True peak limiting PCBs?

tegendemuur

Well-known member
There's plenty of neat compressors, but I don't seem to find anything that clearly states to be a fast attacking / high ratio limiter; something I would feel comfortable putting behind some gear (Filterbank, T-Resonator, AeganMatrix, etc) that comes with warnings that they should be used with peak limiters right behind them because of extreme bursts of feedback when experimenting.

Keeley for instance answered someone's question about his compressors being used as a limiter: "You would want the blend past halfway and the sustain almost off. That pedal really is not made to act as a limiter as much as say the gc2 or compressor pro but that should allow you level out and reign in some of those peaks."

Not sure if that's what I need. My guts say no. There's plenty of simple boards like the SoloDallas Storm (which calls itself a limiter), or the Flatline Compressor, that would do a similar job as the Keeley with a lot less work. Shit, I'd probably build a Guyatone PS-020 before any of those because it has some other uses than just compressing, if the compressor range is all I got to choose from.
 
Virtually all the compressors pass through the signal and then have a side process that feeds back an attenuation. This means the large Vpp is already past the attenuation stage and out the door.

The issue is with feed forward attenuation, ie where the signal is attenuated after it's sensed then you have to add phase delay in so the attenuation is done on the wave as it progresses. If you don't then what happens is you get a distorted waveform as the attenuation is attempted part way through the waveform.

The alternative to pass through is to sample, sense then recreate the signal at the attenuated level. Digital attenuators for example. Issue is that there can be lag introduced due to the ADC, the processing and then DAC compared to analogue forms.

A hard limiter if you're concerned - a front end buffer opamp with a limiting diode clamp can offer unit gain and enforce a limit. The opamp power supplies have a current limiter, for example: https://www.ti.com/lit/an/sbva011/sbva011.pdf
The opamp then can't actually create the output high enough to damage your equipment but would create a distortion.
 
Back
Top