Sony SS-7660 ULM66
A floor-standing 3-way speaker system with variable bass tuning and ULM magnetic circuit technology, built for high-fidelity audio performance.
Overview
The Sony SS-7660 ULM66 is a floor-type 3-way speaker system. Its enclosure is a bass reflex/closed variable design, which is unusual. It has a 30 cm cone woofer and a horn-type tweeter, and the frequency response runs 30 Hz to 20,000 Hz. It takes up to 100W of pink noise and puts out 89 dB/W/m. Sony never imported it to the US, so it is rare outside Japan.
Specifications
| Model Rating Method | 3-way, 3-speaker, bass reflex / closed variable system, floor type |
| Unit For low band | 30 cm cone type |
| Unit For High Frequency | Horn Type |
| Playback frequency band | 30 Hz to 20000 Hz |
| Output sound pressure level | 89dB/W/m (New JIS) |
| Impedance | 6 Ω |
| Maximum allowable input | 100W (weighted pink noise) |
| Crossover frequency | 600 Hz, 3 kHz |
| External dimensions | Width 499 x Height 750 x Depth 421 mm |
| Weight | Approximately 40 kg |
Design
The SS-7660 uses Sony's Ultra Linear Magnetic Path (ULM) technology. That means a notched center pole with copper plating to reduce magnetic distortion. The woofer has a metal bobbin and a high-rigidity cone paper made with Sony's own paper manufacturing process. The crossover uses large air-core coils to keep distortion down, and there are level controls for the mid and high frequencies. A bass controller switches between closed, bass reflex and intermediate modes below 100 Hz. A bypass switch takes the LC network out of the circuit for direct driver operation. The enclosure is 24 mm lauan plywood with acoustically shaped edges to reduce interference. It also has a noise-suppressing dust cap.
Market
The SS-7660 was priced at ¥68,000 per unit around 1972. It is now rare on the collector market. One pair was listed for $950, described as "RARE!!" and noted as never officially sold in North America.
Similar items on eBay
No exact Sony SS 7660 listings are live right now — these searches show current Sony and similar vintage audio gear on eBay:
As an eBay Partner, we earn from qualifying purchases. This helps support our independent vintage technology research.
Related Models
- Sony STR 202 (1972)
- Sony STR 6000 (1973)
- Sony STR 6450 (1973)
- Sony STR 6500 (1973)
- Sony STR 6550 (1970)
- Braun AUDIO-1 (1965)
- Braun AUDIO-250 (1965)
- Magnavox Component Systems (1972)
- Acoustic Research AR (1967-1976)
- Acoustic Research 11