EHX big box FX powering needs

[tuffteef]

so out of curiosity is there a way to mod the older versions of the ehx big box pedals that have the attached power cables on them with transformers inside to run on adaptors
my little knowledge is that they need to run off stepdown transformers if used around the world?

id like to collect some of them like the electric mistress micro synth so on so forth but i dont really wanna lug transformers around just to use them or find the newer non transformer versions well i can but eh

[McSpunckle]

Frankly, I'd just go with the newer ones unless the old ones just sound OMGWTF better.

If you can figure out what the power supply is doing, you can mod them to take DC power supplies. But if they're using the AC to run bipolar, you'd end up needing either two power supplies, or using a bipolar dc-dc converter (which can be way cheap/easy if if you don't need much power).

I assume this is the right schematic for the electric mistress:

http://www.generalguitargadgets.com/dia ... mistsc.gif

It's not bipolar, so if you just connect a 15V adapter after the regulator, you'd be good.

[Scruffie]

Charge Pumps will be okay for a large quantity off old EHX effects, even the Bipolar voltage ones (An LT1054 can put out +/-9/V18V/24V etc.) and are fairly simple to build ($5 worth of parts? and 8 or something components off the top of my head) and allow you to run off 9V.

But some of the larger effects might draw more current than a charge pump can put out so you might need two.

Also if clocks are involved (Memory Man, Mistress) you'll have to be careful of wiring and proximity to avoid heterodyning from the charge pump.

But it can be done... I helped someone on here mod there Deluxe Big Muff (+/-5V) to run off a standard boss supply in the past.

Or yes you can just remove the transformer and use higher voltage power supplies if it runs off +V

Be warned about the regulators in old EHX effects though... they regularly used NE5554s which die a bit if you aint careful... or even if you are, they can be replaced with modern regulators but then you're really cutting in to things.

[eatyourguitar]

they regularly used NE5554s which die a bit if you aint careful... or even if you are, they can be replaced with modern regulators but then you're really cutting in to things.

is that anything like the new 555 timer charge pumps? those are cheap and available but its not my first choice as a charge pump. I could probably do the job if anyone is in the USA. shipping to and from australia is too expensive for a heavy pedal with a transformer and a cord.

[Scruffie]

they regularly used NE5554s which die a bit if you aint careful... or even if you are, they can be replaced with modern regulators but then you're really cutting in to things.

is that anything like the new 555 timer charge pumps? those are cheap and available but its not my first choice as a charge pump. I could probably do the job if anyone is in the USA. shipping to and from australia is too expensive for a heavy pedal with a transformer and a cord.

Nothing at all like it, out of production Regulator chip, not a charge pump or timer IC as it were.

[tuffteef]

i pretty much understood close to nil but one could lets say build a charge pump in a box to power some of these ?

[eatyourguitar]

this discussion relates to the charge pump being inside and you just remove the transformer and power cord permanently. after that you can use a 9v or 18v with a high enough milli-amp rating. depends on what the builder or the customer wants and what the pedal needs to run. you can source your own power brick from thrift stores or dumpster diving but you have to build the charge pump around the pedal and the power supply you found.