[gojira_matt]

I'm wondering how one would go about making a very simple cmoy (even simpler than the standard cmoy!) without a switch, whereby it would automatically turn on when the input and output jacks had jacks in them, like the Fii0 does.

And while I'm here, could one use 1/2 W reistors rather than the 1/4 resistors in Tangent's tutorial? What would the difference be if you can?

 

[fordgtlover]

You could use a switching jack to power up the amp when you plug headphones in.

As for resistors, 1/2W are fine to use. They may be physically larger than the 1/4W ones, which may make them harder to fit.

 

[BlizzofOZ]

Or you can use the ALPs pot that has the on/off and volume all-in-one.

I know I've seen those jacks that power up when the get something plugged into it.

 

[Juaquin]

The CmoyBB uses one of those switch jacks for it's headphone out - take a look at the site and they should list the exact part. Or you can go with the ALPS pot with switch, it's a great pot.

 

[Kirby1356]

On the topic of Alps pot, do you have to wire it differently on the board?

Also what is the difference between the Panasonic one recommend and the Alps?

 

[Juaquin]

The Alps is slightly better, but a little larger and might be overkill for a Cmoy. Tangent does list the Alps as an alternative, though (and sells it on his site). It's wired the same, although the exact pin location may be different, in addition to having pins for the switch.

 

[tamasic1]

Quote:

Originally Posted by gojira_matt /img/forum/go_quote.gif I'm wondering how one would go about making a very simple cmoy (even simpler than the standard cmoy!) without a switch,

Right, no switch and a fixed value resistor for gain. Let the souce control volume. I wanted to do something like that but with all surface mount components. Very small and simple.

 

[gojira_matt]

Thanks for the advice. The pot and the switching jack look like nice parts, but they seem to be a bit harder to come by here in Australia... Mouser obviously has them, but their shipping is quite expensive for hobbyists like me. I'll have to see if I can do some split shipping with people...

 

[Fred_fred2004]

I'm in Australia so I understand the problems with parts

This was my attempt at a super basic amp with a small slide switch on the board,

The idea was that earbuds and interconnect fit in the case for storage

cheers
FRED

 

[gojira_matt]

Nice one Fred... that looks really neat. Mine have had had to have a fair bit more wiring than that thus far, but that was the kind of thing I was thinking of.

 

[Alpha 1 Omega]

very clean work fred top notch..

 

[Forte]

Quote:

Originally Posted by gojira_matt /img/forum/go_quote.gif Thanks for the advice. The pot and the switching jack look like nice parts, but they seem to be a bit harder to come by here in Australia...

The switching jacks are available here from Jaycar 3.5mm Stereo SWITCHED PCB Socket - Jaycar Electronics or Altronics as are all the parts and tools needed for a basic C-moy.

If you want your build to be as small and neat as Fred_fred2004 you will need to etch your own PCB's. Check out Fred_fred2004's photo album for his Eclipse Mint Tin Cmoy, that is one [size=xx-small]compact[/size] build.

 

[Fred_fred2004]

Quote:

Originally Posted by Forte /img/forum/go_quote.gif The switching jacks are available here from Jaycar 3.5mm Stereo SWITCHED PCB Socket - Jaycar Electronics or Altronics as are all the parts and tools needed for a basic C-moy. If you want your build to be as small and neat as Fred_fred2004 you will need to etch your own PCB's. Check out Fred_fred2004's photo album for his Eclipse Mint Tin Cmoy, that is one [size=xx-small]compact[/size] build.

Unfortunatley the Jaycars/Altronics jacks have switches which are normally closed and they open when you put the plug in, I haven't been able to figure out a way of making the amp turn on by opening the circuit, but I wish I could

 

[gojira_matt]

I've just had a look at your extended gallery Fred, and it is very impressive. Actually, the reason why I was originally asking about the possibility of a simpler cmoy was because I was considering attempting to put one into an eclipse mint tin, and I see you've already done it... but I guess that an original etching would be necessary to make it that small. Is etching reasonably easy enough to learn? Possibly coming up with the design that you are going to etch is the hard bit. Do you just source your parts from America and pay the postage usually?

 

[Fred_fred2004]

Hi if you look at the pictures of builds thread (msg4466) I put a simple explanation of how to do the etching its not hard but like all things you have a learning curve to get through. The amp with 5chips is my clone of a Pimeta it has a dual op amp for left & Right channel, a single opamp for the ground and 3 buffers one for each channel. I did it just to see if I could do it

Parts from Jaycars/Altronics/eBay and Farnells (overnight delivery and cheap postage)

Your welcome to use any of my layouts if you want to try them out
cheers
FRED