Original caps in HF-85

Discussion in 'Eico Place' started by 365nut, May 20, 2018.

  1. 365nut

    365nut Member

    We all know there is good reason to replace old capacitors in old audio tube equipment and we do so faithfully because we know old capacitors deteriorate with age—and originals just never sound as good as modern replacements—not always true and I will share an exception.

    For years I have run an Eico HF-85 preamp with a pair of Eico HF-60 amplifiers in a “second” system that I play about once a month for an hour or so. I recapped the HF-60s a long time ago and recalled I had also done likewise with the HF-85. The system has always sounded great—so I just kept running it. Recently I pulled a Scott 130 preamp, which I had been storing for years, off the shelf. I re-capped it, and replaced my HF-85 with it. (The 130 sounds even better, I must admit).

    No longer needing the HF-85, thought I would put it for sale on EBAY. Before doing so, decided to take pictures of it. When I took the bottom plate off, I was amazed to find all original capacitors—because I thought I had recapped this preamplifier. Included were 4 paper capacitors and the usual black Pyramid caps. I took measurements on the electrolytics and all were within original spec and with low ESRs. This surprised me because the HF-85 had (and was still) performing well.

    I do plan to re-cap the HF-85 before selling—because that is the expectation—but did want to share my experience with those of you in the know. Some might say the caps lasted as long as they did due to light use—and that may be true—but even without use 55 year old parts typically deteriorate significantly. Draw your own conclusions—just sharing my experience.

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  2. tubeactive

    tubeactive AK Subscriber Subscriber

    Some of the Eico gear stands the "test of time" very well. Even heavily used and often used HF-85 preamps as well as the HF-81 integrated amps are still sounding very nicely with their original parts. However, maybe they would sound even better with upgraded parts ?

    Selling can demand a different set of priorities. Perhaps, before you recap the HF-85 for sale, since it sounds fine, maybe there are some buyers who prefer the original parts. Many discerning folks prefer their own choices of replacement parts. While you might think they will welcome metallized polypropylene caps, they might prefer vintage PIO type caps, or some other plastic film and foil type caps...Some might even prefer the original parts for the "survivor" status...

    On the other hand, if you were to recap the 85 and possibly even beef up the power supply, might it not better that Scott 130 ?

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