EICO HF-81 Integrated Tube Amplifier 4 Restoration Working Iron AND NEW TUBES
Thursday, May 7th, 2026












EICO HF-81 Integrated Tube Amplifier – Restoration Candidate – Working Iron. Some units are plug-and-play. This is not one of them. This EICO HF-81 is a largely original example and should be viewed as a restoration project. The transformers appear healthy, but the amplifier will require electronic servicing for stable, long-term operation. This is for someone who will selectively change parts for stability but retain the sonic character the HF-81 is famous for. Operational Status (Please Read Carefully). Powered up slowly on a Variac. Output transformers pass signal. Video included demonstrating that both channels produce output. One channel is weaker and exhibits distortion. The stronger channel distorts at high volume. Power switch (integrated into treble knob) does not function properly. Unit is likely running on original capacitors. Given its age, full recap and restoration is recommended before regular use. Tube Complement (Installed & Working). The original Eico factory installed tubes tested weak or shorted and were replaced with. Quad Sylvania EL84 / 6BQ5 – New old stock (NOS) and new in box (NIB). Tubes are functional, but the distortion issue suggests underlying circuit components (likely caps or resistors) require attention. Classic gold faceplate with vintage wear. Appears largely unmodified internally (based on current inspection). Why This Is Worth Restoring. The HF-81 is widely regarded as one of the most musical EL84 integrated amplifiers ever made. Properly restored examples command strong market value and are known for. Balanced push-pull EL84 output. Highly respected transformer set. The transformers are the heart of these units – and this one passes signal. Collector seeking original platform for rebuild. If you’re looking for a fully restored, daily-use amp, this is not that listing. If you want a strong foundation with working iron and upside potential, this is an excellent candidate. Will require recap and service. Distortion present in one channel. Power switch requires repair. See video for operational demonstration.









































