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DIY Stompboxes => Building your own stompbox => Topic started by: jdub on March 21, 2012, 09:29:05 AM

Title: DOD FX70 stereo flanger schematic?
Post by: jdub on March 21, 2012, 09:29:05 AM
Anyone know where to find one?  Google and forum searches turned up nada.  This is the older one, not sure how similar to the later FX75, 75B, etc.- MN3007 with 3101 driver. Thanks!
Title: Re: DOD FX70 stereo flanger schematic?
Post by: Mark Hammer on March 21, 2012, 10:00:33 AM
Google image searches are often successful.  A quick search brought me this info: http://www.americaspedal.net/fx70/
Title: Re: DOD FX70 stereo flanger schematic?
Post by: Fender3D on March 21, 2012, 10:16:48 AM
lol
it's hard to believe a 3007+3101 @ 0.5ms
Title: Re: DOD FX70 stereo flanger schematic?
Post by: jdub on March 21, 2012, 10:17:27 AM
Thanks, Mark- I did an image search (usually how I search for schems) and found that page, but there is no schem there for the FX70, just a component-side gutshot.  That same site does have a schematic for the FX75, but I'm not sure how similar the two circuits are (an obvious difference being the width control on the FX75).  Appreciate the reply all the same, though.  :)
Title: Re: DOD FX70 stereo flanger schematic?
Post by: jdub on March 21, 2012, 10:20:28 AM
Quotelol
it's hard to believe a 3007+3101 @ 0.5ms

You ain't kiddin'... :D

Title: Re: DOD FX70 stereo flanger schematic?
Post by: Govmnt_Lacky on March 21, 2012, 10:41:56 AM
If I were to be a bettin' man.....

FX75 = FX70 with "dropped in" WIDTH control + splitting of the original stereo output jack into (2) mono jacks.
Title: Re: DOD FX70 stereo flanger schematic?
Post by: jdub on March 21, 2012, 10:55:15 AM
Could be, could be... I 'spose I could just trace & compare with the FX75 schem...but finding time to do it is tough these days
Title: Re: DOD FX70 stereo flanger schematic?
Post by: Govmnt_Lacky on March 21, 2012, 10:57:48 AM
Quote from: jdub on March 21, 2012, 10:55:15 AM
Could be, could be... I 'spose I could just trace & compare with the FX75 schem...but finding time to do it is tough these days

John,

I HIGHLY doubt that DOD re-invented the wheel.

I would focus on the width portion of the schematic and see how they "added" it into the original FX70 circuit.

As for the outputs. Dollars-to-donuts that they just seperated the stereo jack into dual mono jacks  ;)

By the way.... Is there a problem with the pedal? Why the interest?
Title: Re: DOD FX70 stereo flanger schematic?
Post by: jdub on March 21, 2012, 11:38:50 AM
Nothing major- a buddy just gave me one the other day and I wanted analyze the circuit, and having the schem just makes it quicker.  It's missing the switching footplate, but I have an old DOD carcass that I can get that from, no biggie.  Needs a cleaning, too- looks to be from around '83, with all the accumulated gig-crud one would expect from a pedal of that age.  But really, I'm just curious.  If I can't find a schem, I can always trace & post for the interest of other flange-heads when I get a little time.  Apparently it's not a very in-demand or highly-rated unit, but what the heck... ;D
Title: Re: DOD FX70 stereo flanger schematic?
Post by: Mark Hammer on March 21, 2012, 02:58:38 PM
Quote from: Fender3D on March 21, 2012, 10:16:48 AM
lol
it's hard to believe a 3007+3101 @ 0.5ms
You CAN get 500usec from a 3007 +3101, but it won't necessarily be a pretty 500usec.  Happily, the remainder of the sweep will be well within the range where the chipset will produce pleasing delay with minimal artifact.