Plaits DIY

From circuitbending to homebrew stompboxes & synths, keep the DIY spirit alive!

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Halfgeleider
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Post by Halfgeleider » Fri May 10, 2019 2:52 pm

So, flashed the firmware, added all the jacks, leds and pots, fired it up for calibration and all went well but.....
-Freq knob does almost nothing, except from 0 to 1, then the sound changes slightly.
- freq knob at 0, no sound, freq knob around 0.5, leds go mental and the sounds turns into noise as if it rapidly moves between the modes.
- there is a constant sound coming out of the module, (except when freq is at 0) can put a signal at v/oct and then you hear the change in pitch between the constant sound.
- toggling between modes is good, but i dont think this is normal behaviour
- if i use the trig input, the constant sound stops and the module listens to the triggers so that seems good.

Someone knows what could be wrong?
Pcb from pusherman, used hex file from antumbra site.

Halfgeleider
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Post by Halfgeleider » Fri May 10, 2019 4:23 pm

Ok, so im a complete moron,
Forgot to put it trough a vca :ripbanana:
Although i do t seem to'understand the frequency knob, it does not have much effect, and as before, at 0, no output and only a slight freq response between 0 and 1.
I read something about the range this knob can be adjusted on mutable instruments manual, but dont quite know how this excactly should be operated...

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cnicht
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Post by cnicht » Fri May 10, 2019 4:28 pm

The manual is pretty clear:

‘Adjusting the FREQUENCY knob range

Hold the second button (A) and turn the HARMONICS knob to adjust the range of the FREQUENCY knob. The first 8 settings correspond to C0 +/- 7 semitones, C1 +/- 7 semitones, and so on. The last setting, with all LEDs lit, corresponds to the full 8-octave range from C0 to C8.’

There is also a LFO setting where the LEDs light in a cyclic pattern.

Halfgeleider
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Post by Halfgeleider » Fri May 10, 2019 5:27 pm

Yes indeed, i did that, but when i turn the freq knob is whatever mode, there is no difference in sound. Wouldnt there be a change in sound when i change frequency?
Also when set full CCW the output completely mutes.
Otherwise the module works perfect, maybe a faulty pot?

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cnicht
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Post by cnicht » Sat May 11, 2019 2:44 am

Check the wiper terminal of the Frequency pot varies in voltage when you turn it and that this voltage is getting to the microcontroller (pin 10)

Halfgeleider
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Post by Halfgeleider » Sat May 11, 2019 6:15 am

Wiper which goes to terminal 10 measured, and is always 3.3v, no matter which stand i pick. I did the same with the harmonics pot, and then i can see a change between 0 to 3.3V.

Strange enough the traces are all intact, so continuity is ok. When i measure continuity between the left pin of the harmonics pot and the cap on C 12 and the middle pin and C 12, this is both closed. The right pin and C 12 is open

When i measure continuity between left pin of freq pot and C11, and middle pin and C11, only the middle pin gives a closed signal. The right pin and C 11 also gives a closed signal.

Halfgeleider
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Post by Halfgeleider » Sat May 11, 2019 7:19 am

Reflowed C11 and terminal 10, freq knob works like a charm :nana: :nana:
Thanks for the help :hail:

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cnicht
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Post by cnicht » Sat May 11, 2019 7:31 am

Does the left pin of the pot have continuity with GND? If you turn Pot R1 fully counterclockwise does the middle pin have continuity with GND?

Halfgeleider
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Post by Halfgeleider » Sat May 11, 2019 3:12 pm

Yes it does in both cases.

Halfgeleider
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Post by Halfgeleider » Sat May 11, 2019 3:23 pm

Makes me think about rings that i did the other day, module does not output sound. I definitely need to do more reflowing because even small issues cant be seen with normal magnification. Thinking on getting a USB magnifier to make troubleshooting go easier.

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JakoGreyshire
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Post by JakoGreyshire » Sat May 11, 2019 11:46 pm

Halfgeleider wrote:Makes me think about rings that i did the other day, module does not output sound. I definitely need to do more reflowing because even small issues cant be seen with normal magnification. Thinking on getting a USB magnifier to make troubleshooting go easier.
I just posted about how USB microscopes solved all my problems in 10-20 minutes on an Elements that I'd been trouble shooting for weeks... I also give a link to the scope I bought... It's a game changer... Get a microscope... They are cheap... You will be glad you did...

My post in the Unsuccessful Mutable Thread..

viewtopic.php?p=3058862#3058862
My YouTuBe Page...
The patch you've created in your brain is more challenging to modify than the patch you have on your modular.

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Agawell
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Post by Agawell » Sun May 12, 2019 3:27 pm

be careful with those usb microscopes they are not very sturdy

I had one and it lasted about 3-4 months - now it just tries to drag too much power from the usb port and the front clear part is melted!!!

but I only paid about 15€ - amazon.de and .co.uk also sell them - must get another and a jewellers loupe for back up
Instagram

Utility modules are the inexpensive, dull polish that makes the expensive, shiny modules actually shine - and stops them tarnishing too!!!

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JakoGreyshire
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Post by JakoGreyshire » Sun May 12, 2019 6:51 pm

Yeah, they are cheap.... I'd love to have one of those expensive ones that you can actually do work while looking through it..

These cheap ones are great for looking at my work after I've soldered ICs using the normal magnification that's strapped to my cranium..

I haven't had mine for very long so, I don't know how long it will last...

There are a ton to choose from on the web so, I imagine that there are a lot of companies knocking them off as cheap as they can... It took me a while to decide on which one to get.... I read a lot of reviews..

I hope mine lasts... It has already saved me so much headache that it was worth the 20-30$ I paid for it...

:tu: :tu:
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The patch you've created in your brain is more challenging to modify than the patch you have on your modular.

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patrickod
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Post by patrickod » Sun Jun 09, 2019 3:00 am

Finishing up a beehive build and having trouble with the LED driver. At first when I completed the build the LEDs worked as expected, however I used the wrong crystal part which separately caused the audio output to fail.

Somehow the process of replacing the crystal with my hot air gun caused the LEDs to stop working fully. Now only the top LED lights green when I cycle through the tonal modes and none of them display red when cycling through the percussive modes.

When I use the octave selection interface with the right and button and harmonics potentiometer I can get all 8 LEDs to light orange at once when selecting either of the the LFO and "all" options, but LEDs 2 through 7 do not light orange when I select the corresponding single octave value.

I've tried swapping out both an LED and the driver with spares just to make sure but neither of these has made a difference. Would really appreciate any input as this one has me stumped for the moment :)

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col
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Post by col » Sun Jun 09, 2019 3:34 am

look for a microscopic bridge between legs on the led driver chip. It might have become active when you accidentally re-flowed the chip swapping out the crystal. I had something similar happen to me recently, was a PITA and not visible unless chip was removed and using 10X microscope.

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patrickod
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Post by patrickod » Sun Jun 09, 2019 9:09 pm

Lifted and reflowed the LED driver but still no luck. Have searched up and down under a microscope for any bridges but there doesn't appear to be any.

One more piece of information: when I switch from tonal mode one to two LED 2 does _very_ briefly flicker before going dark. :despair:

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col
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Post by col » Sun Jun 09, 2019 9:25 pm

Have you swapped out the STM32?

johmannbush
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BeeHive is quiet

Post by johmannbush » Tue Jun 25, 2019 10:42 pm

Just finished a DIY BeeHive and it sounds great, but is extremely low volume output. Can anybody point me in the right direction with what I should look at? (I have examined the PCB very carefully and I think it all looks ok.) Thanks for any help!

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cnicht
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Post by cnicht » Wed Jun 26, 2019 1:05 am

Check component values round IC8 and IC6D

twentyfive2lyfe
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Post by twentyfive2lyfe » Sun Jul 14, 2019 3:59 pm

Anyone ever seen an issue like this where models are randomly changing as if signal was being sent to the model jack? This is a Knit that I recently got second-hand.

Lemmy
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Post by Lemmy » Sat Oct 26, 2019 10:01 am

I'm a bit stuck with my uPlaits - All seems to be working but the output is very quiet compared with the AUX. A few other people seem to be having output issues here - anyone found a solution?

i have reflowed IC8A and checked the components there. Also IC6. The only thing I can see on my board is that C61 looks a bit dodgy but that doesn't seem relevant. (I don't have a spare one to replace it.)

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cnicht
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Post by cnicht » Sat Oct 26, 2019 11:02 am

Are the signal levels going into IC8 about the same? If so suspect component values round IC8.

Lemmy
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Post by Lemmy » Sat Oct 26, 2019 1:12 pm

No but then the OUT signal is not the same as the AUX signal. The signal going into IC8A is typically smaller than that going into IC8B. The output of IC8A is generally very small and offset by +10V. Maybe IC8 is faulty. The feedback resistors are the same on both parts of the IC.

Lemmy
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Post by Lemmy » Sat Oct 26, 2019 5:13 pm

If anyone has some measurements from a good Plaits for comparison that would be great! E.g. for tone number x, all pots fully counter clockwise, voltages at DAC pins 6 and 7, and going into the IC8 op amp.

Lemmy
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Post by Lemmy » Sun Oct 27, 2019 7:41 am

I fixed it... R22 and C45 were swapped. The labels on the uPlaits PCB are quite confusing, be careful and check the .brd file!
:party:

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