Roland AP-7 Jet Phaser - let's get it working! (Aion FX Octatron)

Well, I'll be the first to throw this up.

It's not "DONE" as the distortion side isn't working and I haven't had the chance to figure it out.
But since we're looking at the behavior of the phasing I thought I'd focus on that.

I initially biased according to the build doc, -1.35v but I wound up biasing by ear to get the best phasing. I found the exact opposite of the build doc in that small adjustments on the trimmer make a pretty big difference in the phasing. I wound up somewhere around -1.78v.

Having said that, I have some oscillation that modulates with the phaser even when not playing. I can't seem to dial it out with the trimmer.
It "could" be dirty power at my house.

As far as the phasing itself, it sounds good. Using the 4 stage it sounds somewhat like a Boss PH-1r. 6 Stages is pretty cool and may be my favorite setting. 8 stages gets into Mutron-ish land.

Regarding the "thunk", @aion can you be more specific about what the issue is? Or point to a clip on the issues?
I'm not hearing anything like a clunk, or a hiccup at the bottom sweep if I'm understanding correctly.

Couple of tips.....if you haven't built it yet.
For Q12, use the 9th JFET that Kevin sent to you. I tried a TO-92 2SK208 initially and wasn't getting any phasing. I popped the JFET that Kevin sent in and it fired right up.

Secondly, Q11, if you're using the Interactive BOM it calls for a 2N5088. The build doc says to use a 2N3904. Use the 2N3904.
It SHOULDN"T make any difference between these two options but in my build, for some reason it did.

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Alright so i got mine together and did some quick tests. I haven’t dug into it much yet but the jet side on mine doesn’t work either. I haven’t explored much like I said but the phaser side does work. I did have to bias at -1.72 to get a good phase effect. The -1.35 starting point had very very very little phasing sound at all. All the controls work as they should and I am not hearing anything odd like the thunk. Maybe the thunk is only there when the jet side is working as well? Anyway we are off and running at least. I am curious to see if anyone else is having luck with the jet side.
 

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Anyone else ever put this together besides @MichaelW and I? Both of us came out with a working effect with no issues. I am curious to see what experiences others had with it. If it works we should let Kevin know so he can add it to his offerings.
 
I’ve got mine 90% populated with what I have on hand. Putting together a sizable tayda order to finish this one and a few other projects up.
 
I’d be interested in building if @aion has any boards. After working through a dozen boards in December, including a batch of phasers, choruses and delays, I think I have figured out isolating issues now.
 
Can anyone explain this thunking to me? I assume it's in time with the rate but does it disappear with depth? Does increasing any of the controls make it more apparent?

Has anyone bothered to check what the voltage offset is like on the phase stage op-amps?
 
IMG_6371.jpeg I did make a real box for mine. I have since fixed the led i messed up when I changed boxes. I bent the legs on the jet led, lol. It works great. I won’t make anyone listen to my playing though. I can tell you it sounds like the original in the popular video.
 
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