Is the Eico HF 81 really that good?

Can't speak for the HF81 but my HF35 6L6GC monos with new caps are outstanding. Lovely musicality, timbre, and delicacy and decent clean articulate bass.

Yes, it really is that good. Its basic design was conceived during a time that tubes ruled and provided a very good foundation for superb sound but many of it's older parts need to be upgraded to realize its full potential.

I have an HF81 which was restored and modified by Sam's Audio.
He changed the mode of operation to triode, I believe, so it now outputs just 7 watts per channel instead of 14 watts, but it sounds amazing.
For sometime I was running it with a pair of Wilson Audio Duettes - not a speaker most would recommend for this amp, but the sound was glorious! Even large scale symphonic works sounded great at moderate levels. Visitors couldn't believe they were hearing just 7 watts!
Lately I have had this amp driving a pair of GoldenEar Technology Triton 2 Floorstanding models which have their own amps for the woofer sections. Since the HF81 is only powering the mids and highs, this is a perfect application for it and the result is terrific.
I don't imagine I will ever recoup my $ 2000+ investment, but it is a experience worth having.
It may be of interest to know that this particular amp was originally used in the sound system of a community club in Winnipeg where Neil Young grew up. Neil's band would practice at this club using the sound system with this amp. A volunteer at the club acquired the amp when the sound system was upgraded years later and I purchased it from his son several years ago.

Dennis Penner
Winnipeg Canada

Amhifi, I think its pretty darn cool that your Eico is associated one way or another with Neil Young. You truly do have a very special piece of gear.

I'm not sure if it's bad etiquette to comment on a thread that has been sleeping for over 5 years but having recently acquired an HF-81 which I am currently restoring I thought I should share some of my experiences. A little background: I have been in the industry for several decades, have worked on and restored many amps and have designed components while working for Mark Levinson (the man), Speakerlab, Antique Sound and others. I believe I have a knack for getting real musicality out of a circuit design and likewise I try to do the same when I restore old gear. The Eico came to me in nearly original condition and quite well preserved. I replaced the electrolytics first and foremost using Elna Cerafine and a JJ multisection cap for which I had to modify the opening on the chassis. I also replaced all tubes with new production JJ and Mullard. I used Cornell Dubilier as DC coupling caps to the output pentodes and Mundorf Supreme in the first two stages. Next phase will be to carefully replace some of the Allen Bradly resistors that have drifted a bit beyond acceptable limits but boy does this thing sound good. As mentioned before the magic is in the output transformers and of course the circuit which is interesting to say the least. I have left the tone circuit intact but bypassed the balance or "focus". Here's an interesting fact I don't hear much about- these OT's are wound for 16 and 32 ohm outputs. In my mind this may be part of what makes the magic as the secondary impedance is rather high- much higher than in other output transformers. The price of these units has gone through the roof but I have to say so far it's worth it. For a tweaker like me it's a great project. Nice to read some insights here.