Building a Volume box for DeVille question

[aab0mb]

I'm building this little volume box for the FX loop of my DeVille. 

http://www.fortunecity.com/marina/newland/2081/id3.htm

I have it as pictured and out of the box it works fine.  I have an Altoids box to put it in and when I do it doesn't let sound through.  The instructions said if you have a metal box which conducts that the ground wire between jacks is  not required.  I tried that and still nothing.

So my question is, Do I need to isolate the potentiometer from the case?  Am I missing something else?  Grounding out, shorting, etc.

Kind of sheepish about an easy question like this but what the heck.    Still learning...   Thanks

Aaron

[aab0mb]

Side note.  I thought this would be appropriate for the "beginner" section.

[Ronsonic]

Almost certainly there is a short somewhere between a signal lead to the case.

You get to start with one of the great troubleshooting problems of all time: "it worked great until I closed it up."

Ron

[d95err]

Get your multimeter out (íf you don't have one, buy a cheap one). Use it to check for continuity (i.e. zero resistance) in various places. Check that the outgoing ground has zero resistance to incoming ground. Check that the signal does not have zero resistance to ground etc.

EDIT: Grounding through the metal enclosure requires the jacks to be metal ones (e.g. open Switchcraft jacks) where the ground lug is automatically in contact with the enclosure. If you use plastic jacks, you need to connect the ground to the metal enclosure somehow (otherwise the you'll get no shielding from the enclosure). Run a wire between the ground lugs of the jacks and another to a lug screwed into the enclosure.

[Paul Marossy]

I built one of those boxes for my own Hot Rod DeVille and it worked fine for me. Are you sure that you have the pot wired correctly? And the jacks, too? It sounds like you have a short to ground somewhere in your box...

[wampcat1]

can you take a picture of what you have?
Also, you may be a little disappointed... the master volume in the amp is the exact same thing that you are building.

bw

[theundeadelvis]

A simpler and possibly more useful build would be an attenuator using an in wall volume control. If your using an 8 ohm setup you can get one at Radio Shack for $17. This will allow you to actually get that nice overdriven tube sounds at reasonable volumes. These work great and are super simple to use.

[aab0mb]

Thanks guys.  I nailed the problem down to a short.  The Altoids box was a little flimsy however, so I threw it in a RS box and gigged with it last night.  There were 13 bands at this gig and the DeVilles and Deluxes were many.  Everyone I showed that little box to thought it was pretty cool. 

I'm only using the volume box on the clean channel to get a little bit of preamp push at a decent volume.  It really helped fatten up some of the thin highs I dealt with at first.

Thanks for the idea about the RS attenuator.  Going to search for it right now...

[theundeadelvis]

Cool! There is all kinds of info about the RS attenuator at 18watt.com, but you have to register. There's probably info at AX84.com too. Basically, you just use it like you would for home stereos, between the amp and the speaker. I think Kerry on this forum had some pictures of one with his 18 watt build post.

[Paul Marossy]

Also, you may be a little disappointed... the master volume in the amp is the exact same thing that you are building.

Yeah, it basically works that way in practice...

[aab0mb]

I realize that it acts the same as the master volume on the drive channel.  Am I wrong to assume that the clean and drive channels have different gain characteristics?  If so than they way I'm using the box is to get the clean channel to act a little more like my Blues Jr. when dialing in a clean edge of break up sound.  True that it doesn't let me get power amp distortion but oh well for now.  It's better than it was before that little box.

Many thanks Amigos,
Aaron

[Paul Marossy]

Am I wrong to assume that the clean and drive channels have different gain characteristics?  If so than they way I'm using the box is to get the clean channel to act a little more like my Blues Jr. when dialing in a clean edge of break up sound.

No, the channels would definitely be different from eachother. I see what you are doing with it. Sounds like a workable compromise.