[millercv]

Ok my "learning" cmoy is done. Got very little sleep last night and there was much weeping and gnashing of teeth. But I got everything working - I think.

One of the problems I had was wire up the pot (its one of the 6 pin panasonics). I just couldn't figure out the grounds I ended up putting the ground from the in/out jack to pin 2 and then connected pin 3 to ground on the board. Should this work or should I go back and put everything straight to the board ground?

Right now it is working fine - no hiss whatsoever but the volume doesn't seem to be boosting the source that much. Any suggestions or do I need to switch to two batteries to get a big boost? I've tried reading the boards but haven't found much on going to two batteries (other than it fixing a problem w/ distortion on creshendos)...

Thanks and I'll post pics of this one tonight (though the innards are quite ugly

)

 

[millercv]

Ok it isn't working as fine as I thought it was

I brought it into work to play around w/ a bit and while looking at it the pin 1 from the pot came disconnected (L.in I believe but don't have the schematic in front of me) but sound was coming from both sides so apparently I have a short someplace (which may account for the low volume also....)

 

[JMT]

Try grounding your components independently.

With the Panasonic EVJ pots, ground is pins #2 and #3. Output is pins #1 (L) and #4 (R). Input is pins #5 (R) and #6 (L).

 

[Dwagun]

JMT:

Is that with the knob pointing away from you and the pins on the bottom i.e. pins flat on the table and the turning part pointing away?

then pin #1 is the leftmost pin and six is the rightmost pin?

I've been having a bit of trouble with my CMOY and...Im double checking my connections right now and I wanted to check with a master builder


thanks

 

[JMT]

That would be with the pins pointing up and the shaft pointing away from you, going from left to right.

 

[millercv]

Whew you had me worried for a second there! I was thinking "So thats whats wrong!" - but then I realized that would be the same as knob towards you with pins on the bottom numbering left to right

 

[millercv]

Big thanks to JMT - yep moving the ground fixed everything!

Heres a pic:

A few more are up here

Please keep in mind that most of it was done very late last night so the innards aren't that pretty - thats why I got the stuff to build another now that I know whats going on

I actually can't believe it sounds as silent/good as it does since I know there are probably a few bad solder joints.

Do most people end up using 2 9V batteries - with one it is a pretty good range but I don't have TONS of headroom.

Has anyone rigged up another battery connector/switch so you can use one but have the option there to use two if you want?

Thans again JMT and everyone

 

[tommyatkins]

Um. I don't think it matters (looks around for support). You'd be setting them up in parallel, which combines the current, and the current consumption should be about the same (except when it really draws more power, for the increased headroom), you should just have twice as much juice. (Not too sure, but this is what I have in mind for my PS for my PCDP...) It's been a while since physics. (Come to think of it I don't really know why I posted...

maybe I'll get some kind of answer, too...)

TA out.

 

[Sol_Zhen]

Is it me, or do I see a lot of non-insullated wire in there?

 

[millercv]

Actually its magnet wire

the kind you have to strip it w/ a soldering iron. I got used to the stuff when I built a Bottlehead Preamp that uses it.

The plain old insulated wire I had was a bit thick and not cooperating in the tiny space so I switched after hooking up a couple of things.

 

[00940]

just a question : where do you buy such boxes ?

 

[JMT]

Whenever I use dual 9v, I wire them in series. Usually because the op-amp datasheet indicates voltage requirements better than +/- 9v. If you are using an OPA2132/2134 you needn't worry about using two, a single battery is sufficient.

 

[millercv]

They are just in with the regular Altoids - there are three "special edition" tins out now. I've seen them at target and several other places. They have pictures of them all on their website - maybe altoids.com ?

 

[Sol_Zhen]

Quote:

Originally posted by 00940 just a question : where do you buy such boxes ?

There are various versions of altoids boxes made in limited production. You just have to catch them when they come out.

 

[Sol_Zhen]

Quote:

Originally posted by millercv Actually its magnet wire the kind you have to strip it w/ a soldering iron. I got used to the stuff when I built a Bottlehead Preamp that uses it. The plain old insulated wire I had was a bit thick and not cooperating in the tiny space so I switched after hooking up a couple of things.

I'd be worried about interference or one of those touching another.