What's the distortion adding feature of the new $$L console?

[Svart]

ha!

How true... er... I mean I wouldn't know..

:green:

 

[CJ]

Where's Keef when you neeg him?
That wouldn't be a conflict iof interest, would it?

There's plenty of work out west, Keef!

:green:

 

[Kev]

yeah ... Keef

go fetch


wayne .. helecopters
:sad:
and clowns
and clowns that fly helecopters
:evil:
grrr

with just the one pot I can't see how you could make the choice
so

Maybe this'n has both?

I recon so
and that's really where I was trying to get the thread to go
that's not to say I don't think a deep investigation of why and how we like 2nd and 3rd
and what parts of the waveform are what our ear switches on to
isn't worthwhile
cos it is
and I don't think it has ever been done in detail before
not from first principles

I do remember an AES paper on distortion in massed strings and voices.
natural distortion ... ?
does it exist or do we just prcess it that way

I wish I could find that paper and always have since the birth of these forums. I saw it refered to in a very erly 80's audio magazine ... with a part print of the paper.
I have never seen the original.

 

[Guest]

Natural distortions does exist, it is distortion of our perception that we learn from birth to filter out. That;s why tube triode sound with more THD than emitter follower's distortions sounds much clean. However, it sounds louder subjectively, even if real power is less.

 

[Kev]

save it for another thread
it's a very deep topic
and it needs specific definitions to terms like Distortion
Natural Distortion may require a new word or term
(how can a voice or two voices be distorted ?)

new thread required
and I will introduce Harmonic Singing
if you have never seen or heard this
... prepared to be amazed
it is fascinating to watch and hear

 

[Kit]

My initial thoughts on this matter was marketing hype.........

This is probably just a simple clipper circuit, not to far from a any guitar stompbox. Sorry.

VHD :roll: ..........a fancy way of saying overdrive, i think.

Lets all build tube screamer.

 

[Kev]

but not all Tube Screamers are equal

just check the stomp box sites and forums

TS9 and 808 have many clones and not so clones
board layout and component choices
to use the RC chip ... or not
it goes on and on

as Dan K says ... the magic is in the detail

 

[Tomba]

Why the 2nd harmonics couldn't be level-depended? Someone was talking about Motown-sound. Isn't it so that in every simple amplifier the distortion is level-depended? If we want to create a kind of old sounding pre-amp, I think to add level-independed harmonics is not the way. It's very easy to construct an amplifier with, let's say, 10% THD and 2nd only. One jfet or bjt is enough for that. (No global or local FB) And then we might need a follower and an inverter. Then we can just mix between 0% amp and 10% amp. Easy and cheap.

But what about 3nd? I have no idea how to make it as easy as this without cliping. So maybe Kit is right. It's got to be very simple and very cheap like all the other circuits in the desk. I vote for diode-clipper.

 

[mikep]

[quote author="Tomba"]

But what about 3nd? I have no idea how to make it as easy as this without cliping. So maybe Kit is right. It's got to be very simple and very cheap like all the other circuits in the desk. I vote for diode-clipper.[/quote]

I agree about the level sensitive part. and it has to be very simple. and multi purpose... how about if the "distortion generator" also provides some useful low-noise gain?

for the 3rd harmonic generator, how about a simple differential pair of JFETs running without any feedback? that will make primarily 3rd. if you want more, load the tail with a simple resistor. like you said, for the second harmonic you can use a sommon source connected FET. I bet there is a sneaky way to use a pot to unbalance a long tailled pair essentially turning it little by little to a single transistor common source amp. presumably this will also give you a crossfade from primarily 2nd to primarily 3rd. getting the gain to stay constant is going to be the trick.

mike p

 

[Guest]

For the 3'rd order just shift bias of the same FET. Or diode, does not matter.

If symmetrical distortions cancel 2'nd order harmonic, it does not mean they and only they generate the 3'rd order harmonic. Squeeze a sinusoidal signal on one side and you will get the whole spectrum dependidng on order of squeezing function. Squeezing function of a diode is exponential, it means that the more you squeeze, the more power of more higher harmonics you get (example - emitter follower).

If you add harmonics with a level that does not depend on the power of signal it will sound mechanically, unnatural. In the nature the louder is the sound, the richer is it with harmonics. No exceptions.

 

[Svart]

:shock:

Wayne is the man.

If you have something that we could see, that would be great!

 

[Kev]

[quote author="mediatechnology"]Most of the cites I've read seem to follow the generalization I advanced earlier that adding second/even is going to create asymmetry and that adding third/odd is going to create soft clipping-like results. One cite characteristed odd-order as being "compressive" distortion. There are examples where this is not universally true so please resist the temptation to pounce on it.[/quote]
in a theoretical discussion it could be the definitions that cause confusion
that's why I centred on the thread topic
A larger thread on defining (flame suit on) distortion has always been needed.
symmetry and asymmetry
symmetrical in the vertical
symmetrical in the horizontal
and here is one of the reasons I worry about the side chain mix idea ... the phase of the wet mixed back in can cause vertical asymmetry ... tubes don't seem to do that ... they remain mirrored about the peaks. That is when not sent into extreme fault conditions.
Also I don't think the simulators get any of this right and is probably due to the fact that the models are flawed.


[quote author="mediatechnology"]The more I experiment with this the greater appreciation I have for why SSL put this in a mic preamp and not the mix buss.[/quote]yep and could be why people use the FETboy and seem to love the ShureLineLockLeveler (is that what it's called?)

I've been looking at those Patents
the second in particular
I don't think it would stand up to a challenge ... most of it is in Tenman 1930 ... but that's another thread I think.

 

[Svart]

hmm that reminds me to finish my fetboys sitting in a box..

I always heard that the FETs gave it a edgy sound..

anyway back to the subject.

Wayne are you planning on modifying the original circuit further or paralleling another circuit with the diodes reversed for rectifying the neg going peaks?

I was envisioning something resembling an inst. amp setup with the rectifying diodes.. catch my drift?

 

[Guest]

Guys, I've posted you a picture already.

 

[Ralf Biermann]

Hello together,

I started to create a website about building an High-End Audio Amp. I also added a chapter about harmonics, please have a look at

http://musicology777.com/index.htm

More later.

Best Regards
Ralf

 

[Kev]

interesting Ralf

the Levels page
on the chart

65dB(A)
increasing risk of cardiovascular disease
3.16228E-06

...... :?
cardiovascular disease


....



:shock:

 

[Kit]

And were back on guitar FX.......

 

[Guest]

[quote author="Kit"]And were back on guitar FX.......[/quote]

Not a problem, I used this both for guitar and voice:

http://wavebourn.com/images/audio/se-pp.gif

 

[Ralf Biermann]

I picked up the thought with the full wave rectifier to create even harmonics and made a circuit simulation with LTspice. The output looks unsymmetrical, that means the positive half wave is different from the negative half wave.

My feeling is that this does not sound nice, even there are only the even harmonics.

If You take a look at my page: http://musicology777.com/harmonics.htm

You will see that even a tube amplifier produces the 2nd and 3rd harmonics. They build a triad, it is like the notes C, C' and G' are played at the same time. My theory is that the higher harmonics produce sounds that do not sound nice anymore, since the human ear is most sensitive in the 2kHz to 5kHz range. That means the first 3 harmonics sounds fine, but the higher harmonics distort the sound.

Best Regards and special Greetings to Wayne
Ralf

 

[Ralf Biermann]

I think the best sound effect is to make the peaks of the sine wave just a little bit more flat. A tube amp makes this very good.

Greetings from Germany
Ralf