Does overdrive suck the body out of your tone?

[cpnyc23]

I recently re-auditioned a lot of pedals that I've built, one by one, and I've discovered that the overdrives/distortions suck a lot of life out of my tone.   My Strat going thru my compressor into my amp has a full body sound - the lower frequencies have a depth and thickness to them.  When I play thru a TS808 or one of the many other overdrives that I've built, I just don't find that it preserves the tone.  It seems to carve some depth out of the bottom end of my tone.

Anyone else experience this?  I still want some grit at times... roll back the volume and its my natural clean sound... wind it up and it growls a little.

Am I asking for too much?

Where should I look?

-chris

[earthtonesaudio]

Most TS-type pedals "hump" the mids, but that's kind of the point.  The  idea of those pedals is to overdrive mainly in the mid frequency area, so that it's not overly bright nor mushy in the bass region. 

If you already like your tone but want some more grit, it sounds to me like you're looking for a not-so-clean booster, rather than an overdrive.  One that does the "volume knob clean-up" well is the ROG Omega.  Maybe also look at the Minibooster, or variants of it.

Have you checked out the "peppermill" over at runoffgroove.com?  That one adds just a touch of grit.

[cpnyc23]

hey

yeah, i've built the ROG Peppermill... it does a good job of adding a bit of grit (actually it can scream a touch if you push it into some warm tubes).  I built a MiniBooster for a friend... I've been thinking I should build another one for myself as I really liked it.

Still, I think that the Peppermill removes a bit of that body that I like so much.  It preserves more than most OD's but I still feel like a blanket has been thrown over the sound, removing some of the detail.

-chris

[Mark Hammer]

Because there is so much more amplitude in the low end of the guitar signal, and because diode-based overdrive applies the same clipping threshold no matter what the input is, it is a common practice to trim back on the low end of the signal so as to achieve a more "even" degree of clipping across the spectrum.  This is a very common reason for what irritates you.  Read the Technology of the Tube Screamer over at geofex to get a firmer grasp on this.

[cpnyc23]

Thanks Mark  -  I had actually been thinking that I should re-visit that particular piece of info.

Could it be that I'm looking for a frequency dependent OD?  Or perhaps I should experiment with parallel processing for my OD sounds?   Any suggestions for circuits on the parallel route.

Earthtonesaudio - have you built the Omega?  I'm intrigued but I, for better or worse, have become dependent on my compressor at the front of my chain.  The writeup for the Omega recommends that it see the unbuffered signal of the pickups at the input....

-chris

[cheeb]

Maybe you could try a blend, and blend in just enough of your clean tone to get some of that body back.

[aron]

When you are in the context of a band, you don't need all of that low end that you might find desirable at home IMO. In any case, the Blue Magic etc.... type of pedal will do what you want and it's easier to put back the missing low end you might want.

[mnordbye]

Another suggestion.. Why not try an EQ? It might be what you're looking for, and if not, it's has many other uses as well.

Magnus Nordbye

[Processaurus]

When I had a red llama (craig anderton tube sound fuzz) clone a while back I liked how the low gain sounded just like the guitar, just a little soft clipped.  Apparently the CA version was even bassier, which you might like.

[SeanCostello]

It seems like an ideal overdrive box would have different behaviours, depending on the amplitude of the input signal:

- Low level signals would be passed through with a full frequency response.
- High level signals would have more highpass filtering, to avoid "flubby" distortion (this is assuming that you want to emulate the Marshall-with-presence-turned-up distortion).

Can this be accomplished by having complementary highpass and lowpass filters, with the nonlinearity in between? This would use a highpass filter and a lowpass filter in series, with the coefficients designed such that the response of the filters in series is allpass (flat magnitude response, with phase distortion permitted). A nonlinearity would be placed between the two filters, where there is a significant area of roughly linear operation for low-level signals. The HP->nonlinear->LP ordering would allow for full-bandwidth signals at low signal amplitudes, while louder input signals would be clipped, but with the desirable highpass filtering on the input of the clipping. As an added bonus, the output of the clipping would have a gentle 6 dB/oct rolloff, due to the lowpass filter.

Or am I just describing a Tube Screamer here? I know that the TS-808 has a highpass RC filter before the clipping, and a lowpass RC filter after the clipping, where both the filters have the same cutoff, so maybe this is what is going on in this pedal. I'm still not very good at the analog side of things (digital I am pretty good at now), so I would defer to someone else's analysis of this situation.

Another possibility would be to have the highpass filtering and the clipping as part of the same stage. This could be achieved with an op-amp with diodes in the feedback loop, and a cap in the front to form a 1st order highpass filter. Or, having a nonlinear amplifier with negative feedback, where an RC network in the feedback rolls off the low frequencies being fed back. The 2nd approach would be closer to the classic 5f6-a / Marshall power amp with presence control.

Cascading several stages of highpass/nonlinearity/lowpass would be useful for creating a smoother distortion sound. For example, cascading two HP/clipping/LP stages would result in an allpass response for low amplitude signals, and a nice smooth distortion sound for high level signals, as the 2nd clipping stage would have lowpass filtering of the 1st stage's clipping. Or, if you wanted to lump all of the lowpass filtering at the output of the network (similar to the BSIAB2/BOR), you would have an identical low-level input sound, but different clipping behavior.

Again, if I am just describing what already exists, feel free to school me. I know that it is very typical to highpass filter the input to clipping stages, and lowpass filter the result, but I don't know if these are usually tailored to have an allpass frequency response for small-scale input signals.

Sean Costello

[Mark Hammer]

It actually doesn't have to be very complex.  Lots of people have the same complaints as you, so a number of sought after boutique Screamers simply use larger value caps to avoid chopping off the bottom, and some diode complement that sets a higher clipping threshold.

So, for instance, use a .22uf cap in the clipping stage instead of .047uf, and a 2+2 pair of diodes or even a pair of LEDS.  Keep in mind the concern about "over-clipping" the low end, relative to mids and highs, is really only a concern when the threshold of clipping is low enough that low-vs-high amplitude discrepancies will show themselves.  Raise the clipping threshold, and that problem starts to go away.  Not only that, the raised threshodl results in a less compressed sound, which also part of the "missing body".

I may have misjudged your needs, but try it and see if that's what you're missing.

[aron]

Here's one answer:

http://www.geocities.com/SunsetStrip/Studio/2987/fatts.html

[cpnyc23]

Thanks for the replies everyone!  I'll have to give it some thought and research a bit more...  Since I generally have never liked the sound of Tube Screamer with my playing (granted SRV and Trey Anastasio nail the full-body tone while going through 808's, so I know it is possible), I might as well open my build back up and try these tweaks.

Thanks again
-chris

p.s. any other suggestions are always welcome

[cheeb]

What guitar and amp are you using?

[Processaurus]

It seems like an ideal overdrive box would have different behaviours, depending on the amplitude of the input signal:

- Low level signals would be passed through with a full frequency response.
- High level signals would have more highpass filtering, to avoid "flubby" distortion (this is assuming that you want to emulate the Marshall-with-presence-turned-up distortion).

Can this be accomplished by having complementary highpass and lowpass filters, with the nonlinearity in between? This would use a highpass filter and a lowpass filter in series, with the coefficients designed such that the response of the filters in series is allpass (flat magnitude response, with phase distortion permitted). A nonlinearity would be placed between the two filters, where there is a significant area of roughly linear operation for low-level signals. The HP->nonlinear->LP ordering would allow for full-bandwidth signals at low signal amplitudes, while louder input signals would be clipped, but with the desirable highpass filtering on the input of the clipping. As an added bonus, the output of the clipping would have a gentle 6 dB/oct rolloff, due to the lowpass filter.

Or am I just describing a Tube Screamer here? I know that the TS-808 has a highpass RC filter before the clipping, and a lowpass RC filter after the clipping, where both the filters have the same cutoff, so maybe this is what is going on in this pedal. I'm still not very good at the analog side of things (digital I am pretty good at now), so I would defer to someone else's analysis of this situation.

Another possibility would be to have the highpass filtering and the clipping as part of the same stage. This could be achieved with an op-amp with diodes in the feedback loop, and a cap in the front to form a 1st order highpass filter. Or, having a nonlinear amplifier with negative feedback, where an RC network in the feedback rolls off the low frequencies being fed back. The 2nd approach would be closer to the classic 5f6-a / Marshall power amp with presence control.

Cascading several stages of highpass/nonlinearity/lowpass would be useful for creating a smoother distortion sound. For example, cascading two HP/clipping/LP stages would result in an allpass response for low amplitude signals, and a nice smooth distortion sound for high level signals, as the 2nd clipping stage would have lowpass filtering of the 1st stage's clipping. Or, if you wanted to lump all of the lowpass filtering at the output of the network (similar to the BSIAB2/BOR), you would have an identical low-level input sound, but different clipping behavior.

Again, if I am just describing what already exists, feel free to school me. I know that it is very typical to highpass filter the input to clipping stages, and lowpass filter the result, but I don't know if these are usually tailored to have an allpass frequency response for small-scale input signals.

Sean Costello

The interesting thing with using the noninverting configuration in opamps, is remember that no matter what kind of filtering/gain/clipping you put in the feedback loop, the ouput will always show a gain of 1 to the signal going in the non inverting input.  So if there is a gain control and a highpass filter in the loop, you get more and more gain to the high frequencies, but the unity gain on the full frequencied signal is still there.  The Rat is like that.  The common Ruetz mod of putting a pot on one leg of the cap making the high pass filter controls the frequencies being amplified (and downstream, clipped).

The non-inverting opamp is a handy way to get two different pre-clipping EQs, depending on the gain, I've done it opposite in a Great Cheddar I made, where it is flat at the lowest gain, and the gain control only applies gain to the lows and mids, to get a bassy, saturated fuzz without much extra hi end noise.

[mac]

(granted SRV and Trey Anastasio nail the full-body tone while going through 808's, so I know it is possible)

The strings gauge helps. What are you using, 0.10, 0.11?

mac

[cpnyc23]

I've been using .10 for the past few years.   When I moved up to .10's, it actually really helped my clean tone... that was when I found the depth that I am trying preserve, now that I think about it.

-chris

[squidsquad]

Not to derail...but after getting used to 0.11 gauge...no goin back!

[bipedal]

+1 on using heavier strings -- .11-.48's have worked well for me and just seem to sound a bit more . . . -- well, I don't know, just like 'em better than lighter strings.

For what it's worth, I've recently been tinkering with a variation on ROG's Tube Reamer with a 0.1 uF input cap, some tweaked values in the high pass filter in the feedback loop to retain more low freqs, a pair of red LEDs for clipping, and an SWTC at the end of the circuit.  Some common TS mods -- and mentioned in an earlier post -- so nothing groundbreaking.  I'm sure others have their own favorite variations, but I'm having good success with this circuit when A/B'd in my rig with my 808-ified Tube Screamer.  To my ears, it's a bit meatier/fuller/richer distortion sound, seems "livelier" even at lower gain settings, and that TS mid-hump is much milder...

Interesting thread topic.   

- Jay

[cpnyc23]

That TS mid-range hump may be part of my problem... I find it is present in a lot of OD circuits, to varying degrees.  Personally I feel that the mid range is already the over emphasized frequency in guitars to begin with, so adding to it doesn't really appeal to me.

The mods you mention are going to be added to my list of potential alterations...

I'm still interested in the parallel processing idea... I've tinkered with it for chains of effects.  I've not done so within an individual box.

Has anyone else taken a widely used circuit and modded it for blendable parallel processing within the box itself?

-chris