Item: Yamaha NS890 Vintage Speakers and Yamaha R700 Amp/reciever
Location: Melbourne (Northcote or Brunswick)
Price: $300 for the lot (or best offer)
Item Condition: Speakers: Average to poor. Dust caps on mid ranges have been pushed in. Believe all the beryllium mids and tweeters are working though. Only one grille included. Amp: Not working. My sister was using it, and said it stopped working. I have not looked into this. Hopefully something small. Sold as not working. As is - not tested, no guarantees.
Reason for selling: Not needed. These were from my late father.
Payment Method: Pickup - Cash, Paypal, COD Only
Extra Info: Given the condition of the speakers, and the non functional condition of the amp this is most likely useful for someone wanting to restore the speakers, or use the famous Beryllium drivers for a project speaker.
The cabinets are in decent condition, but not perfect. These are pick up only, as they are very heavy!
This is taken from https://audio-heritage.jp/YAMAHA/speaker/ns-890.html and translated to English to give a full description
Yamaha's first four-way speaker system that uses Yamaha's high-purity beryllium diaphragm in the mid-high range.
The 30 cm cone type Woofer is carried in low-pass.
Corn paper is a conical type with corrugation, which suppresses split vibration and has a wide piston area. Moreover, the roll edge of the outstanding urethane foam is adopted as the edge. Furthermore, the damper which supports the vibration system has also carefully examined the material and impregnating agent to improve the linearity.
The ferrite magnet of 156φ mm and weight 4.4kg is adopted as the magnetic circuit, and the total magnetic flux 200,000 maxwell and the magnetic flux density 10,000 gauss are obtained.
Employs DuPont nylon fiber Nomex as the voice coil bobbin, and because of the edgewise winding long voice coil of the copper ribbon wire, the voice coil does not deviate from the magnetic field even at large input, and excellent linearity is obtained. . Moreover, the center pole is covered with a copper cap to suppress offensive third harmonic distortion over the entire band.
The 12cm corn type mid bus is carried in the middle low region.
Corn paper is light in weight using carefully selected materials. In addition, the voice coil is a heat-treated copper ribbon wire with a good space factor, and has a size of 42 mm.
The edge is made of a specially processed cloth made of resin material, and the linearity is sufficiently enhanced for the amplitude in the used zone.
The magnetic circuit is a 90mm mm 1kg ferrite magnet with a total flux of 60,500 maxwell and a flux density of 11,300 gauss.
In order to avoid the influence from the woofer, the back cavity is attached to the back and glass wool is fully packed to suppress unnecessary resonance.
The mid high with the dome-shaped beryllium diaphragm of 50φmm is carried in the middle high region.
The heat-resistant copper ribbon wire edgewise wound voice coil is directly connected to the diaphragm that makes use of the characteristics of the beryllium material, and is supported by the tangential edge of a special fiber double coated with a visco-elastic resin and a thermosetting resin. You are
Moreover, the movement of the edge is smoothed by opening an air hole in the outer pole on the back of the edge, and a better linearity is obtained.
The magnet of 100φ mm, 1.2 kg, total magnetic flux 72,000 maxwell, and total magnetic flux density 15,500 gauss is adopted as a magnetic circuit.
The air chamber with a tapered center pole suppresses unwanted resonance behind the diaphragm and suppresses distortion during large input. Moreover, the acoustic diffuser is attached to the front of the diaphragm for directivity improvement.
The 3cm dome shape tweeter is carried in the high region.
A beryllium diaphragm molded into a 30φ mm dome shape is adopted as the diaphragm, and it is directly connected to the heat-resistant aluminum ribbon wire edgewise wound voice coil and double coated with viscoelastic resin and thermosetting resin. It supports with the special fiber tangential edge. Moreover, the center pole in the space behind the voice coil is tapered to fill the gaps with a sound absorbing material to suppress unnecessary resonance inside the unit.
The magnetic circuit uses a ferrite magnet of 80φ mm, weight 0.8 kg, magnetic flux density 14,500 gauss, and total magnetic flux 20,000 maxwell.
The frame of each unit is made of aluminum die cast.
The network part adopts MP capacitor and is designed by electrical characteristics and aural check.
Moreover, the mid high and the tweeter are equipped with continuously variable level control.
The enclosure is completely sealed, the surface is oak finish, and only baffle plate is black finish.
The same particle board is used as the material on the entire surface, and each side has an integrated structure joined with a strong adhesive. The baffle plate and back plate are 25 mm thick and others are 188 mm thick, and reinforcement is given in various places.
4 way · 4 speakers · closed system · book shelf type
For low range: For 30cm cone type
middle low range: For 12cm cone type
middle high range: For 5cm dome type
high range: 3cm dome type
Regeneration frequency band
40Hz to 20kHz
Lowest resonance frequency
600Hz, 2kHz, 6kHz
Output sound pressure level
92 dB / W / m
Maximum allowable input
Width 375 x height 745 x depth 317 mm