Maleficent Mids Confusion

Horganovski

New member
Hi I'm trying to build a Maleficent Mids Kit I bought from Musikding and have a couple of things I'm not clear on.

1 - How do I know which revision the board is ? The bag that came from Musikding had 'V2' on it but there's nothing on the board that I can see to indicate revision, it just says 'PCB054' on the underneath. It does look visually the same as the board currently on sale on the PedalPCB store page.

2 - I ran into some confusion when installing the power LED - the board has the round and square holes which I assumed indicated negative (round) and positive (square) so I installed the LED that way first and it didn't work, so I then noticed that the round one is labled 'A' and the square one 'K' (Anode and er.. Kathode ?? !) so I swapped the LED around and now it lights up when the switch is engaged. But I get no sound at all from the pedal when on (I do when bypassed).

I've checked the obvious 'is the dual gang pot shorting' and I believe it's not as I've put a modified plastic cover over it between it and the board and the pins of the other pot right behind it.

So I'm stumped, might I have fried the circuit by placing the LED the wrong way around the first time ?

And ideas appreciated!
 
Hi I'm trying to build a Maleficent Mids Kit I bought from Musikding and have a couple of things I'm not clear on.

1 - How do I know which revision the board is ? The bag that came from Musikding had 'V2' on it but there's nothing on the board that I can see to indicate revision, it just says 'PCB054' on the underneath. It does look visually the same as the board currently on sale on the PedalPCB store page.

2 - I ran into some confusion when installing the power LED - the board has the round and square holes which I assumed indicated negative (round) and positive (square) so I installed the LED that way first and it didn't work, so I then noticed that the round one is labled 'A' and the square one 'K' (Anode and er.. Kathode ?? !) so I swapped the LED around and now it lights up when the switch is engaged. But I get no sound at all from the pedal when on (I do when bypassed).

I've checked the obvious 'is the dual gang pot shorting' and I believe it's not as I've put a modified plastic cover over it between it and the board and the pins of the other pot right behind it.

So I'm stumped, might I have fried the circuit by placing the LED the wrong way around the first time ?

And ideas appreciated!

#1 — You've got to post pics.


You won't have fried the circuit by installing the LED backwards, but you can fry the LED at times if you don't have a CLR.
The revision you have is good if its layout matches what you see still currently being sold — so not something to worry about.


No sound at all unless bypassed...
Check and reflow your board/3PDT connections.
Sound is bypassing so the jacks to 3PDT are okay, so focus on the connections to the board, reflow anything suspect, but note that 3PDTs need sufficient cool time between soldering each of the lugs.

Other common errors to watch for are due to the pedal being upside-down/backwards:
  • Make sure you've plugged into/out-of the correct jacks
  • Make sure you've got the VOL up and not down

Lastly, POST PICs. Clearly show all the connections. Front and back. Use LOTS of light so we can see the colour-bands on the resistors etc.
 
Hey thanks for the detailed reply, much appreciated.

I tried reflowing some of the more suspect looking connections and now I have sound when engaged, and the volume control works (ie at max it seems at unity with the bypassed sound and I can turn it down to where I get no signal when fully down) but the mid/sweep/switch controls don't have any effect on the sound. I have a hunch I damaged one or both of the chips during the build as I got a bit impatient (lesson learned, don't keep working on something when tired and getting frustrated!) and likely applied too much heat. I tried taking out the top chip, and the pedal functions exactly the same ! so maybe that's correct. I've ordered replacements for both chips and I'll try them once they arrive. In the mean time I'll attach some photos.
 

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Good to hear you've made some progress with it.

I've all too often made the mistake of working on something (whether on a pedal or a forum-post) when tired and frustrated, you'd think I'd know better by now. 😸

Always best to keep the chips out of the equation when soldering on the board. Just don't forget to put them back in when done...
"Dang circuit's still not working! More trouble-shooting... %^@# ... oh, I forgot to put the chips back in.".


Hmmm I was working off the old build doc (2017) — I see now Robert has a new build doc and it differs ... greatly. Seems not just different in the way it's drawn, but the circuit is different to the old... I must investigate and see which board I have and whether it matches the new or old doc.
 
I’m wondering if you still have some solder issues. Some of the joints look starved to me. I try to get the solder to basically come flush with the pads on both sides of the board. It makes the inspection really easy, from the top of the board. This is kind of what I aim for.
1736716696250.png
For the soldering try to keep the tip clean then add a tiny amount of solder to the tip to keep it wet. If you have flux it helps a lot with getting the solder to penetrate and stick where it’s supposed to.

If you have any other dual ICs 4558, 5532, ect you could try them in place of the TL072 and it should work for testing. I’m guessing the 5532 works as I don’t think it would pass sound without it.
 
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