Flanger VCOs?

[Scruffie]

I've looked in to this a fair amount, but I can't really find the info I want with the search or google.

In the A/DA there's the 4007, the Mistress has a 311 with a current source, and the MXR M-117 has... some transistors doing something.

But I can't really tell what they're doing, are they just amplifying the LFO output current to get a thicker/wider sweep? I've tried just an LFO hooked straight to a 4047/4049 clock & buffer set up before and it's clear, that LFO to Clock connection section is important to get a great flanger sound.

The other thing i've wanted to know is what is the smallest one out there, regards PCB space, which is mainly where this question comes from. I've been wanting to cram a flanger with a nice big sweep in to a 1590B with a battery and that little bit of extra circuitry always takes it too far when the buffer is in there. The A/DA seems to just be using a N & P MOSFET pair inside the 4007, I can't find a schematic of the 4007 chip internals though. I don't need it to be perfect but if I could simplify it down.

Schematics for the flangers mentioned.
http://thmq.mysteria.cz/em3207/big/EM3207_v1.1_schematic_1280.gif

http://moosapotamus.net/images/FlangerClone_SCH_rev5_MN3007_jan2010.gif

http://i82.photobucket.com/albums/j279/bainzy007/flangerm117_12.jpg

[Lurco]

Datasheets are always useful http://www.onsemi.com/pub_link/Collateral/MC14007UB-D.PDF . A good source is Mouser. http://de.mouser.com/Search/Refine.aspx?Keyword=cd4007. For your convenience the part no./keyword has already been filled in by me. Click on the magic word (Data Sheet) under that tiny "Acrobat Reader" logo there. Wow!: http://www.mouser.com/ds/2/405/schs018c-127328.pdf

[Scruffie]

Datasheets are always useful http://www.onsemi.com/pub_link/Collateral/MC14007UB-D.PDF . A good source is Mouser. http://de.mouser.com/Search/Refine.aspx?Keyword=cd4007. For your convenience the part no./keyword has already been filled in by me. Click on the magic word (Data Sheet) under that tiny "Acrobat Reader" logo there. Wow!: http://www.mouser.com/ds/2/405/schs018c-127328.pdf

I've looked at datasheets, it doesn't quiteee explain what i'm after though as I don't fully understand what's going on.

Information directly related to flangers would be helpful so that the datasheets do make sense.

[Mark Hammer]

In some of these instances, I imagine that part of what the additional components are doing is some sort of linear to exponential conversion.  Keep in mind that there is likely more than one way to turn a simple triangle wave into something that produces a more dramatic sweep on the downward turnaround.

Of course, if youask me how the additional components do that, I will look atmy non-existent watch and mention a very imortant meeting I have to attend.

[Scruffie]

In some of these instances, I imagine that part of what the additional components are doing is some sort of linear to exponential conversion.  Keep in mind that there is likely more than one way to turn a simple triangle wave into something that produces a more dramatic sweep on the downward turnaround.

Of course, if youask me how the additional components do that, I will look atmy non-existent watch and mention a very imortant meeting I have to attend.

that makes me feel slightly better that you're unsure too, learned a lot from your modulation posts.

So yeah, the only bit i'd like to know about is basically, on the A/DA Schematic, R65 to and including IC5 and the same sections on the other flangers.

[Fender3D]

...So yeah, the only bit i'd like to know about is basically, on the A/DA Schematic, R65 to and including IC5 and the same sections on the other flangers.

well that's pretty easy...

4007 works using MOSFETs as variable resistors, just like in EH clone theory whereas you have a JFET...
IC3c simply adjusts LFO voltage:
with T5 you set the LFO max AND min voltage by setting IC3c gain,
with T4 you set the center point where the above voltage spans from

After few fast breadboard checkings, 4047+4007 has the widest clock range, followed by 4047+JFET.
With JFETs you'd better try different candidates though...  

If you want to predict HOW your LFO interacts with VCO, well that's far harder....