Author Topic: Boss odb-3 mod help  (Read 730 times)

Thebrainless

Boss odb-3 mod help
« on: October 23, 2021, 12:11:09 PM »
Hey everyone!
I need to mod my boss odb-3 so that the PSU plug on it instead of drawing current from an external PSU unit, it must provide the current coming from the battery in order to power another pedal with the daisy chain wire.
I can't understand the way the external PSU plug works in this pedal, when there's a plug inserted it totally bypasses the battery. I know it's basic electronics here, but still I need help, how do I arrange this? I'd like to make non destructive mods if possible... Thanks to whoever will help!!!

bluebunny

Re: Boss odb-3 mod help
« Reply #1 on: October 23, 2021, 01:16:51 PM »
Are you saying that you'd like the battery in one pedal to power another pedal via the DC jacks, and with no other PSU involved?

(BTW, do you want this thread moved to the general building forum where it will see more traffic?)
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Thebrainless

Re: Boss odb-3 mod help
« Reply #2 on: October 23, 2021, 08:55:51 PM »
Yes, that's exactly what I'd like, but not because I'm completely nuts  ;D
I've already "modded" the odb-3 by puttin an old cellphone rechargeable lithium battery inside of it, wired to a TP4056 based charging circuit with an usb-c input to charge the battery, and a step up dc-dc converter to bring those 3.7 V to the 9 V needed by the pedal, all connected to the pedal 9v plug, so if I want it back to its original form I just need to remove those things from inside.
Since the battery is 3.7 V and 1450 mah, if I got the math right, by stepping up to 9 V I got a little less than 600 mah, which is plenty to power way more than 1 pedal for enough time. That's the idea, since I've already put the battery in there, why don't share it with other pedals? (all 'cause I need to use a noise gate with the odb-3  :icon_biggrin: )
I know, an external power bank could've been a better solution, but I didn't mean to use more than 1 pedal when I thought about this, I underestimated the noise the odb-3 generates...
So, I know this mod will involve soldering and unsoldering stuff, no easy "back to normal" this way, but I'm ok with it, at least I know I'll never use an external PSU with pedals again, knowing all the unwanted noise it adds, batteries are way cleaner AFAIK.
I'm also thinking of another solution: get completely rid of the PSU plug and put 2 usb females instead, one would be an usb-c charging port (now I have to open the battery slot to charge it 'cause that's where the TP4056 circuit is) and the other would be the "sharing" output, usb-c as well.
In this case can I simply unsolder the PSU plug without consequences? AFAIK when there's no PSU plugged in the socket is useless, so removing it should'nt make a difference, am I wrong?
Now for the question about moving this thread it'd be nice to have more traffic, so yes please! (I'll pay more attention to where I post next time!)
Thanks!




« Last Edit: October 23, 2021, 09:08:21 PM by Thebrainless »

duck_arse

Re: Boss odb-3 mod help
« Reply #3 on: October 24, 2021, 09:32:25 AM »
a dc jack is basically brainless - tell it what to do. wire your [new, internal, battery] power source - to centre pin, and + to barrel, leave the swinging switch pin empty, then whatever plug you plug in gets the juice, for to distribute as you see fit. any stock-wired pedal should be happy w/ a standard dc plug fed from your source.
I went full circle.

Thebrainless

Re: Boss odb-3 mod help
« Reply #4 on: October 24, 2021, 05:42:28 PM »
That's what I thought, but now the question is: which one's the swinging switch pin and what you mean by "leaving it empty"? :icon_question:

bluebunny

Re: Boss odb-3 mod help
« Reply #5 on: October 25, 2021, 05:01:40 AM »


Big tab on the left (1) is ground.  Top tab (3) is +ve, always on.  Right tab (2) is switched +ve (usually connected to a battery).

Duck means to connect battery to (3), and leave (2) unconnected.
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DIY Bass

Re: Boss odb-3 mod help
« Reply #6 on: October 25, 2021, 05:33:34 AM »
That's not what Boss uses for their plugs though - They use the PCB mount rectangular ones

duck_arse

Re: Boss odb-3 mod help
« Reply #7 on: October 25, 2021, 09:00:43 AM »
you people should have learnt to ignore me by now. what I should have said is link the barrel and the barrel switched, that is, both contacts that are not the centre pin. then the internal supply is connecting to both the internal circuit, and the contact that will connect when an external plug is in-plugged.
I went full circle.

bluebunny

Re: Boss odb-3 mod help
« Reply #8 on: October 25, 2021, 01:31:21 PM »
That's not what Boss uses for their plugs though - They use the PCB mount rectangular ones

Yep, quite right!   :icon_redface:   I blame lack of coffee...
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antonis

Re: Boss odb-3 mod help
« Reply #9 on: October 25, 2021, 02:18:00 PM »
you people should have learnt to ignore me by now.

And exactly who are you, sir..??
"I'm getting older while being taught all the time" Solon the Athenian..
"I don't mind  being taught all the time but I do mind a lot getting old" Antonis the Thessalonian..

bluebunny

Re: Boss odb-3 mod help
« Reply #10 on: October 25, 2021, 05:16:31 PM »
Never mind the caffeine shortage...  You can of course work out the equivalents to the 1,2,3 for the Boss socket using a DMM to find out what pad connects to what else.
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Thebrainless

Re: Boss odb-3 mod help
« Reply #11 on: October 25, 2021, 06:52:53 PM »
So if I connect battery to 2 and 2 to 3 will it still work or should I left 2 out of the equation? 'cause being it pcb mounted I'd like to avoid desoldering...

Thebrainless

Re: Boss odb-3 mod help
« Reply #12 on: October 25, 2021, 07:30:46 PM »



So this is all it took, works like a charm! Thanks guys for helping a noob!!!  :icon_mrgreen: