XC phase questions

[mkstewartesq]

A couple of questiosn for those who have built the XC Phase. Since my components all seem to check out and my voltages seem roughly in line with what others have reported, I just wanted to determine if what I'm experiencing is actually "expected behavior" before starting a thread in the troubleshooting forum for what may be a non-issue.

1. On my 250K trim pot for biasing, the space where the sound actually phases is TINY - i.e., maybe a millimeter. About half of the throw is "no phasing", then a millimeter where it is phasing within which to adjust, then back to "no phasing" for the rest of the throw. Is that others' experience?

2. As others have reported with their builds, my phasing is subtle (at least on clean - when run after an OD, it's fairly noticeable). But I'm a novice with phasers so my expecations may be out of line. But have others had difficulty setting a bias that wotks for both stage settings? My block and script settings sound pretty good on 45 (Stages switch to the left) but on 90 both are much more crunchy rather than phasey. But given the tiny area in which to adjust the trim, I'm not able to get the 90 stage setting to clean up - at least not without throwing all of the other settings out of whack.

Thanks,
Mike

 

[Erik S]

I remember setting the trim was pretty finicky. That part sounds right.

Mine came out plenty phase-y though. I wouldn't say it's subtle.

I've read a lot of threads on here about sourcing or matching your own jfets and that being pretty important to getting a good phase effect out of it. I bought a matched set from guitarpcb.

 

[mkstewartesq]

I remember setting the trim was pretty finicky. That part sounds right.

Mine came out plenty phase-y though. I wouldn't say it's subtle.

I've read a lot of threads on here about sourcing or matching your own jfets and that being pretty important to getting a good phase effect out of it. I bought a matched set from guitarpcb.

Thanks for the input, much appreciated. I purchased a matched set of JFETs from Banzai (although I have not independently confirmed their respective readings - not entirely sure how to do that having only a multimeter).

Thanks again,
Mike

 

[Erik S]

I just read through some of the similar threads. Lots of good info here, but it seems like a lot of the problems were with alternate parts. I see Banzai has 2n5952s, so I'd think you'd be good there. If you built it per the build sheet and didn't swap in anything funny, I'd start simple and triple check all your component values and solder joints.

I think I also saw someone said they had an issue with poor grounding due to powder coat in an enclosure that contributed to this problem.

I'm just a follow the instructions and hope for the best guy. If you want the real smart folks to take a look, I'd say post it up as a troubleshooting thread.

 

[mkstewartesq]

I'm just a follow the instructions and hope for the best guy.

Thanks, Erik. It sounds like you and I are brothers from different mothers.

Mike

 

[Rixroxx]

A couple of questiosn for those who have built the XC Phase. Since my components all seem to check out and my voltages seem roughly in line with what others have reported, I just wanted to determine if what I'm experiencing is actually "expected behavior" before starting a thread in the troubleshooting forum for what may be a non-issue.

1. On my 250K trim pot for biasing, the space where the sound actually phases is TINY - i.e., maybe a millimeter. About half of the throw is "no phasing", then a millimeter where it is phasing within which to adjust, then back to "no phasing" for the rest of the throw. Is that others' experience?

2. As others have reported with their builds, my phasing is subtle (at least on clean - when run after an OD, it's fairly noticeable). But I'm a novice with phasers so my expecations may be out of line. But have others had difficulty setting a bias that wotks for both stage settings? My block and script settings sound pretty good on 45 (Stages switch to the left) but on 90 both are much more crunchy rather than phasey. But given the tiny area in which to adjust the trim, I'm not able to get the 90 stage setting to clean up - at least not without throwing all of the other settings out of whack.

Thanks,
Mike

It could be an issue with your transistors pin orientation. On the XC phase I built, I noticed also what you mentioned here. But since I used transistor socket for those transistors so I could experiment. Initially I used 2N5458, then 2N5457. They had different response and orientation also. I am not sure though if what I am saying here make sense. But I am speaking from my experiences using 3 types of transistors.

I was able to have the 2N5952 and the sonically, it is a night and day difference. I regretted that I only bought 4 pcs of 2N5952 while is it still cheap. I should have bought more. Now it's out of stock from the online store i bought it.

In using the 2N5952, the transistors flat side is towards the potentiometer's direction. I turned it clockwise until I get the phasing sound while matching the clean tone of the bypass sound. In other words I tuned by ear. You might be tempted to get more swirly phasing sound as you turn the trimpot but the problem is the sound is too compressed or somewhat overdriven. I tuned it by turning it while comparing the bypass sound and while the effect is on. With the 2N5952, it sounded very good.

 

[mkstewartesq]

It could be an issue with your transistors pin orientation. On the XC phase I built, I noticed also what you mentioned here. But since I used transistor socket for those transistors so I could experiment. Initially I used 2N5458, then 2N5457. They had different response and orientation also. I am not sure though if what I am saying here make sense. But I am speaking from my experiences using 3 types of transistors.

I was able to have the 2N5952 and the sonically, it is a night and day difference. I regretted that I only bought 4 pcs of 2N5952 while is it still cheap. I should have bought more. Now it's out of stock from the online store i bought it.

In using the 2N5952, the transistors flat side is towards the potentiometer's direction. I turned it clockwise until I get the phasing sound while matching the clean tone of the bypass sound. In other words I tuned by ear. You might be tempted to get more swirly phasing sound as you turn the trimpot but the problem is the sound is too compressed or somewhat overdriven. I tuned it by turning it while comparing the bypass sound and while the effect is on. With the 2N5952, it sounded very good.

Thanks for the reply. Actually, both by getting a better matched set of transistors and by switching out one of the TL072s with a TL022, every single issue I was having with that build (there were multiple) vanished and it now works perfectly. More details on the fixes here. Since I shared my findings on swapping out the IC, others have reported that, after making the same swap, their previously unsuccessful builds are now working properly as well.

Mike