[zurn]

Anyone ever try these?

Birdcord USB to 9V Converter Cable

 

[mhammer]

Never tried it but after finding a USB-charged backup battery my son left behind I was pondering making myself one with a charge pump. The limitation is that most charge-pump chips are limited in how much current they can provide. For most analog pedals, it's more than enough, but digital pedals would draw more current than is safe for the chip.

I imagine Birdcord have their own proprietary circuitry that manages to upvert 5V without being too constrained with respect to current.

Of course the irony is that digital pedals are going to convert the 9Vdc coming in the power jack down to the 5V or even 3.3V they use. Ideally, it should be possible to plug a USB battery pack into a digital pedal directly, without need for any up-and-down conversion.

 

[Hammerhands]

This would be very useful to me right about now. I think I can find an Adafruit 2777 and a 1-Spot reverse polarity cable. I’m going to give it a shot.

USB to 2.1mm DC Booster Cable - 9V

Truetone - 1 Spot Reverse Polarity Converter

 

[cboutilier]

Never tried it but after finding a USB-charged backup battery my son left behind I was pondering making myself one with a charge pump. The limitation is that most charge-pump chips are limited in how much current they can provide. For most analog pedals, it's more than enough, but digital pedals would draw more current than is safe for the chip.

I imagine Birdcord have their own proprietary circuitry that manages to upvert 5V without being too constrained with respect to current.

Of course the irony is that digital pedals are going to convert the 9Vdc coming in the power jack down to the 5V or even 3.3V they use. Ideally, it should be possible to plug a USB battery pack into a digital pedal directly, without need for any up-and-down conversion.

I'm surprised we're not seeing an upsurgance of micro USB ~5V inputs on the new digital pedals. Center positive PSA style jacks are archaic in today's electronics.

 

[oldjoat]

micro USB ~5V inputs

look at any micro / mini USB device connection after a few months of use ... now add extreme abuse to that and your unit would always be in for warrantee work.

 

[cboutilier]

look at any micro / mini USB device connection after a few months of use ... now add extreme abuse to that and your unit would always be in for warrantee work.

Most digital pedals live confortably strapped down to a pedal board.

But you're right, it wouldn't live long with a gear abuser like myself.

 

[oldjoat]

they also tend to wiggle and lose connection at times ,

reminds me of a show I was at ....
a pedal was acting up but was deemed OK by the house sound check person
2 minutes in to a rocking solo, the guitarist hit the pedal and ................... dead silence ....
he grabbed the pedal , pulled the cords and threw it at the sound person and stormed off stage.

during "short intermission" the sound person faithfully returned the pedal to the stage.

the guitarist returned , saw the pedal , grabbed it and the cords and proceeded to beat the sound person with it.

then went back on stage , plugged in , wiped his face , calmed right down and proceeded with the set again.... minus the pedal.

 

[Guitar101]

Never tried it but after finding a USB-charged backup battery my son left behind I was pondering making myself one with a charge pump. The limitation is that most charge-pump chips are limited in how much current they can provide. For most analog pedals, it's more than enough, but digital pedals would draw more current than is safe for the chip.

I imagine Birdcord have their own proprietary circuitry that manages to upvert 5V without being too constrained with respect to current.

Of course the irony is that digital pedals are going to convert the 9Vdc coming in the power jack down to the 5V or even 3.3V they use. Ideally, it should be possible to plug a USB battery pack into a digital pedal directly, without need for any up-and-down conversion.

Hey Mark. What about converting down from 12V to 9V?

Update: Mark, I hope you know this was joke. I drew this up for a chuckle. It's a fake.

 

[oldjoat]

LM7809 at under 2.00

 

[mhammer]

Hey Mark. What about converting down from 12V to 9V?

View attachment 254580

I suppose it would depend on what sort of current drain the pedals impose. The standard 3-pin regulators, like oldjoat suggested (which I use because they're simple, cheap, available, and do the job well) require at least 2 volts more at their input than they can put out. So if a 12V battery, for whatever reason, drifts down below 11V, the regulator will not function well. It won't blow up, but may not reliably deliver what a given pedal is expecting.

But if the complement of pedals being powered aren't seriously draining the battery, and the battery is charged, battery-plus-9V-regulator is an elegant and noise-free solution.

 

[Hammerhands]

This would be very useful to me right about now. I think I can find an Adafruit 2777 and a 1-Spot reverse polarity cable. I’m going to give it a shot.

USB to 2.1mm DC Booster Cable - 9V

Truetone - 1 Spot Reverse Polarity Converter

It works.