[tintin47]

Hi Everyone,
 
My main amp is a Beta 22 that I built.  It has worked perfectly for 4+ years now (and is actually the reason I dropped off of the boards here.  It does everything I want and more).  It is the 3 channel version (R+L+G). Anyway, I think the attenuator has has crapped out on me.  I went through all of the first time setup with my multimeter and everything looks good in terms of key voltages, dc offset, etc.  
 
The one compromise on my B22 build (kind of an oxymoron) was the stepped attenuator.  I skimped a little and went with a ~$50 chinese version. When I measure the resistance across the attenuator, it is wildly different across the two channels depending on the step, so I think this is definitely the issue. 
 
THE QUESTION:
I am way out of the game both in amp building and headphones.  I need a recommendation on what I should replace the POS attenuator with.  AMB recommends this discontinued (http://www.mouser.com/ProductDetail/ALPS/RK27112A-S20-C1-MN104/?qs=qjUENa6g21stTDXjfVYCwA%3D%3D) part, and I'm wondering what would be a suitable replacement.
 
Here is the amp in case you'd like to see it:
http://imgur.com/a/1XfyU

 

[Zashoomin]

First of all, what is wrong with it, and why do you suspect the attenuator?  Secondly, how much do you want to spend on a pot?

 

[tintin47]

Maybe my first post wasn't clear enough.  I went through the first time setup from amb.org with my multimeter and checked all of the key voltages across all 3 channels.  They are identical and within operating range, so there is nothing wrong with the boards, which means its a connection issue somewhere.  I checked all physical connections and everything looks OK,  Finally, I'm convinced that it is the pot because there are a couple steps that do produce sound from both channels, while most don't.  When I measure resistance across the pot at each step, the left consistently steps down but the right usually reads >10 megaohms, which seals the deal.
 
I don't know.  I'm not married to the idea of a stepper anymore.  Probably less than $100, but I definitely want a well-regarded brand name so I'm not doing this again in a few years.

 

[Zashoomin]

Well there are a couple of different options. You won't find any stepped attenutators for that price though so I would go with a nice pot.  
 
You can get a standard alps pot. http://www.mouser.com/ProductDetail/ALPS/RK27112A00AK/?qs=sGAEpiMZZMtC25l1F4XBU4o6BXVFiwl906EoDfKpcJM%3d
 
TKD makes some of the best pots http://www.mouser.com/ProductDetail/ALPS/RK27112A00AK/?qs=sGAEpiMZZMtC25l1F4XBU4o6BXVFiwl906EoDfKpcJM%3d
 
Other than that you can do ebay again, but those are my suggestions.  
 
Good luck.
 
Edit: If you feel like you can get lucky by searching around Noble, Alps (not the blue rk27, but their old black beauty rk40), and Alpha make some good pots as well.  They are no longer made though so they are hard to find.   

 

[ephrank]

Do Not Compromise! 

 - http://www.ebay.com/itm/161668292282

 

[tintin47]

Haha, not a chance.  My ears aren't that good.  I built the Beta as a fun project.  I honestly can't hear a single iota of difference between it and my CK2III (which cost about as much as that goldpoint).

 

[MisterX]

Amazingly, I have never even looked.
 What's the BOM cost for a LCDuino and Delta 1?

 

[GrindingThud]

I use these on my builds: http://www.ebay.com/itm/Original-ALPS-RK27-VOLUME-Dual-10K-Potentiometer-Round-shaft-/121142301731?pt=LH_DefaultDomain_0&hash=item1c34a4d423

 

[tintin47]

 What's the BOM cost for a LCDuino and Delta 1?

 
That is a good point. I may just buy an RK27 for the short term and look at something like the LCDuino/δ1 as a summer project.  I don't mind going a bit high on price if it is part of a DIY project and I haven't done one since my Beta.  Would be fun to case something again.
 
...aaaaaaand this is how I get back into posting here every day.

 

[MisterX]

 

[MrMajestic2]

I've used Alps RK27, Goldpoints and stepped relay attenuators in my builds. I would say don't use anything lesser that the Alps RK27.