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Hey guys,
I’m having trouble with Dr Phybes over here. As of now, it passes sound but with no effect on the red LED and no sound at all on the yellow LED. I’ve checked and double checked the connections and can’t find the source of the problem. An extra set of eyes would be appreciated. Thanks!
The first thing that I can think of, check which model of transistors you’ve got : some have the pin pattern reversed and you simply need to insert them the other way in their sockets. That is the case with 2N5457 vs the 2N5952 documented. Also they need to be matched.
Can’t see what’s going on with your CLR on the 3PDT pcb you need a resistor soldered in there to limit current to the LED rather than just held by the bent resistor pins which I think you’ve done can’t tell if you’ve soldered it to the other side? If not and it’s dislodged it could blow your LED
It sounds like you’re just getting bypassed clean signal ( red LED) and nothing when switched to effects mode (yellow LED) is that correct?
Let us know what matched transistors you’re using and where you got them from as Christian said
Have you tried adjusting the trimmer
Thanks for the fast responses!
I got the transistors from Das Musikding. Q1-Q4 are matched. They seem the right way to me but I’ll try to flip them and see if that solves the problem. Maybe just flip Q5 first no?
The CLR was not soldered on the photo but it is now and the problem persists.
Yes. I get bypassed sound on Red LED and no sound on Yellow LED.
Musikding supplies both 2N5952 and 2N5457 as Christian said they have different pinouts which do you have 5952 or 5457
They show in their build document which way round you should install them
Billy, I thought maybe Musikding wrote their own build document for this GuitarPCB project, which I was very curious about, since a lot of people ignore my “quick start guide” included in our kits (at Pedal Parts and Kits). But alas, I looked, and the musikding site links direct to the GuitarPCB build document on this site, similar to what I do on my site. It appears that the current build document does not have any statement about the pinouts for different JFETs unless I missed it in my cursory review of it just now.
Andreisidro, if you are using 2n5457 or 2n5459 match quad set, then those 4 FETs only need to be installed backwards from the printing on the PCB, as the PCB was designed for the 2n5952. Christian and Billy are all over it. Q5 should be the same as specified in the build document, a 2n4125, which goes in normally, matching the printing on the PCB.
https://www.google.com/search?q=Pinout+2n5952
https://www.google.com/search?q=pinout+2n5457
As seen in the above searches, the pinout is reversed on these.
Hey Bruce!
Thanks for the response!
In fact building this was a bit of an headache since Das Musikding sent me the kit for v2 but the pcb for v4. The instructions as well are for v2 so there was quite a bit of confusion going on during the build since I had to buy extra components and discard one or two of the old ones.
I’ll change the transistor positions and report back.
Thanks a lot
Hey, so quick update. Just changed the transistors. Still no sound ☹️
Messed with the trimmer. No sound.
Tried flipping the IC’s the other way around.No sound.
Checked if gound connections were ok
Checked the soldering one more time
Nothing.
I’m out of ideas.
Any suggestions?
You’re right Bruce I meant musikdings phaser build doc
I confused myself with the mention of musikding their own phaser build doc shows 5952 and 5457 pinouts
Andreisidro you have a few solder joints that look like they may be dry I’d reflow those hold your iron on them for around 4 seconds until you see a nice solder flow
Your G2 connection also looks like it could do with a reflow
I wouldn’t change anything unless you have a reason to flipping the ICs could damage them for example
Make sure your in cable goes to the in jack with the pcb out of the enclosure and the wrong way around it’s easy to plug your in to your out and visa versa that would still give you bypass but no effect signal
Hey guys!
So, after a few more tests I realized that, at the very least, I had a bad footswitch. After a bit of alcohol and turning it on an off for a while, I managed to get sound on both the red LED and the yellow LED. It’s still not sounding as it should though. On the red LED it passes clean sound, on the yellow LED it passes clean sound and a high pitched squeal that reacts to the potentiometer.
I’ll need to get a new soldering station since mine is on it’s way out, but after I do I’ll definitely replace the switch and reflow most of my solder joints and see if that fixes things.
Anyway, this is turning into more of a headache than I anticipated, but oh well…
Hi Andreisidro, a few clarifications :
How comes that your ICs are non marked ? How can you tell the TL 061 from the TL 071 ? MUSIKDING usually ships ICs marked.
After you flipped them ICs “the other way around”, maybe they are burned…
What do you mean by “changed the transistors” ? did you have another set of matched ones ? What exact model do you have ?
Keep on debugging it, this is a lovely pedal !
Hey!
The IC’s are marked, my phone just sucks. I don’t know if they’re burned but they don’t get hot when the pedal is connected, so that’s good right? Are there other ways to tell if the transistor is burned?
By “changed” I meant “flipped”.
Sorry! English is not my first language hahaha!
You can take voltages on your IC and transistor pins to check, the matched FETs should be fine flipped
Flipping the ICs means you inverted the voltage ie pin 4 ground would connect to power and pin 8 power would connect to ground
If you didn’t have the ICs flipped too long they should be fine
FETs you want just over 2 to 2.5v on the gate pins (set using the trimmer) or it won’t phase
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