MXR Micro Chorus?

[Fret Wire]

Has anyone ever tried one? It gets good reviews. Now it seems to have cult ($) status. They always bring a big buck on ebay. Funny, I always liked MXR stuff, but back when they were in production, I wasn't into chorus or flanging. Now, it peaks my curiousity. With just a rate control, how does it stack up against a Boss CE-2 for instance.

Has anyone ever seen a schematic? Might make a nice build. Or maybe it's better attributes could be melded into the CE-2 for something unique. I've never tried the Micro Flanger either.

http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=3708496199&ssPageName=ADME:B:SS:US:1

http://www.harmony-central.com/Effects/Data/MXR/Micro_Chorus-01.html

[Mark Hammer]

I've never tried one or knowingly heard one, but the fact is that it is possible to make a one-knobber modulation pedal that sounds fine throughout its LFO range, even though it may lack the flexibility of a 2 or 3-knobber.  This is true of the Small Stone, Small Clone, and Phase45/90, and countless others of less notoriety.

Even when they have the same number of functions/controls, and ostensibly the same core technology, there is no guarantee they will sound the same.  I have an MN3007-based Zombie chorus with speed, sweep width, effect intensity (mix), and a mode switch.  I also have a Washburn SC-7 chorus that I stuck an MN3207 into.  It too has a rate, width, and effect mix control in addition to a "mode" switch I installed as a mod.  They don't sound at all alike because the sweep ranges they have are not identical.

The Micro-Chorus probably uses an SAD512D, I would imagine.  I say "I imagine" because the Commande series used this chip for short-delay devices, and because it was the most convenient way of producing short delay at that time (the 512D only needs a single clock signal and does the dividing on-board) .  This is a handy chip but it does not automatically "sound better" than other chips of the era.  Chances are that the chip will be set to a one-size-fits-all delay range and the variation in sweep rate will be narrow enough (i.e., nothing nearly as slow as what you might find in a flanger) that it is easy to peg a single sweep-width setting that will sound decent at both the fastest and slowest sweep rates.  To the best of my knowledge, there are no one-knobbers in this category of effect that use any sort of dual-ganged pot or other method to compensate sweep width with changes to sweep rate.

[Fret Wire]

Thanks Mark. I didn't even think of the phase 45/90 type pedals. I just blindly assumed that a chorus needed at least a rate and depth control to sound good. Same with their Mirco Flanger. I've never heard one, but just figured it was too simple to offer anything useful.

[Mark Hammer]

Chorusses produce the effect they do by sampling out faster or slower than they sampled in to produce a pitch shifting effect.  Because of how our ears work, when the rate at which the pitch change slows down, we can tolerate wider deviations in pitch without noticing it.  Conversely, as the rate of pitch change picks up, ALL we seem to be able to notice is the wobbliness of the pitch-shifting.  Consequently, most chorusses have a depth control to adjust the sweep width for what is tolerable at different speeds.  I suppose you could consider it a control, but really and truly it is a compensation adjustment that ended up on the chassis instead of on the PCB.

In general, the bigger the change in speed, the greater the need to alter the width from where it currently is.  If you pick your speed range appropriately, you should be able to find a width setting that is acceptable throughout the full range of speeds available.  That's how all the one-knobbers work.

The need to adjust wobbliness is also a function of the approach to chorus generation used.  Devices which use what is called multi-phase chorussing (2 or more BBDs used in a complementary way) tend not to have such wobbliness, partly because they do things in a way which produces rich chorus without needing to generate obvious pitch changes.  One of the nicest chorusses there is out there, the Boss Dimension C, lacks both a rate and depth control, having only 4 buttons and presets.  It uses a pair of BBDs that operate complementary to each other so that each is always at the opposite end of the delay swing to the other.  As a result, you don't hear the back and forth movement nearly as much.  The 4 button settings produce combinations of two preset speeds and widths, and that's it.  Try one and you'll find yourself totally disinterested in having any knobs to twiddle.

[Fret Wire]

Thanks Mark for taking the time to explain that. That was a much better answer than the simple one I was originally looking for! Now I have some understanding into the how's and why's on the subject. I can always get a schematic, but I can't always get an explanation like that.

Thanks again Mark.

Pete

[jubjub]

I had the MXR chorus with two speed controls that were switchable. It was great. Don't know how this would sound compared to it but that one was fantastic. I now use the old roland chorus ensamble. That's just got one control. It's instant Andy Summers. Big as a concrete block and just as sexy.