Strange effects pedal/battery problem

[p90fool]

I have a problem I've never encountered before, and thought at first I was imagining it until I repeated the experiment.
A few months ago I modded an old Danelectro Fabtone distortion pedal, in order to clean it up a bit and to get rid of its inherent "cocked-wah" tonality.

It's the big ol' metal cased pedal from the first series. I removed a couple of caps (C5 + C8, I think) and a couple of clipping diodes, put the battery back in and voila! Nowt. No LED, no sound. So I plugged in a 9v/300ma power supply and it worked fine, leading me to think I'd maybe damaged a solder joint somewhere during the slightly fiddly reassembly.

Anyway I loved the sound and started gigging it so I though I'd better do another as a backup. This one worked fine when I put the battery back in, but it was a Duracell in this one so I started swapping batteries around.

Now here's the anomaly I don't understand;
BOTH pedals will light up the LED and sound good with a Duracell, even an old one which is down to 7.5v but;

NEITHER pedal will light up the LED or work with a standard Eveready or Panasonic battery, even when brand new and reading OVER 9v.

Any ideas anyone? I wondered whether it was a current thing, a bit like the cold cranking amps rating of a car battery even though they're all 12v. Is there a component in there which now needs a little bit of a jolt to get it to switch on/trip over/whatever? Am I going mental?

Both pedals worked fine on all battery brands before the mods btw.

[welly_59]

have you tried testing for current with the crappy battery?

[StageStruck]

It could be the current ratings of the batteries, especially with those cheapo Panasonic Zinc-Carbon batteries.

[p90fool]

Cheers guys, was just wondering if it was caused by a particular type of component suddenly finding itself in a different part of the signal chain since I modded it.

[ICBM]

Battery clip not making proper contact to the battery? Terminal size varies slightly...

[p90fool]

Battery clip not making proper contact to the battery? Terminal size varies slightly...

They seem to be good, they're pretty tight when I clip them on.
It's odd how it's happening on two identical pedals, with identical mods, both of which worked with any battery brand before.

[welly_59]

Check voltage on the board with a multimeter