This Week on the Breadboard: Gator's OD - cb mod

[Chuck D. Bones]

Check resistor values too. Easy to misread the color bands.

 

[The Gator]

Good call. R8 was a 5.1K which just pushes a bit too far when dimed. Put the proper 5.6K in and it is good. Dimed this circuit is a distortion pedal.
The multitude of low gain sounds are really great. The drive can add in a great variation of punchy sounds at various level to add to your favorite gain setting.
Did some testing with a stock telecaster and it is great to have lots of eq settings.
It can pull some sharpness off an SG without sacrificing all the highs.
The Gretsch 5420 and stratocaster are next...
Did I mention thank you? I am having a great time!

 

[Chuck D. Bones]

I don't usually stack treble cut knobs like that, but hey, it worked!

 

[cooder]

Hmm. I will check connections.
I really like the addition of the double pot and the toggle.
Two versions of the circuit could be made. This one as the deluxe version, and then a simpler version. Perhaps just bass, mid, and treble, with volume, gain and drive. Discuss that at another time.
I like the idea of putting this in a 1590BB2
Turned tall.7 knobs, a toggle and two footswitches. Maybe the 4 band EQ all in one row. Everything else in the other.
One footswitch to put it in the chain and one that bypasses the drive to a resistor to equal the R7 and removes the VR8 volume boost limit as well.

If you'd like me to design a board for you in this configuration lemme know.

 

[The Gator]

I think we need to talk circuit board design at this point.
I know szukalski seemed interested as well.
I know everyone likes the compact 125B size, I do too, however once it goes up to 4 knobs in one row I prefer more room for my fingers. I don't like small diameter knobs all that much. 1590BB2 gives room for people to use a variety of knob sizes and styles. How hard is it to keep the tone section all in one row?

I am serious about the addition of a dual pot on the drive along with the toggle and extra footswitch. I feel it would make this circuit into an extreme useful and compact overdrive/distortion/boost combo all in one circuit. I will draw up what I am thinking.

 

[zgrav]

Especially after going back to a dual op-amp, the parts count to knob ratio here must be record-setting and a tweaker's paradise.

 

[The Gator]

Lol. No kidding. I do have a disease called "can't leave well enough alone-itis". I would wager several of us do here on the forum...lol
I originally just wanted to toggle switch for a mid cut to the original circuit just to get different tones. And then we started looking at tone stacks. Then Chuck came up with this and I thought oh man I do like having a presence knob.
I stated earlier I thought about making a simplified version as well. maybe just a six nom version with tmb tone stack. And one foot switch. But that would require a difference schematic to go off of for a different circuit board and design it to be in a 125b.

 

[zgrav]

Lol. No kidding. I do have a disease called "can't well enough alone-itis". I would wager several of us do here on the forum...lol
I originally just wanted to toggle switch for a mid cut to the original circuit just to get different tones. And then we started looking at tone stacks. Then Chuck came up with this and I thought oh man I do like having a presence knob.
I stated earlier I thought about making a simplified version as well. maybe just a six nom version with tmb tone stack. And one foot switch. But that would require a difference schematic to go off of for a different circuit board and design it to be in a 125b.

I think the low parts count and high knob count is a good landing spot -- it is more or less the OD equivalent of the fuzz foundry. I like sticking with the IR leds as well instead of adding switches for other clippers.

 

[The Gator]

I would agree with that. Most pedals that I've tried that you can just change clipping diodes on a toggle, it doesn't really do much in my opinion. You can't really do that in this circuit anyway, without affecting how much signal was going into the next stage and then values need to change and other places. I actually tried several different clipping diodes when I was working on the simplified circuit for the contest. I realize that going to the extremes and either direction was not of much use. The IR LEDs really do not sound different then just using some diodes. I've always just liked them because it was a way to get that higher forward voltage with just one component. Certain cameras you can actually see a little purple glow when they're clipping.

 

[Chuck D. Bones]

Unlike the Fuzz Foundry, there are no bad knob settings on this pedal.

A pair of Si diodes have about the same Vf and curve as an 850nm IR LED. It's really down to the builder's preference which way you go with the clipping. If you do go with IR LEDs, keep in mind that 940nm LEDs have a lower Vf than 850nm. Longer wavelength = lower energy = lower Vf. That's why blue LEDs have higher Vf than green.

 

[Chuck D. Bones]

Here's how I would implement a BOOST* stomp switch. When Boost Mode is off, DRIVE is set to minimum and the NORMAL VOLUME knob controls the output level. When BOOST is on, DRIVE is controlled by the DRIVE knob and the BOOST VOLUME knob sets the output level. If all one wants is a volume change when Boost Mode is engaged, then set DRIVE to zero.

* needs a better name.

 

[The Gator]

Interesting. I'm going to have to wrap my head around that. Perhaps do it up on the breadboard. I think maybe I should draw up what I was thinking about too. I meant to download tinycad over the weekend, however one of my appliances decided to take up my weekend. I've been keeping an old Kenmore clothes washer alive for 26 years. Just about replaced everything. Finally the outer tub broke and flooded the laundry room so I had to clean up a disaster, and then of course buy a new machine and do the swap.
I'm going to try and take a look at this tonight and maybe download some tiny CAD.
Thank you

 

[Chuck D. Bones]

A couple of weeks after we moved into our present abode, our vintage Kenmore toploader's transmission failed. The motor kept spinning, but the belt couldn't move, which overheated the belt. The laundry room filled with smoke pretty quickly and the Wife called the fire dept. If I had known that washer was going to give out so soon, I never would have moved it to the new house. Replaced it with a Whirlpool front loader, which lasted until just after the warranty expired. Rotten engineering on that one. Replaced it with a Bosch front loader and except for the irritating beep! beep! beep! beep! beep! when it finishes, it has been a real gem. Had to replace one of the solenoid valves and that's about it.

But I digress...

 

[Brett]

Had to replace one of the solenoid valves and that's about it.

Fingers crossed we get a Boneyard Bosch front load washing machine project soon... My Maytag has seen better days...

This circuit looks interesting. I've been quietly watching its progress. I'd offer to design a board, but it seems you already have two candidates that are more than capable of doing this one justice. @cooder and @szukalski both make some nice stuff!