What's the best Transparent Distortion pedal?

[Coldacre]

Despite its intended design, the Guv'nor really doesn't have "metal approved" distortion capabilities, IMO. It might do hard rock and classic metal adequately enough, but you need the extra distortion with the CB or Riot to go for more modern metal tones, or "nu metal," or whatever they refer to it as currently being.

well that's if you're playing off a clean platform and are relying 100% on the pedal to provide all gain. the Guv'nor is great into an amp breaking up. you might be surprised to hear that it was Bill Steers pedal of choice in the late 80's. some of the heaviest recordings ever made were done with the Guv'nor

 

[Gnobuddy]

I found this regarding the PSA-1. It's a fairly detailed discussion:

http://www.groupdiy.com/index.php?topic=40781.0

Good find!

I can also say that the "slew rate thing" was mentioned as being an important facet. A TL072 has a slew rate of about 17V/uS, and the TL2262 has a slew rate of ONLY .55V/uS, so that could be rather important for a non-diode clipper-bound distortion circuit.

I was curious about how much of a limitation 0.55V/uS actually is, so I did a little math to calculate the highest clean sinewave frequency that can get through an amp with a slew rate of 0.55 V/uS.

To find the worst case situation, I assumed the highest possible supply voltage (16V) and a rail-to-rail sine wave signal, i.e. 16 volts peak to peak or 8 volts peak.

Turns out that even in this worst of all possible cases, the answer is 10.94 KHz - lets round that to 11 KHz. Any sinewave signal with a frequency lower than 11 KHz will not be affected at all by the 0.55V/uS slew rate limitation.

Considering that typical guitar speakers don't reproduce anything much over about 5 or 6 KHz, and have virtually no output at 11 KHz, I think it's safe to say that the slew rate limitation of the TLC 2262 will have no audible effect whatsoever on a guitar signal going through it.

Which is a bit of a head-scratcher! If it's not the slew-rate limitation, what makes that CMOS opamp sound different? Perhaps it clips more softly when it runs into the supply rail limits than a BJT based opamp output stage?

I did turn up something else interesting, though. Check out post #32 at the following URL: http://www.talkbass.com/forum/f36/j...lation-circuit-463535/index2.html#post6691042

For reference, that post says:

GT2 is totally analogue. The "secret" is the ic TLC2262, and it is how this ic "clips" at the power supply rails that gives the sansamp GT2 its sound, that and the filter eq's and gain settings.

The first one i made of these i used TL072 throughtout, and it was only good on the clean setting, and only when i changed the opamps to TLC2262 that the "sound" was there. (leave the first dual op amp as TL072, as this doesnt affect the sound. Sansamp have it this way on their build)

I didnt use little slide switches as 3 position ones are hard to get, i just used rotary 3 position 4 pole switches, as i put this in a rack along with other pedal clones.

Tonepad doesnt say to use TLC2262, but if you dont, you wont get the sound. If you read the build notes some people (including me) recommend using the TLC2262 chip

So the mystery remains unsolved, and the plot only continues to thicken!

-Gnobuddy

 

[czech-one-2]

well that's if you're playing off a clean platform and are relying 100% on the pedal to provide all gain. the Guv'nor is great into an amp breaking up. you might be surprised to hear that it was Bill Steers pedal of choice in the late 80's. some of the heaviest recordings ever made were done with the Guv'nor

As far as Gov'nors go, this one sounds amazing. You guys with DIY skills should check this one out,best distortion I've owned,and thats a looong list!
http://www.grindcustomsfx.com/wp-content/uploads/2012/12/Octane_build.pdf

 

[11 Gauge]

Considering that typical guitar speakers don't reproduce anything much over about 5 or 6 KHz, and have virtually no output at 11 KHz, I think it's safe to say that the slew rate limitation of the TLC 2262 will have no audible effect whatsoever on a guitar signal going through it.

Which is a bit of a head-scratcher! If it's not the slew-rate limitation, what makes that CMOS opamp sound different? Perhaps it clips more softly when it runs into the supply rail limits than a BJT based opamp output stage?

Given that calculation, it can't be a result of the slew rate. It has to be "other factors." Like germanium transistors, I think they are things that do not show on the data sheets. The current theory with why germanium transistors sound "more musical" is because of their inherent leakage, which varies from unit to unit, and isn't on a data sheet. Apparently, it is the "gain lost" the produces "the sound." There are DIY folks running a pair of silicon BJT's in quasi-parallel, which only gives a fraction of the gain, but they aren't really sure what is happening. In many cases the hFe's that are measured are "too low," yet the sonic results are excellent. The measured gain might have qualities that are very similar to germanium leakage.

I think the best thing to do would be to build sub-circuits with op amps, and test them with standard chips vs. this TLC2262. By altering the sub-circuit, differences in sound should be audible.

 

[11 Gauge]

well that's if you're playing off a clean platform and are relying 100% on the pedal to provide all gain. the Guv'nor is great into an amp breaking up. you might be surprised to hear that it was Bill Steers pedal of choice in the late 80's. some of the heaviest recordings ever made were done with the Guv'nor

No, I'm not surprised. Using a combo of amp and pedal is obviously one more way to get "more distortion."

I'm just talking about what the Guv'nor itself is capable of, specifically WRT other distortion pedals. It's only a dual op amp design. There are other pedals with more gain stages that don't require an "amp assist" to get into the super-heavy sounds.

This is why it's no surprise that Danelectro marketed their Guv'nor clone (the Daddy-O) as an OD and not a distortion.

The T/M/B tone circuit after the gain/clipping stages is passive, and really kills a bit of the signal. That's why the Crunch Box and Riot are much more distorted - they remove most of the original tone circuit's lossy nature.

 

[LGWonder]

I feel my namesake is very open but not quite a distortion.

However I also have its cousin Stone Grey Distortion - very 'not' compressed
You might like it I think its based on Cliffhanger II or somthing.

Anyhow I vote for the SGD being a good open Distortion.

 

[11 Gauge]

I feel my namesake is very open but not quite a distortion.

However I also have its cousin Stone Grey Distortion - very 'not' compressed
You might like it I think its based on Cliffhanger II or somthing.

Anyhow I vote for the SGD being a good open Distortion.

The Stone Gray Distortion is another example of an op amp stage driving CMOS inverter stages. The op amp stage has clipping diodes in the negative feedback loop, and two CMOS stages are used. It looks like a sort of hardwiring of TS into Tube Sound Fuzz/Red Llama.

It is interesting that the op amp stage is more than just a boost, and more than just an "input impedance fix" - you actually get two types of distortion at three separate gain stages.

I've experimented with "TS into TSF stacking," and it can be pretty neat. The biggest caveat that I experienced was that things were typically very bright. I've heard similar comments from SGD users.

I do applaud their efforts to offer something that is left-of-center. IDK how popular the SGD is in their overall line, but IMO it's a good addition. I'd think that it might produce better results than the Dyna Red Distortion, but that's just a subjective statement (DRD is sort of like a hotrodded Honey Bee, IMO).

 

[11 Gauge]

Bill Steers pedal of choice in the late 80's.

I was curious if you meant "that Bill Steer" (I didn't click on the link).

So along those lines, I think that some of the heaviest tones around that same time - late 80's/early 90's were from Alex Hellid's and Uffe Cederlund's use of the Boss HM-2. Word has it that their tones were amp-independent, as they were running the pedal with all controls full-up. Folks have tested this, and have found it to be true. Some argue that it must be loaded into a cranked Marshall, but experimentation with other amps (even solid state ones) seems to suggest otherwise.

Justin Broadrick also used a HM-2 into the low input of a JCM800, but word has it that he set the tone controls so that the pointers were "facing each other." There are intros to songs on the album Hymns with the pedal off, and his tone was absolutely clean. The harmonics and sustain on songs like Slateman (not on Hymns) are somewhat remarkable, given the amount of distortion, and that it is all derived from the pedal.

Michael Amott and David Blomqvist also got a very similar tone to Hellid's and Cederlund's on Dark Recollections IMO, but IDK if the HM-2 was used for that.

 

[LGWonder]

11 Gauge,
your dead right about the SGD being very bright, at first I thought there was somthing wrong with it but within about 2 seconds I came to love the idea that this was a totally different voice - in a good way!

What I sometimes do is run my LGW into the SGD to beef up the bass a bit.
But switching from LGW to SGD to say a Fuzz pedal really does give 3 distinct voices.

I am a happy bunny.

and also thanks for your spec, I didnt know any of that.

 

[LGWonder]

Also within their product line I believe the SGD isnt as prominent as it should be.
I wonder if thats because it only comes in the less expensive PCB version (no handwired version)
I hope snobbery isnt keeping folks from using it?

 

[11 Gauge]

I hope snobbery isnt keeping folks from using it?

I think it's just a very competitive space - the "distortion with a twist" marketspace, and folks just clearly have stuff that they prefer. Aside from pedals like the Emma Reezafratzitz or the DIY stuff like the Dr. Boogie, I don't claim to know what it is that the "very high distortion user" is looking for.

I simply know that "something with inverters in it" might actually be a viable option, because they tend to behave differently from traditional op amp w/diode clipper designs.

The Tube Sound Fuzz has been around a long time to demonstrate this, and the Red Llama made it popular enough for the average guitarist to experience it.

I'd also argue that "inverters for overdrive" are probably going to be more popular - I think the Blackstone Mosfet Appliances OD is solid proof of that. I think many guitarists have simply conceded that "distortion" and "natural sounding" are at odds with each other. For that reason, there might be a much smaller number of potential users looking for such a pedal. The "standard crop" might be sufficient from their perception.

I'd also argue that this is borne out by examining the fairly recent Carvin amps that are supposed to be like a Rectifier alternative, because they use clipping diodes in the circuit! This is somewhat amazing, as Carvin has done quite a bit of R&D with their solid state amps to come up with good approximations of tube-only distortion. Or maybe Carvin has just realized that the average user of something with "that much" distortion might not be able to really tell the difference, if A/B'ing a Recto and a V3, or whatever Carvin calls theirs.

...I think Carvin even puts clipping diodes in their little EL84-based "tweed" line of stuff, for the OD channel. I was kind of surprised to learn of that.

If nothing else, this all just sort of shows that there's more than one means to an end, despite what we might think.

 

[cousinpaul]

The Stone Gray Distortion is another example of an op amp stage driving CMOS inverter stages. The op amp stage has clipping diodes in the negative feedback loop, and two CMOS stages are used. It looks like a sort of hardwiring of TS into Tube Sound Fuzz/Red Llama.

It is interesting that the op amp stage is more than just a boost, and more than just an "input impedance fix" - you actually get two types of distortion at three separate gain stages.

I've experimented with "TS into TSF stacking," and it can be pretty neat. The biggest caveat that I experienced was that things were typically very bright. I've heard similar comments from SGD users.

I do applaud their efforts to offer something that is left-of-center. IDK how popular the SGD is in their overall line, but IMO it's a good addition. I'd think that it might produce better results than the Dyna Red Distortion, but that's just a subjective statement (DRD is sort of like a hotrodded Honey Bee, IMO).

The Way Huge Camel Toe is another example of "TS into TSF stacking": the Red Llama being only a few component changes away from the TSF and the Green Rhino a tweaked TS.

 

[11 Gauge]

If it's not the slew-rate limitation, what makes that CMOS opamp sound different? Perhaps it clips more softly when it runs into the supply rail limits than a BJT based opamp output stage?

Bingo!

It took some research to unearth this info, but that seems to be the advantage of the chip. I found this specific explanation, which really just puts it into the perfect words, IMO:

"...the TLC2262 can get to within a mV or so of the supplies, so it should have no effect on the distortion waveform..."

Many other chips, despite their gain bandwidth product being "good," despite their slew rate being "preferable," despite "having musical recovery characteristics, simply can't get as close to the rails before distortion occurs. With an op amp, since this means that the positive and negative signal swings are no longer "mirroring each other," I can only assume that the "rail banging" is quite audible "in a less good way." By quite audible, I don't mean a profoundly different sound - just that the "stuff" in the clipping part will sound "good" in comparison.

This probably isn't even something that is a facet that I'd call "premium tone." It's more like "premium function," IMO. Diodes were originally used for functionality, to deal with clipping. I'm talking with some audio applications where (audible) distortion is not wanted.

So the TLC2262 essentially kills 2 birds with one stone:

- no need for clipping diodes

- when it clips, it does so "properly"

...I'll have to go back and double-check the schems to the SansAmp stuff, but I'd be willing to bet that the treble-reducing caps in the feedback loops are "oversized" compared to other op amp-based designs that used clipping diodes. This would make things a bit "smoother" still. It would also explain why a Baxandall is the post-level tone circuit of choice - you'd want active treble adjustment to "recover" the treble. This would also explain why the gain and tone controls are so twitchy with my GT-2.

I'm now REALLY eager to try this chip with a Crowther Hot Cake, as I think it would sound a bit different than either the LM741 or TL071. The dual to single change would require a custom pcb, but no big deal with such a simple circuit. Since the Hot Cake doesn't used clipping diodes either, I'd expect this chip to potentially "sound better." Just the difference between the 741 and '071 is pretty noticeable, IMO.

 

[cbtd]

I always have trouble with these types of discussions, it seems the terminology is confusing. I know there have been lots of discussions in other threads about what is overdrive v. distortion, and really it seems like things tend to fall on a spectrum rather than being easily lumped into one group or another. When I looked at the OP I thought the transparency aspect of this would put it into the Overdrive bucket.

It doesn't seem like you can even look to circuit design to entirely describe what a pedal is going to sound like. If you look at something like the Rat, I think it is all over the board, you dial it down it is like an overdrive dial it all the way up and you are into fuzz territory.

It would be nice to be able to look at it like we do for printers or cameras that have diagrams describing the color space that the device is capable of.

When I looked at that Boss diagram in the HD-1 thread, I thought it would be kind of cool if we could come up with a way to describe the sonic space these things fill in a similar way. I've attached a diagram to explain what I mean. The Axes probably don't have the correct labels and where I placed the devices is arbitrary. I just thought it would be nice to call everything a distortion and just be able to say it falls in the quadrant 2 type of distortion for example.

This post clearly indicates that I have over thought this, so feel free to label me insane.

 

[11 Gauge]

This post clearly indicates that I have over thought this, so feel free to label me insane.

No - I like that you are thinking about this. Of course, that might just hint at me being insane!

The problem with simply trying to separate between OD and distortion IMO is because neither is really a definition. An OD isn't overdriving anything, despite what one may think. And distortion is "just a term" that means your amplified output has been altered versus your input.

I like to use terms like soft clipping and hard clipping. I think soft clipping is more synonymous with a slightly distorting tube amp. Hard clipping is therefore anything where the output is altered significantly.

Another issue is that distortion doesn't always occur in one "place." you can have it at the preamp, at the power amp, and even at the speakers.

Contrary to popular opinion, tubes can hard clip just like solid state can. Lots of folks seem to equate hard clipping with solid state - either producing fuzzy stuff, or buzzy/nasty/un-musical sounds. but tubes can do that too, and go into "cutoff" just like a semiconductor does. Tube circuits can also suffer from a phenomenon called blocking distortion. Part of what we like about amps like the tweed Deluxe have to do with low supply voltages and heavy speaker breakup.

So one axis could potentially be over-simplified with soft clipping at one end, and hard clipping at the other. I don't know how we'd treat the other axis though. Maybe gritty/uncompressed/"clear" vs. smooth/compressed/colored?

By that reasoning, a "transparent" distortion would have a gritty and uncompressed characteristic to it, with a minimum of EQ treatments to "smooth it out." I guess that if soft clipping were analogous to "natural" sounding, then it would have to be a distortion with a "tendency towards less hard clipping," which would put it close to the intersection of the axes, because anything in the "soft clipping quadrants" would be more analogous to what we define as being OD.

IMO.

 

[cbtd]

How about this version then.

 

[david henman]

...the distortion pedal i keep going back to is the radial bones london, although i'm curious to try the suhr riot.

 

[Gnobuddy]

I just thought it would be nice to call everything a distortion <snip>

I admire your intentions and approach, cbtd, but I am dubious about whether it will work.

I was involved in Hi-Fi electronics long before I began dabbling in guitar electronics. Coming from my background, I would use exactly the terminology you suggested: anything that alters the waveform of the signal by putting it through a nonlinear device is causing harmonic distortion. This is something you can see and measure with the appropriate instruments, so it's not just some arbitrary term, it is a real physical thing (the generation of new frequencies that were not present in the original audio signal, and which are harmonically related to the original frequencies).

When there is significant nonlinearity there is also intermodulation distortion (which also generates new frequencies that were not in the original audio signal, but this time the new frequencies are not harmonics of the original frequencies).

Clipping diodes, overloaded transistors, overdriven opamps, all of these are nonlinear devices, and all cause harmonic distortion and intermodulation distortion.

So to my mind sub-categories like "fuzz" and "overdrive" and "distortion" never really made sense. To an audio engineer they're all just various forms of "distortion".

The trouble is, the single (technically accurate) word "distortion" doesn't really serve us guitarists very well, either, because there are so many different types of non-linear distortion, and from the musicians perspective they do all sound a bit different. So we come up with terms like "warm" or "rich" or "harsh" or "transparent" or "spiky" or "violin like", and none of them is really accurate either.

It's a bit like watching people in a bead store discussing the hundred different shades of yellow beads on the shelf. The catch-all term "yellow" is accurate, but insufficient in this context, so people add on all these other adjectives - "golden", "amber", "greenish", "pale", "silvery", and dozens of others - and even with all of that, no two people are quite going to agree on exactly how to describe one particular shade of yellow.

And if you think I'm exaggerating about the bead thing - you should try it some time! I've accompanied my better half into a few bead stores over the years, and it feels like a visit to an alternate universe where Y chromosomes are incredibly rare and owners of said Y chromosomes have no clue what everyone is so interested in. It's probably roughly the equivalent of the experience a woman has if she wanders into a radio-control hobby shop full of men who are gaga over little replicas of vehicles.

-Gnobuddy

 

[cbtd]

So to my mind sub-categories like "fuzz" and "overdrive" and "distortion" never really made sense. To an audio engineer they're all just various forms of "distortion".

I completely agree. This is why I was trying to find some better, more visual way to describe the broader sound characteristics.

The trouble is, the single (technically accurate) word "distortion" doesn't really serve us guitarists very well, either, because there are so many different types of non-linear distortion, and from the musicians perspective they do all sound a bit different. So we come up with terms like "warm" or "rich" or "harsh" or "transparent" or "spiky" or "violin like", and none of them is really accurate either.

I agree, the chart would really need to be multi-dimensional to cover everything. I was trying to find a way to cover the main details with a sort of broad stroke and figured the extra dimension would be handled by discussion in the forum

It's a bit like watching people in a bead store discussing the hundred different shades of yellow beads on the shelf. The catch-all term "yellow" is accurate, but insufficient in this context, so people add on all these other adjectives - "golden", "amber", "greenish", "pale", "silvery", and dozens of others - and even with all of that, no two people are quite going to agree on exactly how to describe one particular shade of yellow.

I have been to that bead store.

Like I said, my sanity is to be questioned. I'm probably tilting at windmills.

 

[SirJackdeFuzz]

I always have trouble with these types of discussions, it seems the terminology is confusing. I know there have been lots of discussions in other threads about what is overdrive v. distortion, and really it seems like things tend to fall on a spectrum rather than being easily lumped into one group or another. When I looked at the OP I thought the transparency aspect of this would put it into the Overdrive bucket.

It doesn't seem like you can even look to circuit design to entirely describe what a pedal is going to sound like. If you look at something like the Rat, I think it is all over the board, you dial it down it is like an overdrive dial it all the way up and you are into fuzz territory.

It would be nice to be able to look at it like we do for printers or cameras that have diagrams describing the color space that the device is capable of.

When I looked at that Boss diagram in the HD-1 thread, I thought it would be kind of cool if we could come up with a way to describe the sonic space these things fill in a similar way. I've attached a diagram to explain what I mean. The Axes probably don't have the correct labels and where I placed the devices is arbitrary. I just thought it would be nice to call everything a distortion and just be able to say it falls in the quadrant 2 type of distortion for example.

This post clearly indicates that I have over thought this, so feel free to label me insane.

GREAT POST IS GREAT !!!

I like th eway you think