Does more phase stages make a phaser better??

[njkmonty]

Im looking at making myself another Phase 90 clone, but before stuffing around, i was hoping to get everyones thoughts on 4,6,8,12 etc stages?
does  going beyond 4 stages make it lush or something?
or the more stages the closer the parts need to be matched?

[Processaurus]

More phase stages can make a phaser sound more impressive.  It does depart from the classic guitar phaser sound, which is the four stage phaser, classics like the phase 90 (FET based ) and small stone (OTA based).  I believe the Mu-Tron Phasor II is 6 stages (optical), the Biphase has the option to run both sides in series, as a 12 stage phaser, and the moog phaser is either 6 or 12.  The Phase 100 is a 10 stage phaser (optical), but only 6 of the stages are swept, the other four are static.

The phaser effect works by combining the dry signal with a phase shifted signal, which generates a sort of comb filter, a series of notches in the frequency spectrum, and shifting the phase around shifts the notches around.  Having more phase stages generates more notches.   Does it sound better? Maybe.  It does make the phase sound more noticeable.  Actually the Phase 45 is a very nice sounding effect, and only has 2 stages, but part of its charm is the subtlety of the sound.

There are some threads here on adding phases to the Phase 90, there is an article at geofex.com on it.  Experimenters have had some challenges cascading that many FET phase shifting stages and keeping the distortion in check.  Many of the higher phase stage count phasers are optical, because they don't suffer from distortion (FET) or excess noise (OTA).  Not that the FET phasers sound bad, the distortion adds interest to the sound, but the effect and non linearities will compound with more stages.

[bool]

It will sound more "focused" and will most likely draw more attention to itself.

Better? It depends on what you're after.

[Mark Hammer]

My exerience is that "more" stages tends to move the sweep range lower.  One of the challenges that begets is that higher feedback settings can start to howl.  The solution to that would be to a) limit maximum feedback, or b) reduce low end in the feedback path, or c) both.

I've heard 12 and 24-stage phasers, and they can sound amazing....on white noise.  For guitars, however, the usable bandwidth, provided by the pickups, cable, speakers, etc., is limited enough that many of the notches produced by all those extra stages are more hypothetical than real.  I.E., there is no frequency content to stick a notch in.  Six stages seems to be about the sweet spot.  More than 6 will certainly sound different, but it won't necessarily sound more fabulous or robust.

[njkmonty]

thanks thats sort of what i was hoping to hear

[Transmogrifox]

For guitars, however, the usable bandwidth, provided by the pickups, cable, speakers, etc., is limited enough that many of the notches produced by all those extra stages are more hypothetical than real... Six stages seems to be about the sweet spot. 

I agree in general.  I have never had more than a 4-stage analog or stompbox phaser, but for a software phaser I created, there are two things I notices with phaser stages 12 and greater on guitar:
A)  Clean Guitar -- Mark Hammer is absolutely correct. More than 6 stages doesn't seem to add anything stunning.
B)  Heavily distorted guitar -- the higher order phasers can get you into sounds more often associated with synthesizers.
C)  Higher modulation rates -- you get much more pitch warble, and higher order phasers can approach a deeper chorus effect.

I made a software barberpole filter that was a bank of 1/3-octave spaced state-variable filters with the option to feed into up to a 12 stage phaser and stereo panner.  This combination can create a dizzying stereo effect.  Feels like you're on an octopus carnival ride where you are accelerating toward and away from the carnie's boom box while rotating in your car at the same time.  You might make people in your audience lose their balance and fall over.

[StephenGiles]

For guitars, however, the usable bandwidth, provided by the pickups, cable, speakers, etc., is limited enough that many of the notches produced by all those extra stages are more hypothetical than real... Six stages seems to be about the sweet spot. 

I agree in general.  I have never had more than a 4-stage analog or stompbox phaser, but for a software phaser I created, there are two things I notices with phaser stages 12 and greater on guitar:
A)  Clean Guitar -- Mark Hammer is absolutely correct. More than 6 stages doesn't seem to add anything stunning.
B)  Heavily distorted guitar -- the higher order phasers can get you into sounds more often associated with synthesizers.
C)  Higher modulation rates -- you get much more pitch warble, and higher order phasers can approach a deeper chorus effect.

I made a software barberpole filter that was a bank of 1/3-octave spaced state-variable filters with the option to feed into up to a 12 stage phaser and stereo panner.  This combination can create a dizzying stereo effect.  Feels like you're on an octopus carnival ride where you are accelerating toward and away from the carnie's boom box while rotating in your car at the same time.  You might make people in your audience lose their balance and fall over.

Any mention of "barberpole filter" is strictly forbidden

[R.G.]

Any mention of "barberpole filter" is strictly forbidden

In a mature bureaucratic society, anything not forbidden is mandatory.

[Mark Hammer]

A word or two about the relationship between #stages and feedback levels....

In principle, the allpass stages we know and love are unity-gain; so 10k input and 10k feedback resistors (or 100k/100k).  BUT, those resistors have a tolerance, and sometimes the feedback resistor in a stage can be the teensiest bit higher in value than the input resistor, making that allpass stage have a gain of, say, 1.05 or something similar.  And the more stages one has in series, the greater the statistical likelihood that the sum total of all those stages might be a cumulative gain of 1.1, or even greater.

Without any feedback, that poses no problem.  But once one applies feedback, any cumulative gain over 1x starts to translate into oscillation.  Obviously one can prevent that by simply dialing back the feedback, or by doing what most companies do, via installing a trimpot set at the factory to make the max feedback setting just below oscillation, but you miss out on a wider palette of tones achievable by using higher amounts of feedback.

One strategy for addressing this would be to select one's resistors very carefully, making sure that the feedback resistor is never a higher measured value than the input resistor.  Another might be to provide for variable or preset bass-cut in the feedback path so that the higher amplitude portion of the feedback signal is attenuated.  The Anderton-designed PAiA Hyperflange used this trick to be able to max out feedback, without the howling.

[Transmogrifox]

Any mention of "barberpole filter" is strictly forbidden

Excuse me, "Array of multi-phase amplitude modulated unilaterally tuned time variant filters with discontinuous tuning reset at zero amplitude"

In layman's terms "A box full of phasers on crack"

[alanp]

Do you mean a Shepard tone generator?

[kingswayguitar]

my 2 stage phaser is nice but more would be better

[Hatredman]

A little video by Boss. This particular model has 4, 8, 10 and 12 stages. More stages, more "singing" (and less natural) sounds. As someone said, may or may not be what you want.

[Mark Hammer]

Just note that this is a digital phaser.  That doesn't make it bad or good.  Rather, the various caveats and suggestions that I noted earlier, simply do not apply here.  Hence, there is no risk of oscillation because there are no multiple cascaded all-pass stages; but rather, a model of what having 4/8/10/12 stages would be like.  As well, the digital model starts the sweep from the same point in all instances.  Throw another 4 stages onto a 4-stage phaser, and you will notice that the sweep range moves down somewhat.

[Hatredman]

Indeed, I overlooked that.

[bool]

More analog stages are imho usable with singlecoils, but not-so-nice with humbuckers.

In 90's I had this one: http://www.tcelectronic.com/classic-tc-xii-phaser/

I used it for a couple of (various) albums recordings (on a couple of bass guitar parts) instead of studio multi-fx, go figure.

But for guitar parts, it's easier to achieve "deeper" phasing with digital fx. Analogs do tend to have their variable peaks quite annoyingly exaggerated and this really needs lots of dynamic post-processing to get it to behave in a mix. Not so good with instruments that move around tonally, like guitar chords etc.

Better to use some short flanger for that imho.