SOLVED Aion Xenotron / Lovetone Flange no BBD modulation

Kris100

Member
Hey, hope I can ask you All for a bit of help and / or advice - Finished this build yesterday... and surprise surprise it doesn't work :) I've built 150+ pedals and never ended up with a build that doesnt work (including couple Aion Lovetone builds) so I really hope I can get this one working as well.

Pedal has 3 separate 3PDT's where 1 is for the effects loop, 1 for time modulation and 1 for space modulation. Time and space LEDs follow rate of modulation set by the pot. There are several internal LED / LDR combo - 2LED / LDRs for the Space on the main PCB, 1 LED / LDR for Time and additional LED / LDR for time on the BBD sub board.

3PDT LEDs light up, space and time ones pulse in tempo with the rate, SPDT switches seems to work, pedal passes signal through but there is no BBD LFO modulation. Space switch engaged works as a tremolo but Time doesn't seem to create any chorus / flange modulations. When I max out Manual control I can get some weird faint modulations with the internal BBD trimpot tweaked right but nothing that resembles typical chorus / flange vibes.

In terms of troubleshooting - I checked IC orientation, polarity of all components, triple and quadruple checked all wiring. I made sure I used a working MN3207 and MN3102 set from a chorus pedal I built a while ago. I also checked both PCBs for shorts or bridges, cleaned them with IPA and reflowed the few components connected to the LED3 that's connected to main 3PDT time f-switch. I tried to connect to Time Out jack and tweak the bias and all controls but I get nothing that sounds like a chorus / flanger.

Looking inside I noticed couple of things
- Space 3pdt engages the internal LED 1&2 which pulse along Rate control (the 2 LEDs which are inside a "fence" made of film caps),
- Time 3pdt turns the internal LED 3 on but this one doesnt pulse at all (bottom left corner of main PCB). Neither bias nor regen trimpots do any difference. I tried to follow the biasing instructions from build docs but having no LFO on any BDD trim setting not much I can do.
- The LED on the BBD sub board lights up and pulses with varying speed depending on Manual, Rate and Depth.

My guess is the LED3 on the main board should also pulse following rate but cannot see or measure anything obvious that could stop it from working. I am adding few pics of the build and schematics from Aion's build docs (pages 21-23).

For reference below a link to a build of another forum member that works perfectly, there's also few photos of internals and a short demo.

 

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Solution
I needed to take a break from this one and built the Ring Stinger which was another intimidating Aion board that was waiting it's turn. Turned out perfect, no issues whatsover :) Freakish yet very musical pedal.

I plan to come back to the flanger once I get correct clear LED for BBD board - after some checking I am sure the ultrabright one I used is way out of spec for this place. The recommended one has brightness around 80mcd while the one I used is I think 10000+mcd... :) which surely affects my issues with Manual control and better bbd biasing. I just cant find anything locally like the transparent green LED Aion recommends so until I get the correct one this project fix is on hold. To be continued!
Short update - I swapped...
I’m having exactly the same issue with this build, I’ve not started troubleshooting yet.
ooohhh noooo... I just have to do the offboard wiring on this and I will be plugging in with a prayer.

I'd read the manual, follow the biasing instructions religiously, and double check everything, especially the wiring and the connections between daughterboard/mainboard, check that the chips are in the correct place and all that.
 
ooohhh noooo... I just have to do the offboard wiring on this and I will be plugging in with a prayer.

I'd read the manual, follow the biasing instructions religiously, and double check everything, especially the wiring and the connections between daughterboard/mainboard, check that the chips are in the correct place and all that.
Have done a bit of troubleshooting and I am actually getting BBD modulation on the time output so it looks like the issue lies somewhere in the summing to the space/mono jack out. I bet it’s the wiring (which was by far the least fun bit of the build)!
 
I think your probe has told you important information, actually, which allows you to tighten focus on the area of trouble.

What it sounds like is that signal is making its way to the BBD and Clock board, and it is being effected in some way, but then it's not getting out. The next thing to do would be to trace the path of signal along the schematic and find the last occurence of effected signal, and then jumper from that last point to the next point in the circuit. See if that has the signal get through. If it does, then there you go, you just solder in the jumper. Sometimes we damage a trace or do dumb stuff that causes a disconnect in the pads or wiring (again, ask me how I know...).
Watch out that you are actually jumpering signal-signal and not voltage-signal. I think I fried some transistors that way.

I want to be clear about your audio probing, though, because you state "Plugging signal into the BBD chip through Pin3"--normally, I don't think you are plugging anything "in" via the audio probe, you are providing a circuit "out". You do plug in a signal source (looper is great) through the in jack, and then you are basically jumpering to signal-out via the probe. Since pin 3 is the in-pin to the BBD, you would be assessing the signal before it has a chance to route through the BBD, basically the signal as it exits whatever component/s in the circuit immediately prior (R79 and C30, looks like) to amplification and processing in the chip. Looks like BBD out is pins 7 & 8--I think that's where you should find effected signal. Pins 2 and 6 of the BBD look like they are send/return to pins 2 and 4 of the clock (CP 1&2) since pins 5-7 are involved in the weird little "OX1-3" loop process with LDR 4 and all that where you detected flanging. I'm not super sure on how the BBD/Clock relationship is arranged, though.
Thanks man, I really appreciate your advice and support on this - I am no good in this part of troubleshooting, never had the chance to go this far :)

I was inserting signal from the input end rather than jumping the output path hoping I can skip the part it gets to the BBD board - and somehow I didn't think of the other end...
 
Have done a bit of troubleshooting and I am actually getting BBD modulation on the time output so it looks like the issue lies somewhere in the summing to the space/mono jack out. I bet it’s the wiring (which was by far the least fun bit of the build)!
Double check on the Ring Lift switch when playing around with it, see below note on this in the build docs:

Ring Lift (toggle switch) disconnects the ring (middle) terminal of the Time jack, which is equivalent
to the “C” solution in the user manual under the “Time Out” heading without requiring a speciallymodified
cable. Note that this prevents the Time signal from being mixed to mono when only the
Space output is used, so it should only be engaged when both outputs are used and only if you
notice a buzz or weak signal from the Time output.
 
Thanks man, I really appreciate your advice and support on this - I am no good in this part of troubleshooting, never had the chance to go this far :)

I was inserting signal from the input end rather than jumping the output path hoping I can skip the part it gets to the BBD board - and somehow I didn't think of the other end...
Well I guess that's one way to do it! Subtractive instead of additive.

[Edit: still not clear to me how you're probing, so here's how I do it, maybe you were doing this all along: 1. guitar/loop/music source to cable, connect to board input jack. 2. Take a regular TS jack, solder a small capacitor and wire to the tip tab of a TS jack. 3. I clip the ground tab to the enclosure, and clip the hot tip signal wire to a multimeter probe. Alternately, you can just use a length of wire. 4. Take your little probe jack assembly and connect it to a practice amp via cable (lower volume is best because you're going to get pops and buzz), 5. Follow your schematic in and touch components with the multimeter probe, listen and rejoice in your diagnostic fun times.]

I think the virtue of additive tracing with the signal-out probe (from audio signal at the in Jack) is that you are following the path of the signal in the circuit chain in order so it's easier to understand what everything does and how it builds to transform the signal cumulatively.

Anyway, you do learn a whole lot from troubleshooting, for sure. I just wish it wasn't so exasperating. Some things are just weird behaviors that I can't puzzle out or solve due to my extreme lack of electronics knowledge.
 
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I have the same issue on my build.

Space modulation works fine.
Loop switch is ok.
Led from the sub-board is pulsating according to LFO Rate, its brightness is set by the Manual control.

No modulation from Space Out/ Mono output when Time is activated. Only some strange distorted "broken" modulation from Time Out output.

This weird modulated signal is responding to the controls, but it isn't affected if i open the enclosure while the effect is engaged. Photo resistors aren't affecting the signal...

I also get a loud buzzing sound when toggling Ring Lift downward, with or without footswitches activated, but only from the Time Out output. Ring Lift has no noticeable effect with Space/Mono output.

On the wiring diagram, i don't understand how the "Time" signal can get to the Space Out/ Mono jack ?
Looks like it only goes to the Time Out jack ?
Screenshot 2023-11-28 at 05-44-16 Xenotron Modulation Machine - Aion FX - xenotron_documentati...png
 
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Let me join you all in the troubleshooting party!

Although for me, it looks like it's the tremolo side not working. Tweaking knobs, I'm able to get some flanging and self-oscillation and able to calibrate BBD. Have yet to do the regeneration calibration, though.

Eh la-bas ma: I had this too. The buzzing might be because you are using a TS cable in the TRS jack, and it's effectively introducing signal to ground, thus the need for the ring lift/disconnection of the ring--I think it's meant to accomodate for a TS cable, but who knows. If I understand correctly, the time out/need for ring lift is only really used if you are splitting the signal. Otherwise, it just goes to the mono out.

Please feel free to correct my hypotheses.
 
Let me join you all in the troubleshooting party!

Although for me, it looks like it's the tremolo side not working. Tweaking knobs, I'm able to get some flanging and self-oscillation and able to calibrate BBD. Have yet to do the regeneration calibration, though.

Eh la-bas ma: I had this too. The buzzing might be because you are using a TS cable in the TRS jack, and it's effectively introducing signal to ground, thus the need for the ring lift/disconnection of the ring--I think it's meant to accomodate for a TS cable, but who knows. If I understand correctly, the time out/need for ring lift is only really used if you are splitting the signal. Otherwise, it just goes to the mono out.

Please feel free to correct my hypotheses.
Make yourself at home, I guess this project might make a community of people traumatized by the Lovetone Flanger build
 
If we all had the same issue, we could legitimately ask Aion to look into it. Problem it doesn't seem like we do, so most likely this is a collection of user errors. In a way, it's reassuring, since it means there isn't an innate defect in the board, which would be really really annoying. And it also means my ambition is still exceeding my building skills. I mean, damn, we are coloring by numbers, here--I shudder to think of the craziness it took to actually design and make the pedal.

I'm going to take a closer look just to make sure, but as far as I can tell, my LED 1 & 2 are non-responsive, which would account for the lack of tremolo.
 
If we all had the same issue, we could legitimately ask Aion to look into it. Problem it doesn't seem like we do, so most likely this is a collection of user errors. In a way, it's reassuring, since it means there isn't an innate defect in the board, which would be really really annoying. And it also means my ambition is still exceeding my building skills. I mean, damn, we are coloring by numbers, here--I shudder to think of the craziness it took to actually design and make the pedal.

I'm going to take a closer look just to make sure, but as far as I can tell, my LED 1 & 2 are non-responsive, which would account for the lack of tremolo.
It's just a bunch of random issues we've caused. Regarding what you said abt LED1 & 2 - LED1 should stay on, LED2 turns on and starts pulsing as soon as you engage Space switch. LED3 turns on when you hit Time switch but should not pulse. LED4 on the sub board will stay on irrespective of main footswitches and start pulsing depending on pot control settings
 
Would it help if I went through and got all of the voltages for the IC’s and transistors?
I think I just hit a breakthrough - I decided to box the pedal back and spend more time testing it in various settings seeing all components are good - through Time out and Space out separately.

First thing I noticed - when I crank Manual all the way I managed to get some modulated settings through Time Out jack. Success! This did not happen before, or I did not notice this when testing the pedal in the first place before pulling the board out of the box. I tried the Space out but this one still had the modulations very faint in volume in the background. I jumped the Time Out jack tip with the Space Out tip and there we go - it works! It still bothers me that I have close to no control with Manual - less than 8/10 and I only get some loud noises coming out or just the clean signal. I crank it and get a variety of sounds through the rest of the pots.

When testing this the first time I must have missed checking it with all settings on the Manual control which in my case needs to be pretty much all the way up. This is not ideal and I still need to identify what's happening with the Time Out / Space Out mixing that need to be jumpered to get the mix corrected for Space Out but it's glorious to finally hear this thing make some weird noises.

Could it be I need to switch LED4 which is controlled by Manual? I used a high brightness green one but I could have a high brightness one that's not the same spec as Aion is referring to... More testing to be done, fortunately I have a bag of various LEDs on hand.

I'm leaving this thread open until I resolve all issues but Guys, today was a good day :D Don't give up!
 
Would it help if I went through and got all of the voltages for the IC’s and transistors?
I don't think it would hurt, if only for posterity and comparison's sake.

[edit: actually, it would be very helpful to me, especially for the LFO section, since a voltage probe seems like the only option there, and I am almost 100% sure my issue is somewhere in there.]
 
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I think I just hit a breakthrough - I decided to box the pedal back and spend more time testing it in various settings seeing all components are good - through Time out and Space out separately.

First thing I noticed - when I crank Manual all the way I managed to get some modulated settings through Time Out jack. Success! This did not happen before, or I did not notice this when testing the pedal in the first place before pulling the board out of the box. I tried the Space out but this one still had the modulations very faint in volume in the background. I jumped the Time Out jack tip with the Space Out tip and there we go - it works! It still bothers me that I have close to no control with Manual - less than 8/10 and I only get some loud noises coming out or just the clean signal. I crank it and get a variety of sounds through the rest of the pots.

When testing this the first time I must have missed checking it with all settings on the Manual control which in my case needs to be pretty much all the way up. This is not ideal and I still need to identify what's happening with the Time Out / Space Out mixing that need to be jumpered to get the mix corrected for Space Out but it's glorious to finally hear this thing make some weird noises.

Could it be I need to switch LED4 which is controlled by Manual? I used a high brightness green one but I could have a high brightness one that's not the same spec as Aion is referring to... More testing to be done, fortunately I have a bag of various LEDs on hand.

I'm leaving this thread open until I resolve all issues but Guys, today was a good day :D Don't give up!
I’m thinking this is consistent with what I’m finding with my build. I’m trying to get my head round the schematic and how the separate modulations are mixed to the space out but I can’t grasp the wiring of the pots in relation to it 😵‍💫
 
I’m thinking this is consistent with what I’m finding with my build. I’m trying to get my head round the schematic and how the separate modulations are mixed to the space out but I can’t grasp the wiring of the pots in relation to it 😵‍💫
We'll get to the bottom of it. I am 100% all wiring is done per the build docs and there are no shorts so it must be something else that is messing with the mix. I need to check how does the time out jack switch off modulations from space out when you use both in stereo - it seems the switching is not working and modulations stay on time out only, irrespective if its being used or not. Jumping time out to space out woris but I assume I wont get the proper stereo if I wanted to connect it this way with the jumper fix. Practically I dont care that much, I dont run a stereo rig anyway but for the sake of learning and fixing this properly I will try to figure it out
 
We'll get to the bottom of it. I am 100% all wiring is done per the build docs and there are no shorts so it must be something else that is messing with the mix. I need to check how does the time out jack switch off modulations from space out when you use both in stereo - it seems the switching is not working and modulations stay on time out only, irrespective if its being used or not. Jumping time out to space out woris but I assume I wont get the proper stereo if I wanted to connect it this way with the jumper fix. Practically I dont care that much, I dont run a stereo rig anyway but for the sake of learning and fixing this properly I will try to figure it out
It’s very odd! Out of curiosity did you get this as a full kit or sourced the parts yourself?
 
I’m thinking this is consistent with what I’m finding with my build. I’m trying to get my head round the schematic and how the separate modulations are mixed to the space out but I can’t grasp the wiring of the pots in relation to it 😵‍💫
It looks like the pots, with the exception of input gain up front, are contained in the different loops: 3 in the LFO (LFO rate, Depth, and Manual) four in the time/BBD loop (Action, Reaction, and the two bias pots), so it looks like they are contained and aren't particularly involved in the summing.

The summing action seems to happen to the right of the first page of the schematic, which looks to be the "backbone" where the loops attach. In particular, towards the switches marked "stereo/mono" and "Time A" (I'm guessing that's the footswitch) there is the link "F" for "Time output."

I don't particularly get what is going on with the stereo toggle and Time A, or the role of the transformer, but ok. Maybe to boost the time signal in stereo? Or to bifurcate the signals somehow? And it looks like the LFO loop is just in charge of controlling the LEDs (intensity and pulsation?) I don't see an audio signal path. Although the square/triangle wave switches routs through there--not sure how LEDs control that. Shows you my limited comprehension.
 
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