Eico HF-85 for Dynaco ST-70, can they be a match?

[HowlerMonkey]

I have been looking for a tube preamplifer for a while but there is rarely anything below $500 in my area. And when there is one, I don't have the cash on hand and miss the opportunities lol (like the Audio Illusions 2A for $450)
Anyways, I am ready to shoot above $500 now and I am going to check out an Eico HF-85 this week.
Is there anything I should watch out for on the Eico? can it be a good match for a Dynaco ST-70?
anything else I should consider below $700?

I have 2 speakers to choose from for now:
Cambridge Audio Model Six(~88dB) and
Legacy Audio 4 way that can be bi amp-ed (92dB).

I have a separate solid state amp and cheapo sub if needed.

 

[tubeactive]

Your title question deserves a resounding, loud Yes ! If you do an AK search, even without logging in, there is a wealth of info on the HF-85, especially in the Eico threads.

The versatility of HF-85s is incredible and unique. If you don't want tone controls, there is a Tape Output, actually after the Volume controls (dual mono volume cntrls) which should be able to drive your St. 70. I actually like the full Eico line stage very much and it can drive most amps with ease ! The tone controls might be worthy. Left centered, they impart no distortion or frequency response errors. My personal HF-85 has been retro-modded to accommodate three turntables and has three phono playback curves available to help my disc obsession.

First recommendation is to buy a near stock circuit, maybe with power supply rebuilt/beefed up and some coupling caps replaced. If you can do your own resto work, even better ! There are still some original survivor units out there. Check for corrosion, dirty input/output jacks and full functions which you need. Do not underestimate the stock stereo / mono switching. If you buy one that is heavily stripped and redone, try and be able to listen in your system, prior to paying. Originals will have genuine Mullard 12AX7s, which can still measure fine and sound great ! There is plenty more to read about in the Eico threads, further down the page...Enjoy and Good Luck !

 

[HowlerMonkey]

so I ended up buying the HF-85. It is in a bit of a rough shape but functional. The top has some rust. The bottom looks clean and had some work done.
I couldn't test it like I wanted but what i heard sounded warm and very engaging. Paid $385
I wont hook it up to the Dynaco yet until I have it checked by a tech.....I hope to do some basic mods/upgrades at some point (new RCAs, power supply)
wish me luck ....lol..

( PS: need referrals for tube tech in Seattle

 

[tubeactive]

Nice ! Lotsa potential....Congrats and good luck with your resto...

 

[century tek]

There's no fear in hooking it up to the Dynaco. Besides, aside from the can capacitor, it looks to have already been recapped.

 

[tubeactive]

It looks like eight coupling caps were replaced. There are still those eight ceramic coupling caps, not to mention the sixty year old phono EQ parts. If you replace two of those disc caps (one per channel) at a time, then have a listen, I think you will appreciate it each time you replace a pair of those ceramics. I do keep the original parts for the next owner, though. While there are still survivor HF81s and HF85s out there, still working with all of their original ceramic disc caps and power supply, the benefits of replacing power supply caps and aged ceramic coupling caps cannot be underestimated.

BTW, HowlerMonkey, your HF-85 fascia surround looks very clean. The cage top looks sweet. The cosmetics are very nice, in fact. Enjoy !
Also, is your photo icon a show car of yesteryear, like a Fiat X/19 ?

 

[HowlerMonkey]

It looks like eight coupling caps were replaced. There are still those eight ceramic coupling caps, not to mention the sixty year old phono EQ parts. If you replace two of those disc caps (one per channel) at a time, then have a listen, I think you will appreciate it each time you replace a pair of those ceramics. I do keep the original parts for the next owner, though. While there are still survivor HF81s and HF85s out there, still working with all of their original ceramic disc caps and power supply, the benefits of replacing power supply caps and aged ceramic coupling caps cannot be underestimated.

BTW, HowlerMonkey, your HF-85 fascia surround looks very clean. The cage top looks sweet. The cosmetics are very nice, in fact. Enjoy !
Also, is your photo icon a show car of yesteryear, like a Fiat X/19 ?

Thanks for the great tips...I have done some caps and resistor replacements but mostly in crossovers so this is a bigger challenge for me...but I will take my time and learn all I can about the HF85 before I do anything. I will post some better pictures during the week.

The show car is a Peugeot 205 T16 circa 1984. Peugeot had to produce this version so they could compete in Group B rally. I love all the group B cars from that time
https://www.autozine.org/Archive/Peugeot/classic/205T16.html

 

[jeb98]

Thanks for the great tips...I have done some caps and resistor replacements but mostly in crossovers so this is a bigger challenge for me...but I will take my time and learn all I can about the HF85 before I do anything. I will post some better pictures during the week.

The show car is a Peugeot 205 T16 circa 1984. Peugeot had to produce this version so they could compete in Group B rally. I love all the group B cars from that time
https://www.autozine.org/Archive/Peugeot/classic/205T16.html

Good luck with the eico preamp. I have an HF81 which has a similar preamp section and I like that amp. Also, I love the old group B cars as well. I’d love to drive one of the Peugeots or a Lancia delta integrale. Let us know how the restoration goes. I also have to second that yours looks in excellent condition. Some of them were put together as kits so the solder joints are not always perfect.

 

[adnick]

Glad you found one, started to build one for myself but was traded a box of PAS parts so....

Let us know the details of the journey.


Regards,
Andy

 

[tubeactive]

Group B...Wasn't that the new "needed" so-called regulations to compete with the AWD Audi Quattro ? Some amazing car refinements and engines came out of that group, including your fave 205. Unfortunately, some of the then newly developed, now over-powered Grp B vehicles, might have been a bit too dangerous during their rally abilities...which caused their unfortunate demise. I am a huge fan of great handling cars that are a bit under-powered. That way, when you are mashing the go pedal, the car can stay predictable.

Having owned a stateside, first year WRX which could be accused of having too much power, it was out-handled and out-braked (at sensible speeds) by my 1968 Mini Cooper S 1275. You know the type, that world rally champ from '64 to '67, with the ten inch wheels. Truly, a giant killer...

As a younger man, I was deeply interested in auto racing. I knew drag racing and road racing. In those years, you could drive the affordable race car to the races on Friday or Saturday, drive home by Sunday with the same car, ready to drive to work on Monday. I was always enchanted by the little car that could. I bought my first Mini Cooper in 1980, when I was 23. That 998 Cooper was only my second car. I have a video (VHS) collection from the Speedway channel days, as well as some cool tapes and DVDs on vintage road racing, but little Group B excitement. I always favored the affordable racing cars, until I was part of a crew for a serious, vintage racing '65 Cooper S. One lap while stuck in pit row at Watkins Glen is all that takes. When you see and hear the bigger cars rounding the last turn, coming onto the new lap's first straightaway, with fire breathing exhaust and sub-sonic thundering, I was hooked...These days, slow and steady wins...

Enjoy your audio and driving toys !......