Hi all,
Just finished another pedal build (Aion Solaris Fuzz Face), my third one, which in theory was much simpler, but again have an issue with something. Power must be going to the right place, as switch turns on and off, LED lights, but no fuzz effect, just a single tone which increases with rolling volume pot up and down - no tone sound if volume all the way down. turning fuzz and contour up and there's some crackle comes in, but no sound via guitar. Click footswitch, so pedal 'off' and I hear the clean guitar through the amp.
Ground issues are the usual problem with my builds so far, but just wondered if this sounded anything obvious, hearing this single whiny tone with pedal on and no signal from the guitar. Any suggestions of where to look much appreciated. Have attached photo's though probably little help - yes, it's a rats nest of wires.
thanks, Rich
Do you have that pdf manual? With basic steps for setting?
And plus and minus power from power IC is at place?
I don't quite under stand what you have going on with your switch wiring. It looks like the ground is on pin 5 and the board in is on pin 2. If that's the case, they should be swapped unless you're going with something other than the standard Madbean stomp switch wiring.
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I think the switch wiring is ok, it's not a madbean board, so it's going to look different, but what I can see makes sense.
Whining sounds can be caused by a charge pump, and there is one of them on board. Was there a special jumper that needed to be soldered (or not) depending on which charge pump you used?
Also there are a few pots missing - assuming that is something that is ok in this build?
If that whinning is from charge pump, you can help yourself with capacitor 100nF (or similar value) at first transistor's collector R2 resistor. As I showed at picture. And for output of fuzz, controll with audioprobe signal at C3 (10n) at output - red point. To be sure, that fuzz as it is, is ok.
Since I don't see much solder on the top of the board it makes me think that you might have a cold solder joint somewhere. Since there are so few components you might be able to carefully solder them from the top.
For example, the resistor next to the fuzz pot looks unsoldered.
Thanks all - yes this pcb allows various options, so there are two pots omitted, one requiring jumper wire and couple of components left out and other pot could just be omitted as far as I can tell. I'll add in build pdf later, and add the IC voltages for the charge pump -again that was an option but recommended to do.
Can see from photo about the resistor by the fuzz pot, so will double check or maybe as you suggest go through solder joints.
For the moment - thanks!
Just an update with bit more info...
Aion Solaris build pdf attached. I omitted the Body and Input control options. Leaving off Input pot required a jumper between 'input pads', which was done. I was slightly confused on the Body control, as said to omit C1 and use CX2 and CX3 if using it. No need for jumper if not using it - so assumed it meant to include C1 if not using this control.
Checked the voltage on the TC1044 IC pins, and as I understand the schematic, think its ok?
Pin 1: 9.2v
Pin 2: 5.38v
Pin 3: 0v
Pin 4: -3.81v
Pin 5: -9.19v
Pin 6: 4.43v
Pin 7: 5.96v
Pin 8: 9.2v
I tried a different power supply (1Spot CS6 on pedalboard) instead of separate 9v adaptor I used initially to test and it doesn't whine, just crackles when on, but again clean signal comes through amp when footswitch is pressed off. Other than don't test with cheap standard adaptor, does that suggest anything? Back to cold solder somewhere being most likely issue?
thanks!
Audioprobe and track signal from input point.
Hi there! Just a quick question -- what transistors did you go with for this build? It looks like they might be 2n2222, or other NPN silicon. If so, you may need to omit the charge pump and set it up for +9V. The Aion build doc provides the steps for using NPN (omit IC, a few caps and add a jumper I believe)
Hi - yes I used NPN silicon 2N2222A transistors - I used the sockets to allow swapping out and try something else if needing too. I thought the voltage inverter could be added either way, as added option for different transistor types. So having means it set up to only use PNP type? I do have a couple of PNP germanium transistors I could try?
...just replaced 2N2222A transistors with NKT275 PNP and...its working a bit more - I'm getting some fuzz, but very intermittent signal, like nothing, then suddenly spits out fuzz tones, so maybe back to the solder joint and previous comment of using an audio probe. But one big step forward using right type of transistors!
Went through all the solder joints and re-heated and tried a different pair of PNP transistors but similar result. With volume and fuzz on full (and guitar volume on full) I get fuzz effect, but after a few seconds it fades quickly and/or sputters in and out. What might be the issue here - still a dodgy solder joint? Would you get any signal if a component wasn't right? Tired tweaking the internal trim pots.
Figured out getting audio probe up and running through ditto pedal and there's no/scratchy sound at R2 resistor, so will look at re-soldering/replacing that.
thanks again for all pointers!
Yeah, the charge pump is only for PNP transistors while NPN transistors need the charge pump omitted (and capacitor polarity reversed in a few places - the default orientation on the PCB is for positive ground).
Here you see where to track signal.
Ah ok, thanks Zerro, that's very helpful as was doing it left to right through whole board.
Hi again - can I ask about the audio probe path? Should you get signal on either side of component or just one side, where you see the track of the pcb? I think the issue is on Q1 collector as that's first point on path that has no signal, but have tried re-soldering but still without signal from looper pedal. I get a signal on the base pin but not emitter or collector, and I see the collector goes to CX4, where there's also no signal. I have transistor sockets - could that be defunct - assume they can't be wrong way round?
I notice that when I put audio probe on Q1 collector pin the signal (amp) noise goes dead, like something is shorting out? Bit stuck on what to do next?
Now controll R3 and FUZZ pot (1k) and that capacitor C2 (22uF) with it.
Thanks Zerro - not sure what you mean control them, but with audio probe signal comes through on R3, but goes quiet (no amp hum) on Fuzz pot or on C2. Does this help?
Two things, check the orientation of the transistor, the note says reverse for npn. Second, look at the back of the board for shorts to ground or solder bridges.
Seems ok. Now measure DC value at collector of output tranzistor.
Ok, will check again for solder bridges... I'm using PNP transistors, as needed as I used the IC part of the circuit - I didn't understand this wasn't required if using NPN.
DC value of Q2 transistor on the collector pin is 9.76v
9,8 V seems to me too much. Q2 is not opened properly = Q1 is too closed. Or emitor of Q2 is hanging off, not connected properly with ground by that pot 1k. It is about feedback via those resistors and pots I asked before. And about resistor in collector of Q1. Measure voltage at Q1 collector.
BTW what is power supply value?
Hi Zerro - thanks again for any help. Watched a video on voltages when things aren't working...and said to supply following to anyone trying to help!
DC jack lug 9.42v
9v pad on board 9.42v
IN/OUT pads on board and on footswtich lugs both read 0v (I suspect that's not right?)
IC chip:
Pin1 9.42v
Pin2 5.52v
Pin3 0v
Pin4 -3.38v
Pin5 -9.4v
Pin6 4.64v
Pin7 6.18v
Pin8 9.42v
Q1 transistor: E 0v B -0.33v C -1v
Q2 transistor: E -0.33v B -1v C -0.34v
thanks, Rich
Hi, at first reading you find at collector Q2 on -9,7V. Now it is -0.34V? What changed?
Ah, meant to add that yes I noticed the difference. Sorry - Human error is what's changed.
Originally I was placing red probe on DC positive lug and and black on the collector of Q2, which gets 9.76v. After watching video on voltages I put clip onto black probe and then connected other end of clip to ground on pedal (enclosure) and took measurements, which gave readings sent.
Don't know video you saw, but power values are measured against ground. Minus pole (mostly black wire) of your multimeter put at ground, and red use for measuring. That's what gives proper infos. Try to do it this way and send values at transistors.
Yep, black probe on ground lug of DC jack and red on transistor legs:
Q1 transistor: E 0v B -0.33v C -1v
Q2 transistor: E -0.33v B -1v C -0.34v
On the base of Q2, I do seem to get fluctuating readings - sometimes 0v, sometimes -1v. ??
Circumstances around Q2 are bad. If at basis is only 1V, at collector cannot be so low power. Controll this element and collector resistors aiming up to power console.
Are those trimmers meant to adjust the bias on the transistors?
Only trimmer BIAS sets something similar. Other Pots are setting some sound charcteristics. But in this case is something wrong around Q1. At collector of Q2 must be something about -5V DC.
thanks all - I think I'm going to salvage pots and transistors, IC and start afresh with new board, understanding a bit more on what's required and what's not, like the voltage inverter. I'll probably be back...!