Eico HF-81

LuckyLyndy

Member
I'm looking for a splined shaft knob (pot) to replace the power/treble one on my Eico. A friend is restoring it for me, and says it is broken. Won't power on/off correctly, and when on...if you move the treble control up a bit, power goes off, up a bit more, power comes on.

I wrote to Michael Percy, and this was his response:
Splined shaft pots are not so easily found. Suppliers tend not to stock them as the demand is much less, and the quantity you have to buy to stock them is high. I suggest your friend replace the knob so that he can use a smooth round shafted pot (such as our Noble AP25 250K).

Does anyone have one, or access to getting one? I was just going to use a surge protector, and power on and off with that, but this may be more of a problem.

I really like the way this fellow cleaned up his unit, but he does say he bought several "parts only" units to complete his finished one. That would be too expensive a route for me
http://home.earthlink.net/~eico_hf81/
 
Those controls were a PITA from day one, so I wouldn't expect a replacement donor part to be a long term solution.

Antique Electronics does stock a MONO switch that works ...
https://www.tubesandmore.com/products/R-VS-500KA

But not a similar combo control for STEREO. They DO have one that works for the treble ...
https://www.tubesandmore.com/products/R-VA2X500KL

But it needs a shaft extension AND you need to add a flipper switch for power. I emailed AE a while back and they weren't aware of anyone who still makes a control that would be an exact replacement.

In your case, I'd try jumping the power connection and see if the treble still works properly. If so, bypass the power permanently to a flipper switch and continue to use the original control for treble.
 
Depending on the inconvenience factor, a power strip is ok to use in a pinch.

Maybe give us a picture of your treble control with its ohm rating. I have a lot of that kind of stuff up the ying yang! :D
 
Problem being ... if the original power switch has gone intermittent, it can still cause short cycling, which kills amps. By all means, use a power strip if you like, but DO bypass the original switch.

I would NOT use the amp until this is taken care of!
 
I have some on off switches that are attached to a pot but i would have to know what value you need. good luck
 
Reviving my post, as I am still in the same boat. Any new ideas to solve this? Just moving into my 'new' house. And would like to set this up in one of my rooms.
Thanks!
 
Working on it.
I have just moved, and in the process of configuring my home theater set up. I saw that there is an area for advice. I drew a diagram of the room, and will try to post it.
 
Problem being ... if the original power switch has gone intermittent, it can still cause short cycling, which kills amps. By all means, use a power strip if you like, but DO bypass the original switch.

I would NOT use the amp until this is taken care of!

my HF-81 may be experiencing this...have cleaned and DeOxit'd the power ON/OFF knob and I leave it ON while using a power conditioner as my actual power switch but I have noticed on rare occasion the power just goes off...I've only used DeOxit D5 and not the G5 (I'm out) preservative so I may pick some of that up to see if that helps at all...

Bill
 
I am a huge fan of the HF-81 amp and HF-85 preamp. When the Eico power switch becomes a "problem" to repair or source, I recommend removing the AC switch wiring which is near any gain/tone stages and placing the AC line wiring (and a switch if needed) solely near the power tranny and rear panel. Removing an AC line "noise" source which is near any gain stage, can only be beneficial in lowering the noise floor. Keeping the AC line wiring near the power tranny is best.
 
Back
Top Bottom