Low Gain, neutral dist/OD

[Killthepopular]

I'm looking for an easy, low gain dist or OD. It will be like an amp emulator, just a flat, neutral sounding OD that can go from clean to gritty with the gain knob. Tubeyness would be a plus but I'm not fussed about that, I just want to add a little dirt without changing the tone. I'm gonna try ROG Eighteen (fets), Crowther Hotcake (opamp clipping) and DOD 250 (opamp clipped by silicon diodes). I'm gonna breadboard these. I'm sticking to designs with only a few components to make things easy. These 3 circuits each require between 20-30 components, so pretty simple.
Are these circuits reasonably low gain? I know the DOD will be fine (especially with LEDs) and the Crowther is known for being good for low gain but I'm not sure about the eighteen...







I was considering a Rat but I don't want to go mid-focussed and I already have an SD-1 for that. I'm considering an OCD too though that has slightly more components (35) and also it doesn't seem to be very low gain; I want to go from totally clean to slightly gritty ideally.
Any suggestions?

[iainpunk]

this seems to be quite clean when turned down, but gets crisp and warm when pushed

the transistors are BF245 and the diodes are 1n4148

[Killthepopular]

this seems to be quite clean when turned down, but gets crisp and warm when pushed

Is it some sort of low gain fuzz?

[Killthepopular]

Actually I think I'll skip the ROG Eighteen, seems like it's not really intended for low gain.

[GGBB]

Pretty much anything that has a variable gain or drive control could be set at low gain. You could even modify the control so that it will only give low gain. It sounds like what you are really after is a pedal that does nice nuetral tubey low gain sounds.  A couple of those that I'm aware of would be the Peppermill and the Timmy. Maybe the Klon as well. I also like Bluesbreakers, but those need tweaking to get to nuetral territory.

[Mark Hammer]

This thing seems to make a lot of people happy:  https://www.diystompboxes.com/smfforum/index.php?topic=107216.0  It can dial in softer clipping, and offers a lot of flexibility in terms of tone shaping.  Aims for low to mid-gain territory, and doesn't use many parts.

[Killthepopular]

Pretty much anything that has a variable gain or drive control could be set at low gain.

So, what, I could say, take an OCD for example and just change one pot or one resistor to reduce the gain of the first boost stage in the pedal and that would give me a lower gain circuit?

It sounds like what you are really after is a pedal that does nice nuetral tubey low gain sounds.  A couple of those that I'm aware of would be the Peppermill and the Timmy. Maybe the Klon as well. I also like Bluesbreakers, but those need tweaking to get to nuetral territory.

Would you recommend the peppermill? I thought it looked promising but the demo clips sounded so terrible to me that i thought it wouldn't be worth bothering with.
I wasn't going to bother with the timmy, I had just assumed it would be a fairly complex circuit but now I see it has a modest 31 components. Maybe I'll give it a go. I know it's like possibly the most widely recommended dirt pedal these days.
Klons sound good to me but it uses maybe twice as many components as these other circuits so I'll skip it I think (this is my first attempt at breadboarding a complete pedal).
Tempted by the bluesbreaker...

[Killthepopular]

Oh yeah, I should probably specify that this will be an amp-like pedal in terms of how I want to use it. It will be like Pedal->clean amp or pedal->cab sim. So ideally it should be something that sounds ok on its own as opposed to one of those pedals where it's like "oh you should NEVER use it into a clean amp!!"

[ElectricDruid]

DOD 250 is fairly hard, "distortion" more than "overdrive" I'd say. Things with the clipping diodes after the gain stage tend to be a bit harder in my experience. But you can back it off, obviously.

I was going to suggest a Tubescreamer since that does nice overdrive sounds and is simple enough circuit, but the tone-shaping is probably not anything you could call neutral. Still, you could leave a few bits out!

[Steben]

Low gain blues driver?

[roseblood11]

Mad Professor Sweet Honey Overdrive!!!
Or maybe Black Cat OD-1 with OP275 opamp

[GGBB]

So, what, I could say, take an OCD for example and just change one pot or one resistor to reduce the gain of the first boost stage in the pedal and that would give me a lower gain circuit?

More or less - the details of "stages" would differ depending on the pedal, for example in a Bluesbreaker, the gain pot simultaneously controls gain for both stages, so use a smaller pot and you have only the low gain settings. That was my point really - use a smaller gain pot and you essentially are preventing yourself from cranking it up.

Would you recommend the peppermill?

It came to mind because you said low gain. Never built one yet, but I like the clips I've heard - it's different than the usual dual opamp fair a la TS, Timmy, Bluesbreaker, ... and most definitely low gain and neutral. It seems to me in limited experience that not a lot of pedals do very light overdrive particularly well - most are best suited at mild to medium overdrive and some higher. I think - based on clips - the Peppermill does the very light stuff quite nicely for my tastes.

[antonis]

Fender Blender without octave configuration..

[Fancy Lime]

Hi Killthepopular,

what you describe is pretty much exactly Craig Anderton's Tube Sound Fuzz, aka the Way Huge Red Llama. This is based on CMOS inverter clipping, which I find by far the best for the transition region between totally clean ad juuuuust a little overdriven. Very natural and pleasing. Tube-like? Some say yes, some say no, I don't care. It's CMOS overdrive and it sounds like a CMOS overdrive. It's low part count and can be extended to be extremely complicated, if you should which so. Very educational circuit. It's also easy to lower the overall gain range, if you want. Have a look at youtube videos of the Red Llama to get an idea about the sound. find the ones with gain at minimum.

Cheers,
Andy

[bluebunny]

I quite like Joe Davisson's EZ-250.  Only 15 parts (+ pots).  Links for: thread, schematic, my layout.

[Killthepopular]

I was going to suggest a Tubescreamer since that does nice overdrive sounds and is simple enough circuit, but the tone-shaping is probably not anything you could call neutral. Still, you could leave a few bits out!

I like the OD1, but I already have an SD1 which I have modded fairly extensively (mainly to make it more neutral) so I think I have the neutralish tubescreamer territory covered if I'm being honest.

[Fancy Lime]

I quite like Joe Davisson's EZ-250.  Only 15 parts (+ pots).  Links for: thread, schematic, my layout.

I see your 15 parts + pots and raise you 8 parts + pots. The good ol' Electra distortion: http://fuzzcentral.ssguitar.com/schematics/electradistortion.gif
One of the most simple, yet amazingly good sounding little circuits. You might want to use two series pairs of Ge diodes instead of two singles and add a gain pot up front (wired like in the Jordan Bosstone: http://fuzzcentral.ssguitar.com/schematics/bosstoneschem.gif called "Attack" here). Or, simpler, just add a "softness" pot. See Arons mod tips: https://www.diystompboxes.com/cnews/mods.html #1 and #7, respectively. Still 10 parts or less.

Andy

[Killthepopular]

Low gain blues driver?

The blues driver layout i looked at required like over 100 components... Even without the input and output buffers that's a lot. This is pretty much the first time I've breadboarded a dirt pedal so I hope to keep it simple.

[Killthepopular]

Mad Professor Sweet Honey Overdrive!!!
Or maybe Black Cat OD-1 with OP275 opamp

Sweet honey is a bit complicated looking. Black cat looks pretty simple but doesn't sound very neutral.

[Killthepopular]

what you describe is pretty much exactly Craig Anderton's Tube Sound Fuzz, aka the Way Huge Red Llama. Very natural and pleasing.

Yeah this looks like a really good suggestion. Lowest part count I've found so far, can do clean and  the tones sound good at low and high gain settings. And yeah, I'm no tube connoiseur but it sounds pretty tubey to me.
What's the sonic difference between those two versions of the same circuit?