CD4049 info

[aron]

Cool that people are "rediscovering" the CD4049. We did a lot of work with this chip and one of my all-time favorite pedals is Frank Clarke's Hot Harmonics.

Here is a schematic:

http://web.archive.org/web/20010618211121/members.home.net/fclarke/fx/hotharm3.gif

From the old rusty Schematics link above, here is the pinout:

http://www.diystompboxes.com/pedals/CD4049.gif

Info from Jack and GFR!

http://www.diystompboxes.com/pedals/jo4049.html

[The Tone God]

There was also a FX-X theme that involved using digital ICs in linear mode that produced some really interesting circuits that people may enjoy.

Andrew

[Mark Hammer]

Don't forget the 4069 and the 7404.  Laney uses the 4069 quite a bit for their overdrive, and I've seen a couple of Japanese schems using the 7404 as a "digital distortion" (really, it's just another hex invertor).

[johngreene]

http://nutsvolts.com/~downloads/fetjul.pdf

--john

[puretube]

Don't forget the 4069 and the 7404.  Laney uses the 4069 quite a bit for their overdrive, and I've seen a couple of Japanese schems using the 7404 as a "digital distortion" (really, it's just another hex invertor).

74HCU04 !

[aron]

Great link John!!!!!

[oldrocker]

I really like the CD4049 chip.  I have a few more and was looking to build a Hot Harm and the Fourtyniner.  Some builds I like is the Mr. Eq (ROG) and the Red Llama.  And I used in the J.Hollis Ultra Flanger.  I was also thinking of building the UBE Screamer and the Double D too.  I'm always looking for new effects to use one.

[markm]

Here's a real good sounding 4069 circuit;

http://aronnelson.com/gallery/album76/CMOS_Boost_LAYOUT

[danngreen]

Here's one where the 4049 turns a guitar signal into a square wave so it can be fed into digital chips (4024 counter in this case)
http://www.commonsound.com/nocto/pcb1.2/schematic.pdf

[9 volts]

I've built quite a few of the pedals that use this chip and really like the sound. I've a basic question about the chip. It's digital, I'm a sucker for analogue, why does this digital chip sound so good? I mean alot of digital multi effects have really crappy distortion sounds. But this one has some soul. Is it just a good example of a chip being used in a well designed circuit? (hot harmonics, Lama etc)

[gez]

I've a basic question about the chip. It's digital, I'm a sucker for analogue, why does this digital chip sound so good?

It's not digital.  It's a logic chip that, by a quirk of its construction, can be biased to work as a 'linear' amplifier: pure analogue.  It sounds so good because it's poor at doing its job as an amp, and you get soft-clipping as the output approaches each rail (similar to - though not the same as - tube distortion).

There are a handful of other chips that can be used in the same way.  For example: 4001UB, 4011UB, 4069UB, 4007 and even 4016 switches (though they require a little extra circuitry).

[MartyMart]

Gez, love your picture mate, looks like "The Bard" himself has dropped by.....350 years late !! 

[gez]

Forsooth, ye takes the piss Marty! 

[MartyMart]

Thou shalt not taketh offence, for it is herewith declared as not my intent !! 

[gez]

Is this a dagger which I see before me?  Or art thou just pleased to see me??

[9 volts]

Thanks Gez

[antojado]

I recently built a Llama clone and that has been very helpful in learning (just scratching the surface!) about circuits utilizing IC's. One of the questions I've had, and I see some of it answered here, is that when I browse the list of various IC's like the 4000 series I see quite a few chips that are listed as 'hex inverters' or 'non-inverting.' Are all of these chips usable in overdrive circuits? If not, how do you determine which ones are?

I also read something a while back (by RG Keen I believe) that said the chip need to be unbuffered (U) for a fuzz type of circuit like the Llama. Does that mean the buffered chips can't be used or just that it will be very different sounding?

Thanks for the info!

[gez]

when I browse the list of various IC's like the 4000 series I see quite a few chips that are listed as 'hex inverters' or 'non-inverting.' Are all of these chips usable in overdrive circuits? If not, how do you determine which ones are?

Only inverting chips work: 'non-inverting' will oscillate.  Explanation from yours truly and I also quoted RG:

http://www.diystompboxes.com/smfforum/index.php?topic=17114.0

To determine what chips will work, you need to check their data sheet for the schematic and have a little think.  I listed some of the ones that work above.  'Buffered' chips are prone to oscillation as they're multi-stage and gain is higher.  I have used them as low-gain amplifiers, but current consumption is ridiculous (buffered inverter = 3 inverters in series = 3 X normal current consumption).

[gez]

PS  Not a serious circuit, but might be of interest:

http://www.diystompboxes.com/smfforum/index.php?topic=49860.msg380639#msg380639

Scroll down for 'Croctavia'

[jmusser]

A couple circuits and can't say enough about are the 4049 based 3 Legged Dog on Run off Groove, and Tim Escobedo's CMOS Drive that uses the 74HCU04. Both Pedals make my SS Crate amp sing!