A dual OD/Distortion using a single 4049 chip?

pott · July 11, 2007, 01:13:02 PM

Since that chip seems very popular here and has a lot of different er... stages (I don't quite know how to call that...), I'm assuming it'd be possible to make a dual pedal using a single of these opamps, such as a Red Llama OD on one side or whatever else uses it, and a boost or another OD, and stack them?

2 footswitches, one side with tone/level/gain and the other with maybe just level/tone and it could fit in a reasonably small case and be quite handy?

Has anybody made a design similar to this or even using a different opamp to the same end?

Dragonfly · July 11, 2007, 01:26:42 PM

i mentioned in the other thread that i'm currently working on a boost/od/dist/trem from a single chip

pott · July 11, 2007, 01:36:17 PM

Ooops nice hehe! I was thinking of something simpler.

Maybe a TS style with reworked EQ on one side (and option to switch the diodes out for a cleaner boost) and something like a Rat or DS1 style distortion on the other stage.

How does it work...? I noticed only output/input for each section of the opamp. Is actually straightforward to use?

puretube · July 11, 2007, 01:53:36 PM

those 6 (HEX) Inverters are not "op-amps".

pott · July 11, 2007, 01:58:09 PM

What's an inverter then... It inverts the phase of the signal?

So that means you'd need to use an odd number to get your signal back to its normal phase?

mdh · July 11, 2007, 02:13:46 PM

If I understand the original question correctly, yes, there is a design like this out there. The ROG Double D (http://runoffgroove.com/doubled.html) has two channels of distortion from a single 4049. It doesn't have tone controls, but I suppose you could graft them in.

pott · July 11, 2007, 02:23:36 PM

WOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOOW That high gain soundclip is NICE!

I love the idea actually! It's pretty much exactly what I had in mind, except they know what they're talking about :p

In a 1590BB case with bypass 3DPT along with channel switching (red and blue LEDs) and maybe a big muff tone stack that could be well fun! Thanks for the idea!

gez · July 11, 2007, 03:12:07 PM

I designed an auto fuzz-wah once using just a single chip. One half for the filter, the other half for the fuzz and envelope generator. Sounds like two cats going at it hammer and tongs...

Unfortunately, I don't have a schematic for it (and I'm not tracing the thing). Just thought I'd point out what you can do with these chips.

The Tone God · July 11, 2007, 03:19:53 PM

Check out the FX-X Entry Archive. We had a theme that involved using digital ICs in linear mode. Many interesting entries were made that shows off some of the fun you can have with these parts.

Andrew

pott · July 11, 2007, 05:46:45 PM

Alright thanks guys

I'll try to build a couple of pedals using these, I'll probably start with a wee red llama and then that Doube D which sounds niiice...

Mark Hammer · July 12, 2007, 09:43:19 AM

Just note that 4049-based circuits, while they don't demand a wallwart, can sometimes consume more current than you might expect. If you have a circuit like a Double D, probably even a little more (the circuit half you aren't using IS still being powered). So, be sure to have a steady and robust enough supply as you experiment, otherwise you may tend to confuse the properties of the circuit with the properties of the circuit when underpowered.

pott · July 12, 2007, 12:07:51 PM

Yeah I was planning on testing it with a 1spot by itself, then trying it with the rest of the board and compare. It may need its own supply after all.

Either way I can't order on the net so right now it's just still a tiny project... But I have ideas.

Ben N · July 12, 2007, 12:57:39 PM

f you have a 1-Spot you will have more than enough current, unless you have mulktiple digital pedals in addition to your 4049-er.

pott · July 12, 2007, 01:05:19 PM

Nope not one. The Big D if I do it would be the 5th pedal on the same power supply.

Mark Hammer · July 12, 2007, 01:08:06 PM

A 1-spot is fine. It doesn't need TONS of current. I was simply trying to avoid the situation where you snag an older battery that passes the "tongue test", and the circuit sounds great for 10 minutes and only ten minutes. If a circuit wants 3ma and it takes you 40 minutes to get the circuit set up right, then an older battery will see you through. If the circuit wants 20ma but you don't know that, you might start to mistakenly attribute malfunctioning to the circuit when it's a battery. I go through that....a lot.

pott · July 12, 2007, 01:15:43 PM

Hehe yeah good point... I think I actually once tried a pedal without a battery

I never did the tongue test though... I usually throw away batteries with less than 8V on the multimeter I guess. Thanks for the help everyone!

Ok I just saw that banzai actually has all I need... I'll ask my dad if he can order some of this stuff for me, I'll order parts for the Big D, Llama and for my current build in Edinburgh so I can finish it.

I also just remembered I gotta study this summer but ah well...

Also if I understand right, the 4049 is actually digital?

Ben N · July 12, 2007, 01:35:51 PM

Quote from: pott on July 12, 2007, 01:15:43 PMAlso if I understand right, the 4049 is actually digital?

Intended to be; not as it is used here. Do a search; there is a fair amount of information in prior threads about this.

Mark Hammer · July 12, 2007, 02:06:09 PM

The 4049 exists in that fuzzy realm between analog and digital. It is intended to be able to change the logic level of things from 1 to 0 and 0 to 1, as the need arises, but it can also provide adjustable degrees of gain. Other CMOS chips like counter chips, NOR/NAND/XOR gates and the like do not have such capabilities.

pott · July 12, 2007, 02:08:31 PM

So it's a super chip and I gotta be careful or else it'll take over the world?

Sorry... I'm clueless with electronics and very slowly learning hehe but I see what you mean. Basically you could for instance hook her up to a PC and he'll see this as an analogue to digital converter within the right programs?

spud · July 12, 2007, 02:24:17 PM

Pott,

I built a DD but it still is not working properly. I swapped the trannies and the chip. BTW, make sure you get the 4049UBE - as it is unbuffered and that is REQUIRED. I guess I'll have to dig up that project - I think it might be some bad solders or a lousy layout. I did it on a Radio Shack IC type perf thing (with two bus strips down the middle - like this:

http://www.radioshack.com/product/index.jsp?productId=2102845&cp=2032058.2032230.2032265&parentPage=family

The chip stradles the 2 bus lines. One half is the "Jiggle" side and other is the "bounce" - I can send you my layout if you want but as it is now I'm not sure if I would trust it. I made a new one that spaces the parts out more as I tried on the original to cram everything as close as possible. Not the best strategy for several reasons. Anyway, I can also post the layout at Bancika's site (DIYFEVER) if anyone is interested. I'm not sure if he is doing any admin on the site because he said he would be in the states sometime this summer. From the look of this site, I don't see that there's been any updates for a while.

If you want the layout, you'll have to wait till I get home as it is on my computer there.

Later

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A dual OD/Distortion using a single 4049 chip?