Help? can't get a milennium board to work on both wall wart and 9v battery

[rkhanso]

I know this should be very easy, but I'm having trouble anyway - maybe my frustrations are clouding my thinking. First post, by the way....

I have built both the Rebote 2.5 and Bluesbreaker found on the tonepad website. I also made Milennium 2 boards for both of the boxes. I'm using the geofex Offboard Wiring 3 schematic for using both 9v Battery and wall wart, with an LED indicator.

The trouble I'm having is I can get just the wall wart to power the board, or the 9v to power the board (but not the 9v battery when connected as the schematic shows - only directly to the 9v and ground connections on the fx board) but can't get them both to work connected at the same time as the geofex schematic shows. I've tried multiple ways, but no success. With the wall wart usage, the milennium board works just fine, LED and all. When I connect the 9v battery just up to the effect board, only then it works with the battery.

I'm thinking that it's possible that I have the wrong 1/4" stereo phono input (it also has a switch in it), or the wrong DC power jack (though it does have a shunt in it), or am connecting them incorrectly...but am not sure.  I've been stumpted for a couple weeks on this.

Thanks for any help/direction.

Here are the parts I am using
1/4" jack:   http://www.allelectronics.com/make-a-store/item/SPHJ-S/STEREO-CHASS.MT-1/4-JCK-W/NC-SW/-/1.html
DC Power:  http://www.allelectronics.com/make-a-store/item/DCJ-21/2.1MM-COAX-POWER-JACK-PANEL-MOUNT/-/1.html

With both the DC Power jack and the 9V connector connected at the same time, I've never been able to power the board with the battery. Yes, I bought a brand-new battery and there was no difference. It appears that when I've had it connected as I thought it should be, there was a short between the snap connectors on the 9v battery connector - which I'm thinking is trouble.

[R.G.]

Without a schematic or picture/diagram of how it's wired, it is very difficult to divine how it is wired.

I believe that you have already figured out where the problem is - it's wiring the DC power jack.

The DC power jack must be wired as follows. The center pin must be the negative contact, the outer sleeve the positive contact. The DC power jack must not be one which has a metal bushing contacting the enclosure, only plastic should contact the enclosure. When you push your wall wart DC adapter into the DC jack, measure the voltage from the center (negative) pin to the other two contacts. The one which is now a positive voltage from the wall wart is the one which supplies +V to the circuit. The third one, which does not show continuity to the wall wart power is where the positive/red battery wire goes.

Now plug one end of a guitar cord into the input jack. With your meter set as an ohmmeter, measure the resistance between the tip contact on the un-plugged end of the guitar cord to the contact lugs on the input jack. The one which shows zero ohms is the signal contact. The contact for the shield/sleeve is easy to find with the guitar cord unplugged and one end of your meter clipped to the sleeve at the hole where the plug goes in. Just remove the guitar cord and check the remaining two contacts on the jack for continuity to the sleeve. The one that's left is the "ring" contact, and it has no connection to either of the other two with the plug removed. Clip one end of your meter (set to ohms) to the ring contact and plug in one end of a guitar cord. Verify that as the plug is inserted the ring contact goes from open circuit to shorted to the sleeve/shield contact.

Once you have identified the "ring" contact, wire your battery black/negative lead to that contact.

Take power and ground to your circuit from the DC power jack.

[rkhanso]

OK,
Here are the schematics.

The small images are kinda hard to read. The links to the originals are below
http://www.geofex.com/Article_Folders/Millenium/mill2bd.gif
http://www.tonepad.com/getFile.asp?id=76 (Offboard Wiring 3 - page 3)
http://tonepad.com/getFile.asp?id=75





My board is working correctly when I use the wall wart to power it, through the millennium 2 board. Because of this, my polarity must be correct on the dc power jack - which is center post positive, outside is negative - which I believe is the most common way these are wired up.

Thanks for your suggestions. I'll try them tomorrow and post the results.

[rkhanso]

It seems my DC jack may be faulty (or maybe more accurately - backwards).



When I measure resistance from where the black wire connects to the metal box I'm using as an enclosure, I get 0 ohms. When I measure from the lead with no wire connected, I also get 0 ohms. When I measure from the red wire, I get an open. This is with nothing plugged into the jack. Shouldn't I have 2 of them as opens?

Here's how I'm guessing it should work:
With no wall wart plugged into the jack, I 'think' that the ground should always be isolated from the other 2 leads of the DC jack. The other 2 leads should be shorted with no wall wart connected into the jack and open with an wall wart plugged into it (to shut off the 9v battery source when using the wall wart).

I did confirm the polarity of the dc jack as the center positive, barrel negative. As you mentioned, this is probably backwards.

So, it appears that my wall wart does need the polarity reversed, then I should move the red wire to where the black is, move the black to where the red is and then connect the battery 9v red lead to where there nothing connected currently. Does this sound reasonable? Before I try it and let some smoke out?

[R.G.]

Except in very rare cases YOU CANNOT USE A METAL-BODY DC POWER JACK. These nearly always have one of the terminals connected to the case and cause you power problems - just as you're having.

[rkhanso]

Thanks.

But, do you think my solution would work? Cut the transformer's cord and swap plus and minus.  Then move the red to the black, black to red and 9v battery snap to the non-currently connected terminal of the dc jack?

Or, are there sources for plastic bodied panel mount dc power jacks? I've only seen PC mount plastic bodied ones.

One other thing I tried, but forgot to mention...
I removed the DC Power jack and both the 1/4" jacks from the metal box and had them 'hanging' in the air, not touching anything. With the 9v battery snap connector hooked up, I had the same results - no power when using the 9v battery, but works OK when the transformer was used.  In that case, the dc power jack body was not touching ground/metal box.

[jefe]

All plastic, panel mount:

http://www.smallbearelec.com/Detail.bok?no=93

And these are my favorite - they mount from inside the box:

http://www.smallbearelec.com/Detail.bok?no=666

[rkhanso]

All plastic, panel mount:

http://www.smallbearelec.com/Detail.bok?no=93

And these are my favorite - they mount from inside the box:

http://www.smallbearelec.com/Detail.bok?no=666

Thanks for that link. I just ordered some of those inside mount jobs. I'm sure once I put them in, it'll work just fine.

Here's what I've done so far:  The Rebote 2.5 is the one with the black/red knobs and the other one is a Blues Breaker. Both have a super bright blue LED.
The delay is wonderfully quiet when not on and I think it's a great box. I'm not as excited about the Blues Breaker sound - it's a little on the mild side, but it does sound OK.
I like the grunge/construction look and will probably leave them as-is: no paint, maybe no knobs on the Blues Breaker.

[jefe]

Very cool! I love my Rebote too. I'm also getting into the rough junction boxes, just picked up a few this weekend. 

[rkhanso]

Without a schematic or picture/diagram of how it's wired, it is very difficult to divine how it is wired.

I believe that you have already figured out where the problem is - it's wiring the DC power jack.

The DC power jack must be wired as follows. The center pin must be the negative contact, the outer sleeve the positive contact. The DC power jack must not be one which has a metal bushing contacting the enclosure, only plastic should contact the enclosure. When you push your wall wart DC adapter into the DC jack, measure the voltage from the center (negative) pin to the other two contacts. The one which is now a positive voltage from the wall wart is the one which supplies +V to the circuit. The third one, which does not show continuity to the wall wart power is where the positive/red battery wire goes.

R.G. - I think you have the correct solution....the wall wart needs to have the center ground, not positive. Most of the wall warts I see have the center as positive. I was assuming (I know, bad idea) that since this seems to be the standard, that guitar effects would be set up with that in mind.  I haven't been able to get a wall wart and a 9v battery to power the board without the 9v battery being shorted to ground when the wall wart plug was removed from the jack.
It appears I'm going to have to swap the wires on my wall warts?  If someone would confirm before I ....... snip ....... the wires.
BTW, I just finished a Heladito (Small Clone) and am ready to put it in an enclosure. I sounds great, super clean, wildly variable. Tremulus Lune is next.

[trixdropd]

Without a schematic or picture/diagram of how it's wired, it is very difficult to divine how it is wired.

I believe that you have already figured out where the problem is - it's wiring the DC power jack.

The DC power jack must be wired as follows. The center pin must be the negative contact, the outer sleeve the positive contact. The DC power jack must not be one which has a metal bushing contacting the enclosure, only plastic should contact the enclosure. When you push your wall wart DC adapter into the DC jack, measure the voltage from the center (negative) pin to the other two contacts. The one which is now a positive voltage from the wall wart is the one which supplies +V to the circuit. The third one, which does not show continuity to the wall wart power is where the positive/red battery wire goes.

R.G. - I think you have the correct solution....the wall wart needs to have the center ground, not positive. Most of the wall warts I see have the center as positive. I was assuming (I know, bad idea) that since this seems to be the standard, that guitar effects would be set up with that in mind.  I haven't been able to get a wall wart and a 9v battery to power the board without the 9v battery being shorted to ground when the wall wart plug was removed from the jack.
It appears I'm going to have to swap the wires on my wall warts?  If someone would confirm before I ....... snip ....... the wires.
BTW, I just finished a Heladito (Small Clone) and am ready to put it in an enclosure. I sounds great, super clean, wildly variable. Tremulus Lune is next.

No!! he means that there should be 3 lugs on your dc jack. when wired right it works with the battery, but when plugging the wall wart into the jack, it disconnects 1 pole of the battery. Re-read what he said to do...