What does the null carrier mod for the green ringer do??

[El Heisenberg]

What is null carrier anyway?


http://www.generalguitargadgets.com/pdf/ggg_gro_sc_null.pdf

[anchovie]

http://www.diystompboxes.com/smfforum/index.php?topic=1440.0

That was the fourth result returned by typing green ringer null carrier into the forum search box. 

[El Heisenberg]

I've built 6 of these effects and every time I build one, I try the null mod, and I never hear any differece. Maybe I'm matching my resistors and diodes well enough that the null mod has no effect?

[Mark Hammer]

The nulling adjustment can optimize, but it can also undermine octaving if set wrong.  So the notion that "maybe its already perfect and all the tweaking doesn't change anything" doesn't sit well with me.  Of course, it could also be the case that a) the extent of nulling you've added is insufficient to do the job, or that b) the drive in the unit is not sufficient to evoke robust octaving even with tweaking.

With virtually any phase-splitter-based octave up, the effect is going to show up more on some parts of the fingerboard than others.  Typically, such uinits like unwound strings played between the 7th and 14th fret.  What that says to me is that null-carrier setting is most likely a 2-person job: one person plays in a fashion that ought to easily generate octave-up notes, and the other one tweaks.  My sense is that relying on acoustical memory to adjust it (play, tweak, play again) may come up short.

Just a thought.  I was playing mine the other night, for the first time in a while, and fed it a hot signal from an SSM2166-based compressor.  It sounded a lot nicer than I remembered it.

[El Heisenberg]

i do already have the filter mod in the circuit i'm testing now. maybe that outdoes what the null mod does?

[Mark Hammer]

No, it doesn't.  The filter mod just assures that the content of the inputis frequency-doubled, only/mostly the stuff you are interested in hearing doubled gets doubled.  You will note that it is recommended practice to turn the tone control down on one's guitar when using an octave-up.  The filter mod moves that treble trimming from the guitar and into the pedal itself, so all you have to do is step on a switch, and not monkey around with your guitar controls.

The nulling mod is there to assure that the two half-signals that are required to be combined in equal measure for doubling to be heard, ARE in equal measure.

Think of it like this.  You are hosting a party for identical twins.  The filter makes sure that only human twins attend the party (no twin chickens allowed!), and the null makes sure that the only twins who attend are identical.

[El Heisenberg]

i'm just having trouble noticing any difference when I move the trim pot I set up. I've tried this mod a bunch of times in every green ringer while it's on breadboard, and even built it into some green ringers, but it seems useless.

[Eb7+9]

... null carrier ?

0

[Processaurus]

MI think mark may be right, that something is wrong with the circuit such that there may not be enough range to get to the ideal point, where the top and bottom halves of the input waveform are full wave rectified to be equal/symetrical to each other.  When this happens the fundamental is minimized.

Mine, that I made the filter mod for, actually had the PNP transistor in backwards for the first couple years of its life, which made the rectified waveform halves unequal, and the effect to be weak.  Do you have access to an oscilloscope, or have a program to make your soundcard into a pseudo scope?  It's easier to see the situation than hear it.

[El Heisenberg]

No, that'd be cool to have an osciloscope on my computer. I've tried messing with the PNP. The thing is on my breadboard. I'm mixing it into a chopped oc-2.

[Mark Hammer]

... null carrier ?

0

yeah, I think "balance" may be a more appropriate and clearer term to use, since that is effectively what it does.

[soggybag]

I built one of these with both the trimmer and the filter mods. The trimmer makes a small difference. It might tune octave in a little. The filter mod really makes the octave standout.

[El Heisenberg]

Yea the filter mod makes the octave stand out alot. I put it in all my green ringers. But everyone loves this null mod, and i can't tell any difference at all.

[mac]

If the null carrier pot is 250k or more, the amount of ringing can be adjusted to taste.

mac

[El Heisenberg]

250k?



where can I get software for a fake osciliscope? Any recommendations?