[CodeToad]

Does anyone know of a replacement for the Alps RK0971221Z05?

 

[Robin W.]

That alps pot is fairly unique I'm not sure if there is a pin compatible device out there.
If your just looking for that pot, mouser.com is usually my first choice but they are out of stock.
Try Tangent or AMB.
Tangent’s Parts Shop
AMB audio shop
If your looking for an upgrade the alps blue is a nice pot for the price, but doesn't have the power switch built in. And it's alot larger, so it all comes down to your application.

 

[ting.mike]

apparently tangensoft and AMB has them in stock.

 

[CodeToad]

Thanks for the replies. Pretty much every cmoy design uses the alps. I guess it's one of those unique parts that fulfills the specific task well.

I guess I'm not used to there being no competition among manufacturers for parts.

 

[linuxworks]

there are LOTS of 'small stereo volume controls'.

problem is, they all suck worse than the alps.

the low end alps sucks. toward the lower wiper range, the balance is totally off. totally. its a crappy pot.

but the rest are all worse or hard to find or made 'just for' some other vendor and are not standard.

 

[Robin W.]

The panasonic evj is also pretty good, I've used them in the past with good results. It's similar in quality and price to the alps.

As you stated it really is one part that fulfills this specific task well.
The only negative is good but not great performance. But it's one of the best you get at this price point. Move up, get bigger and they can get alot better, for a price.

 

[linuxworks]

deja view:

http://www.head-fi.org/forums/f6/whe...-rk097-274085/

 

[CodeToad]

So I guess the question evolves: "If you were building a cmoy in absence of the Alps pot, what would you use?"...preferably something that sucks less.

 

[linuxworks]

I like to keep things in proportion.

cmoy is a starter cheaper amp. it does not 'need' super quality parts. that's not balance.

pick a better diy amp and THEN it makes sense to start 'spending' on pot quality

if you care this much, why put a good pot in front of 'only' a cmoy amp?

 

[Robin W.]

If I was building a cmoy without the alps, I would leave out the volume control completely and depend on the source for control. I'm not sure if that's an option or not in your application but simpler is usually better. But if it's for portable use your ipod or similar DAP probably has a usefull enough level control, possibly in the digital domain which probably has better channel matching than low end pots.

But if size wasn't important I'd build the cmoy around an Alps RK27, it's a great value at around $16US.

 

[linuxworks]

and, if you do build an amp and are thinking of leaving its input 'open' I think it might be worth having a 10k thru 50k fixed metal film single R sitting there, just to stabilize things.

 

[CodeToad]

Quote:

Originally Posted by rwaudio /img/forum/go_quote.gif DAP probably has a usefull enough level control, possibly in the digital domain which probably has better channel matching than low end pots.

Interetsing thought...is there a DIY solution for digital volume contol? Yes, yes...over the top for "cmoy" but is it doable?

 

[linuxworks]

you could buy the PGA volume control chip ($10 or so), and that's a very good digitally controlled (but analog domain) vol control chip.

here's one from error401:

http://www.head-fi.org/forums/f6/min...ontrol-280515/

I have one similar to that and I like the PGA chip quite a lot. its extremely good and even tests quite well

 

[ting.mike]

Quote:

Originally Posted by linuxworks /img/forum/go_quote.gif I like to keep things in proportion. cmoy is a starter cheaper amp. it does not 'need' super quality parts. that's not balance. pick a better diy amp and THEN it makes sense to start 'spending' on pot quality if you care this much, why put a good pot in front of 'only' a cmoy amp?

that's an interesting concept. a cmoy with no pot, and adjust volume from DAP.
I just told a friend who's building cmoys to give it a try.. see how it works out. it does simplify things a lot.

now why not push the idea further and make a small cmoy with SMD resistors (like sijosae's build), with no volume control, so that it's just a small box that plugs in between your headphone and DAP. might also work as an extension cable. now that would be very very neat.

how small of a battery can work with CMOYs?