if your amp has no crunch its a solid state amp. if you dont want to buy 100 pedals that will still make is sound like a solid state amp pretending to be a tube amp, you can slice the speaker with a razor blade or hot glue a lamp pull chain so it rattles on the speaker.
I think volume of playing has some to do with it. If you are running an amp/mic combo close to breaking up, when you hit it with more volume and a good cup (which also move much more volume into the system) that translates into more signal, which causes clipping, breakup, overall crunch. If you get more clean volume out of your playing embouchure you are closer to getting that tone when amped.
Obviously there are folks who relate to this subject from different rules of thought and understanding.
My experience is...when I play acoustically and crunch the sound "manually",then - I am employing human rather than mechanical energy to produce crunch...A crunch that has yet to be manipulated, saturated or colored by electronics.
In other words,when playing acoustically - the crunch has already accrued - created by the players skills...but - it's full explosion of power is heard in all its glory when amped.
Amp your man made crunch and it is electrically transformed into bolts of energy that magnify, enhance and spark the crunch giving the human ear the ability to hear it's grandeur in new and glorious ways :)
Frank, for the sake of clarification, which this thread intends, how about identifying a representative example of crunch produced acoustically. A specific section on one of the proceeding videos. And, btw, an interesting topic to kick around. It's actually very different for me to argue the gear side because I am completely committed to acoustic tone tone tone. That's the distinction here, to me. 5-10 seconds of video...
Littoral - For me a lot of Walters playing in this video demonstrates what I class as acoustic crunch. To clarify what I mean, to me acoustic crunch is the "intentional slop" that is created when one plays , chords, octaves, double stops, other interval splits and utilises tongue blocking for slaps, pulls and flutters. Now as to whether anyone else classes it as "crunch" doesn't really matter to me. I'm merely posting it for clarification of my view on it. I believe that might be what Frank is referring to as well, but I'll let Frank confirm or deny that.
Kingley, excellent example. What term do do give to what he does 2:09-2:11? The attack to get that sound is really great to see -violent. Studying his movements show where he's TBing vs. LPing single notes -and octaves are obvious.
So, how about this: Can you get crunch out of an amp without good technique?
Last Edited by Littoral on Jun 08, 2013 7:28 AM
If Joe Harp Player plays through a guitar amp that is as stiff and twangy as a banjo string his acoustic crunch will not become the lovely mellow tones we like.
Harp amps need a gain ramp not as steep (see Heumann, Greg) and a power source not as stiff and speakers that will have a chance to break up when you hit them with the crunch. That is when the magic happens.
-I think the microphone has a lot to do with the sound of your crunch, from warm to ragged.
-Lots of people have mentioned clipping as the source of crunch, but true clipping occurs in the output stage (your power tubes) when they exceed the rated power for the amp and distort. In most amps that is majorly LOUD. I think instead what we are hearing is transient preamp tube overdrive from a hot bullet mic. Mix in the nice tones from the "acoustic crunch" and you get a very cool sound.
But it all starts at the player. You gotta PLAY the amp. You gotta bring something to the table.
@Rick - I agree with most of what you've been saying but for the sake of accuracy, a couple of corrections and then some "amplification"....
1) Mics have a lot to do with it, but the better you are at cupping, the less the mic matters. (Problem is, MOST beginning and intermediate players THINK they're good at cupping but really have no idea how to tell, and aren't)
2) Clipping can happen ANYWHERE in the audio chain, not just the power tubes. Clipping is simply what happens when an audio device is pushed beyond its design limits - a sine wave in becomes "not a sine wave" out. The peaks cannot be reproduced so they tend to flatten out and contain a lot of distortion. The mic can clip, the pedal can clip, the preamp section can clip and the power section can clip. The earlier it happens in the chain, the more repercussions as the distorted signal cascades through the amp.
3) In addition to clipping, amplifier distortion happens during signal level transitions within the clean range. If you put a perfect square wave in, the output won't come close to matching it. And if you look with an oscilloscope you'll see that most the distortion will appear during the transitions. Electrical engineers call this the "rise time" - in our square wave example if the bottoms are 0 volts and the tops are 2 volts, the time between 0 and 2 volts at the input is zero - but no circuit truly responds instantly (though digital computers come damn close!). The resulting wave will have some sort of messy curve on the way up and back down.
Now then: The techniques discussed above - particularly attack and ending techniques such as tongue slaps and pulls - are ways to briefly add multiple notes to what, in the middle, was a single note. This is where most crunch comes from - they are percussive in nature and very short in duration - so we tend to hear more of what the mic and amp are doing at the "edges" of the notes than in the center. A headshake is a good way to listen for crunch because there is a much higher percentage of time spent on note edges compared to note centers.
ANY time we play more than one note on the harp, "difference tones" are generated. These are way down in the bass range compared to the fundamental frequencies and tend to overdrive a mic or amp more easily - even though they are barely audible (if at all) when played acoustically. But this is precisely where the "bass" comes from when playing amplified. It also tends to produce more crunch because, even if nearly instantaneously, it takes a lot more power to produce the bass notes so the distortion at the "edges" is greatest. So tongue slapped transitions between a 3 or 4 hole chord and a single note bring out a lot of crunch! -------------------- /Greg
Clipping generally is taken to mean the distortion that occurs when an amp exceeds it's rated power. That is why and how a rated power is specified: It is the highest power at which the amp can produce a clean tone. The wave form distorts more as you pass beyond that point. I used the term "clipping" in that context -- as it is commonly used -- to draw a distinction with distortion that originates in other components and at other levels.
There seemed to be some conflation of "overdrive" and "clipping." I think in common usage the first term applies to preamp tube distortion and the second applies to the output section. They are different phenomena and certainly sound different.
Rick- Maybe only among musicians is clipping described that way. Clipping can occur anywhere in the amplification chain. If you clip early in the chain,it carries through the rest of the chain. Preamp clipping may sound different from power amp clipping,but it's still clipping.
"Kingley, excellent example. What term do do give to what he does 2:09-2:11?"
Littoral - I'd usually refer to it as a pull. That kind of sharp pull creates a very percussive slap. I often use a similar technique played multiple times in rapid succession to create a machine gun like rhythmic effect.
Greg - That's a great description.
Rick - I love the sound of those Kalamazoo amps. Mark Prados gets a lovely tone out of his in this clip.
Last Edited by Kingley on Jun 08, 2013 10:10 AM
+1 on what Greg & Tuckster say on crunch/clipping. It's pretty well impossible to determine by ear (e.g. from an unknown amp on a recording) whether crunch is coming from the preamp or power amp section, because even if the power amp stays clean, it is still transmitting crunch from an earlier stage.
Power supplies (PT, caps, rectifier) can sag because of the draw on them by the power tubes, but if the power tubes themselves are operating outside their clean capability, then this is made evident by the waveform kinking/notching, because either the tubes can't draw enough current to hold it together, or because they have drawn so much current that they have pulled down the voltage to a point where the current conducted is not enough to preserve the clean waveform.
In short, overdrive (break up/distort/whatever...all words for the same thing) power tubes and they go "cold", bias-wise, relative to what they need to supply.
There seem to be 2 dscussions intertwined here. If crunch is coming from a player/technique then it's not "coming from" the amp, at least not from the amp alone. If you work on slaps, pulls etc to make a crunchy sound, then you will make it acoustically, or through a clean amp (like a PA, which is still an amp). Crunch "coming from an amp", as I see it (you may differently) is therefore something that affects the whole note, the body of the note, not simply a percussive effect, or articulation by the player.
Single ended amps crunch easily, as do cold biased push-pull amps. Even in hot biased push-pull amps, the preamp sections are single-ended, and you hear the effect of this, unless you retube to really low gain preamps...then it can be unlikey that you will push the power tubes hard enough to distort...? Very old amps tend to "grind" (often a more greasy, softer edged sound) a little more than hard "crunch", because the power amp may sag, but has enough current to hold together, but they had very low voltage & grid leak biased preamps that dirtied up early, soft rectifiers that sagged & dropped voltage & subsequently bias.
I struggle to think of more than a handful of really crunchy amplified harp recordings from before about 1960? Little Walter’s amp on Muddy’s “Country Boy” session is fairly crunchy, "Crazy legs/Don't Have to Hunt" too, Cotton’s harp on “Evil/Let me Hang Around” is compressed, but the body of the notes are also crunchy/fuzzy, not smooth (that's when you hear him get down the low end anyway). Imagine a steel bar being rubbed with sandpaper, rather than the rim of glass ringing when rubbed with a wet finger..?
This, I guess has some crunch...papery too though?
This is archetypal "crunch to me..
Broadly crunchy, but papery crunch?
---------- www.myspace.com/markburness
http://www.facebook.com/markburness
Last Edited by 5F6H on Jun 08, 2013 12:44 PM
Not too sure if I agree that distortion from preamp and power amp sections are indistinguishable. Amp aficionados are always talking about getting to that sweet spot where the power tubes saturate and all that.
Line out circuits that come from the preamp section are though to be inferior to those that come from post-power section.
But all that is a BIG tangent. If a newer player asks me how to get crunch I make sure he has a suitable amp and then talk about playing technique. You don't have to be an e-squared to get crunch, you just have to play it.
Given the same player, same starting tone and same amp my brief technical answer is:
Use a hot mic. and cup it tightly, Bias the amp cold. {fixed bias push pull anyway}
I was amazed at how much more "crunch" I could get out of the same amp by biasing colder. This includes both my BMRI and a vintage blackface Deluxe Reverb.
biasing is not as easy to change on cathode bias amps, but those are often good crunchy & singing as is.
- What Mark 5F6H says goes -
my fudgy definitions of amp distortion part A and B 'Crunch is just a part of what can make an amp great
"Crunch" = gritty, breakup, distortion, - dirt, grind, darker toned {are we going in circles yet?}
"Sing" / Sustain - Violin like, quick responding amp that gives a natural compression. Brighter toned. You don't have to attack as hard to get a very electric tone.
Good amps have some of both. My Bassman is crunchier, my Gibson GA6 'singier' - compared to each other. Both are great amps ----------
"The techniques discussed above - particularly attack and ending techniques such as tongue slaps and pulls - are ways to briefly add multiple notes to what, in the middle, was a single note. This is where most crunch comes from - they are percussive in nature and very short in duration - so we tend to hear more of what the mic and amp are doing at the "edges" of the notes than in the center. A headshake is a good way to listen for crunch because there is a much higher percentage of time spent on note edges compared to note centers."
"Not too sure if I agree that distortion from preamp and power amp sections are indistinguishable. Amp aficionados are always talking about getting to that sweet spot where the power tubes saturate and all that." So how would you determine where the crunch is coming from in a recording of an unknown amp/player? You can reduce crunch in an amp you are familiar with by reducing preamp gain...but unless you specifically get MORE power at the speaker, with more crunch...then you are only reducing preamp crunch, not increasing power amp distortion/crunch. Depending on where yo start, you increase "power tube" distortion by biasing hotter (smoother, brighter, brassier, sometimes more compression) or cooler (tighter crunchier)...either way, you are trying to shift the character from where it is cleanest. If you make changes elsewhere you affect the overall sound.
Mostly players talk in terms like "saturation", power tubes in "saturation" don't make any sound, there is no signal swing (and are usually glowng red hot & about to die). People hear a warm, slightly compressed sound with nice sustain and call it "saturated" (it's a turn of phrase, not a technically derived term - like if I said someone was "yellow" when meaning a coward), it's most probably the plates drawing enough current to pull down the voltage in a pleasing way...the tubes aren't saturated, beyond this pleasing point they will be driven to crunch by demanding more current still when the amp is pushed. Transformer saturation is more frequently discussed.
Harp amps rarely drive the power tubes to the levels of output that guitar does (~1.5x W RMS rating), the big harp signal voltage gets clipped way before the power tubes see it...then it's hard to determine what is coming from where. I built an amp that specifically didn't crunch in the preamp (by eliminating the S-E stages as much as possible), just sounded a little bland with harp...clean/warm...the design worked better for guitar where the the amp sagged & bloomed nicely at high outputs...still didn't crunch just a greasy, clean tone.
"Line out circuits that come from the preamp section are though to be inferior to those that come from post-power section." That's because line out from the preamp are totally single-ended, voltage amplifiers...if you fed that signal into a tube power amp it would sound fine...Danelectro & Kendrick have done this amongst others. The reason you usually want a speaker driven line out is because you want to pick up the normalising effects of significant current draw through the power supply from the power tube plates (if you tap the signal beforehand, the power supply barely notices a few mA from a couple of 12A#7 tubes) and the kick-back voltages from the speaker. However, some amps with a speaker driven line out still sound harsh & crunchy with harp unless you drop preamp gain (say, if you started with all 12AX7s) because you lose the frequency filtering of the speaker and you are again taking the amp tone (S-E preamp into a S-E or P-P power amp) & feeding straight into another single-ended preamp again. Wherever possible I prefer to line out a small amp into a bigger tube amp.
If you can hit an amp hard enough then it'll crunch, some amps like push-pull cathode biased amps, with no cathode bypass caps (like some P-P Premiers) are harder to push into crunch than single-ended amps & cool biased P-P amps. They still distort & sag, but usually in a smoother, greasier, blurred note kind of a way.
---------- www.myspace.com/markburness
http://www.facebook.com/markburness
Last Edited by 5F6H on Jun 08, 2013 4:39 PM
Rick, not IMO, because I feel crunch comes from the amp not the players. Of course anything in the signal chain can contribute.
Last Edited by Harpaholic on Jun 08, 2013 4:48 PM
In the context of the topic of this thread (the player already has a suitable amp and is asking how to get crunch) I think the technical stuff will sound like a lot of mumbo jumbo. As I said earlier, it is a big tangent.
If a guy asks you what time it is he doesn't want to hear about how to build a clock, ya know what I'm saying?
I think Greg had the good answer. It is a learned technique. This thread has been interesting because of the differing ideas of what amp crunch is! Is it the player or is it the amp? It is surely both, but since the player in my example already has an amp we know is suitable for harp it is left to the player to get the sound.
"But all that is a BIG tangent. If a newer player asks me how to get crunch I make sure he has a suitable amp and then talk about playing technique. You don't have to be an e-squared to get crunch, you just have to play it."
It's not a tangent in a thread titled "How do I get crunch from my amp?"...and you're telling them to get an amp and put some crunch into it (not from it)...then that would then be crunch heard acoustically, or into a clean PA. It's great to learn to make some crunch yourself, I remember the first time a great player showed me how he played acoustically with slaps & articulation...I just couldn't believe the "amped" sound came from just him and a harp. But if you want "crunch from an amp", an attribute generated by the amp that wasn't there before, then that comes from the amp & not the player, though it may augment the player's articulation...which looks like what you really meant. ---------- www.myspace.com/markburness
Mark, no.... you are missing it. The player ALREADY has an amp that I know will crunch nicely. The missing piece has to be technique. And expectations.
IMO, a beginner could get crunch out of a crunchy amp playing guitar or harp, because the crunch is coming from the gear. I know I've done it. Sure with skill and technique one can make better use of that crunch and it will be more pleasing to the ear, but skill isn't necessary.
How do you get crunch out of a crunchy amp? Play it!
Last Edited by Harpaholic on Jun 08, 2013 5:45 PM
"Clipping generally is taken to mean the distortion that occurs when an amp exceeds it's rated power"
That may be true for hi-fi gear, but it is far from a complete picture. You can overdrive your mic and cause it to clip. You can overdrive the preamp tube and cause it to clip.
Greg, yes, that is why when players are talking about the distortion that occurs in preamp tubes they generally call it "overdrive." You know, they call it an overdrive pedal, not a clipping pedal.
Great minds can certainly differ - but that acoustic Little Walter recording, though great, and filled with chords and slaps and other stuff that make it a masterpiece, has ZERO "crunch" in the way most of us are talking about it here.
@Kingley - same for the vid you put up. What is he doing at 2:09? Tongue slaps. Sounds great - but that ain't crunch.
Crunch, at least to me, is a byproduct of amplifier distortion that comes from when we play stuff like that (slaps, pulls, chords) but amplified.
This is an awesome topic!! Was listening to some Rod Piazza today. One cut in particular caught my ear: "Up The Line" I have it on George Harmonica Smith's Bacon Fat - Complete Blue Horizon Sessions CD1 Disc 1 (killer CD btw) If you have it take a listen to Up The Line. @Greg, I am curious what you and anyone else would categorize the "sound" a distinct break up. Can that be considered crunch? I think my dad would start screaming "distortion" and "he's over-modulating!" But I like the sound. The tongue slap really produces that hint of crunch -- or whatever it's called.
This is not the same Cd that I have but maybe it's the same cut:
---------- The more I learn about harmonica, the more I learn how much more there is to learn.
Rick, Im sure you already know the answer to that ? As with most tube amps, its easy to get a clean tone out my amps, it just depends on the mics I use, speakers, and how hard I push them to distortion.
"@Kingley - same for the vid you put up. What is he doing at 2:09? Tongue slaps. Sounds great - but that ain't crunch."
Greg, I didn't cite 2:09 specifically as an example of crunch though did I? I referred to it as a "pull" which creates a percussive slap. I wouldn't strictly call what Walter does at 2:09 as a slap. I think of it as much more of a pull. That's a whole other conversation though. Either way it doesn't really matter, because as you quite rightly say it sounds great.
As for what constitutes "crunch" I've already made my thoughts on it clear. I guess some folks don't hear "crunch" in acoustic playing and only think of it in terms of amps clipping. Personally speaking that's not the whole enchilada for me though. I perceive it as entailing a lot more than that and not purely being exclusive to an amped sound.
I understand that some folk can only conceive of crunch as living totally in the world of electronics.
For me, when I want to tame my crunch - I will remove the bullet/amp...and go acoustic. From a lions roar, which sounds ferocious to an alley cats hiss, which can sound mean but much less so than a lion.
I hear notes crunching acoustically through the multiple ways they can be manipulated - the sky's the limit really, only stifled by ones imagination...
Skillful use of the many hand and vibrato variations available can really help bring acoustic crunch to LIFE.
Add a mic/amp to that and, BANG...that life becomes supernatural or unearthly - because an electronic spirit has been breathed into it :)
I agree with Frank that a very real crunch comes from the player and can exist w/o an amp in the picture at all. You just have to know what you're listening for. Total crunch is a both a function of player crunch and amp crunch.
I look at it this way: a pure "note" is a single sine wave (which we never really generate as harmonica players anyway; all of our "single notes" are colored with various overtones from the get-go). If you want to argue that "crunch" originates in the amp's clipping of a signal (as a simplified way of looking at this we view the amp as converting a "sine wave" into a "square wave" -- where a square wave has a theoretically infinite frequency content), you then have to agree that a good tongue slap generates similar infinite frequency content (with its percussive impulse).
It's like Tuvan throat singing: so much of what you hear is what you are actually listening for. Most beginners diving into the world of overtone singing don't initially hear many of the overtones because they just don't know what to listen for.
Since nobody here is really defining what the frequency envelope of a "crunchy signal" looks like, all of this is completely subjective anyway. But I do think that one can very easily argue that acoustic crunch is just as real (and, IMHO, just as appealing in its sonic complexities) as amp crunch.
This thread is amazing me just in the sheer number of posts it is attracting. There are a bunch of cool videos embedded, I hadn't seen the hound dog Taylor/lw clip before. I like the videos. I like the OP. i like the tech info. Anyway here is another post for the most prolific post attracting thread I've seen for a little while. It's bizarre. ----------
"But I do think that one can very easily argue that acoustic crunch is just as real (and, IMHO, just as appealing in its sonic complexities) as amp crunch."
@Yonderwall "Since nobody here is really defining what the frequency envelope of a "crunchy signal" looks like, all of this is completely subjective anyway. But I do think that one can very easily argue that acoustic crunch is just as real (and, IMHO, just as appealing in its sonic complexities) as amp crunch."
The classic "crossover notch" on a scope trace is one clear indication of electronically generated crunch. It is well established, identifiable and perfectly repeatable.
I don't think that there is any disagreement about acoustic/amplified crunch being any more/less "real". It's more a question of terminology & finding a common syntax - how those terms are described. If your crunch comes from articulation techniques, then it is irrelevant to the concept of "amp crunch" specifically, because you don't need an amp to do it (and nor should you). A crunchy amp tone (to me at least, I'm not trying to dictate what it is) is something that affects & colours the middle & end of a note, even if a single note rather than a chord and not just the result of a pull or a slap affecting the transition from one note to the next. For instance if you were to draw long held 3 draw bend, the crunch would be there from start to end.
This can be approached/emulated without an amp, by drawing very gently and surpressing the crisper, higher frequecies.
For all my attempts at describing "amp crunch", I'm personally not that keen on it (well, apart from occasions - that crunch from a brown Concert always gets me) and try and avoid it, I'd rather the amp conveyed what I was doing with a little more warmth & richness.
---------- www.myspace.com/markburness
http://www.facebook.com/markburness
Last Edited by 5F6H on Jun 09, 2013 7:53 AM
5F6H, Well Said: "I don't think that there is any disagreement about acoustic/amplified crunch being any more/less "real". It's more a question of terminology & finding a common syntax - how those terms are described." -signed, Jan. 1960 Concert
and, easy now... Frank "Some players hear the crunch played as is acoustically." yonderwall "You just have to know what you're listening for." What I hear acoustically isn't what I hear amplified, and I'll say you CAN hear the difference. That difference is what I hear as the topic, "crunch". Or: Greg: "Crunch, at least to me, is a byproduct of amplifier distortion that comes from when we play stuff like that (slaps, pulls, chords) but amplified."
Last Edited by Littoral on Jun 09, 2013 7:43 AM
@5F6H please don't get me wrong, I completely agree that there is a very real amp crunch participating in all of this (certainly beginning at the crossover notch, but perhaps even originating in other aspects of the amp design as well, such as speaker choice -- and let's not forget the microphone!). In fact, I'm actually thinking of building an amp this summer and plan on paying close attention to which circuit design I choose, speakers, etc, to shape the amp's sound character to my liking (and 5F6H, I will very likely be asking for advice along the way!)
@Littoral, you may have just hit on the answer to all of this… maybe we just need to define crunch as "the different thing that the individual hears *when using an amp*" (i.e., insist that crunch involves the amp, and recognize that the definition of crunch will vary from individual to individual, since what one person "hears" is often quite different from what another "hears :)
Truth be told, I think we all agree that there is both a human component, as well as an electrical component, to all of this (even if we choose to define the question as purely one of amp crunch, some players will still be better at extracting better crunch from a given amp than others, so the player is always an exponent in all of this).
What an informative, and just generally interesting, thread this has been!
