Double D at Runoffgroove

[Carlos]

Hi everybody!

Has anyone tried and built the "Double D" at

http://www.runoffgroove.com/doubled.html

It's a "two-channel" CMOS distortion using a 4049 and j-fet buffers.
The two sound samples do sound promising.

http://www.runoffgroove.com/jiggle.mp3

http://www.runoffgroove.com/bounce.mp3

Carlos

[Peter Snowberg]

I have not built that Double D, but I have built a number of similar CMOS inverter circuits in the past and I loved the sounds. As you can hear, there is a wide range from clean to fuzz available. CMOS distortions have a sound all to themselves.

I say go ahead and build one. You will not be sorry.

-Pe ½;z

[will]

Hi Carlos,

I built the "Double D", well most of it. It sounds excellent.   I used different JFet's (2N5457) for the input and output buffers. At the time I didn't have enough volume & drive pots so I used the same ones for both the Jiggle & Bounce sides. Which is not a good idea as there are huge differences in the gain between the 2 sides. I think I used the same components for the rest of the circuit as the schematic.

The Jiggle to me sounds a bit like a fender clean tube amp, you can mildly overdrive it. On my strat it reminds me of the sound of Eric Clapton doing layla fairly cleanly. I really like that sound as it is clean yet coloured. Is that the Brown sound of simulated virtual tubes?  :wink:

The Bounce like the clip is much heavier. It's interesting I just plugged it in after listining to the clips again. I like my Jiggle sound better than the clip, yet I like the clip of the bounce better than my version. Maybe i changed some values. I better take a look and finnish the circuit.

I also built the hot harmonics which sounds great (I boxed it) I use it quite often and I built the 3 legged dog. Which was too trebbly and harsh for me so I doubled all of the coupling capacitors and added some pf caps across the feedback resistors. It sounded better to me, but I like the Double D better.

I also built the insanity box which also contains the same CMOS chip, boy does that circuit drain batteries fast. It is also quite good, very high gain. A combination I really like is my MXR Dist + clone with the RC4558 opamp into the Hot Harmonics. I was hoping that the insanity box could get that sound as The 1st stage in the Insanity Box is very similar to Dist + and the CMOS section is kind of similar to the Jiggle. But that is not the case, it is yet a different sound again.

Bottom line is all of the CMOS circuits I have tried sound different, but they all sound good. Then again I am very new to the building of stomp boxes, but I find it addictive. I love it!

Regards,
Will

[gtrmac]

I'm just bouncing this topic since I built a few of these and I think they're great. I gave two to a couple of friends since they loved them and I kept one for my self. I made mine on a PC board that I laid out with Protel and it works nicely. I used the 2-color LED suggestion also which is cute too.

I raised the gain in the first stage of the jiggle channel by increasing the value of the feedback resistor a bit.

I'm considering making a version with two Bounce channels so you can set two levels of heavier distortion.

Great pedal, I use it both with an amp and with a preamp for recording direct. It has the most pleasing  "Marshall type" amp simulation of all my pedals. I guess i'll have to try BSIAB also since this one gets great reviews too.

[JimRayden]

The chip eats batteries for breakfast. But sounds damn good. I would choose it if I were designing a high gain channel of a solid state amp, since it has wall power all the time. Or if it was a pedal, just use a wall wart to feed it.

But if you're using only two to three inverters with a current limiting resistor in the power supply, you'll be fine with a battery too. I think the Hot Harmonics or the Tube Sound Fuzz had that resistor.

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Jimbo

[Steben]

It does work with adding resistors to ground and V+, which reduce current draw. Tim Escobedo's CMOS journeys are a good source for that.

[JimRayden]

It does work with adding resistors to ground and V+, which reduce current draw. Tim Escobedo's CMOS journeys are a good source for that.

Doesn't a resistor to ground increase the current consumption?

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Jimbo

[Steben]

No, no.
I mean resistor to ground from the chip, not V+. Let's say putting in "drain" and "source" resistors, but it's not that exactly.

[JimRayden]

Oh, in series with the power supply. I understand that it will increase the overall load resistance on the battery, thus decreasing the current flow. Hmm, what if I go too high with the resistor value? I might get too low a supply voltage on the chip?

I like knowing what happens at extreme values of a certain variable, I can learn and remember stuff easier by that.

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Jimbo

[gtrmac]

I'll have to check out the suggestions for lowering the current draw sometime if I choose to run it with a battery. For the moment I use all my FX with a Axion power supply that has 8 outputs.

[lovric]

Hi all!
An article about 'Spectra' distorsion can be found on the Gen. Guiatr Gadgets that makes the variable supply current change the sound. Sound smaple from ROG made me make the 3legged dog. I have schems where paople used 4011 chip for distorsion and I red that 4007 could be used.