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Boss - AW-2 Auto Wah  [schematic]

Posted: 25 Oct 2007, 13:19
by modman
After having so much fun and little trouble playing with my DS-1, I had to turn to a dusty but near mint Autowah I have had for long time but never used.

My google kung fu failed me -- I couldn't find a schematic for this one, only for its predecessor the TW-1.

I know you can get it for $5 from ronsound.com -- but then again he doesn't even guarantee it to be complete
:shock:

Might just start replacing the caps, but I'm not sure it will do away with the ultra shrill piercing sound it has. It uses just an ordinary transformer coil. But a decent one will cost me half the value of this box.


I might put this one in the Pimp-my-Cheapo folder once I find anything to pimp.

Re: Boss AW-2 Autowah

Posted: 25 Oct 2007, 14:43
by MoreCowbell
modman wrote: Might just start replacing the caps, but I'm not sure it will do away with the ultra shrill piercing sound it has. .
You mean you don't consider the "ultra shrill piercing sound" a feature ?

:D

Re: Boss AW-2 Autowah

Posted: 18 Oct 2008, 11:08
by modman
MoreCowbell wrote:
modman wrote: Might just start replacing the caps, but I'm not sure it will do away with the ultra shrill piercing sound it has. .
You mean you don't consider the "ultra shrill piercing sound" a feature ?
:D
Until a native speaker reminded me of the difference! :D If not describing physical aspects, 'feature' has a positive connotation. Ok!

But I'm still looking for the AW-2 schematic

saw # 12737050 at http://www.rangeraudio.com but the request quote form errors on me...

Re: Boss - AW-2 ( Autowah Auto Wah )

Posted: 15 Aug 2009, 14:48
by willp
Hi All

I did some mods to my AW-2 and found that the state variable bandpassfilter is identical to the one in the TW-1. The AW-2 is just a TW-1 with a LFO mixed in to the envelope detector output. Although I did not do a complete schematic, you can find notes, a table with TW-1 vs. AW-2 components (selected ones) and other information at the blog I put up to document it:

http://autowahmods.blogspot.com/

Other mod-blogs include the unholy marriage of TubeScremer and Tube:

Tubescreamer + 12AX7 = Screamer Tube: http://screamertube.blogspot.com/

Boss CH-1 SuperChorus: http://superchorusmods.blogspot.com/
Boss PH-2 SuperPhaser: http://superphasermods.blogspot.com/
Ibanez TS-9 TubeScreamer (been done to death, but these are my 3 favorite mods): http://tubescreamermods.blogspot.com/
Roland MicroCube RX Amp Mods: http://microcuberxmods.blogspot.com/

For the record - I am in the business of education at the college level.

Will P.

Re: Boss - AW-2 ( Autowah Auto Wah )

Posted: 07 Sep 2009, 23:08
by laminategorilla
Not to be rude, but the TW-1 and the AW-2 are considerably different. For starters the Aw-2 has two more potentiometers and three more dual opamp chips, not to mention the extra components that accompany those opamps. They do share some similarities in their circuit structuring, at places, but even that is with value differences in a few of the components. I was actually able to dig around and find the original Boss schematics for the AW-2. It is at:

http://www.eserviceinfo.com/downloadsm/ ... s_AW2.html

Don't click on the link that says "preview AW2" you get a real crappy looking image.
Instead scroll down and click where it says "Download >> To download the file, please, click here! << Download"

I'm actually waiting on a DS-1 I ordered off the Bay that I'm going to modify, that's what has gotten me interested in modding the AW-2 again. It
took way too long for me to find schematics for this thing. I'm going to change out a few of these less efficient opamps for better ones. I was pretty impressed with the mitsubishi opamp (M5218L) in the filter section, when I looked up the specs 110dB Gain(vo) and only 0.0015% THD. I'm probably going to double stack two OPA2134PA's in it's place, since they're probably one of the few chips I'd notice much of a difference right there. Of course, there will have to be some cap/resistor changes too, at least to better quality, if not to change values any. I've been looking into true bypass switching for my boss pedals as well. Whoever said you should be happy with what you get obviously wasn't an engineer/modder/jury-rigger of any type. Good luck to everyone who is trying to make this little gem of a pedal shine a little brighter.

Best of luck,
lami