Does anyone know of a schematic or layout of a pedal equal to just the doubler part of an MXR Flanger/Doubler?
Doubling or what some refer to as "ADT" (Automatic double tracking) is essentially what a chorus does, except bumped over more in terms of delay range. So, where a chorus might sweep from 2-15msec, an ADT unit might sweep from 8-30msec, or something like that. It is the more pronounced time-stagger that creates the impression of one person reacting to what another has done (which is what happens when you double-track, right?).
So, if you wanted to experiment, a good place to start would be to increase the value of the clock cap on a chorus pedal so that the delay range used is bumped over.
Is that enough? Not at all. The longer the delay time, the more lkely that changes in delay time will produce drastic pitch wobble. Stated another way, much less of the sweep-width range control will be usable if the overall delay range is nudged over to longer times. As well, reducing the HF clock speed to produce longer delay times out of the same BBD can have the side-effect of producing much more audible clock noise. That, in turn, demands that the filtering be adjusted to have a lower rolloff point. One way around that is to use a higher-capacity (more stages) BBD, and run that at a high enough speed; something like what MXR did for the doubler section of the unit you inquired about.
Coolaudio makes an 8-pin version of the 3208 2048-stage BBD (http://www.coolaudio.com/products.html), which is pin-for-pin compatible with the MN3207 used in so many chorus pedals. Pop the MN3207 out and stick a V3208D in, and you've doubled the delay time without having to do any additional changes. Could be worth trying out.
Quote from: Mark Hammer on April 01, 2010, 11:16:16 AM
Doubling or what some refer to as "ADT" (Automatic double tracking) is essentially what a chorus does, except bumped over more in terms of delay range. So, where a chorus might sweep from 2-15msec, an ADT unit might sweep from 8-30msec, or something like that. It is the more pronounced time-stagger that creates the impression of one person reacting to what another has done (which is what happens when you double-track, right?).
So, if you wanted to experiment, a good place to start would be to increase the value of the clock cap on a chorus pedal so that the delay range used is bumped over.
Is that enough? Not at all. The longer the delay time, the more lkely that changes in delay time will produce drastic pitch wobble. Stated another way, much less of the sweep-width range control will be usable if the overall delay range is nudged over to longer times. As well, reducing the HF clock speed to produce longer delay times out of the same BBD can have the side-effect of producing much more audible clock noise. That, in turn, demands that the filtering be adjusted to have a lower rolloff point. One way around that is to use a higher-capacity (more stages) BBD, and run that at a high enough speed; something like what MXR did for the doubler section of the unit you inquired about.
Coolaudio makes an 8-pin version of the 3208 2048-stage BBD (http://www.coolaudio.com/products.html), which is pin-for-pin compatible with the MN3207 used in so many chorus pedals. Pop the MN3207 out and stick a V3208D in, and you've doubled the delay time without having to do any additional changes. Could be worth trying out.
So there is no current pedal or DIY layout that does this doubling effect?
Anything that is capable of generating delays in the slapback range, and also has modulation capabilities, will do what you want. I don't follow the current stuff that closely to name you a product.
I neglected to ask you: Was it something about the MXR unit specifically that you wanted to duplicate, or did you simply want something in that family of effects?
You know, an idea popped in my head that kind of mish-mashed the clarinot with a chorus, and is related to this.
This stems from the idea that no LFO-based (even a slow one) modulation could very closely mimic another player doubling a guitar part.
But...why not, in addition to a slow-LFO pitch wobble, build in a fairly insensitive envelope control? The harder you hit the note, the more the pitch will bend. You could make it really subtle, I think, and it would make for some interesting variation. Plus, if you built it to have a lot of ripple, it might actually benefit the situation here.
Just a thought :)
Quote from: Mark Hammer on April 01, 2010, 08:54:07 PM
Anything that is capable of generating delays in the slapback range, and also has modulation capabilities, will do what you want. I don't follow the current stuff that closely to name you a product.
I neglected to ask you: Was it something about the MXR unit specifically that you wanted to duplicate, or did you simply want something in that family of effects?
I would like to duplicate the doubling of that effect as a pedal.
I've been wanting to do a whole MXR Flanger/Doubler, but the obsolete Reticon chip is a stumbling block. The flanger sounds pretty sweet as well.
I've tried reproducing what the doubler does inside my DAW using a delay, but it just wasn't the same. I e-mailed MXR a few months back to see if they had any NOS chips which they do not.
You could look at the Magnus Modulus which is like a Rebote delay with modulation capabilities. At very short delay lengths and with subtle LFO settings, it sounds close to a doubler.
That's the closest I came to a doubler with a DIY pedal.
cheers
The Echo Base (http://www.diystompboxes.com/smfforum/index.php?topic=60662.0) will also do slapback with modulation.
Quote from: therecordingart on April 02, 2010, 02:53:55 PM
I've been wanting to do a whole MXR Flanger/Doubler, but the obsolete Reticon chip is a stumbling block. The flanger sounds pretty sweet as well.
If we've been able to make alternate versions of the A/DA Flanger collectively without the MN3010, then surely we should be able to accomplish this with one of the BBD chips currently in production.
Believe it or not, I have no idea what BBD is used in the MXR unit. One is clearly an SAD1024 but what the heck is that 22-pin monstrosity?
does anyone know where you can buy small quantities of the cool audio chips?
Quote from: Mark Hammer on April 02, 2010, 03:47:55 PM
Quote from: therecordingart on April 02, 2010, 02:53:55 PM
I've been wanting to do a whole MXR Flanger/Doubler, but the obsolete Reticon chip is a stumbling block. The flanger sounds pretty sweet as well.
If we've been able to make alternate versions of the A/DA Flanger collectively without the MN3010, then surely we should be able to accomplish this with one of the BBD chips currently in production.
Believe it or not, I have no idea what BBD is used in the MXR unit. One is clearly an SAD1024 but what the heck is that 22-pin monstrosity?
Not sure. I was talking about the Reticon chip.
I thought I read somewhere that the MXR used the Reticon chip, which is no longer made. Some have said to use a short delay to get that effect but it doesn't sound right( with my delays anyway). I tried an original Flanger/Doubler a few years ago and should have bought it.
Finallly found a better quality picture. It is a Reticon R5101.
Even found a thread for it here: http://www.diystompboxes.com/smfforum/index.php?topic=42710.0;prev_next=prev