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Old 12-05-2021, 01:15 PM   #31
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Join Date: Aug 2016
City & State: Constanta
My Country: Romania
Line Voltage: 230VAC 50Hz
I'm a: Hardcore Geek
Posts: 3,248
Default Re: Op-amp preamp discussion

Out of curiosity, I went to my parts bin and dug out that big Alps pot I mentioned as being perfect in terms of balance and it turns out it's not really Alps and it's not really a "pot" either

First off, there's no info on this part whatsoever - RH2702 only gets me links to random sellers and references to the "real" thing which apparently is the RK271 series. RH is not even an official Alps series of its own, which leads me to believe it's a knock-off. Should come as no surprise given that I got it off Ali and it's common practice for sellers to spoof official names and models by altering a letter, such as Sqny instead of Sony and so on. In this case, it's RH instead of RK.

Backing this up is a discussion I found here where they talk about the same exact doubts about the authenticity of said pots. Someone said the real ones do not have a stepped feel and knurled shaft and also a serif font for the ALPS logo on the back....mine has both of the former and plain text as well, so it's deffo fake.

Looking past that, what IS this thing then ? I mentioned how it's got a stepped feel to it and how it's not really a pot. It's a "stepped attentuator" if you ask me. I found a picture of it dismantled here and the way it works is by moving the wiper across a series of fixed value SMD resistors, hence the stepped feel when you turn it. Out of curiosity, I took mine apart as well and sure enough, there's your 22 SMD resistors in series. It works fine, no complaints there and I guess one redeeming aspect is that it offers "true zero" when the wiper is at either end (why can't more pots do this ?), but the stepping is kind of rough and results in large jumps in volume. I also don't like the force required to turn it....

This got me thinking of getting a real RK one, since it seems to be praised by audio guys....
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Last edited by Dannyx; 12-05-2021 at 01:34 PM..
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