A/C adapter won't power pedal but Battery will...what gives?

[Hiwatt25]

I recently built the Smalley NPN boost and it was working quite well until I tried to remove the battery and replace it with a power connector for use with an AC adaptor.  I believe RG said I could basically swap one for the other but once I rewired my pedal I had no luck getting anything but the slightest sound from it. 

Here's a link to the exact part.

http://www.radioshack.com/product/index.jsp?productId=2102491&cp=&origkw=panel+mount+size+m&kw=panel+mount+size+m&parentPage=search

I dutifully checked all my connections against the schematic and nothing had changed so I figured I'd stick a battery to the two bare leads that were now swinging free in the Connecticut sunshine.  And what do you know, BOOST!

I am at a total loss as to why my Radio Shack Panel Mount Size M Connector doesn't work.  I've used it in the past to power LED's but never to power a circuit.  In fact the one I'm using will light an LED if I touch the leads of the LED to the terminals on the connector.  I thought the adapter might be shorting to ground but I didn't get continuity between any of the terminals and the enclosure.  I've pretty much exhausted my troubleshooting skills so I humbly turn to the gurus here.  I am baffled. 

Anyone know what's up?

[Torchy]

This customer review from the link you gave might help '''

Ohm meter ck indicates shield connection is isolated from body (mounting hardware). This suggests you can use either polarity for tip & shield connections. However, when a plug is inserted this is no longer true. This can result in shorting any positive shield connection when mounting in a metal cabinet.

[Hiwatt25]

Oh, if I understand that right, that really sucks.  So does anyone know if there are better connectors to use...ones that don't short?  I know others use AC power for their projects so I'm hoping there is a viable solution.  thanks.

[Paul Marossy]

Is your DC jack metal? And is it center negative? Is your enclosure conductive? If so, you are shorting out the power supply, and you'll get no sound out of it. I made that mistake on my very first build. 

You can insulate the metal jacks with some creativity. And you can also get plastic bodied DC jacks. I've been using those for a while now.

[Hiwatt25]

Yes to both questions I'm afraid Paul.  Thanks for the insight.  Anyplace special to buy the plastic jacks or can I get them from the usual suspects?

[Somicide]

Why, the Usual suspects, of course!  Steve "Keyser Soze" Daniels carries them, IIRC.

[Pushtone]

Of the plastic 2.1mm DC jacks there are two types.
Ones that mount from the outside of the chassis (looks nicer).


And another that mount from the inside (no de-soldering when disassembling a pedal).


Here they are together:

[Paul Marossy]

The inside mounting one is exactly like the ones I use. I like that type because if you ever want to pull all the guts out of the enclosure, there's no unsoldering involved. I'll agree that the other one looks better, though.