Clipping threshold?

[phaeton]

I wonder if they have anything here in Hawaii?

Do you play keyboards in a jazz/fusion band named 4fathers, or does everyone confuse you with that Aron Nelson?   I stumbled across the IUMA site in my early days of websearching for resources:

http://www.iuma.com/IUMA/Bands/4Fathers

Some interesting tunes there, whomever it is. 

I received a Masters in Electronic Music composition from San Jose State University. We were doing some DSP stuff, but nothing like now. Then there is the issue of time...... icon_rolleyes

Yeah, time.  If it weren't for time I'd be going to a community college to study some things- typically some EE stuff.  Probably wouldn't follow it through to the level of Masters but it seems like the most efficient way to get a good working understanding.  Maybe then I wouldn't have to re-read R.G.'s posts so many times

BTW, years ago I made the Shaka HV and even put a voltage regulator in it for sag. It didn't affect the pedal as much as you might think for certain things.

I figured someone had tried that...

[aron]

4fathers is dead unfortunately.... Not enough interest.

Here's the precursor:

http://www.iuma.com/IUMA/Bands/importexport/

I even got the guitarist of Zawinul syndicate to comment on the music! He loved it!!!!!
Another great pianist Otmaru Ruiz likes it too! (Played on the live album of Jing Chi and with Mahavishnu)

I do have a weird Koto band going on right now. 

[Paul Marossy]

I even got the guitarist of Zawinul syndicate to comment on the music! He loved it!!!!!

That's cool. Who is his guitarist now anyways?

[aron]

I noticed Scott Henderson is doing gigs with them lately.

[Paul Marossy]

I noticed Scott Henderson is doing gigs with them lately.

Really? He's played with Joe in the past. Scott is in the top three favorite guitar players for me, I just love his phrasing and what he chooses to play.

[petemoore]

  I was kind of hoping someone would shoot down or like the 'speaker under the diodes to change the place the diodes start clipping' idea, or think of a reason [say connecting a speaker wired for output so near an amp input]
  Or some gullible sort 'like me' just would happen to have a high enough signal voltage diode clipper on the bench with the diodes socketted, think maybe that'd be cool and try it out a little bit.
  Ok...I type, I think...feedback...or possibility the speakers would be messing withthe output of the opamp too much...insert damping, or voicing caps.
  Feels like I'm pouding a dedhorse, and wondering why it's dead...seemed like an interesting enough idea, I guess it's just because it had occured to ME, and I'd not seen or heard of it done before.

[MrGuitardeath]

I'm not sure if I follow what you meant but I used some LED's on on my speakers wired with a pot so I could get an overdriven tube power amp effect to perfect solid state rigs. I also wanted the responsive light effect from them. It worked great only the damn pots end up exploding and sometimes so did the LED's. Can it be done, YEP. Do I know enough to do it, NOPE.

I do however suspect the right LED's in place of the clipping diodes in a lot of simplistic gain circuits should yield an overdriven tube effect. When I used them on the speaker end of things, the distortion they yielded was VERY responsive as was the light they produced. Some of them were hard to get to overdrive, some were very abrupt when I overdrove them in the way they distorted and lighted up and some were incredibley smooth...I recall the greens I used being very smooth anbd possibly the smoothest.
...Everyone talks about organic and the greens were LED's with a wavelength rating at EXACTLY what yields the best vegetative growth in plants. The reds that performed the best just so happen to be those hitting the light wave length for plants blooming stages.

[petemoore]

m not sure if I follow what you meant
  Diodes clip because they are between a signal path [which has voltage swinging + and _ from a bias point] and a reference voltage....0v...ground.
  This is why only a certain amount of 'knee' can be made to happen in the clipping, it's hard to get the swing of the voltage to cross the clipping threshold at a 'soft enough angle to get past a certain size knee.
  If the ground was moving up and down, especailly a little bit, from actually being 0v at around the same rate as the signal +/- voltage swing, larger knees would theoretically occur.
  An easy way I thought to get the ground to move a little up and down in near cyncopation to the signal swing, is connect a coil, moving at near the same frequecies as the signal, [ie speaker or mic coil driven by the cone, which is in turn driven by the air in front of your speaker, which is vibrating at the rate of the guitar string]...IOW introducing a moving reference point instead of ground to 'clip against', so possibly right at the knee, the threshold would be 'spread' because the reference point is moving in the same [or opposite direction if you simply 180 the speaker cone/coil] direction [voltage wise] as the signal.
  My thinking is that the speakers nonlinearness, the air, resonances, and the fact that signal path voltage strength might vary more in relation to the speakers movement would make for touch and amplitude sensative distortion response caused by the 'feedback' in the form of the bottom half of the two diodes [which are usually connected directly to ground] moving up and down a little bit or alot [it could easily be made adjustable many ways] as a reference point. it would tend to be a little or a little more slightly out of sync from the signal path because of air, distance, speaker cone resistance to movement...this might make for very interesting 'moving' responses ranging from sponginess, to spikeyness.
  Here's the basic setup.
  Take a Dist+, connect a small speakers lugs between the where the diodes normally connect to ground [one lug to ground, the other lug to where the diiodes used to connect to ground] Drive the 'reference moving device' [the little speaker] with your amps speaker, facing cone to cone, your regular amps speaker cone will move the little speaker cone.
  Same Dist+, each diode gets it's own little speaker, each diode speaker series connection would go from signal path to ground.
  Insert speaker connections between diodes to ground, drive the speaker with the air pressures by placing it near enough to the speaker that is amplifying your guitar.

[MrGuitardeath]

Sounds like it will yield a really cool effect pete..do you suspect it will yield that groggy tube like response?
It seems as though it would.

I suspect a circuit could be built based around diodes or high strength LED's that just pops on the back of the speakers terminals and delivers easily the sound of an overdriven tube power amp. It would likely be able to deliver a much more fine tuneable response. I mean it's just toying with diodes and resistance. A simple passive circuit with a high wattage pot to fine tune it.

I can give this final bit of information. It seemed if you used a vast amount of LED's with really low output specs, you would get the smoothest groggy effect. The result was most definitely groggy like tubes, this is why I kept referencing voltage sag with the analog pedals and higher end digital gear. Something about pushing the diodes over their threshold reminded me of the effect caused by voltage sag that I've heard.

I think knee is a rather poor term to use. Now that I understand it properly I feel like it is a term to confuse people. Wouldn't the term threshold make more sense?
Just my two cents...

[MrGuitardeath]

One more puzzle piece...

I've noticed the deal with tube amps is sensitivity. All the mods people do to them so they end up with that brown sound or whatever. Solid state and digital gear isn't being deisgned to be sensitive to the voltage fluctuations of the pickups output. Comparing a finely tuned solid state to a tube amp is really difficult because of the sensitivity of the tube amps response once it has also been ultramodified. I use a lot of clean gain run into a moddestly dirty, gritty gain and that does a great job. The LED method I spoke of should probably be the easiest route.

I've modified my solid state rigs and can now very clearly see it's about getting these circuits more current/voltage sensitive. What I noticed made my gear more sensitive was the higher quality resistors, capacitors and the materials they were made from that I chose based specifically on the compound's actual physical structure.
I notice you run a signal through a silicon pedal, it sounds rubber.. like silicon boobs. The solid state chips, lots of metal inside. Hense the tinny, sterile sound associated with them.

I think the tube overdrive is actually really easy to simulate, it's more the voltage sensitivity causing issues with peoples feelings towards solid state and digital.