# XC Phase Modifications Thread



## Big Monk (Oct 14, 2021)

Inspired by my studies over the last few days and the recently posted @caiofilipini XC Phase build, I thought maybe a repository of the many known Phase 45/90 mods might be in order.

Let's list them and see what we can add/subtract/clarify:

1.) Intensity/Depth Control
2.) Rate LED
3.) "Resonance"/Feedback Control
4.) Volume Control
5.) Dry/Wet Mix Control
6.) Univibe/Warble Mods
7.)  Expression Mod (Speed)
8.) Lower/Upper Limit Speed Trims
9.) Phase 45/90 Switch*
10.) Script/Block Switch*
11.) Slow/Long Cycle Mod

*Already accounted for in the XC Phase

My plan is to incorporate many of these into an Orange 1590BB. I have not started planning yet but will likely do this in tandem with my Hydra build.

Let's talk about it!


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## Bricksnbeatles (Oct 14, 2021)

On top of the dry/wet mix control, you can always just do a dry kill switch if you don’t think you’ll ever use a 70/30 mix or any like that to warrant the additional space for a pot, and that’ll give you something relatively similar sounding to a magnavibe. 

I’ll post my planned layout for my Modded XC later on or tomorrow (seeing Todd Rundgren tonight, so I might not have time today before I leave)


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## Bricksnbeatles (Oct 14, 2021)

In a BB there’s probably enough room to add a modified take on RG keen’s easyvibe speed ramping method by eliminating the LFO portion of his circuit and just using it to control the resistance where the speed pot would be


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## Big Monk (Oct 14, 2021)

thewintersoldier said:


> Having been down this road before myself, I have tried to incorporate some of the mods above but ultimately went back to the stock pedal. The most useful mods are incorporated into the pcb already. A blend may be useful to some but this isn't an overpowering effect to begin with. You could ditch the script switch and make a depth pot. Some mods may require an external bias pot to change bias of the jfets like in the Univibe mod. I think the one I would like the most is the fast/slow mod.



The list was really a conversation starter.

In addition to the stock pedal, I like the idea of the following:

1.) Intensity/Depth
2.) Resonance/Feedback
3.) Univibe Mods


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## Bricksnbeatles (Oct 14, 2021)

thewintersoldier said:


> Having been down this road before myself, I have tried to incorporate some of the mods above but ultimately went back to the stock pedal. The most useful mods are incorporated into the pcb already.


as far as guitar goes, I wholeheartedly agree. I have an MXR variphase, which has the depth control (the 1M pot off of the wiper of the bias trimmer) and it’s extremely subtle. The mix knob is mildly useful, but frankly a switch to go from 50/50 to 100% wet is more useful. I’m only doing those two mods on mine because I’m planning on using this one for keys, and the full frequency range of a 6-octave keyboard is where these mods really become useful. If this was for guitar I’d just build it with the two switches that are already on the PCB, and leave the rest ‘stock’. 

The univibe mod is cool on guitar, but takes up a lot of space unless you only do it to the first two stages, in which case it’ll only really be the “univibe mod” in the 45 mode, and it’ll only make a marginal difference in 90 mode. Still potentially worthwhile, but ymmv.


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## Big Monk (Oct 14, 2021)

What's a good alternative to the 2N5952?


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## JamieJ (Oct 14, 2021)

A simple slow phase without any mods sounds immense. I’m again fan boyin’ over Tommy B here but it feels appropriate to leave this here -






I always figured that I would want a mix knob on a phase 90 but i am sold on just a slow phase.

It would be cool to hear the effect of that mix mod if you do go for it @Big Monk 

Also @Big Monk - you definitely need to do the univibe mod so you can have three univibe pedals on your board 🤣 I don’t think you’ll be able to choose between the electrovibe and good vibes!


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## Big Monk (Oct 14, 2021)

JamieJ said:


> A simple slow phase without any mods sounds immense. I’m again fan boyin’ over Tommy B here but it feels appropriate to leave this here -
> 
> 
> 
> ...



Funny you say that. I’m starting to sour on the Good Vibes. It seems impossibly bright now and the overlap with the Electrovibe is easily served by my Script Phase 90. 

What would be really great would be a Super Phase 90/45 that had decent enough Univibe tones to kick all three off my board!

Just need to find these FETs now!


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## Big Monk (Oct 14, 2021)

JamieJ said:


> A simple slow phase without any mods sounds immense. I’m again fan boyin’ over Tommy B here but it feels appropriate to leave this here -
> 
> 
> 
> ...



You could use the Trimit! and put the resistor that sets the lower threshold of speed on that.


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## Big Monk (Oct 14, 2021)

thewintersoldier said:


> Any jfet in the same general range. Most important is the matching. I've used 5457, 5458 and others with great results



Awesome. I’ll grab some just to have them and enough to do some matching.


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## finebyfine (Oct 14, 2021)

Big Monk said:


> You could use the Trimit! and put the resistor that sets the lower threshold of speed on that.



On the XC Phase would that be R26 or R21, or a different one?


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## Big Monk (Oct 14, 2021)

finebyfine said:


> On the XC Phase would that be R26 or R21, or a different one?
> 
> View attachment 17041



I’ll pull the BYOC Royal Phaser docs in a few minutes and confirm.


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## finebyfine (Oct 14, 2021)

Big Monk said:


> I’ll pull the BYOC Royal Phaser docs in a few minutes and confirm.


Thanks. I just placed a Tayda order for an enclosure for my build and am definitely gonna do this mod before it shows up.


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## Big Monk (Oct 14, 2021)

finebyfine said:


> Thanks. I just placed a Tayda order for an enclosure for my build and am definitely gonna do this mod before it shows up.



I guess it would depend on whether the rate control is faster or slower at its max resistance. 

Does slow speed correspond with zero resistance on the pot? If so, then lowering R26 should lower the floor for slow speed. 

I guess. I’m new to building modulation pedals so I may not be the best person to ask.


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## Big Monk (Oct 14, 2021)

Bricksnbeatles said:


> The univibe mod is cool on guitar, but takes up a lot of space unless you only do it to the first two stages, in which case it’ll only really be the “univibe mod” in the 45 mode, and it’ll only make a marginal difference in 90 mode. Still potentially worthwhile, but ymmv.



Well, I’m scheming on that in my head now. I see a 4PDT switch and a custom breakout board for it the hold 8 caps. This will involve flying leads, 8 to be exact, but will allow footswitchable univibe mode in both 45 and 90 mode.


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## Big Monk (Oct 15, 2021)

thewintersoldier said:


> Any jfet in the same general range. Most important is the matching. I've used 5457, 5458 and others with great results



2N5459?


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## benny_profane (Oct 15, 2021)

Big Monk said:


> 2N5459?








						Anyone contemplating using J201s for xc phaser?
					

Them 2N5952 And equivalents are hard to get a hold of these days anyone give SMD subs a go like the the J201? Just curious.




					forum.pedalpcb.com


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## Big Monk (Oct 15, 2021)

benny_profane said:


> Anyone contemplating using J201s for xc phaser?
> 
> 
> Them 2N5952 And equivalents are hard to get a hold of these days anyone give SMD subs a go like the the J201? Just curious.
> ...



Thank you for that. Small Bear has the Fairchild/ON J113 whose data sheet values are in that range. I was thinking of grabbing about 30 as they are not very expensive.


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## benny_profane (Oct 15, 2021)

J113 should be workable, but may require some modifications. People have used them and documented their experience on other forums.


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## Big Monk (Oct 15, 2021)

benny_profane said:


> J113 should be workable, but may require some modifications. People have used them and documented their experience on other forums.



My goal is to breadboard and tweak before going the PCB route anyway. The J113 had Vgs values right on the money for the 2N5952 and 2N5457 sheets that I looked up.

I figured 30 was enough to get a good quartet!

EDIT - I did some searching over at DIYSB and marked down some posts detailing tweaks to accommodate different JFETs here. Thanks again @benny_profane


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## Big Monk (Oct 16, 2021)

I’ve officially become obsessed with the inner workings of the Phase 45/90 circuit and then some. 

This will be a breadboard circuit for sure.


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## Big Monk (Oct 26, 2021)

I'm going to be drawing up a breakout board design for a 4PDT Stomp switch so that I can switch the Univibe mod in on Phase 90 and Phase 45 mode. Stay tuned...


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## Big Monk (Oct 26, 2021)

I was able to get the board laid out but I need to tweak a few things and start a Corel Draw file for my XC Phase build to plot out how the hardware and internals will sit with all the mods. 

The concept is simple: a 4PDT switch and breakout board with 8 caps. You’ll need 4 pairs of flying leads to the board but the UniVibe mod will work in both 45 and 90 mode. 

Once I have everything squared away, I can either order a gang of the boards or post the DipTrace file here for everyone.


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## Big Monk (Oct 27, 2021)

Ok Gents...

Here we are:







Tayda sells a 4PDT Stompswitch and it would just require running 4 pairs of wire to the board.


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## Bricksnbeatles (Dec 11, 2021)

Anyone have thoughts on if 2SK30As would be a good sub for the now-unobtanium 2N5952s? That’s what was used in the Boss PH-1, which is pretty damn similar to a phase 90. They’re readily available for cheap as SMD units, so they might be a good solution for finding a cheap and reliable option.


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## Kroars (Dec 11, 2021)

Bricksnbeatles said:


> Anyone have thoughts on if 2SK30As would be a good sub for the now-unobtanium 2N5952s? That’s what was used in the Boss PH-1, which is pretty damn similar to a phase 90. They’re readily available for cheap as SMD units, so they might be a good solution for finding a cheap and reliable option.


That would be great.  AionFX sells matched sets of 2SK208’s (which apparently have near exact specs as 2sk308A’s), as well as unmatched for a bit cheaper:









						2SK208-GR JFET (matched set of 4)
					

This is a matched set of 4 2SK208-GR JFETs for use in phasers such as the BOSS PH-1r, pre-soldered to adapter boards for through-hole applications.




					aionfx.com


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## Bricksnbeatles (Dec 11, 2021)

Kroars said:


> That would be great.  AionFX sells matched sets matched sets of 2SK208’s (which apparently have near exact specs as 2sk308A’s), as well as unmatched for a bit cheaper:
> 
> 
> 
> ...


That matched set would definitely be an easy and cheap option. I planned on just getting 100 2SK208-GRs (which as you mentioned are identical to 2SK30A-GRs, just in a SOT23 package instead of TO92) from Digikey, and ordering a panel of SOT23-TO92 adapter boards from JLCpcb, but the Aion set is probably a more practical (albeit a bit more expensive per unit) option


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## Bricksnbeatles (Mar 22, 2022)

since the LFO gets slower with greater resistance, is there any reason (other than the speed range being more fiddly) that a resistance of 1M+ couldn't be used to get the LFO even slower? Im thinking up what I think may be a rather clever way of implementing a momentary brake switch which would, over the course of 500-1500ms ramp the speed down to be so slow that it gives the impression of a fixed-phase sound.


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## fig (Mar 22, 2022)

Fig. FETs. Free. Follow?


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