power issue

[ugly_guitar_guy]

So strangely, my sequencer wah will work fine with a battery (plugged in through the DC jack - kinda hooptie, I know...), or with my voodoo lab pedal power II plus, but it will not work with a BOSS PSA or ACA adapter. Any thoughts on why??

[newfish]

Four quick questions...

1) Do you know how much current your Sequencer Wah needs to operate properly?

2) Are you daisy-chaining your effect power, or simply testing the one pedal to get these resuts?

2) Have you tried your BOSS adapter with another pedal?

I think the new BOSS adaptors are good for 400mA or so.  This is more than adequate for a single pedal - even a hungry digital device.

4) Have you checked for correct polarity?  I *know* this should be 'standard', but it's one less question to ask later.

Hope this gets you started...

[ugly_guitar_guy]

Four quick questions...

1) Do you know how much current your Sequencer Wah needs to operate properly?

2) Are you daisy-chaining your effect power, or simply testing the one pedal to get these resuts?

2) Have you tried your BOSS adapter with another pedal?

I think the new BOSS adaptors are good for 400mA or so.  This is more than adequate for a single pedal - even a hungry digital device.

4) Have you checked for correct polarity?  I *know* this should be 'standard', but it's one less question to ask later.

Hope this gets you started...

1) I have no idea how much is required for the pedal to operate, but if it has been tested and run on a battery AND a Voodoo Lab Pedal Power (which outputs 100mA) then I know that *should* be more than enough, right??

2) Testing the one pedal. One power supply plugged directly into the pedal.

3) Yes, the pedal works with everything else it was plugged into. Actually I tried it with the BOSS PSA-120T (wall wart style), PSA-120S (newer style), and the ACA-120 with no difference.

4) Yes, the polarity is correct.

The only thing I can think of at this point is that it has something to do with the BOSS adapter jack that I used because it was in the dead pedal casing that I got.



Tip is wired to ground. Sleeve is wired to positive. The extra solder point seems to be an extra sleeve connection.

[ugly_guitar_guy]

Ok, here's where it gets crazy...

So I spent some time with it and figured out that my battery puts out 9.2V, and the pedal is happy. The Voodoo Labs Pedal Power 2 puts out 9.3V, and the pedal is happy. The BOSS adapters put out over 9.4V and the clock section freaks out and freezes. Also, using the SAG function on the Voodoo Lab pedal power 2 I can drop the voltage all the way down to 4V and it still works. So, I'm thinking that in order to make it BOSS PSA compatible I should put a current limiting resistor on the power positive, so the question is, how do I figure out what value resistor to bring 9.4V to 9V (or thereabouts)?

(The really cool thing though was finding out that the current draw of this pedal is literally about 3.85mA, so if I decide to use a 9V battery it will last for freaking ever!)

[newfish]

if you want to drop your 9.4v to somewhere near 9v, you could set up a voltage divider to shave off half a volt or so, ....

OR....

Wire a single diode in-line on your pedal's + voltage wire, with the band facing 'towards' your board.

This will give you a voltage 'drop' of anything from 0.4v (Germanium diode), to 0.7v (Silicon diode) - and has the added bonus of providing very simple protection against any reverse-polarity accidents.

You've already established that your pedal will work with anything over 4v, so the 8v or so you'd end up with is fine.

Hopefully, this will be a really simple, effective solution to your power issue.