sounds decent with a good pair of headphones. Hence 32 Ω coils will provide much better sound definition and resolution at the expense of power output.

For the tape transport design, Aiwa utilises their alpha minus 2 (α-2) mechanism, which was one of the most reliable at that time and became the basis of many later designs by other Japanese manufacturers. In this design, a three-phase disc motor drives a pair of capstan flywheels via a single drive belt. The auto-reverse system consists of a program cam wheel, and solenoid actuation. The tape path consists of an amorphous head with bi-azimuth head alignment taking the engineering technology to extreme levels. The amorphous alloy usually exhibits high flux density resulting in exceptionally high playback fidelity.Via Peter Vis