Eico HF85........thoughts?

kerouacknew

Active Member
I am looking for a tube preamp for a Mcintosh Mc250 i just picked up. I would prefer to buy a Macintosh one(C20/Mx110z) but the prices are crazy. Should have bought one 5 years ago.
Someone on the Canuck audio board has a restored Eico HF85 for sale. I am just wondering if this preamp is well respected. I would be using it with 3 sources. Phono, CD, and iPod.
The tubes are 6x4 rectifer USA eico, Rogers branded, Torvac and Tungsol.
Interested in any and all opinions. I know nothing about tube amps.
Thanks
Shawn
 
I had one, I modified it per some popular mods on the yahoo Eico board and put in a film cap power supply, it was *excellent*. I'd highly recommend it while it's not as fashionable as some of the crazy price ones.
 
Now way you can go wrong, but it will require subtle mods and re-capping if it's barn fresh. If you've ever heard an 81, it's the same front end. The active tone controls are waht makes it stand out IMHO, even if you don't use tone controls.
 
Eico HF85s are great and will sound good in most any tube system.
They are not cheep stock or restored so beware.
mmine is a total teardown/rebuild with all new parts as it was in godawful filthy condidion but unmolested stock.
Every part is new except transformer,sockets and chassis.Rewired from blank and painted to my taste.
It sounds wonderful and now looks good. Tone PECs are descreet built on perf boards, as are RIAA phono eq parts.
 

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Ok thanks guys. Ferninado yours looks fantastic. I am going to think it over. Might be a good option for less coin than the Mac ones.
I love my Mc250 but i think it would sound even better with the tube pre.
Are the tubes mentioned alright or would i need to go out and find some better ones
Thanks again
 
Ok thanks guys. Ferninado yours looks fantastic. I am going to think it over. Might be a good option for less coin than the Mac ones.
I love my Mc250 but i think it would sound even better with the tube pre.
Are the tubes mentioned alright or would i need to go out and find some better ones
Thanks again
Hard to say about the tubes, it depends on their strength and a number of other details. I'd say at minimum the line stage and phono stage (2x12ax7 each) should have matching tubes so if yours are mismatched you may think about getting either matches are pairs to replace them. I wouldn't worry about the rectifier brand. I would recommend confirming whether the power supply caps are original or replaced before settling on a price, if they're not recently replaced you should make sure you get that done (and account for that expense if any).
 
none of the tubes in my 85 are ''matched'' but are good quality tubes, all 12ax7s.
I have not yet found a need to match them. but doing so will not hurt anything.
In a preamp I feel its not necessary.
But I know others believe otherwise.
 
IMHO, the 85 tube "pairs" will definitely need to be matched and have very well matched triode sections (there are two triodes in each bottle). This will drastically help the distortion numbers as far as the matched sections, I rolled a lot of tubes through my 85 and the best SQ I got for my ears were Teles in the phono, running DC fils., and Mullard, DC fils as well in the line stage. Something else that is very important are the two capacitors right before the preamp output terminals. That's where you may want to put a little extra money. I also found that it sounded better with slightly higher plate voltages, but not much or you risk the run of some nearly inaudible hum. I may still have my schematic, I'll have a look today and also see if I can get you a pic or two of her top and bottom. On mine, I ended up disassembling the volume, and other pots completely to clean out some dry gresae they used that de-oxit won't touch. These really are a labor of love, and quite a bit of work, but there's plenty of room underneath and your efforts will be greatly rewarded. All the power supply lytics should be bypassed at least twice imho, once with PIO, and once with poly. One more thing that gets overlooked sometimes but is very important, is you'll want to polish the inside and outside of the RCA connectors on back. I use a product called "Wenol". Q-tips cut in half work great chucked into a dremel tool at low speed to do the inside, then a socket with a small piece of rag inside that just fits over the outside is good for that. You'll want them looking like chrome. Ha, all that said, and I love the 85 over any vintage tubed pre, but I use a SS Rotel simply because it has a a terrific MC stage and remote control.
 
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Thank again guys for all the great info guys.
heres the listing. Anything else i should be concerned about or ask about.....thanks again.

Eico HF85 tube preamp-bare chassis stripped down and rewired.
The chassis was cleaned, lettering installed on back panel to indicate inputs and outputs.
All new sockets installed-All 9 pin sockets are Belton .
All rewired as per original drawings.
Main power supply cap replaced with a JJ 50uf/50uf@500v can cap plus a 220uf cap under the chassis.
Fuse holder installed. One AC plug was removed and capped off.
All resistors in signal path and cathodes are carbon film and Kiwame 2W carbon film for the plates. Metal Oxide resistors in the power supply Rail.
All the coupling caps in the signal path are K40 PIO Russian. The smaller bypass caps are all quality poly and silver mica.K42 PIO on the line out.
The phono RIAA components were mounted on the terminal strips near the 12ax7 tubes, the original design was to have them installed in the selector control. This eliminates runs back and forth of cable and eliminates hum in the phono stage, plus the tape head etc inputs which are not required today.
Installed rca gold jacks on the back of the chassis and now has 3 line inputs, 1 phono input, one line out and preamp out. This now allows you to have the jacks spaced further apart to accommodate today's larger rca cable connectors.
The selector control was replaced with a 6x2 switch. The blend control has been bypassed.
The volume pot has been replaced with an ALPS 500k pot, thus the loudness control is eliminated, the unit thus has no balance control but performs amazingly.
It comes with following tubes:
6X4 Rectifier USA Eico
Line Stage 12aX7’s Rogers Branded Made in Canada Have I65 /r34 I65/ 4D2 dates codes Mullard tooling
Phono- 1 12AX7 Torvac Made in England , other 12AX7 Eico-Made in Germany, Final Output stage 12AX7 Tungsol Made in USA
All volume/treble and bass controls work excellent.
New power switch and power cord
 
what is asking price.? I'm guessing $600-700
sounds like he did same as me only more-so.
Mine also has ALPS vol pot, new 2pol6pos selctor sw and new tone pots, .
All tape functions removed.

Sounds like a nice buy if price is rite.

Jay is correct about matching the dual triodes in each bottle.
I faied to consider that.
I need to go back and top off some caps with better ones one of these days.
IMO you cannot go wrong with one of these Eico 85s tuned up to their best performance.
I have a friend who says they are better than the infamous marantz 8B.
This friend gave me the one I rebuilt as he already had one and mine was so ugly.
I did a standerd R/C refurb on his as I was still a somewhat of a new-B to the 85. Not no more!!!
 

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Love my 85, find myself using it as much or more than my Fisher 400 CX-2. That listing text sounds almost word for word identical to the one used by the seller I purchased from on Audiogon a couple of years ago, don't remember the name but he was in Canada.
 
what is asking price.? I'm guessing $600-700
sounds like he did same as me only more-so.
Mine also has ALPS vol pot, new 2pol6pos selctor sw and new tone pots, .
All tape functions removed.

Sounds like a nice buy if price is rite.

Jay is correct about matching the dual triodes in each bottle.
I faied to consider that.
I need to go back and top off some caps with better ones one of these days.
IMO you cannot go wrong with one of these Eico 85s tuned up to their best performance.
I have a friend who says they are better than the infamous marantz 8B.
This friend gave me the one I rebuilt as he already had one and mine was so ugly.
I did a standerd R/C refurb on his as I was still a somewhat of a new-B to the 85. Not no more!!!

Just about exactly like mine, I figured it was worth a total tear down to bare chassis. They're pretty when you go all the way like that. Those Rogers branded Canadian tubes should be very nice, could be Canadian made GEs which are excellent IMHO.
 
Thanks again guys. He is asking $800 canadian or about $560US.
I am going to make him an offer. hopefully he accepts it. If not i will keep looking for that Mx110z i guess.
thanks again
 
If you cant get it, try to find a stock unmolested junker needeing total rebuild for maybe $200(guess).
then do the job yourself .
It lotsa fun and something to be proud of.
 
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