Anyone havew or know where to find a schematic of a "soft clip" circuit. I'm curious to know how these work. NAD comes to mind but I imagine that's proprietasry and can't be posted. All I can find on a web search related to guitar amps.
On LT-spice I stuck an oposed pair of diodes in the NFB loop. It does indeed round off the top a bit when clipping but generated heinous harmonics even when well below clipping. So obviously it's not as simple as that. (I also noticed that the diodes need to be snubbed or be Schottky's lest a visible crossover appears in the wave form.
On LT-spice I stuck an oposed pair of diodes in the NFB loop. It does indeed round off the top a bit when clipping but generated heinous harmonics even when well below clipping. So obviously it's not as simple as that. (I also noticed that the diodes need to be snubbed or be Schottky's lest a visible crossover appears in the wave form.
A pair of diodes across the LTP inputs can work for higher gain
power amplifiers, for 'normal gain ' power amplifiers you probably
need 4 in series/parallel but they'll probably act a bit too late.
The other alternative is a pair of zener diodes in series,
connected across the large feedback resistor of the feedback
loop, varying the effect by the voltage rating and regulation of
the zeners (or adding a resistor). Here you need to be mindful
of the compensation of the amplifier as you are reducing gain.
With a line level circuit, before the power amplifier, here there's
an awful lot you can do, you can include capacitors for frequency
dependence for example.
A good soft clipping circuit will have no effect at low volume,
But hideous distortion specifications at medium to high outputs.
It should not add any crossover non-linearity.
I haven't really thought about diode turn off spikes.
Another alternative is a compressor - different kettle of
fish all together - much less distortion involved here.
🙂 sreten.
update : just seen Geoffs post - it is in effect a line level circuit.
power amplifiers, for 'normal gain ' power amplifiers you probably
need 4 in series/parallel but they'll probably act a bit too late.
The other alternative is a pair of zener diodes in series,
connected across the large feedback resistor of the feedback
loop, varying the effect by the voltage rating and regulation of
the zeners (or adding a resistor). Here you need to be mindful
of the compensation of the amplifier as you are reducing gain.
With a line level circuit, before the power amplifier, here there's
an awful lot you can do, you can include capacitors for frequency
dependence for example.
A good soft clipping circuit will have no effect at low volume,
But hideous distortion specifications at medium to high outputs.
It should not add any crossover non-linearity.
I haven't really thought about diode turn off spikes.
Another alternative is a compressor - different kettle of
fish all together - much less distortion involved here.
🙂 sreten.
update : just seen Geoffs post - it is in effect a line level circuit.
Thans for the schematics. I'll stick in with an existing amp simulation and see what happens. I presume it has to be tuned somehow to the rail voltage of different amps. How it works isn't immeadiatel clear but jooking at it simulation will help.
Diodes in the feed back loop, in any configuration seem problematic at best.
BTW, my practical philosophy hore actual home listening just to be sure I have enough power so that clipping isn't an issue. I understand, though, that there could be considerable appeal in a commercial product.
Diodes in the feed back loop, in any configuration seem problematic at best.
BTW, my practical philosophy hore actual home listening just to be sure I have enough power so that clipping isn't an issue. I understand, though, that there could be considerable appeal in a commercial product.
None at all, well outside guitar and bass amplifiers.
the most apposite application could have been subwoofers,
if it wasn't for the compressor approach being far better.
🙂 sreten.
cannot you make the normal V-I limiter into a soft clipping device? sounds doable if you can slow-down the turn-on / turn-off of the transistor in the limiter.
Soft clipping idea
made by NAD is little bit swindle for human ear. It works like voltage limiter, but cause increase of distortion in " middle " of power. Much more better are antisaturation circuity, which cause stopping of " avalanche " saturation of all stage in amplifier. Example of this circuits you can find for example in amp Ampzila.
made by NAD is little bit swindle for human ear. It works like voltage limiter, but cause increase of distortion in " middle " of power. Much more better are antisaturation circuity, which cause stopping of " avalanche " saturation of all stage in amplifier. Example of this circuits you can find for example in amp Ampzila.
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