All internal parts and wiring have been replaced and expertly hand-soldered by an experienced audio engineer. Brand new precision components have been installed, resulting in a stable and reliable, audiophile-quality amplifier that runs extremely quietly, while maintaining the warmth and character of the original circuit design. The Eico HF-35 was renowned for its extremely detailed sound stage and solid bottom end, attributable to the legendary Chicago Transformer Company output transformers. These two matched units have been converted to full fixed-bias operation, enabling a wide range of output tube types, with less stress on the power supply, resulting in longer tube life and much cooler operation than stock. The original circuits have been expertly modified with the following upgrades: - Significantly improved power supply stability and ripple reduction with a new 600V poly-film capacitor directly off the rectifier tubes - Original dried-out aluminum-can filter capacitors have been repacked with new, over-spec electrolytic capacitors, resealed and poly-bypassed.All new 1% precision resistors, and high-quality polystyrene and polyester capacitors. New rectifier and power tube sockets; fitted with a set of four Shuguang EL-34 output tubes - A separate -90V adjustable bias supply, with 1000V silicon rectifiers and large electrolytic filter capacitors. Convenient rear panel precision 10-turn bias adjustment potentiometers and meter test sockets - 4 of the excellent NOS Russian K40 paper-in-oil coupling capacitors - High-quality gold-plated RCA input jacks - An IEC powerline filter with EMI/RFI noise supression and detachable 3-prong power cables - A new set of speaker barrier terminal connectors - New power switches and LED indicator lamp All tubes test at or above new on a Hickok 6000 tester: 2 - Svetlana 6J32P (EF86) 2 - Svetlana 6H8C (6SJ7) 4 - Shuguang EL-34 2 - Shuguang 5Z4P The fixed bias modification allows the purchaser to substitute a wide range of different output tubes ranging from 6L6-class, EL34, 5881, KT66, etc. A convenient 3-position meter socket enables quick bias readings for each of the power tubes. The dual 5Z4P rectifier tubes belong to the 5AR4 class of soft-start indirectly-heated cathodes. Condition is rated as "Good". The original enameled chassis show some tool marks and small scratches on these 50-year-old amps.
Electronically and sonically, they're a perfect 10 out of 10. The amplifiers have been finished in one-inch-thick solid ash with a cherry wood stain. The transformers and bottom plate have been re-enameled and look new, plus a set of large isolation feet with neoprene pads. This set is a unique and collectible item, and would be well suited to a serious music-lover's home. Not only are they a true piece of audio history -- but they are also exemplary high-end performers.
The units are heavy and delicate, and have been carefully packed into a double-boxed corrugated carton. No trades or lowballers please. Only serious enquiries will be acknowledged. The item "Pair of Eico HF-35 Mono Block Tube Amplifiers 30 WPC, Professionally Restored" is in sale since Saturday, November 16, 2019. This item is in the category "Consumer Electronics\Vintage Electronics\Vintage Audio & Video\Vintage Amplifiers & Tube Amps".
The seller is "ve3dmc" and is located in Toronto, Ontario. This item can be shipped to Canada, United States.