Eico ST-97 (1968)
Some say it's the best-sounding FM tuner ever made - quiet, warm, and shockingly alive.
Overview
The Eico ST-97 is a rare FM stereo tube tuner that gets talked about in service manuals and forum threads. EICO (Electronic Instrument Company) built solid, repairable hi-fi gear from the early 1950s through the mid-1960s. Owners claim the ST-97 outperforms even the most revered names in high fidelity. EICO made its name with amplifiers like the ST-40 and ST-70, and the ST-97 flew under the radar until people started listening. Some then declared it the best-sounding FM tuner ever made, better than any of the Marantz, McIntosh, or Fisher tuners that dominate collector wish lists.
It's not flashy, and it wasn't mass-produced like the giants of the era. But in the right system, with a clean signal and properly restored internals, the ST-97 is said to sound three-dimensional and free of the clinical edge that creeps into later solid-state designs.
Specifications
| Manufacturer | EICO (Electronic Instrument Company) |
| Model | ST-97 |
| Type | FM Stereo Tube Tuner |
Key Features
Matrix Decoding for Natural Stereo Imaging
Many FM tuners of the era used switching or sampler-type stereo decoders. Those could introduce switching noise, channel imbalance, or a "toggling" effect during weak signal conditions. The Eico ST-97 uses a matrix decoding scheme instead. This blends the left and right audio channels more smoothly, avoids abrupt transitions and preserves phase coherence. According to those who've heard it, the stereo image is more stable and natural, and it doesn't collapse or flutter when the signal wavers. Owners point to this as one of the key reasons for its sound quality.
Shared Circuitry with the Eico MX99
The ST-97 shares its internal circuit and printed circuit board with the Eico MX99, another tuner in the company's lineup. That means the same analog path, laid out for low noise and high stability, runs through both units. For restorers and technicians this helps, since service documentation and troubleshooting techniques for one often apply to the other.
Potential Decoder Commonality with the HF-97
This isn't confirmed, but circuit analysis and owner observations strongly suggest the ST-97's decoder may be similar, if not identical, to the one in the Eico HF-97.
Collectibility & Value
The Eico ST-97 is not a mainstream collector's item, but its reputation keeps up steady interest among analog purists and restoration enthusiasts. A working unit with original paperwork was listed on eBay for US $72.21, including standard shipping. That price likely reflects condition and completeness more than market saturation, since truly restored examples are rare.
capacitor degradation is the primary concern. Restoration kits specifically for the ST-97 are available, marketed as "filter capacitor repair rebuild fix" solutions, with prices ranging from $95 (as listed on August 18, 2022) to $128.00 from specialty vendors like HiFi Audio. These kits typically include all necessary electrolytic and film capacitors, with components rated for up to 12,000 hours of lifespan. Owners note that a full recap, combined with tube replacement and alignment, can transform a lifeless chassis into a strong performer.
Pricing data is sparse. There are no verified original prices, and current market values vary widely based on condition and whether the unit was factory-assembled or kit-built.
Similar items on eBay
No exact Eico ST-97 listings are live right now — these searches show current Eico 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
- Eico 2536-FM
- Eico 96-FM
- Eico ST-96
- Eico HFT-80 (1957)
- Kenwood KR 3200 (1973-1975)
- Kenwood KR 3400 (1977-1979)
- Kenwood KR 4070 (1977-1979)
- Kenwood KR 4200 (1975-1977)
- Marantz 1515 (1976-1978)
- Marantz 4220 (1974-1976)