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DIY Stompboxes => Building your own stompbox => Topic started by: MrStab on March 04, 2013, 01:29:02 AM

Title: Huminator at 12v?
Post by: MrStab on March 04, 2013, 01:29:02 AM
hi guys,

i'm interested in adding a small stripboard build of Beavis Audio's "The Huminator" (http://www.beavisaudio.com/Projects/Huminator/ (http://www.beavisaudio.com/Projects/Huminator/)) into my pedal, but it seems to be focused on 9v supplies for fx chains and there's no mention of whether i'd need to change the values in the schematic for a 12v supply. the reason i'm interested in a higher voltage is (allegedly) greater headroom in the nubish buffer circuit i built. so would i need to change any of the values mentioned?

now that i actually know what an inductor looks like (besides the red Fasel that after years i only just noticed i had in my wah the other week...), i'm gonna look into stripping one from an old GPU or something if the specs fit (then probably buy a new one for reliability's sake if it works out), as i hear using one of those is superior for hum reduction. i haven't read how though, i'll get to that later. or can i just be a lazy arsehole and stick one in parallel in the Huminator circuit? lol

cheers!
Title: Re: Huminator at 12v?
Post by: bluebunny on March 04, 2013, 09:42:30 AM
Quote from: MrStab on March 04, 2013, 01:29:02 AM
i'm interested in adding a small stripboard build of Beavis Audio's "The Huminator" (http://www.beavisaudio.com/Projects/Huminator/ (http://www.beavisaudio.com/Projects/Huminator/)) into my pedal, but it seems to be focused on 9v supplies for fx chains and there's no mention of whether i'd need to change the values in the schematic for a 12v supply. the reason i'm interested in a higher voltage is (allegedly) greater headroom in the nubish buffer circuit i built. so would i need to change any of the values mentioned?

I don't think anything would need changing, really.  Just make sure your capacitors can handle the voltage (most likely they already can), and perhaps adjust the LED drop resistor in case it's too bright at 12V vs. 9V.  Otherwise, use as-is.
Title: Re: Huminator at 12v?
Post by: MrStab on March 04, 2013, 11:38:31 AM
thanks for the input, bluebunny. my weakest cap is rated at 15v - shame, as the rest far exceed that, but it's just in the (useless!) LED anti-pop section so i could swap it out at some point. the LED is actually fine at 12v, it's blue but not obnoxiously bright (can't remember what value i used).

moreover: would this actually be worth it if i just found a better adaptor? i mean, surely in ideal circumstances, such a circuit shouldn't be necessary. but maybe it'll help in getting rid of noise generally, as opposed to just that mains drone.

random curiosity: i wonder if people who put anti-mains notch filters in their circuits take their pedals abroad much... lol
Title: Re: Huminator at 12v?
Post by: bluebunny on March 05, 2013, 09:51:21 AM
Quote from: MrStab on March 04, 2013, 11:38:31 AM
moreover: would this actually be worth it if i just found a better adaptor? i mean, surely in ideal circumstances, such a circuit shouldn't be necessary. but maybe it'll help in getting rid of noise generally, as opposed to just that mains drone.

This is a good point.  If you're really getting a "mains drone", then a poor adaptor could well be the culprit.  Try with a battery instead, just to rule out hum getting in from some other route - should be silent.
Title: Re: Huminator at 12v?
Post by: MrStab on March 05, 2013, 10:26:34 AM
it's definitely the power supply as the battery's always been fine (forgot to mention). i just figure i may as well have venues pay for my electricity if i can! lol

i'll sift through a bunch. i have countless unused adaptors, but i'll try for one that was originally used in an audio-ish application. if not, i'll go by the "bulky = probably less crap" rule.
cheers :)
Title: Re: Huminator at 12v?
Post by: bluebunny on March 06, 2013, 11:50:52 AM
Quote from: MrStab on March 05, 2013, 10:26:34 AM
i'll sift through a bunch. i have countless unused adaptors, but i'll try for one that was originally used in an audio-ish application. if not, i'll go by the "bulky = probably less crap" rule.
cheers :)

Sift and measure.  May be some unregulated ones in there.  Or try a 1Spot?  By the hand of our esteemed friend and colleague R.G.  Not at all "bulky", but definitely not crap either.
Title: Re: Huminator at 12v?
Post by: MrStab on March 06, 2013, 07:33:46 PM
just googled that - i live in Scotland (UK) so even if me being unreasonably broke wasn't an obstacle, i'd need such an adaptor that conforms to 230V/50Hz standards. i'll have a wee look around for variations from this side of the pond, though.

i rushed together a Huminator + inductor yesterday, i need to re-do it properly but it didn't seem to get rid of the hum entirely. still fine with just a battery. once i buy more solder i'll look into it.
Title: Re: Huminator at 12v?
Post by: bluebunny on March 07, 2013, 11:01:18 AM
I'm a few hundred miles south of you.   :)   The 1Spot works anywhere (it's an SMPS) and there's a UK-plug version available.  Check out a few of your fave UK music stores.