Been sourcing a Blue Alps pot for a while. I did get one in the end, but I fear it is fake.
This one has been linked before, but shipment is triple the price of the pot itself:
ALPS 20KAX2 20K Ohm Audio Taper Stereo Potentiometer 6mm Shaft
And then I found this one:
STRK27102 ALPS - Distributors, Price Comparison, and Datasheets | Octopart component search
They look the same to me, but seems very different part numbers are given on the two different sites, so I am a bit baffled…
«Alps 516G» returned no significant results.
So the question is: will the RK27102 work the part, or should I go for the one from Parts Express despite the high shipping costs to my country?
And yes, I could have bought the kit from the store. But I allready sourced all the other parts before the kit was made available, including Toshiba J74s matched withing 0.1mA, and set up a jig for the 113’s, so…
Any insight appreciated.
Regards,
Andy
This one has been linked before, but shipment is triple the price of the pot itself:
ALPS 20KAX2 20K Ohm Audio Taper Stereo Potentiometer 6mm Shaft
And then I found this one:
STRK27102 ALPS - Distributors, Price Comparison, and Datasheets | Octopart component search
They look the same to me, but seems very different part numbers are given on the two different sites, so I am a bit baffled…
«Alps 516G» returned no significant results.
So the question is: will the RK27102 work the part, or should I go for the one from Parts Express despite the high shipping costs to my country?
And yes, I could have bought the kit from the store. But I allready sourced all the other parts before the kit was made available, including Toshiba J74s matched withing 0.1mA, and set up a jig for the 113’s, so…
Any insight appreciated.
Regards,
Andy
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And a bit greedy too 
Nice site, and close to home. Didn’t find any 20k ones, so ordered from Hi-Fi Collective. Thank you, and thank you Peppenino!
Regards,
Andy
up to 50K, that's just matter how your sources are able to feed that pot
having nothing with stage after pot itself
btw. buying it from Dantimax is way to get proper and controlled quality
frankly, nowadays - Blue Alps - I don't care is it original or correct copy - they're both good enough for money (and really nothing to write home about)
my experience, at least
having nothing with stage after pot itself
btw. buying it from Dantimax is way to get proper and controlled quality
frankly, nowadays - Blue Alps - I don't care is it original or correct copy - they're both good enough for money (and really nothing to write home about)
my experience, at least
Thanks! We’ll see how these lifesucking fakes or genuines perform. At least it is a PnP solutions better than nothing.
I do have a long term plan of a more lively orange solution, based on some kind of Iron Curtain design, with inductive volume control
but for now the GH way is my solution.
Maybe a choice full of regrets. We will see. My only encounter with Alps Blue, with an Electrocompaniet EC4.5, was riddled with crackling and channel imbalance. And that was an original part. Aged, but still.
I do have a long term plan of a more lively orange solution, based on some kind of Iron Curtain design, with inductive volume control
but for now the GH way is my solution.Maybe a choice full of regrets. We will see. My only encounter with Alps Blue, with an Electrocompaniet EC4.5, was riddled with crackling and channel imbalance. And that was an original part. Aged, but still.
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They may or may not be fakes. In sourcing the Alps pots for the kit and looking at getting them in larger quantities for the future, we discovered that there are only a couple of actual Alps distributors in the US (for commercial/retail use anyways) and they are metering things out to distributors as they are short like everyone else.
As for the make/model numbers - that was confusing too as it seems they have a number of marking schemes which makes things confusing figuring out the actual model number (as you have found).
My advice right now is to only use reputable places like Mouser, Digitkey or PartsExpress that are also official Alps distributors and get them there. The prices might be higher and there are considerable delays these days compared to the others, but you will be assured of getting the real part. Beware of amzn and other "discount" places as we have found that while they may have a lot of stock of the alleged part, they often unknowingly sell counterfeit parts marketed as the real thing and there is little or no way of authentication so you can be left literally holding the bag of fake parts.
--Tom
I’ll await the order from Hi-Fi Collective. They seem serious. I will also check out the TKD, as the future is bright and other builds hopefully to come. Thank you!
Tonight I finally got my rudimentary first matching jig up and tested some 113’s. Jig set up according to Papas setup. Like Papas batch, most of the 113’s tested had high IDSS of an estimated 20-ish. (I used 150R in the jig, exact IDSS @ 100R therefore not verified). Testing the final JFET, I finally found a match for the one lower value GH estimated 13-14mA I could find among the ones in the batch. The two matched within 0.01mA. Now on to find the correct resistor values for R4, and I expect 160-175R to maybe to the trick. Matching not strictly necessary, but hey, makes life a few seconds easier as I can use the same R value for both R4’s.
Parallell dialogue with Mighty ZM whilst testing, enlightened me as usual telling me that not only does a high IDSS+higher R in a CCS not have a detrimental effect on SQ, it is in fact advantageous for a CCS. So there we are.
I have some more higher IDSS 113’s that I might be able to match up and find R’s for, should someone be in a tight spot. Able meaning might have time, and might not. My life.
Good night!
Regards,
Andy
Tonight I finally got my rudimentary first matching jig up and tested some 113’s. Jig set up according to Papas setup. Like Papas batch, most of the 113’s tested had high IDSS of an estimated 20-ish. (I used 150R in the jig, exact IDSS @ 100R therefore not verified). Testing the final JFET, I finally found a match for the one lower value GH estimated 13-14mA I could find among the ones in the batch. The two matched within 0.01mA. Now on to find the correct resistor values for R4, and I expect 160-175R to maybe to the trick. Matching not strictly necessary, but hey, makes life a few seconds easier as I can use the same R value for both R4’s.
Parallell dialogue with Mighty ZM whilst testing, enlightened me as usual telling me that not only does a high IDSS+higher R in a CCS not have a detrimental effect on SQ, it is in fact advantageous for a CCS. So there we are.
I have some more higher IDSS 113’s that I might be able to match up and find R’s for, should someone be in a tight spot. Able meaning might have time, and might not. My life.
Good night!
Regards,
Andy
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I reread my post and dialouge with Mighty, and I believe Mighty ZM’s words regarding high IDSS and R in a CCS were not as black and white as I seem to have quoted him on. Sorry about that. (bloody Greenhorn!). It was more along the lines of «not necessarily a bad thing», and «in some ways advantageous, but within reason wrt IDSS level», and circuit dependant, meaning I should not sweat it if I need a bit higher R than 125 for example (my asking was based on fear of too high voltage drop, though not knowing the potential consequence in this circuit, just remembering the BA-3 article wrt FE (not CCS-related, but still).
I am glad to hear this is not an issue, within reason, with the J113 in this circuit, as it saved me a reorder of a 113 batch.
Regards,
Andy
I am glad to hear this is not an issue, within reason, with the J113 in this circuit, as it saved me a reorder of a 113 batch.
Regards,
Andy
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well, common logic here
with 10mA of target current, there is hardly any voltage shaven from allowable voltage headroom, whatever R value is - 10R or 300R
appropriate reading - Erno Borbely site , zip file – for benefit of DIY community – Zen Mod Blog
with 10mA of target current, there is hardly any voltage shaven from allowable voltage headroom, whatever R value is - 10R or 300R
appropriate reading - Erno Borbely site , zip file – for benefit of DIY community – Zen Mod Blog
Hi. Your board has differences from the last version posted, V.1. The position of j113 is reversed. There is also modification to allow the use of radial capacitor in C1. Could you clarify? Thanks.