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I ask this for information, too. And just for the heck of a poll  ::)

As an added question, which diode do you think gives a smoother distortion?

Smoothness also a function of the filtering before, in parallel with, and after the diodes, not to mention the voltage relative to the Vf for the diodes used and the symmetry of the clipping. ;)

curse you and all your complexity  :icon_redface:

Hehehe... it's just a complex world.

I like all three diodes for their individual qualities.

How's that for a non-answer answer? :icon_mrgreen:

To answer your second question, Ge diodes have the best chance of producing the "smoothest" fuzz of the three.

"what kind of distortion diode do you prefer?"



Yes.

Quote from: phaeton on March 12, 2006, 11:47:10 PM
"what kind of distortion diode do you prefer?"



Yes.

False.

Beer.

Andrew

Quote from: 343 Salty Beans on March 13, 2006, 12:01:21 AM

Quote from: phaeton on March 12, 2006, 11:47:10 PM
"what kind of distortion diode do you prefer?"



Yes.

False.

you're both wrong, it's 62 proof:

Quote from: Craig Anderton
The answer as to the best diodes for distorting is clearly 62.

isn't that the same answer to 'what is the meaning of life?'

EDIT: I'd also like to note how productive and helpful this thread is.

Quote from: 343 Salty Beans on March 13, 2006, 01:12:34 AM
isn't that the same answer to 'what is the meaning of life?'

That was 42.

Quote from: 343 Salty Beans on March 13, 2006, 01:12:34 AM
EDIT: I'd also like to note how productive and helpful this thread is.

The red pill.

Andrew

best = 1N4148
smoothest = 1N60

C'mon, you know it's the truth.

Yeah, MXR distortion with germanium diodes?
Thats pretty darn smooth (i built 1), you can make believe to yourself your using valves.

OK, you have forced me to be the serious one???  GE's clip at "around" .3v SI at .7v and LED at 1.7v.  The GE's have a softer "knee" and sound sort of "fuzzy" to me, the SI's sound typical and the LED's are reputed to "chunk" more.  I typically mix them and use 2 of 1 and 1 of another.  IMHO the different clipping levels force the op amp to work more or less which also effects the tone.

Diodes in the feedback loop sound different than diodes going to ground.  Also the feedback loop set up as non-inverting sounds different than inverting.  Bass and treble roll off also effect the "smoothness" of the distortion.   

I'm currently using Mosfets and they have a sort of organic sound to them that I like.   :icon_cool:

  ok..the kind that clip in GE Transistors.
  My best non-answer to:
  "What is the meaning of Life?"
  IS
  "LIFE IS WHAT HAPPENS WHEN YOU"RE MAKING PLANS"
  J. Lennon

About 8-10 years ago I introduced a concept I called "proximity to clip".  It may exist under another name in electronics texts, but here it was introduced with reference to distortion.  A brief review:

1) Any diode reacts to signal voltages by either passing or not passing the signal.  The voltage at which that transitiion takes place is relatively fixed for the diode type, although there is variation within diode types such that part X of any given diode number type may make that blocking to passing transition at a different voltage than diode Y.

2) While diode forward conduction and voltage drop is physically fixed for the diode itself, the input signal is highly variable.  remember that the guitar is not an oscillator or fixed signal generator cranking out a constant 1v P-to-P.  The signal level vaies depending on string thickness, plucking strength and where you are in the lifespan of the note after plucking.

3) The signal level of guitar pickups, unaided, is generally below the clipping point of many diodes unless some gain is placed in between the guitar and the diodes.  What the gain does is increases the proportion of of wave peaks that exceed the clipping threshold of the diodes in use.  When a larger proportion of wave peaks exceed the clipping threshold, the resulting sound is a much stronger and more compressed fuzz, that lasts across much of the duration of any note held.  It sounds compressed because the "ceiling imposed" is applied consistently across a long period of time in the life of the note.

The notion of proximity-to-clip incorporates the distance between clipping point and signal.  Hotter pickups and stronger picking close the gap.  More gain in the distortion unit, or gain applied in preceding stages (via "clean" boosters, etc.) also close the gap.  As evidenced in the Tube Screamer, pre-clip tone-shaping also varies the gap.  Changing diodes also alters the gap.  Selecting either a diode type or units within a type that have a lower clipping threshold will bring the threshold closer to the available signal level without needing as much gain applied to close the gap.  Very often, much of what gets attributed to diode types in different "designs" is really more a question of what is in place to bring the signal level closer to the point where clipping occurs.   Though diodes DO clip a little differently when the same relative amplitude signal is applied (i.e., one at the specific clipping threshold of that component), post-clip tone-shaping also plays a big role in the "sound" of different diodes.

Finally, clipping results from signal that is NOT passed on to the output.  This means that using a diode with a low threshold will result in low circuit output level, unless some additional gain is applied AFTER the clipping.  LEDs, because of their high threshold for clipping, permit a high output level without additional gain.  Of course, because of that high clipping threshold, it also takes more gain to bring the signal up to the required amplitude to produce clipping; i.e., to achieve good proximity-to-clip.  Since the kinds of gain levels needed to push the signal up into serious clipping territory when using LEDS is so high, you'll see LEDs used both when the tonal goal is a circuit that only produces a bit of crunch on hard strums, and when the goal is out and out gonzo metal fuzz.  The reason is simple.  Moderate gains don't result in enough proximity-to-clip to achieve hard clipping across the whole lifespan of the note, and the much higher gains needed to produce hard clipping tend to be the sort that strain the circuit in pleasing ways.  LEDs are also sometimes used for double-clipping purposes, where  diodes with several different thresholds are used.

In the grand scheme of things, it is always easier to get nice fuzzy clipping with only modest gain when using Ge diodes, but that's only one of the goals of designing a distortion circuit.  Most players will also want a tonal contribution form their amp and speakers, and that requires output level.

I know what I don't like - Ge diodes. I prefer the Si ones, 1N4148/1N914 or LEDs sound nice to my ears.  :icon_cool:

I like the stock DS-1s the best of all I tried. Anyone know what these are? Zener?

I voted silicon. I like one to be a 1n400x, and the other to be a signal diode with about 20mV to 30mV difference in forward voltage. All my experimenting was in a feedback loop circuit, all types of diode combinations.

I like leds in an opamp feedback loop for their crunchy sound, like in the Red Fuzz at GGG.
If the diodes go to gnd as in a MXR+, I like 4148 at low gain and Ge at high gain.
I prefer Ge to compress signals as in the Vulcan Overdrive.
Did not try Ge or leds in a Big Muff Pi. I guess some bias tweaking is needed.

mac

Quote from: WGTP on March 13, 2006, 10:32:12 AM
OK, you have forced me to be the serious one???  GE's clip at "around" .3v SI at .7v and LED at 1.7v.  The GE's have a softer "knee" and sound sort of "fuzzy" to me, the SI's sound typical and the LED's are reputed to "chunk" more.  I typically mix them and use 2 of 1 and 1 of another.  IMHO the different clipping levels force the op amp to work more or less which also effects the tone.

Diodes in the feedback loop sound different than diodes going to ground.  Also the feedback loop set up as non-inverting sounds different than inverting.  Bass and treble roll off also effect the "smoothness" of the distortion.   

I'm currently using Mosfets and they have a sort of organic sound to them that I like.   :icon_cool:

I might have to try that mosfet deal, because I'm a huge U2 buff, especially J-Tree. I've been looking for a more organic-feeling pedal to give to our guitarist, because we're all U2 fans, and have some very U2ish songs. of course, nowadays, who doesn't  :icon_rolleyes: but I'll have to check that out, maybe design my first distortion circuit :D

In most circuits, I like the LED's (of the 3 choices in the pole) because they seem more dynamic and less overly compressed.

If your intersted in Mosfet clipping, here is the discussion.   :icon_cool:

http://www.elixant.com/~stompbox/smfforum/index.php?topic=38581.0

If you can squeeze one in try a 1N5401 gives the same kinda gain as an LED

Quote from: Austin73 on March 14, 2006, 04:27:59 PM
If you can squeeze one in try a 1N5401 gives the same kinda gain as an LED

I like the 1N400x series... they've all got a forward voltage resembling ~1.1v

Btw, does the standard OHM's law stuff work for computing diode forward voltages in parallel?

Quote from: WGTP on March 13, 2006, 10:32:12 AM
OK, you have forced me to be the serious one???  GE's clip at "around" .3v SI at .7v and LED at 1.7v.  The GE's have a softer "knee" and sound sort of "fuzzy" to me, the SI's sound typical and the LED's are reputed to "chunk" more.  I typically mix them and use 2 of 1 and 1 of another.  IMHO the different clipping levels force the op amp to work more or less which also effects the tone.

Diodes in the feedback loop sound different than diodes going to ground.  Also the feedback loop set up as non-inverting sounds different than inverting.  Bass and treble roll off also effect the "smoothness" of the distortion.   

I'm currently using Mosfets and they have a sort of organic sound to them that I like.   :icon_cool:

I like the Ge's in my Distortion plus..the seperation and pick gain is great..

Mark Hammer is really the CLIP MASTER around here.  Check out his posts on clipping diodes.  Also check out the Rosey Ray for an example of how to use several clipping variations in one Distortion.

It's funny, with the Mosfet clippers, I keep jacking up the gain for more distortion, but it just seems to sustain more and the noise level increases.  I'm using BS170's

A discussion from a while back pointed out how non-inverting op amps like the Tube Screamer and SD-1 inject some direct undistorted sound into the output of the op amp that does not go thru the clipping diodes in the feedback loop.  This is part ot the TS type tone so many folks like.  Use of the inverting op amp set up, has different characteristics that I don't fully understand, and does not have the direct sound thing going on.  I prefer this one myself.  This is typically characterized as soft clipping

Hard clipping usually is associated with diodes goiing to ground after the op amp and produces a sharper clip.  This is used in the MXR Dist+, Boss Ds-1, Rat, etc.  A feature of this that I think is often overlooked, is that it is actually 2 stages of distortion.  At max drive, the op amp is melting down before the signal gets to the diodes.  In the TS type circuit, the diodes in the feedback loop somewhat limit this (another area I don't understand much about).  :icon_cool: