Current Draw

[aettin]

Hi folks-
I'm looking for a diy reverb or envelope filter that can run easily on batteries (bit of a contradiction, I realize). For convenience, I was going to purchase the ggg digital reverb or perhaps the DOD440. They also seem like reasonably small circuits. But after sending them an e-mail, I've learned that they don't actually have the current draw info on hand. Has anyone built either of these pedals/ can give me a sense of the current draw for either these two?

Thanks and praises.

http://www.generalguitargadgets.com/projects/19-filters-envelope/119-dod-440-envelope-filter
http://www.generalguitargadgets.com/projects/25-reverb/243-digital-reverb

[Seljer]

For the reverb, the datasheet of the actual reverb unit specifies the supply current as 60mA, max 100mA http://www.smallbearelec.com/Projects/BTDR-1H.pdf
A bit on the high side for battery power.
Otherwise the only active components drawing a lot of current are the opamps, since they're more or less interchangeable it depends on what you use. The datasheet for the TL072 specifies supply current max 2.5mA per amplifier with a +-15V supply and no load so you can expect the current to be in the range of a couple of times that for the four opamps in the circuit.

The TL022 listed for the DOD filter is a low power opamp, datasheet say 0.25mA +-15V with no load. Add the loads and the total current should still be reasonable for powering the circuit with a battery.

[iccaros]

I have a Belton Brick Reverb pedal, it does OK with Batteries. I use it weekly and replace batteries once a month.
http://buildyourownclone.com/reverbinstructions.pdf

[Mark Hammer]

Reverbs will generally always have more current draw than the majority of envelope-controlled filters, simply because of the technology involved.
As for ECFs, there too you might fnd a division between units/circuits based on current draw and associated technology.  I suspect that units employing OTAs, or transistors as variable resistances might draw less current than LED/LDR-based circuits, though I might be wrong about that.  Still, most of the optoisolators we are collectively accustomed to using, likely employ "old school" LEDs internally, rather than a newer-technology high-brightness unit that draws less current.  It may be possible to reduce current consumption of such designs (e.g., a Mu-Tron) by making your own optoisolators with superbright LEDs.

Of course, all of this is subject to confirmation by those with more expertise in the area.  I don't have any real sense of what portion of the total current draw of something like a DOD440 or Mu-Tron comes from the LEDs alone.

[aettin]

thanks so much folks-- this helps a bunch!