Looking for recommendations on which phaser to build...

Started by MetalUpYerEye, November 26, 2010, 12:10:26 PM

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MetalUpYerEye

In the midst of my glorious battle with the Tiny Trem and my everlasting wait for parts for my EA Trem, i've had a request come in...

This time i'm looking to build a phaser. I've looked at the Phase 90, 180/Revolution, Small Stone and the Casuality 4. I was also eyeballing the EVH Phase 90 though i'm not sure how much different it is from the typical P90 or if there is documentation available for building a clone of it. (a clone of a clone! dur dur dur...)

I'm looking for something thats going to be a relatively straight-forward build (i'm not interested in effing around with part matching) so I was thinking the Casuality might be up my alley. Experience-wise I guess i'm intermediate; i've built several pedals (Electra distortion, a TS808, Colorsound Inductorless Wah, a pair of Dr. Boogeys, AMZ mini-booster, Ruby mini-amp as well as 2 or 3 of my own 386 based mini-amps) I can read schematics fairly well and have a pretty basic understanding of troubleshooting techniques, etc.

I've never really had the chance to sit down with a Phaser so sound-wise i'm pretty dumb. This is going to be for my Dad and he mentioned the Phase 90 and the EVH P90 so if the Casuality comes anywhere close sound-wise then that will likely be my choice.

All suggestions are welcome but if you suggest a circuit please post the necessary documentation as well.

And thanks for the help!  ;D

Spidermonkey


Mark Hammer

Its hard for a Phase 90 to disappoint anyone who likes phasers.  It's as classic a sound as you can get.  That being said, there is the matter of a) getting andmatching FETs, and b) setting the bias.  neither of those is especially hard, but they do add to the complexity.  Including options that produce the sound of the different issues is dead easy, and wads of info here about it.

Building the Small Stone involves more parts and labour.  The Ross/Ropez phaser is a nice substitute and uses parts that are much easier to get and no matching or biasing is needed.

The Causality 4 is a cousin of the Ross and Small Stone, though the sweep is different, and the sound less "classic".  Decent phaser but perhaps not your dad's.


jkokura

My vote is the Phase 45. It's a bit more subtle, but it's a super easy build with low parts, easy to get two matched transistors, and it sounds wonderful.

Jacob

MetalUpYerEye

If Phase 90 is a classic sound then thats probably what I want to go for. I was having trouble describing the sound I was thinking of but 'classic' pretty much hits the nail on the head.

So I can get my matched FET's from GuitarPCB.com... That fixes one problem... I've biased my 2 Dr. Boogey pedals more than once without too much trouble, is the Phase 90 any different?

I'm gonna need some documentation on the Phase 90... Schemo, parts list, vero or perf layout if anyone has them... All help is very much appreciated!

Does anyone know the difference between the regular Phase 90 and the EVH one...?  ???

Jacob - Any documentation for the Phase 45?

Mark Hammer

I don't know where specifically, but the script-vs-block modifications has been beaten to death here.  Poke around, you'll find it.

Schem and layout can be found at Tonepad, though there are undoubtedly other layouts, including perf, around too.

MetalUpYerEye

Sweet, I found the one at tonepad. Looks pretty clean.

Anyone on here willing to make a PCB for this? Tonepad wants $18 for one shipped... At that rate I might just consider trying my luck with the vero layout that I found. I've heard bad stuff about the vero layout though, I guess it clicks like mad unless you modify it.


frequencycentral

#8
I highly recommend you try the guitarpcb.com PCB, it's my own layout and includes a block/script switch: http://www.guitarpcb.com/apps/webstore/products/show/1754801  There have been dozens of successful builds, and there is great support at the guitarpcb.com forum. The board is only $12.95, and you can also order a set of matched FETs plus a 2n4125 for $5.95. Barry is a really nice guy and ships really fast.



http://www.frequencycentral.co.uk/

Questo è il fiore del partigiano morto per la libertà!

Mark Hammer

Makes sense to me.  Tonepad boards are VERY nice, but Francisco doesn't sell matched FETs as far as I know.  Small Bear will sell you matched FETs at a reasonable price, and Mouser will sell you more (unmatched but matchable) FETs than you'll ever need for $6.  But none of them sell the board AND the FETs.  May as well save yourself paying shipping twice.

MetalUpYerEye

Quote from: frequencycentral on November 26, 2010, 04:00:47 PM
I highly recommend you try the guitarpcb.com PCB, it's my own layout and includes a block/script switch: http://www.guitarpcb.com/apps/webstore/products/show/1754801  There have been dozens of successful builds, and there is great support at the guitarpcb.com forum. The board is only $12.95, and you can also order a set of matched FETs plus a 2n4125 for $5.95. Barry is a really nice guy and ships really fast.

Ok cool, I had seen that layout there but I didn't know it was the same circuit as the Phase 90. Getting both of those together there would save me about $15 overall even though that board lists for only a dollar less than the tonepad one...

I can see this project being close to the "you might as well go spend the money and buy one" point. But its still more fun to build one and you learn a hell of a lot more.

Mark Hammer

You CAN get a respectable Phase 90 from Behringer for probably $30 or less.  The difficulty with it is that it is 80% surface mount (as are most inexpensive pedals these days) and you have no idea where the critical parts are.  So if you wish to mod it to taste, you're going to have a tougher time doing that.  Going DIY is not going to save you a ton of money, but it WILL save a certain amount of aggravation if modding is in your blood.  Getting a pre-made PCB and matched FETs will save some time and headaches.

Note: The pictures on the website suggest that the boards are etched and drilled but not necessarily tinned.  If that's true, I strongly recommend buffing the board with fine steel wool when you get it, and then keeping it safe from humidity and "finger juice" until it's time to solder parts in.  If you have the patience to tin it, I'd recommend doing that too, but it is not an absolute requirement.

MetalUpYerEye

Yeah I looked at Musiciansfriend.com earlier and they have a standard MXR Phase 90 for like $58. I have this one figured in at right around $55 with no surprises. The thing is that it would be awesome to give my Dad a personally hand-wired Phase 90 and even better if I could mod it out a bit for him. I understand you can make the circuit a 'script' version by removing 1 resistor and jack up the gain by changing another one to a higher value. It would be cool (once I get the original circuit of course) to throw each of those on a switch to give the pedal a couple more sound options.

Right now i'm planning to get the IC's, diodes, pot, trimmer, switch, jacks and enclosure from Small Bear. The PCB and FET's from guitarpcb.com. I was gonna go with a power coated B-size enclosure ($7.75) and they have their 3pdt switches for $9.00. Unless you guys know of a place that has all the IC's, diodes, etc. and cheaper enclosures and switches...

azrael

Newer Phase 90s are not moddable, not easily, anyway, since they have SMD parts.


You should have poked around more, there's more to "script specs" than pulling out the feedback resistor.
Behold:
http://www.aronnelson.com/gallery/main.php/v/Schematics-etc/MXR_Phase_90_to_Script.gif.html

MetalUpYerEye

Quote from: azrael on November 26, 2010, 11:39:30 PM
Newer Phase 90s are not moddable, not easily, anyway, since they have SMD parts.


You should have poked around more, there's more to "script specs" than pulling out the feedback resistor.
Behold:
http://www.aronnelson.com/gallery/main.php/v/Schematics-etc/MXR_Phase_90_to_Script.gif.html

Yeah, it doesn't surprise me that there's a lot more to script than 1 resistor. But then i'm sure its like saying "my TS808 sounds better than yours because it has a NOS 4558." When you get down to it the difference is likely pretty negligible.

Even so, spec is spec I suppose. I'd like to get this on breadboard and go a few rounds with it before I decide to worry about any mods; I gotta get the basic setup going first!  :-X

azrael

I dunno, I did the R28, then the other mods, the difference was noticeable IMO, and worth it!

MetalUpYerEye

I'll probably try all the mods once I get my breadboard and get the circuit put together. Since its not a pedal for me i'd rather not put in switches for every mod available. Then again having just a rate control by itself is a little boring.

I'll likely choose 2 mods that I like the best and put 2 switches along with the rate pot. I also noticed that you can change R20 for a 1M pot and you'll be able to control the depth, which might give the pedal a whole other range of sounds. I'll just have to try everything and see what I like best. Maybe take the breadboard to my Dads and give him a listen with the different mods.

I mean hand-built pedals are cool, but hand-built and personalized to taste are even better.