Author Topic: 3207 MXR Micro Chorus  (Read 4425 times)

Scruffie

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3207 MXR Micro Chorus
« on: January 23, 2012, 05:39:16 AM »
Here's one that doesn't get much mention unless it's 'My SAD512D Broke'.

Pretty awesome little box with a nice cheap and simple design, pure 80s hair metal sound but... I wont claim that's not influencing me wanting one.

If it could fit a 1590B with space for a battery (yes, I still use them on occasion) with the usual onboard pot and no stand up or 1/8W resistors that'd be awesome... if you think your up for the challenge that is Brian  :P

Working it for the 3207 is pretty simple, and the build uses no special parts other than the BBD, I wouldn't even use the voltage limiting trick here as the V.Ref & Bias share the same path so it would limit headroom.

I might mod it to use a TL072 instead of a TL071 for the LFO and use the other half to buffer the V.Ref just for the sake of it to save half an Op-Amp going to waste with no extra parts needed.
Works at Lectric-FX

Mich P

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Re: 3207 MXR Micro Chorus
« Reply #1 on: January 23, 2012, 07:30:22 AM »
Here a DIMEBUGG version from his blog a 3007 version :
http://rapidriotboxes.blogspot.com/2011/01/mxr-micro-chorus-mn3007-retrofit.html
Mich P.

Scruffie

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Re: 3207 MXR Micro Chorus
« Reply #2 on: January 23, 2012, 07:47:01 AM »
Here a DIMEBUGG version from his blog a 3007 version :
http://rapidriotboxes.blogspot.com/2011/01/mxr-micro-chorus-mn3007-retrofit.html
Mich P.
Seen it  ;)

I'd prefer a bean board also... not very keen on that layout... or wasting a 3007 at 9V with a slightly questionable V.Ref/Bias Set up (not really questionable but not optimal). Also why has that got 2 trimmers instead of one? And it wont fit a 1590B with a battery and onboard pot properly etc.
Works at Lectric-FX

Bucksears

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Re: 3207 MXR Micro Chorus
« Reply #3 on: May 03, 2012, 02:12:17 PM »
Bumping this one - this needs to happen!
I love the sound of the Micro Chorus, but I don't like the volume issues it has (either too much or volume drop). If that issue could be resolved in a MB build, it would probably bump off my current HUGE Boss CE-20.

Scruffie

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Re: 3207 MXR Micro Chorus
« Reply #4 on: May 04, 2012, 04:24:03 AM »
Bumping this one - this needs to happen!
I love the sound of the Micro Chorus, but I don't like the volume issues it has (either too much or volume drop). If that issue could be resolved in a MB build, it would probably bump off my current HUGE Boss CE-20.
That should be a pretty easy fix on any Micro Chorus, DIY or otherwise. Unless the new ones are SMD and you don't like SMD that is.
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Bucksears

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Re: 3207 MXR Micro Chorus
« Reply #5 on: May 04, 2012, 05:54:29 AM »
That should be a pretty easy fix on any Micro Chorus, DIY or otherwise. Unless the new ones are SMD and you don't like SMD that is.

I haven't looked at the reissue Micro Chorus, but my new Micro Flanger is all SMD. I haven't tried messing with SMD yet, but it looks like a bit sensitive.
Has the schem on FSB been verified? There's a schem & PCB on the Micro Chorus thread, but the PCB is double-sided. I'd thought about designing my own PCB based on that schem, but MB's projects are more thorough.

Scruffie

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Re: 3207 MXR Micro Chorus
« Reply #6 on: May 16, 2012, 11:50:31 AM »
That should be a pretty easy fix on any Micro Chorus, DIY or otherwise. Unless the new ones are SMD and you don't like SMD that is.

I haven't looked at the reissue Micro Chorus, but my new Micro Flanger is all SMD. I haven't tried messing with SMD yet, but it looks like a bit sensitive.
Has the schem on FSB been verified? There's a schem & PCB on the Micro Chorus thread, but the PCB is double-sided. I'd thought about designing my own PCB based on that schem, but MB's projects are more thorough.
Missed this! Any chance of a gut shot of your Micro Flanger? Just interested in what's going on in there these days.

And the schematic may not have been verified but it should work from looking at it.
Works at Lectric-FX