Question About Diode Clipping Sound

Started by Agung Kurniawan, February 15, 2017, 04:49:06 PM

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Agung Kurniawan

Did wire colour spectrum really matter in stompbox?
Multiple gain stage followed by some active EQ is delicious.

EBK

#41
Quote from: Agung Kurniawan on February 20, 2017, 12:45:02 PM
Did wire colour spectrum really matter in stompbox?
Sadly, no, other than keeping organized, as Mark suggested.  To be more specific, the wires are exactly the same inside, regardless of insulation color. 
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ashcat_lt

Quote from: merlinb on February 20, 2017, 07:10:29 AM
1: Compression/bias shift, e.g.. changes in clipping threshold with signal level. In most pedals it is constant which is why they don't sound much like real tube OD.
I mentioned power supply sag a while back, which is what I think you're talking about here.  Basically the clipping threshold (and bias/symmetry?) is dependent on the average level of the signal over some period of time.  I think it's the hardest to get just right in emulations both analog and digital.  The concept is relatively simple, but the timing constants and actual amplitude of the effect are big questions, at least in my mind.  I'd definitely be interested in discussion and/or links that could help me quantify "typical" sag behavior.

Also, does anybody have any insight on that thing about whether saturation has a different knee shape from cutoff in either a tube or transistor?

thermionix

Quote from: Mark Hammer on February 20, 2017, 11:58:32 AM
I use white for input and blue for output.

Purely coincidentally, I've been doing the same thing.  It started a few builds back, a Rat clone in a blue box.  In my mind, white represented the "blank" or "uneffected" signal, and blue was for after the "blue effect" was applied.  And I've just kept doing it like that since.  For pots that have 3 wires going to the board, I've been using red, white and blue, because it's easy to remember in order.

Current build has purple for ground, only because I ran out of black, and don't have much green.

Mark Hammer

Quote from: thermionix on February 20, 2017, 02:04:53 PM
Quote from: Mark Hammer on February 20, 2017, 11:58:32 AM
I use white for input and blue for output.

Purely coincidentally, I've been doing the same thing.  It started a few builds back, a Rat clone in a blue box.  In my mind, white represented the "blank" or "uneffected" signal, and blue was for after the "blue effect" was applied.  And I've just kept doing it like that since. 

Funny.  That's precisely my reasoning too.  When comedians tell jokes with naughty words or ideas in them, they are described in the industry as "working blue".  I figure since the majority of circuits built add dirt of some kind, what comes out is "blue".   :icon_lol:

EBK

Quote from: Mark Hammer on February 20, 2017, 03:29:28 PM
Funny.  That's precisely my reasoning too.  When comedians tell jokes with naughty words or ideas in them, they are described in the industry as "working blue".  I figure since the majority of circuits built add dirt of some kind, what comes out is "blue".   :icon_lol:
You mean like Big Muff Pi and Super Hard On?  :icon_wink:
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PRR

I think box color is much more important than wire color.

Nearly all diodes are "the same" except for volume (and you have knobs for that).
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merlinb

#47
Quote from: ashcat_lt on February 20, 2017, 01:17:07 PM
I'd definitely be interested in discussion and/or links that could help me quantify "typical" sag behavior.
There's a whole book on it:
http://www.lulu.com/shop/ulrich-neumann-and-malcolm-irving/guitar-amplifier-overdrive/paperback/product-22447917.html

Quote
Also, does anybody have any insight on that thing about whether saturation has a different knee shape from cutoff in either a tube or transistor?
There are so many variables that it is possible to blend grid-current clipping from being softer than cut-off, to being harder. (see fig. 1.19 and 1.20 of my book http://valvewizard.co.uk/Common_Gain_Stage.pdf). However, this is not as important as the general symmetry, and that is also less important than bias shift. Power amp sag can play a part in power amp distortion, but it is usually negligible in the preamp. What matters there is the charging/discharging of coupling caps. This causes the clipping threshold to 'track' the signal envelope to some extent, preserving a lot of its dynamics.

You can still recreate this effect in an opamp dirt pedal, too. The trick is to do a little clipping in the feedback loop as usual (this somewhat simulates cut-off clipping) and a little clipping with diode/s to ground after a coupling cap, which simulates the grid-current. With more than one clipping stage and a lot of tweaking, it should be possible to create a very dynamic, tube-like overdrive this way. It's something I intend to attack eventually!

rutabaga bob

All right, Merlin!  I'll get the popcorn!   ;D
Life is just a series of obstacles preventing you from taking a nap...

"I can't resist a filter" - Kipper

duck_arse

Quote from: EBK on February 20, 2017, 01:15:24 PM
Quote from: Agung Kurniawan on February 20, 2017, 12:45:02 PM
Did wire colour spectrum really matter in stompbox?
Sadly, no, other than keeping organized, as Mark suggested.  To be more specific, the wires are exactly the same inside, regardless of insulation color.

diodes come with different coloured bands - which colours sound best? also, where's my coat?
don't make me draw another line.

Kipper4

Ma throats as dry as an overcooked kipper.


Smoke me a Kipper. I'll be back for breakfast.

Grey Paper.
http://www.aronnelson.com/DIYFiles/up/

highwater

Quote from: Kipper4 on February 23, 2017, 03:31:17 PM
GeoFx has an answer. :)

http://www.geofex.com/FX_images/realtube.jpg

That works great if you fingerpick like Neil Young, but if you play Scruggs style, or with a flatpick, I'd recommend a different type of hammer.
"I had an unfortunate combination of a very high-end medium-size system, with a "low price" phono preamp (external; this was the decade when phono was obsolete)."
- PRR

thermionix

Quote from: Kipper4 on February 23, 2017, 03:31:17 PM
GeoFx has an answer. :)

http://www.geofex.com/FX_images/realtube.jpg

Picture is kinda blurry, but that looks like an 8417.  The pinout is NOT correct for a TS-9.

rutabaga bob

Life is just a series of obstacles preventing you from taking a nap...

"I can't resist a filter" - Kipper

Agung Kurniawan

Multiple gain stage followed by some active EQ is delicious.

antonis

Quote from: Agung Kurniawan on February 24, 2017, 01:03:34 AM
I love this thread :D

Does it mean that you encourage a "Lead-free solder joints affect diode clipping waveform"-like discussion..??
"I'm getting older while being taught all the time" Solon the Athenian..
"I don't mind  being taught all the time but I do mind a lot getting old" Antonis the Thessalonian..

EBK

Quote from: antonis on February 24, 2017, 06:58:13 AM
Does it mean that you encourage a "Lead-free solder joints affect diode clipping waveform"-like discussion..??
Everyone already knows that silver solder sounds best in a Tubescreamer.  Didn't John Landgraff teach you anything?   :icon_lol:
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GibsonGM

Quote from: EBK on February 24, 2017, 07:31:26 AM
Quote from: antonis on February 24, 2017, 06:58:13 AM
Does it mean that you encourage a "Lead-free solder joints affect diode clipping waveform"-like discussion..??
Everyone already knows that silver solder sounds best in a Tubescreamer.  Didn't John Landgraff teach you anything?   :icon_lol:


Hendrix's tech guys used gold solder.  I think he picked it up from Roger Mayer.  They claim you can hear it on the Monterrey Pop recordings...
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MXR Dist +, TS9/808, Easyvibe, Big Muff Pi, Blues Breaker, Guv'nor.  MOSFace, MOS Boost,  BJT boosts - LPB-2, buffers, Phuncgnosis, FF, Orange Sunshine & others, Bazz Fuss, Tonemender, Little Gem, Orange Squeezer, Ruby Tuby, filters, octaves, trems...

Groovenut

#58
That TS-9 has the pcb mounted DC power jack. It'll sound totally different than the rarer and better sounding panel mount DC power jack version, but only in front of a Marshall. If you play a Fender you should still be good...
You've got to love obsolete technology.....