# mxr phase 90



## gibsonlp04 (Apr 26, 2007)

i am looking to add some phase into my guitar life!

was wondering if the mxr phase 90 would be good or is there something better? 

any suggestions would be great 

thanks.


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## Tarl (Feb 4, 2006)

I use one and can tell you it is solid,reliable and one knob to turn is as easy as it gets. Some folks mod them a bit by removing a resistor but I like mine as is. I have zero experiance with other phaser pedals so i am sure there are better and worse ones out there.


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## Guest (Apr 14, 2008)

I had the EHX Small Stone and didn't bond with it. The Phase 90 was an almost immediate love affair. Lots of fun to mod too. I recently put mine through the script modifications and it sounds killer. A little lighter. A little sweeter than before.


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## Vincent (Nov 24, 2007)

Its a cool pedal

I recorded 2 songs a while back with the phase 90...i used an mxr phase 90 and an mxr overdrive for the lead work.

"Love is risky"
"Way it goes"

Im working on improving my recording sound right now for my next batch of recordings however these are not to bad i guess.

http://www.mp3.com/artist/travelers-tale/summary/?tag=login;myartists;1


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## violation (Aug 20, 2006)

I've got the MXR EVH Phase 90 (basically a regular Phase 90 + the script mod and a fancy finish) which I bought specifically for Van Halen covers (which is the only time it gets used, really) and it works well... sounds good.


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## devnulljp (Mar 18, 2008)

iaresee said:


> I had the EHX Small Stone and didn't bond with it. The Phase 90 was an almost immediate love affair. Lots of fun to mod too. I recently put mine through the script modifications and it sounds killer. A little lighter. A little sweeter than before.


I was the opposite -- loved my old 70s small stone but ditched the phase 45 pretty quickly. Might get a Phase 90 though as the smallstone is just too big.


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## mhammer (Nov 30, 2007)

Both the SS and P90 are severely underdeveloped devices with scads more potential in them than is actually tapped.

Consider the recent issue EHX Stereo Polyphase. Sure, its about double the money, but its about 4x the pedal too.


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## hollowbody (Jan 15, 2008)

I currently own a EHX Small Stone and a Ross Phaser. Both are really decent units depending on what you need them for. 

The Small Stone can be really in-yer-face and over the top if you want it, but sliding the Colour switch to the down position can get you a more subtle, watery phase.

The Ross Phaser is really neat. It's got a Speed knob as well as a Recycle knob, so it's a little more tweakable than the Small Stone, but it's way more subtle. It also isn't quite as "lush" sounding, but that's a taste thing.

I've also own the Ibanez Flying Pan in the past, and that was a great unit, but well past the point of diminishing returns on it's current asking price. As good as it sounded, I wouldn't go forking out 10-15x the price of another pedal for it. Though it's really nice to have heard at as a reference point.


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## mhammer (Nov 30, 2007)

As always, I refer people to the fully tricked-out Small Stone: http://moosapotamus.net/THINGS/frankenstone.htm

Actually, that one isn't even fully tricked out. Missing are an adjustable starting point in the sweep (The stock color switch selects between one start/width/regen combination and a second one. These are all independently variable.), as well as variable phase-blend.

The orange FET-based Ross does not accommodate all those mods plus the Frankenstone ones, but the black LM13600-based issue *does*.

The Flying Pan was an interesting beast, but the fixed panning depth was a real problem. The panning needed to be subtler to be usable as a step-on-and-forget-about-it effect. It has novelty value for a little while, but I imagine most owners neglect it after a month or so. Best to sell that particular headache to the highest bidder and buy yourself a variable autopan pedal with the proceeds.

If there is demand, I suppose I could provide instructions for how to accomplish the various SS/Ross mods. They ARE pretty simple to do and turn a one-knobber into a really flexible sound tool.


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## a Pack of Wolves (Sep 5, 2007)

i've owned a russian e.h phaser,a phase 90,an ibanez tonelock phaser
and a boss phase shifter

i dig the boss one the most 

it's got alot of options 
and you can get them fer less than $90 used
'cause alot of guys get tired of phasers quickly


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## Guest (Apr 14, 2008)

mhammer said:


> As always, I refer people to the fully tricked-out Small Stone: http://moosapotamus.net/THINGS/frankenstone.htm


D. Amn! I can't believe he fit all that in there! The 4PDT with the caps is a particularly impressive feat of stuffage! :bow: Well, if anyone wants to part with a Small Stone let me know. Mark has, yet again, left me with a lust to mod one. 

Edit: how is that PCB board held in there if not by the 3PDT switch? Just by leads to the rate pot?


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## Ti-Ron (Mar 21, 2007)

Just by curiosity, did someone here try the new MXR variphase?


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## Ripper (Jul 1, 2006)

while we are on the subject of phasers, does anyone know where I can lay my hands on a few ca3094 chips? I would be willing to trade for some chips I have etc.


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## mhammer (Nov 30, 2007)

The CA3094 is now out of production, or at least general production. I have no idea what sort of Faustian deal Mike Matthews has entered into to keep the Small Stone alive with that chip. We know that following the unusual episode in the early 80's when someone in Matsushita decided to sell delay chips to Japanese customers first (and probably only) just at the time when the Memory Man was fast becoming EHX's "cash cow", when the opportunity for purchase came again in the 90's, Matthews bought up the overwhelming majority of the world's stock of MN3005 chips to maintain the viability of the reissued Memory Man.

If you are desperate for them, Small Bear Electronics has them for about $5 a pop.


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## mhammer (Nov 30, 2007)

iaresee said:


> D. Amn! I can't believe he fit all that in there! The 4PDT with the caps is a particularly impressive feat of stuffage! :bow: Well, if anyone wants to part with a Small Stone let me know. Mark has, yet again, left me with a lust to mod one.


You can try mine when you come over. It sports 3 knobs (rate, regen, blend) and 3 toggles (wide/narrow, phase/vibrato, phaser/phasefilter).  It is remarkable what a chameleon that simple design can become with just a few select mods.

The Ross is similarly modable/maleable. I have one on the bench where the intent is to add 90 degrees more phase-shift over the entire spectrum and provide a second output with the notches bumped over a bit for a truer stereo phasing. The intent is to provide inversion of the second phase-shifted signal as well (prior to mixing) for a different kind of phase-shifted tone. Then there is the plan for the rack-mounted 12-stager, but that's another few months away at least......


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## Ripper (Jul 1, 2006)

mhammer said:


> The CA3094 is now out of production, or at least general production. I have no idea what sort of Faustian deal Mike Matthews has entered into to keep the Small Stone alive with that chip. We know that following the unusual episode in the early 80's when someone in Matsushita decided to sell delay chips to Japanese customers first (and probably only) just at the time when the Memory Man was fast becoming EHX's "cash cow", when the opportunity for purchase came again in the 90's, Matthews bought up the overwhelming majority of the world's stock of MN3005 chips to maintain the viability of the reissued Memory Man.
> 
> If you are desperate for them, Small Bear Electronics has them for about $5 a pop.


Yeah I know what you are saying about those chips. Interestly enough my local EH dealer just told me the small stone has been discontinued due to inavailability of some components. I'll give small bear a try thanks!


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## mhammer (Nov 30, 2007)

There was a brief period when the LM13600 was used for making Small Stone pedals. It is functionally equivalent to a pair of CA3094s, and happily it is still in production and *cheap*. The later Ross Phaser uses them and also uses the same LFO/sweep circuit from the first issue (6-chips not 5 as in later models) Small Stone, adapted to the LM13600. Sounds fine to my ears. It is quite possible that EHX will resurrect the LM13600 Small Stone, though their general direction to move towards more DSP-based pedals would suggest the SS will eventually disappear in favour of more-bang-for-the-buck pedals.

When it comes to distortion, DSP struggles against analog. When it comes to modulation-type effects, like phasing, chorus, tremolo, flanging, etc., there are plenty of occasions where digital can hold its head up proudly alongside analog. The upshot is that if EHX discontinued the SS at some point, or made it a digital pedal like the Stereo Memory Man, I don't think many would notice or care.


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## hollowbody (Jan 15, 2008)

mhammer said:


> As always, I refer people to the fully tricked-out Small Stone: http://moosapotamus.net/THINGS/frankenstone.htm
> 
> Actually, that one isn't even fully tricked out. Missing are an adjustable starting point in the sweep (The stock color switch selects between one start/width/regen combination and a second one. These are all independently variable.), as well as variable phase-blend.


Zoinks! That has to be the most ridiculous modding job I've seen to date. I only wish I had the time/ability/energy to do that to my Small Stone! Jeez, I'll have to brush up on my soldering skills for this one.



mhammer said:


> The orange FET-based Ross does not accommodate all those mods plus the Frankenstone ones, but the black LM13600-based issue *does*.


I have the black Ross. Have you ever had a chance to A/B a fully tricked out EHX and Ross? Is the Ross still a more subtle phaser than the EHX after all the mods?


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## mhammer (Nov 30, 2007)

hollowbody said:


> I have the black Ross. Have you ever had a chance to A/B a fully tricked out EHX and Ross? Is the Ross still a more subtle phaser than the EHX after all the mods?


I've made SS and Ross clones, but have never been in a position to directly compare multiple examples of each. As is often the case, unit-to-unit variation from normal component tolerances can too often be confused with model-to-model or issue-to-issue differences. That is, I may THINK I am hearing such-and-such a difference between this model and that, but the specific unit that I am treating as representative of EVERY Small Stone of that type in fact has a little more bass shaved here and there, a discrepancy in capacitor value in the phase shift stages compared to another unit, and the mixing resistors that set wet/dry balance are not as similar (or MORE similar) than on another unit; a bit like judging all men or all women on the basis of one person.

The Ross CAN be as pronounced, or even more, than any off-the-shelf SS, whether by luck, or by tweak. A schematic for it can be found at the Tonepad site here: http://www.tonepad.com/getFile.asp?id=99 Of course, where to find the parts identified for mod purposes on the original board is another matter, though I believe I have a picture of the original board at home. You can also refer to this schematic in case it helps to identify parts on the board: http://www.home-wrecker.com/ross_phaser_black.png

If you wanted a more pronounced phaser sound (which I assume means a little more regen/resonance), reduce what is identified in the second schematic as R20 down to 24k, and reduce what is identified as C8 down to .47uf or even .22uf. The first change will permit more recycle feedback at maximum settings, almost up to the point of oscillation, and the 2nd change will shave off some bass in the recycled signal so that the regen is less pronounced in that region and less prone to actual oscillation (as opposed to "mere" intensity). If you wanted a little more speed at the fastest end, you can drop the 4k7 resistor that is identified as R30 down to 3k3 or even 2k7. This will result in the most infinitesimal speeding up of whatever the slowest speed is, but if you can hear you shouldn't be in a band, you should be ina museum.

The original 6-chip SS does a neat trick that involves placing a capacitor between R25 (the end where it connects to the four phase shift stages) and ground. If you stick a 10uf cap (+ end to the resistor, - end to ground) there, the 10k/10uf combo acts as a lowpass filter with a rolloff commencing around 1.6hz.

Why is this important or worth knowing? Well, the sweep generator in the SS employs what is referred to as a "hypertriangular" sweep, which is a sine wave at the lowest point in the sweep, and a very pointy triangle wave at the highest part of the sweep. That makes for a slowish "turnaround" at one end, and a superfast turnaround at the other. While this is the type of sweep the ear prefers at slow speeds, at faster speeds you can't really hear it. Moreover, the ear generally prefers less sweep at faster speeds. This simple lowpass filter essentially smoothes out the top part of the sweep and also reduces the sweep width a bit so that the bubbliest speeds are more pleasant. If you like to use a phaser on fast for fake Leslie sounds, you'll appreciate this mod. And of course, if you have modded the pedal for even faster fastest speeds, you'll want it Ironically, it was not continued in the later-issue 5-chip Small Stones. Don't really know why.

The "phase-filter" mod is somethng I'm really proud of. With two stages set to lowpass and two stages set to allpass (phase-shift) and the pedal in vibrato mode (i.e., no clean signal, just processed), you get this sound which is an almost indescribable mélange of vibrato, auto-wah, and tremolo that is luscious, seductive, and "swampy". The kind of sound you imagine John Fogerty relishing (he apparently has a custom pedal that replicates the vibrato+tremolo thing he used to get from his old Kustom amp), or the way that Slim Harpo's "Baby scratch my back" *ought* to be played. I've never heard anything like it anywhere else. A truly unique sound.


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