Hf-85 volume pot

Madman1

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So I’m having a tech do some work on my hf-85 and of course the volume pot is a mess. So I’m looking for info on replacements. Seems the alps 500k dual will work since I’ve read some of you guys have used that. I also see I’ll probaby need the shaft extension and the adapter. I guess my biggest question now is how to make the double knob work out. Do you just glue them together and the larger rear is a dummy and the front knob actually controls the volume? If you can share what you’ve done and maybe a picture or two, I’d really appreciate it.
Thanks guys!
Mark
 
There is no off-the-shelf solution that allows you to keep your knob original. Your tech. will have to cobble something together by either modifying the EICO knobs, using new-style knobs or modifying the shaft adapter to fit EICO knobs. The other issue are the taps for the Loudness switch. You can do without this function or contact Mark Oppat at Old Radio Parts and I'm sure he can construct an exact copy out of his stash of NOS parts. http://www.oldradioparts.net/
 
Ok, I did talk to Mark and I will most likely go with that solution but, I was curious how much if any an improvement the alps would be over the carbon type pot. I think I found a alps dual with loudness but, it’s from China and I’ve read about counterfeit alps.
Thanks,
Mark
 
I just put one in last week for a friend and I used a stepped ALPS. It has taps but I didn't use them as my friend wanted the loudness gone. I glued the two knobs together. I ended up cutting the inner and outer end off an extra pot I had and used a sleeve (epoxied) to attach the two.
I didn't notice any difference between the original and new pot sound wise but he wanted a stepped ALPS pot.
 
Is this from the Alps RK27 "Blue Velvet" line? Those are widely counterfeited, so, you really have to know your supplier to make sure it's legitimate. Parts Express has a few RK27 types, but not in 500K and nothing with taps. I just checked the alps.com website and they don't even make a 500K in the RK27 line! I assume anything ordered from China, Hong Kong, Taiwan, etc. with a name-brand has to be counterfeit. As to your other question, I'm sure it would be an improvement over the original, but, I haven't tried it yet.
 
Vendo81, I had no idea Alps made a stepped attenuator. Where did you get it?

Ston_cold, I think they're all fake, with the possible exception of the one from Germany. It's often very hard to tell if a part is genuine simply by looking at its exterior, because that is where counterfeiters put all their effort, right? Stick with well-known suppliers and you can't go wrong.
 
Thanks guys! Yea, my tech was not interested in doing a lot of fabrication to make the pot fit so, I have Mark putting one together. Also like what most of you said I was having a hard time finding them except from China...no thanks. Regardless the new one will be leaps ahead of the old one. Thanks again for all your advise.

Mark
 
I bought 2 of them several years back from a place in Germany. They do work quite well but the original I removed was working fine and sounded ok to me. I didn't try it out in my stereo system before and after so the comparison was on my work bench with test speakers.

STAY AWAY from any Alps made in China, although I've read they are getting better.
 
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Better-quality counterfeits?!
On the Alps website, they have a worldwide inventory locator, and it shows only one supplier in the US (Mouser), one supplier in Europe (RS Components), 3 in Japan and none in the rest of the Pacific Rim. So, consider that as your legit supply chain. I also see that the RK271 series is now obsolete; so, grab up the remaining supply while you can! The recommended replacement is the RK1681xMG series, which are all motorized types.
http://dilp.netcomponents.com/cgi-b...er1=RK271&partnumber2=&partnumber3=&pq=Search
 
I bought 2 of them several years back from a place in Germany. They do work quite well but the original I removed was working fine and sounded ok to me. I didn't try it out in my stereo system before and after so the comparison was on my work bench with test speakers.

STAY AWAY from any Alps made in China, although I've read they are getting better.
I bought 4 of those counterfeit stepped and loudness tapped 500k on taobao. tbh, they are good, costing 3 dollars each. I used one on one of my hf85 and modded the preamp to use Russian 6h2n-eb.

I am happy.

Terence
 
I bought 4 of those counterfeit stepped and loudness tapped 500k on taobao. tbh, they are good, costing 3 dollars each. I used one on one of my hf85 and modded the preamp to use Russian 6h2n-eb.

I am happy.

Terence
They must be getting better. I've heard that the quality has gone up. A lot cheaper than the $50 ones from Germany.
 
Early stereo vintage, volume controls were troublesome from the beginning. Reading some early reviews will confirm this.
58 to 60 years later, their tracking is even worse. Eico did not include a balance control in the HF85, unfortunately. With my hf85, I decouple the concentric clutch, by pulling the top knob, then carefully tweak each channel as needed. For my mono listening, in "thrilling dual mono," I often have to slightly adjust the vol. controls so the mono soundstage image comes alive.
The three KT- 600 preamps I had also suffered the same poor tracking in stereo. Fortunately, like the HF85, the KT600 vol controls are "clutched" and easily separated for independent channel control.
The Eico HF81 integrated had one volume and one balance control. The tracking on some HF81vol. controls is terrible, forcing us to tweak the balance control as needed. That's why balance controls are there...
Enjoy that HF85 !
 
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