Okay, a question before I embark on this electrical experiment

[syciprider]

The experiment: Splicing DC adapter wires together to make a daisy chain

The object: To power a BMS and a Qtron + from the same brick

The materials: A couple of very expensive pedals w/ their power supplies, wire strippers, some tape and some good ol' American ingenuity.

The question: To get the same voltage to the two pedals the wiring has to be PARALLEL correct?

That is I take connect all positives to the positive power lead and all negatives to the negative power lead.

Comments?

[Rune Bivrin]

Yes. Should be OK, unless they keep different ground polarity.

[syciprider]

They use identical model # power supplies and use + center - barrel tips.

Okay. BRB in a few.

You can have my pedals if I fry myself. Just email my lawyer.

[syciprider]

That's weird. Everything works (the LEDs light up) when the pedals are not connected in the chain. The BMS powers down as soon as I connect the QTron to the pedal chain?

Current flowing through my pedalboard cables?

[Asa Samuel]

Surely you'd be running half the power from one brick?

as your splitting say a 12 volt into two pedals so thats only 6 volts each right?

you'd need a 24 volt into two to splice it into 12 volts for each pedal?

[syciprider]

No, not if they are connected in parallel. That's how the Visual One Spot Daisy Chain works.

I think my problem here is that the brick is not providing enough current (aka amperes). I can definitely understand that but what I am not understanding is that I only experience current shortage when the pedals are connected in the pedal chain (with the BMS in a bypass loop even, which as we know is a form of electrical isolation) and not if they were sitting on the floor connected to nothing but the same brick.

[Asa Samuel]

Originally Posted by syciprider

No, not if they are connected in parallel. That's how the Visual One Spot Daisy Chain works.

I think my problem here is that the brick is not providing enough current (aka amperes). I can definitely understand that but what I am not understanding is that I only experience current shortage when the pedals are connected in the pedal chain (with the BMS in a bypass loop even, which as we know is a form of electrical isolation) and not if they were sitting on the floor connected to nothing but the same brick.

so it works when the brick is jsut plugged into the pedals but not when the pedals are plugged into other pedals?

[syciprider]

Yup. I guess plugging the Q Tron into the chain increases its current requirements (even in bypass mode) so much so that the brick can no longer power both pedals.

[Asa Samuel]

Originally Posted by syciprider

Yup. I guess plugging the Q Tron into the chain increases its current requirements (even in bypass mode) so much so that the brick can no longer power both pedals.

dude, thats basically what i said, mabey i'm getting confused between volts and amps but its the same.


you need double the power for both the pedals to work.

[theshadow2001]

Each pedal will have a current rating. Find out each current rating. Look at your power supply. If that can then supply equal or greater (preferably greater) power than the sum of both current ratings then you know you have enough power.

My thinking is that you don't have enough power. Don't pedals only turn on when you plug something into the input? So when you connect them together you can't supply enough power for each pedal.

Run one off a battery and the other off the power supply. If the both stay on then you know you don't have an adapter that can supply enough current.

[bongomania]

Originally Posted by theshadow2001

Find out each current rating. Look at your power supply. If that can then supply equal or greater (preferably greater) [current] than the sum of both current ratings then you know you have enough [current].
My thinking is that you don't have enough [current].

+1.

[syciprider]

My only question really is why connecting the (bypassed)pedals to the rest of the pedal chain suddenly increases the current requirement for the two?

All by themselves together the brick has enough current for both.

[Trevor.A]

Originally Posted by Bass Junkie

dude, thats basically what i said, mabey i'm getting confused between volts and amps but its the same.


you need double the power for both the pedals to work.

Not quite the same.

Double the available current: Pedals work
Double the voltage: Pedals explode

[Trevor.A]

Originally Posted by syciprider

My only question really is why connecting the (bypassed)pedals to the rest of the pedal chain suddenly increases the current requirement for the two?

All by themselves together the brick has enough current for both.

So, bass -> pedal 1 -> pedal 2 -> amp doesn't work, but when you bypass one of them it does? I know a lot of my pedals won't even turn on when nothing is connected to the in/out jacks, which is essentially what you're doing with the bypass and would explain the current draw when it's not bypassed. check each pedal individually with each of the power connections to make sure there's no problem with your wiring. Start simple then work your way up and start adding things, it will eliminate a lot of the things that could be going wrong.

EDIT: What are the power ratings for the pedals and the power supply? If the supply is putting exactly the amount of power needed, that may be your problem. The pedals may be drawing slightly more than the specs say, and the supply might be a few mA below. Under load, the pedals will draw more and the supply will provide less.

[Wren and Cuff]

hi again man,

Volts are volts on a daisy chain. You could put 20 pedals on a daisy chain, and you'd still have 12 volts, or 9 volts etc...

It the MA's that count. Are you splicing two power supplies together? That's not good to do and may be your problem. Forget the not enough power stuff. I could be wrong, but I'd be very surprized if that was it. Take ONE power supply, add the daisy chain, and I bet it works. If not, it just won't work, you won't hurt the pedals.

p.s. Don't use a power supply with more volts!

[syciprider]

Let me backtrack here and explain what I did and what happened.

I took one EHX power supply and daisy chained two pedals with identical voltage requirements to it in parallel. When the pedals (which are not in the pedal chain) are connected to the power supply they both work, individually and at the same time. So far so good or so I thought.

When I returned the pedals (with their shared power supply) to their respective places in my pedalchain the BMS stopped working. So I'm wondering what it is about connecting the Q Tron to the pedalchain that increases its current draw enough to shutdown the BMS even when both are in bypass mode.

[bongomania]

Ooh! Ooh! I know what's happening! The power supply jacks for these pedals are reverse-polarity from the other pedals. The ground for all the other pedals is carried on the sleeve of the instrument signal plugs, and typically connected to their housing as well. So when the two EHX's are together "alone", they will work fine, but when they are connected to the rest of your chain, their ground is out of polarity with the rest of the system. I don't know the BMS circuitry well, so I can't say exactly why that is causing the failure, but I am 99% sure that is what's happening, as I've had similar problems in the past.

[Wren and Cuff]

Oh, I just saw your post that says it is + center. Bongo is right, That IS reverse of all the others. BUT, Since you are using a separate wall wart, that still shouldn't matter.

Digital pedals can get tripped up by daisy chains. Maybe you're best off just using the 2 wall-warts. Let me give it some thought though....

[Wren and Cuff]

Wait, just figured it out (I think). For it to work you have to have them side by side (the audio chain) because they are sharing the same ground. No neg. ground pedals in between. If your set-up won't accomodate that, then you have to bail the daisy chain. Try it and see if I'm right!

[syciprider]

Okie.

I'll do that in the AM and report back here. Thanks Matt!