DIYstompboxes.com

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

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

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).

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

--john

Quote from: Mark Hammer on July 11, 2007, 04:05:48 PM
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 !

Great link John!!!!!

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.

Here's a real good sounding 4069 circuit;

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

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 (http://www.commonsound.com/nocto/pcb1.2/schematic.pdf)

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)

Quote from: 9 volts on July 14, 2007, 04:31:54 AMI'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).

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

Forsooth, ye takes the piss Marty!  :icon_razz:

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

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

Thanks Gez

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!

Quote from: antojado on July 14, 2007, 02:49:35 PMwhen 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).

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'

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!