A Graphical Represenation of a Pedal's ouput?

[YouAre]

Anytime I read an article about EQ's/tonestacks on the AMZ website, I find myself paying attention to the frequencies effected by the circuit, especially when it comes to the tubescreamer.

Here is the AMZ article the shows a couple of graphical representations of the tone control

http://www.muzique.com/lab/tstone.htm


So is there anyway to get a graphical representation of what a circuit does? For example, if you have a parametric EQ, is there anyway to see a physical representation of the EQ curve that is dialed in on it? And if you had a tubescreamer, how would you see what frequencies are boosted, and what's rolled off?

I figured an oscilloscope might be the answer, but is there anyway to do it with a home PC? I remember in one of my physics classes, we had a bit of a faux oscilloscope by having a function generator coming from the speaker out into the input of the circuit, and the output went to the mic on on the pc.

Thanks,
Murad

[miqbal]

Hi,

If you are a PC user and like to play with some CAD/design or simulator softwares:

You can try Visual Analyzer (Sillanum Soft; free), but you'll need real signal source/generator.
Or you may try Linear Technology LTspice/SwitcherCAD III (also for free): draw the layout and run the simulator; need to read the manual, though
For the massive one: National Instrument NI Multisim; highly recommended....., but not for free

MIQ

edit: I have no idea for MAC

[YouAre]

Hi,

If you are a PC user and like to play with some CAD/design or simulator softwares:

You can try Visual Analyzer (Sillanum Soft; free), but you'll need real signal source/generator.
Or you may try Linear Technology LTspice/SwitcherCAD III (also for free): draw the layout and run the simulator; need to read the manual, though
For the massive one: National Instrument NI Multisim; highly recommended....., but not for free

MIQ

edit: I have no idea for MAC

luckily, i use pc 

With Visual Analyzer, the signal source goes into the actual circuit, and the output of the circuit goes to the PC somehow?

[miqbal]

With Visual Analyzer, the signal source goes into the actual circuit, and the output of the circuit goes to the PC somehow?

Like this: Signal Source (guitar, cd player, function gen, etc)  -->   Sound card  -->   Visual Analyser.    That simple.
Stompbox is optional 

But I suggest you to try LTSpice. It's some kind of a 'How Circuit Works' software. You can tweak any component value you want, and see the result of the signal. With this software, I know that a DS-1 circuit already produce 'not good looking' signal right after the 2nd transistor in the circuit..

[YouAre]

Like this: Signal Source (guitar, cd player, function gen, etc)  -->   Sound card  -->   Visual Analyser.    That simple.
Stompbox is optional 

But I suggest you to try LTSpice. It's some kind of a 'How Circuit Works' software. You can tweak any component value you want, and see the result of the signal. With this software, I know that a DS-1 circuit already produce 'not good looking' signal right after the 2nd transistor in the circuit..

Haha, how is the stompbox optional? One of the uses i was looking to get out of this setup was to see the curve i create with a parametric EQ (that i don't know the schematic of) So how can i implement an actual stompbox? I understand in LT spice i can make a mockup of the schem, but whats the signal chain of that setup?

thanks for all the help!

regards,
murad

[FiveseveN]

Here's a thought: if you want to see the frequency range, Q and amplitude of a parametric EQ just use a realtime spectrum analyzer and a good source of white noise. I usually use the one in SoundForge since I already have it but I'm sure there are free alternatives and also more complex dedicated plugins or programs (Ozone Spectron might also work). Set your options for a good precision vs. refresh rate tradeoff and start fiddlin' with those knobs and note your results.
I've used that spectrum analyzer to look at the various harmonics generated by distortions and amp syms using a note or a powerchord as signal source.
As for white noise, I've found a little Java application but you could also use a prerecorded track.