YAMAHA K-1d

Commentary

This is a cassette deck with improved sound quality using newly developed head and quality parts based on K-1a.

A multi-laminate low-impedance pure sendust head is used for the recording / reproducing head.
This head uses Pure Sendust, which is produced by Yamaha's proprietary high vacuum centrifugal casting method, as the core material in a multi-layer (five sheets) laminate structure. Along with Yamaha's proprietary low impedance structure, high-frequency characteristics, phase characteristics, bias current efficiency, and separation have been greatly improved.
In addition, a double-gap ferrite head with excellent erasing characteristics is used for the erasing head.

By using DC amplifier configuration in all amplifier circuits such as recording amplifier, line amplifier, head amplifier, noise reduction, etc., excellent performance is obtained in overall recording and reproduction.

The recording amplifier uses a pure current servo amplifier that is used in Yamaha amplifiers.
In this circuit, a constant current is always supplied from the power supply to the amplifier by a pure current servo amplifier, so that no signal current flows into the ground line or power supply line. Therefore, this circuit is not affected by non-linear (wiring or dissimilar metal bonding) which inevitably exists in the power supply line or ground line, and non-linear (vibration of capacitor foil, diode, transformer, etc.) inside the power supply.

The recording amplifier operates with a ± 35 v high-voltage IC and a ± 27 v high power supply voltage to achieve a headroom + 6 vu in all bandwidth. The recording amplifier is directly connected to the recording amplifier via a bias trap to improve recording characteristics.
The head amplifier is a single-chip Dual-FET differential-input direct-coupled DC amplifier, which greatly improves various characteristics such as SN ratio and distortion factor.

The line amplifier uses a DC-amplifier configuration of FET differential-input semi-DC push-pull circuit, which improves the distortion factor, noise and dynamic range compared to the case where the amplifier built in the Dolby IC is used as the line amplifier, and the complimentary service is improved.
This line amplifier ensures that the dbx and Dolby circuits are completely disconnected from the signal path in the through position.

As a noise reduction system, dbx is installed in addition to Dolby B type.

The MPX filter used for FM recording is designed so that no inductance remains in the signal system when turned OFF.
This reduces the negative impact on sound quality as much as possible.

We have reduced the impedance of the entire amplifier system, adopted a volume with a lower resistance value than before, and improved the separation of the entire amplifier system by paying attention to wiring.

For the parts that affect the sound quality, we use quality parts that are selected by audibility.

Uses a 2-motor separate drive mechanism with dedicated motors for the capstan drive and reel drive. In addition, inertial mass 2000g ・ cm²The use of a large flywheel with dynamic balance on both sides realizes stable tape travel.
Also, quick response is realized by using Yamaha's original full logic IC for the operation system.

Equipped with a bar graph peak meter.

Equipped with a focus switch that lets you choose the sound quality according to the source.

There are 2 color variations, black and silver.

It can be operated from a remote location with the separately sold wired remote control RS-10.

Model Rating

Type	Cassette deck
Tape speed (deviation)	4.75cm/sec + / - 1 per cent
Wow flutter	0.028% or Less (JIS-WRMS) 0.1% or less (DIN-45500)
Fast forward and rewind time	70sec(C-60)
Recording and reproducing frequency characteristics	LH (-20VU) : 30 Hz to 17 kHz ± 3 dB CrO2 (-20VU) : 30 Hz to 19 kHz ± 3 dB Metal (-20VU) : 30 Hz to 22 kHz ± 3 dB (0 VU) : 30 Hz to 14 kHz + / - 3 dB
Overall signal-to-noise ratio	100 dB (dbx in, metal tape)
Dynamic range	110 dB (dbx in, metal tape)
Overall strain rate	Not more than 1%
Channel separation	40dB
Input Sensitivity / Impedance	Mic : 0.3mV/5k Ω Line : 50mV/100k Ω
Output Level / Impedance	Line : 340mV/1.6k Ω Phones : 1mW/8 Ω 5mW/150 Ω
Attachment mechanism	Dbx NR / Dolby NR Sound focus Tape selector and bias adjustment volume Bar graph peak level indicator Subsonic filter MPX Filter Output level volume Memory Stop Timer recording switch
Pwer	100 VAC, 50/60Hz
Power consumption	30W
External dimensions	Width 435x Height 140.8x Depth 305.5 mm
Weight	8.0kg
Sold Separately	Remote Control Unit RS-10 (¥ 6,000)