Craig Anderton super tone control / Need a RC4136 and advise on this schematic

Started by John Lyons, June 01, 2006, 05:11:06 PM

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John Lyons

Building the Craig anderton Super tone control here.
Where does point "M" connect to???



I ordered a "compatible chip" but it's not the same pin out. Anyone have a RC4136 I can buy from ya! Please!

Thanks

John


Basic Audio Pedals
www.basicaudio.net/

MartyMart

"M" goes nowhere and is not mentioned as part of any mod in his book.
I guess that it could be used to "patch in" another effect/controller ? He does
that with several other projects :D
I'm 99.99% sure that you can just ignore it.

Just use a pair of NE5532's or similar dual opamps, to replace the "odd" quad.
Follow the schem as normal and replace with the pair of duals, I did this with a
few of these older projects and it works fine.

MM
"Success is the ability to go from one failure to another with no loss of enthusiasm"
My Website www.martinlister.com

John Lyons

The "M" coonection isn't mentioned in the book as Marty said. I was thinking it may be for an envelope control from the book as a few of the other projects have mods in this area...but this isn't the case.

I have a PCB all wired and ready to go so I don't want to rebuilt this thing with 2 dual opamps. I guess I'll have to just bite the bullet and order the correct part, $3.75 each too! Oh well.

Thanks MartyMart

John

Basic Audio Pedals
www.basicaudio.net/

Dan N

I may have a house numbered one from an organ around here somewhere. If you have not ordered yet, send me a PM and I'll have a look.

Nasse

IC 1D is just an inverting summing stage, a mixer circuit, you can add inputs if you need or want, the input M can be ignored if ot needed for anything

there is some info in geofex, search for dead bug assembly method or something, about adapting different pinout ic´s

Wonder if anybody have done a vero layout with easily available opamps for this. Can´t remember if TLO7X could be used with this circuit or not
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John Lyons

Thanks dan...but I just ordered a couple. I appreciate the offer though.
Nothing like paying more for shipping than the parts....

John



Basic Audio Pedals
www.basicaudio.net/

Mark Hammer

As noted, and confirmed here, "M" is not for the envelope control, but is simply a point on the summing bus.  If a person wanted to have some bass boost added to the normal signal, then the normal unfiltered signal would go from a buffer, before the main input, to M, perhaps through a pot.  As a filter, this circuit (Super Tone Control) aims to eliminate content above (if lowpass), below (if highpass), or around (if bandpass) the centre/cutoff frequency.  If you wanted to have all the content, but just a bit more bass, then you'd combine straight signal at point M, with some of the lowpass filter signal from point F.  The various kinds of shelving and parametric EQ functions can all be mimicked by combining  different filter outputs and straight signal.  You may also note that this circuit is what is called a state-variable filter, and SVFs are the heart and soul of just about ALL high end parametric EQ sections.  So, point M basically offers the option to use the STC like one.

As for chips, the RC4136/XR4136/LM4136 was simply a convenient low-noise quad package at the time, and could easily be subbed with a pair of duals.  The noise specs on a 5532 are likely as good if not better than a 4136 anyways.  The 41/36 won't disappoint, but at this point in op-amp history has no special redeeming features other than fitting the pinout of a PCB.  Note that the 4136 does NOT have the same pinout as more commonly found quad packages like the TL064/74/84, the LM324, and numerous others.  Once upon a time, there WAS a chip called the TL075, which was a TL074 with 4136 pinouts, but I suspect it has long since joined the Dodo bird.

Noplasticrobots

Points H and M are also confusing. Where are these leading to? The outputs of the first dual op-amp?
I love the smell of solder in the morning.

Mark Hammer

Yes.  The inputs to the dual-ganged frequency control pot each go to the output pins of the preceding op-amp stage (pins 10 and 12).

John Lyons

Sorry about that! the schematic posted above was my partial "drawing board" for adding a rotary switch to select between a foot controled frequency and a manual knob on the unit itself... The Points H and B connect to the line just above, outs 10 and 12. I broke the line to draw in a switch and my pencil marks didn't show up... My fault!

M is connected to nothing, ignore it.

John



Basic Audio Pedals
www.basicaudio.net/

redeffect

Mouser catalog page 295. RC4136N / DIP14 /  $1.20. Mouser part # 595-RC4136N. Hope this helps.
red

jrc4558

http://www.geofex.com/Article_Folders/protostyles/proto_styles.htm
Read this, especially Dead Bug and Hanging Garden for inspiring ideas on how to interface chips with different pinouts! :)