Sonic difference between Saturated Opamp and diode clipping

[Vivek]

How does the sound of a saturated Opamp differ from hard clipping and soft clipping

When pre distortion EQ, clipping radians, post distortion EQ and final volume are kept the same ?


(I'm studying the possibility of changing the Rockman X100 distortion stage which is currently saturated Opamp into hard clip LEDs

into soft clipped gain stage feeding hard clip LEDs)

[iainpunk]

pure opamp clipping is often described as 'harsh'
i personally like opamp clipping over diode clipping, especially when using lower voltage levels, it can feel very 'pure' and 'raw' which i love. i'd call it a ''gravel texture''
diodes clip more 'softly' more controlled and processed. i'd call that more of a ''sandy texture''.

the slew rate of the opamp also has a lot to do with the tone of the distortion, slower is smoother, without becoming dull, like filtering does to a signal. its hard to explain the sound, but slew rate reduction is better than filtering when it comes to opamp clipping.

i strongly suggest testing and experimenting on a breadboard yourself!!!!!

cheers

[amptramp]

Op amp clipping depends on characteristics that have a boundary but are not necessarily accurately known or controlled.  For example, a TL071 amplifier powered by ±15 VDC has an output swing of  ±12 volts into a 10 K load which is typically ±13.5 volts at 25°C and an output of ±10 volts into a 2 K load.  If you are operating from a 9 volt single-supply, this means you have a guaranteed ability to supply 3 volts AC into a 10 K load and no guaranteed ability to drive a 2 K load at all.  The 3 volt drop at 10 K and a 5 volt drop at 2 K are worst case - there is nothing saying that they cannot deliver an amplifier that will do better than that and there is some temperature dependence since they offer better specs at 25°C.  Typically, a TL071 does better than this but how much better is not specified.  With some op amps, recovery from saturation takes place at a slow speed since the overdriven elements are usually current sources that must charge internal capacitances before resuming linear operation.

Some op amps have malignant clipping characteristics, especially if they are biased out of their common-mode range.  You can get op amp outputs that suddenly go from positive to negative or vice versa if the common-mode range is exceeded.

With diode clipping, the forward voltage of the diode is known and controlled to within a small amount with a known temperature dependence and a known impedance.  The first thing you will get with diode clipping is guaranteed characteristics that do not depend on unverified or simply worst-case bounded characteristics.  If the clipping is done as an active clamp, the diode characteristics are inside a feedback loop meaning you have an ideal diode that switches from open circuit to full clamping within millivolts, removing all diode characteristics and leaving an accurate, repeatable clipping voltage that has little dependency on individual device characteristics.

[marcelomd]

How does the sound of a saturated Opamp differ from hard clipping and soft clipping

When pre distortion EQ, clipping radians, post distortion EQ and final volume are kept the same ?


(I'm studying the possibility of changing the Rockman X100 distortion stage which is currently saturated Opamp into hard clip LEDs

into soft clipped gain stage feeding hard clip LEDs)

Just breadboard it. Shouldn't take more than a few minutes. No amount of math can give you the feel for hearing the real thing.

I personally like how opamps saturate. Once I was playing with a Marshall Guvnor style circuit and tried a bunch of combinations. Just the opamps were aggressive without being fizzy.

Brian wampler has a nice video where he does combinations of opamps, diodes, etc.

[iainpunk]

if anyone has taken a look at the CA3130, it has a CMOS output stage.
we can use pin 8 (strobe and compensation) as the output pin if we regard the (-) and (+) inputs as having switched places. we can then use the CMOS stage as a stand alone gain stage, without feedback, to utilize its soft-clipping nature, just like CMOS inverters!
of course we bias the ''first half'' of the opamp so the CMOS stage's output is in the correct operating range.



cheers!

[anotherjim]

^That is a clever idea, Iain. So clever, you nearly killed the thread!

As to the thread question, I say it depends.
I like amp clipping more for trashing/heavy playing where the guitar never really shuts up or lets the clipping drop out. Amp clipping can sound bad at the point the guitar output level begins to drop below clipping. Guitar levels don't decay with the certainty of a synth release envelope, they can swell up & down a bit. So if you follow it with clipping diodes you can keep the clipping going longer, but you still have that glitchy decay only at a lower level.

[iainpunk]

if anyone has taken a look at the CA3130, it has a CMOS output stage.
we can use pin 8 (strobe and compensation) as the output pin if we regard the (-) and (+) inputs as having switched places. we can then use the CMOS stage as a stand alone gain stage, without feedback, to utilize its soft-clipping nature, just like CMOS inverters!
of course we bias the ''first half'' of the opamp so the CMOS stage's output is in the correct operating range.



cheers!

EDIT: the CA3130 and 3160 are both eligible for this trick.

am currently experimenting with a bridge tee filter in the feedback loop from pin 8/strobe, to pin 3/non-inv.
it can really do that desert rock sound, especially if the guitar's volume is dialed back and the gain at 8, it really does that pushed mid-range "not quite fuzz, not quite distortion" tone, and a woolly overdrive when the gain knob is dialed back.

cheers

edit: the CA3130 really likes a 20pF to 1nF capacitor in between pin 8 and 1, despite the implemented feedback loop trick also coming off of pin 8.

[reichelmarcia]

Depending is the answer I would give to the thread's query.
For trashing or extreme playing, where the guitar never stops and the clipping never drops off, amp clipping is my fave effect. Amp clipping can occur when the guitar output level drops below clipping, leading to an unpleasant tone. In contrast to the regular decay of a synth release envelope, guitar volume tends to increase and decrease irregularly. Therefore, if clipping diodes are used afterward, the clipping can be maintained for a longer duration, but the glitchy drop will still occur, albeit at a lower volume.

[duck_arse]

reichelmarcia, are you some sort of ai bot, perchance? asking for some friends.

^That is a clever idea, Iain. So clever, you nearly killed the thread!

As to the thread question, I say it depends.
I like amp clipping more for trashing/heavy playing where the guitar never really shuts up or lets the clipping drop out. Amp clipping can sound bad at the point the guitar output level begins to drop below clipping. Guitar levels don't decay with the certainty of a synth release envelope, they can swell up & down a bit. So if you follow it with clipping diodes you can keep the clipping going longer, but you still have that glitchy decay only at a lower level.

[Fancy Lime]

reichelmarcia, are you some sort of ai bot, perchance? asking for some friends.

^That is a clever idea, Iain. So clever, you nearly killed the thread!

As to the thread question, I say it depends.
I like amp clipping more for trashing/heavy playing where the guitar never really shuts up or lets the clipping drop out. Amp clipping can sound bad at the point the guitar output level begins to drop below clipping. Guitar levels don't decay with the certainty of a synth release envelope, they can swell up & down a bit. So if you follow it with clipping diodes you can keep the clipping going longer, but you still have that glitchy decay only at a lower level.

The AI-pocalypse the tech bros keep promising is gonna be so @#$%ing weird. Who'd of thunk they would come for our nerd-forum posting jobs so soon. Who is going to pay my exorbitant fees for incomprehensibly rephrasing old answers from necro threads, if a machine can do it for free? Depending is the answer...

[duck_arse]

old mate ai bot is so stupid they copied the same post twice. the first was deleted, because bots. the dumb thing is they are let loose to learn, but they instead teach us what to look for by their repetition.

the question, and maybe reichelmarcia can help us here, is what is the point of using chatbot thing? what advantages? easier posts? faster posts? certainly no evidence of useful or helpful posts, or creative. or entertaining, for that matter, they seem to churn out dull drivel. the only evidence we have so far is the bot farmers want an in, so they might look legit and then sneak in some spam link. bad luck on them, cause we either wipe their posts or catch the links. otherwise, they want an in, backdoor, chance to get closer to the database of users and emails. then what? blackmail? zombie attacks? arseclowns the lot of them.

do we have any tame programmers with any insights to the bot hivemind hereabouts?

[Fancy Lime]

Well yes, arseclowns, as you said. I think what we are seeing here isn't part of some grand nefarious plan. It's script kiddies fiddling with a new toy because that's what they think their online "friends" find amusing this week. There is nothing to be gained here, except "the lolz". Annoying teenager being annoying. As well they should, I'd just rather they were annoying their parents by playing rock music too loud, like in the good ol' days. *oldmangrumblgrumbl* But hey, it's pretty harmless given that that's the same demographic that at other times tends to amuse themselves by trying to one-up each others misogynistic or antisemitic rant (or whatever dehumanizing bullshit some algorithm nudged them into that week) on certain other message boards and forums. All for the lolz, of course. As long as we're not flooded with that, we should probably count ourselves lucky. Isn't the internet just the most depressing study of human nature? Sometimes, at least.

[duck_arse]

I was too scared of the repercussions of saying script kiddies. but really, literally ANY idiot with an email addy can join this forum, and then post, so where are the subversives l[o|u]lz coming from? it's not like the old days when they were cracking the NRA servers, or process controlling the Iranian centrifuges. is it?