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Best way to model guitar signal?

PostPosted: 01 Apr 2015, 22:21
by mistapitts
What is the best way to model a guitar signal? Currently I'm using a +/-1V 800Hz sine wave in Multisim, and I'm currently battling op-amp clipping in a clean boost I designed. Is the voltage too high?

The circuit is supposed to be able to boost the signal over 20db but I'm saturating the amp at about 10.

Re: Best way to model guitar signal?

PostPosted: 01 Apr 2015, 22:25
by Crowella
Try using 100mV/0.1V first. :) 1V is rather high.

Re: Best way to model guitar signal?

PostPosted: 01 Apr 2015, 22:32
by mistapitts
Thanks :D I figured I was just driving it too hard. Is that 100mV peak-to-peak or amplitude?

Re: Best way to model guitar signal?

PostPosted: 01 Apr 2015, 22:35
by Crowella
Apologies. Amplitude. :)

Re: Best way to model guitar signal?

PostPosted: 01 Apr 2015, 22:59
by mistapitts
Awesome! Thank you.

Re: Best way to model guitar signal?

PostPosted: 01 Apr 2015, 23:32
by grrrunge
The highest output passive pickup i have, is a Dimarzio X2N, with an output of 510 mV. I always use that for "worst case" testing ;)
Simulating that case, i usually run simulations at +/-500mV.

Re: Best way to model guitar signal?

PostPosted: 02 Apr 2015, 23:43
by Crowella
I should have mentioned that it is naturally going to be different throughout a course of a note. The attack will most definitely be in the high range, sometimes even approaching 1V amplitude.

If I could find it, there was a nice way to simulate a guitar pickup in LTSpice using a transformer and/or inductor. For all intents and purposes though, a simple supply will suffice but just be aware it is by no means comprehensive but very suitable for simulations.

Re: Best way to model guitar signal?

PostPosted: 22 Nov 2016, 15:42
by poiureza
I recently tested the bridge HB on 3 guitars with a scope.

"Normal" strumming gets rarely above 0.2V amplitude.
If you bang on the strings like a chimpanze, the attack is about 0.5V amplitude but goes down to 0.1-0.2V amplitude after only a swing or two.
That's not music, that's pick attack noise.

I build all my circuit models with 0.1V amplitude and then I check what happens when I raise amplitude.

As for including pup characteristics in the model, there's a good read here.
The voltages I mentioned would obviously be after this circuit snippet.
The snippet is not really necessary IMO unless you build something without input buffer or very low input impedance (some fuzz', some wah's ...).

Re: Best way to model guitar signal?

PostPosted: 07 Jan 2017, 16:12
by clintrubber
Once tested a passive bass, single coil, directly connected to a scope.
The sun was shining, the breakfast was good, the coffee strong, the pick heavy,
so the initial peak on the scope no less than 4V(peak), it might even have been 10V(peak).

Will this distort ? Sure, for instance it's totally incompatible with the a 9V supply of the first stompbox.

But you'll actually WANT that peaks like this are clipped/limited, no use in reproducing these.
And they'll be so short that the distortion is unnoticable.

Bye