What is the smoothest low gain OD circuit you know of at low volume?

[oliphaunt]

My band plays a lot of really low volume gigs, where my amp (Carr Rambler) is not working much at all.  I have a lot of low gain pedals (think Tube Screamer with the gain at 10 o'clock or a King Of Tone with the gain at 2 o'clock), but it seems there is always some "rattiness" to them when the amp's volume is so low.  They often actually work more smoothly at higher gain, but I need something really low.  I am looking for a circuit that will drive silky smooth, with no harsh pops or crackles.  I have tried so many things I can barely remeber them, commercial and buitlby myself.  Have any of you folks found a really smooth low gain pedal at low volume?

[Mark Hammer]

What you describe is really more of what many would call "coloration" rather than OD.

There are essentially two requisite aspects to such a circuit that one would need to produce what you want:

1) That the introduction of harmonic content not present in the original have a gradual near-linear onset, rather than a threshold and non-linear onset.

2) The the output have some lowpass filtering to remove the addition of any higher order harmonic coloration.

[oliphaunt]

Mark, can you suggest a specific circuit (or partial circuit) that has a gradual onset?  I get where you are coming from on this completely, just don't have enough experience to fully recognize when a circuit has harder or softer, more gradual clipping.  Thanks!

[jacobyjd]

I built a Lovepedal Eternity that does what it seems like you're asking. I fiddled with the gain pot so it's more to my liking (i.e. less clipping when maxed), and I love it.

[Mark Hammer]

The Eternity is essentially a Tube Screamer, right?  ( http://www.madbeanpedals.com/projects/Neutrino/docs/Neutrino_ver.3.pdf )  So we know in advance it will do two things:

First, it will provide a titrated clipping such that lower notes will not clip that much more than higher ones.  Second, it will have the requisite lowpass filtering to smoothe the sound out.

But it is still using diodes, and those still have a more sudden transition to clipping than tubes will.  That doesn't mean it will sound bad, just that it will only meet one of the objectives noted.

[jacobyjd]

Yeah, it's basically a bufferless TS with more of a treble control than a normal tone stack (IIRC). I may be interpreting the OP's use of 'rattiness' incorrectly.

[CynicalMan]

One trick I use for "smoothness" is to put a compressor in front of an overdrive. Because you're reducing the dynamic range of the signal, you're increasing the transition range between clean and clipped sounds, which, like Mark noted, is often quick with diode clippers. Also, because the overdrive would normally be compressing, you can turn down the clipping and still have an overdrivey sounding tone.  But, that means there are less upper harmonics and less clipping, so you don't have as much rattiness. I especially like this to simulated cranked amp tones, because IMO, most ODs have more clipping and less compression than the tube distortion they're trying to emulate.

[aflynt]

I've found that the Zendrive works pretty well for low volume situations where the amp isn't being pushed very hard. I'd also suggest buying a lower wattage amp for those situations as the ideal solution.

-Aaron

[alfio]

I've got many stompboxes, much of them are "boutique", but as a smooth low gain overdrive in my opinion nothing compares to Boss OD-3.
Basically sounds like a compressor + an OD. Great sustain even at low gain.

[Johan]

But it is still using diodes, and those still have a more sudden transition to clipping than tubes will. 

+1...tubes are tubes and diodes are diodes, but...you can make the diodes a little "softer knee" by adding a small resistor in series with each diode, say 100-200 Ohm. I think Jack Orman touched on this ages ago in an article about TS opamps, but I might remember wrong, might just as easily have been Mark or R.G. ( look back to late 90's)
J

[Mark Hammer]

But it is still using diodes, and those still have a more sudden transition to clipping than tubes will. 

+1...tubes are tubes and diodes are diodes, but...you can make the diodes a little "softer knee" by adding a small resistor in series with each diode, say 100-200 Ohm. I think Jack Orman touched on this ages ago in an article about TS opamps, but I might remember wrong, might just as easily have been Mark or R.G. ( look back to late 90's)
J

+1
....and you can produce coloration rather than distortion by not concentrating your gain and coloration-insertion all in one place.  Cascaded stages, people, cascaded.

[oliphaunt]

Thanks for all the thoughts, folks.  Mark, one of the best pedals I used at today's gig is one I "designed" a while back by cascading three JFET boosts in to each other, all just barely adding gain. 

I really dug through the bottom of my pile looking for options and found this pedal I built sevral years ago, basically a COT with soft clipping diodes (rather than the usual hard clipping setup) that I stuck in there.  I used zeners just variety.


This thing by itself sounds ok but has a very hard threshold of clipping, and can crack like crazy, but I found that if I put a buffer (tube) in front of it it smoothed out very nicely.  This was pretty much my go-to overdrive all day.  Any thoughts on why the buffer makes such a difference?