Boss pedals from ACA to PSA

Started by KarbonHed, August 01, 2004, 02:03:03 PM

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KarbonHed

I've got a MIJ Boss FT-2 that needs an ASA power adaptor, it works fine off a normal power supply but the indicator doesn't light.

What's the simple fix to convert it to PSA friendly?

RickL

At the risk of seeming overly simplistic, does the LED work when you use a battery? If not, maybe it's just burned out. I've used PSA adaptors when ASA were called for and the LED has always worked.

RDV

I've used a PSA with a pedal designed for an ACA and the LED did work, but very dimly. A suggestion would be to just use any generic 9v wall wart(making sure it has the right polarity of course) for your Boss pedal that requires an ACA, cause that's what an ACA is. It's just a unregulated 9v supply.

RDV

travissk

There is a site that explains the differences, but I believe you can use a PSA instead of an ACA. The downside is that there is a reduced voltage across the LED, so it's not as bright as it would be using an ACA.

Ah yes, here's the site:
http://members01.chello.se/pastorn/fx/mods/bossadapt.htm

There is a summary at the bottom that is helpful.

Kent S.

Quote from: travisskThere is a site that explains the differences, but I believe you can use a PSA instead of an ACA. The downside is that there is a reduced voltage across the LED, so it's not as bright as it would be using an ACA.

Ah yes, here's the site:
http://members01.chello.se/pastorn/fx/mods/bossadapt.htm

There is a summary at the bottom that is helpful.

I know that besides the PSA being regulated (and better filtering ... that's subjective though ... more like what I've heard ... it would make sence though as they are used with a lot of digital pedals) the ACA puts out 9V up to 300mA draw. The PSA puts out 9.6V but only up to 200mA draw. If that helps any.

RDV

If U measure a ACA-120, that thing puts out about 13v, give or take a few tenths.



RDV

Wailin

The ACA pedals have a small resistor (100-470 ohms) and a diode between the 9v dc plug ground and the ring of the input jack. When using these pedals with a PSA adaptor,  I always short these two out.

Check this schematic:
http://www.generalguitargadgets.com/v2/boss/BossCE-2.gif
It is R53 and D5

and this one:
http://www.generalguitargadgets.com/v2/boss/BossDM-2v1.gif
Its is R2 and D1

jplaudio

Quote from: KarbonHedI've got a MIJ Boss FT-2 that needs an ASA power adaptor, it works fine off a normal power supply but the indicator doesn't light.

What's the simple fix to convert it to PSA friendly?

The simple fix is to disconnect the blue wire from the DC power jack from  the board end and reconnect to the pad connected to the ring terminal of the input jack. Leave the components on the board in case you want to restore it.

KarbonHed

Thanks for the replys.

jplaudio's suggestion was indeed the easiest fix.

The daisy chain thing mentioned here - http://members01.chello.se/pastorn/fx/mods/bossadapt.htm - worked too, peculiar set up..

But problem fixed and easily reversible if the pedal ever has to go back on ebay to pay for something else :wink:

Kent S.

Quote from: RDVIf U measure a ACA-120, that thing puts out about 13v, give or take a few tenths.



RDV

I only have one ACA-120, it's an old one and it measues 9.12... V with exactly 120VAC ... so what gives?