To choose between Arturia standard (tip = 5v / sleeve = MIDI TX) or Korg Standard (tip = MIDI TX / sleeve = +5v).
Most of the euro modules that have midi works with Arturia standard but Performer only support Korg standard.

Thonk will soon stock the stereo version of the thonkiconn jack, so this might be a better alternative to the current jacks.

add a buffer to MIDI TX, SN74LV1T34 seems to be a good solution.

The cutout on the frontpanel for the USB connector is too large.

While the footprint is correct, the alignment to the frontpanel cutout is not.

Move Recom far enough to allow placing a shrouded header. Also move the silkscreen labels.

Use TTL versions of shift registers and remove the level shifter IC. Also, connect OE pins to STM32 to allow disabling the matrix.

The current M2 standoff is not readily available.

Use correct capacitor value for loading capacitance of crystal. 33pf 50V NP0 is a good value.

• add pull-down to LCD_RES to keep LCD in reset state on startup
• check if there is internal pull-up on LCD_RES on OLED module

The 5V regulator overheats due to excessive power dissipation. The linear regulator needs to replaced with a dc/dc step down regulator with higher efficiency.

• use step down to generate 5V at 1A for the whole module
• feed 3.3V regulators from the 5V supply
• a possible part is the RECOM R-78E-1.0 (https://www.recom-power.com/pdf/Innoline/R-78Exx-1.0.pdf) although the package height is 10.4mm which barley fits below the front panel and would be too high when using THONKICONN connectors

There seems to be an issue with the front panel. The v-cut line is missing.

As you are revising the hardware, in lieu of other solutions, it may be worth adding a hardware supervisor eg a mic803 (along with its 10k resistor and 100nf cap).
I added one to my performer and it resolved all my troublesome bootup issues. Not had a single failed boot since adding it.

Multiple levels of improving current design:

• add protection diode to prevent negative voltage on transistor base
• add LM311 to add proper protection and hysteresis

The C grade have 5V full scale output, but due to VCC at 3.3V we only use half range at 2.5V and loose 1 bit of accuracy. We could replace with DAC8568A which has full range at 2.5V, so this would allow us to use all bits, however, we loose some accuracy due to lower grade of internal reference.

The LED matrix is flawed. The 74HC595 cannot sink the current of 8 LEDs in a row. Possible solutions:

• sinking 74HC595 with a part like TPIC6x595
• add a darlington array to allow sinking more current

Make sure that sourcing current for the LEDs is within the specs of the 74HC595, otherwise we also need to increase sourcing capability.

Here's a few ideas I was thinking of if there ever will be a mk2 or whatever:

Internal linking between multiple performers so they stay in sync without having to patch between them, with something like i2c or similar they could also share data so let's say one could modulate the other or similar.

Expansion port for (could be the same as the internal linking) e.g. i2c or similar for allowing to expand the module with more gate/cv in/out.

Maybe i2c trs jack on the front for things like the 16n faderbank (https://16n-faderbank.github.io/) to allow for controlling the performer?

There are SMT standoffs from Wurth: https://www.mouser.ch/datasheet/2/445/9774090151R-611438.pdf

Hey, I'm trying to find a list of the error codes. I'm getting an "error 13" when I try to update fw with SD card.

I also can't save files to SD.

Thank you.

Pin 2 on SDCard slot can be used for card detection if SDCard is used in SD mode.

It would be a big time-saver if there was a way to spread a curve over multiple steps, set by F5.

e.g. you could have a slow ramp over - let‘s say 8 steps - without having to manually set min and max with each of the following steps, but still had the fine step size for quick modulation (rather than changing the divisor).

This is problematic because the part does not fit below the frontpanel. One solution would be to mill a 1mm groove on the backside of the frontpanel (as done in newer Mutable Instruments modules).

Make sure the referenced part is the right footprint.

2x rev 1 boards completely dead. I have the correct power at the headers and flashed the chips successfully but neither the screen or LEDs show show boot up indication, in fact nothing at all.

MCP6004 has max +/-6V power supply, but it's sourced from +/-12V, so just replace with pin-compatible TL074.

• add 10k pullups to all signals
• move SDIO_CMD from pin 2 to pin 3
• add card detect line

It was working perfectly and now will not power on.
Don't know where to start. I bought this second hand a week ago.

0603 footprints are really small, especially for hand-soldering. Should be replaced with larger footprints for the DIY version!

The 18pF capacitor should be in the direct feedback path.