BOM: (BOM update 12 jun.2015)

please see attachment list above

the file: ARP1601_PartList_ sorted is sorted for resistor and capacitor values -please use this for building ARP 1601 Parts List_sorted.xls

for Kipplings groupbuy round2 you need a 12uH Inductor and 47uF/25V cap too  (this parts are not in the BOM)

Mouser part nr.: 652-RLB9012-120KL and 1-off 667-EEU-EB1E470SH

for Round 1 BOM: dont buy the expensive ferrit bead on mouser.. this part dont fit.

please use: 2x  875-28L0138-80R-10

keycapps: 3 needed -   if you buy the keycap kit, it includes 14caps (instead of 13)

Builders Guide: (left rev.1  - right rev.2)

PCB Designator/Component Numbers

ARP 1601 Sequencer Rev 4 - PCB (full).pdf

Known Issues: (rev1. and rev2)

The start/stop pushbutton is a little prone to contact bounce giving multiple triggers. The ever-helpful Nordcore has a fix involving changing one IC, two additional resistors and one capacitor and one track to cut with a little point to point wiring. Unfortunately it is too late to incorporate these changes into the round 2 PCBs so they will remain as PCB rev 2. A quick fix kippling have tried with good success is increasing C5 to 33nF, and adding a 1nF capacitor soldered directly across the SW1 terminals, and for me at least gives no noticeable lag.

Further tips will be added as I think of them or they are pointed out by users

Mods for Start/Stop: As mentioned above change C5 (10nF) to something around 33/39nF, and add a 1nF directly across the pins of SW1 to eliminate the contact bounce causing the unreliable start/stop push-button operation.

take a look at Page 9 of the Buiders Guide rev.2  (for Rev.1 Users are this fix too)

further its possible to change the IC "Z1" CD 4011 to CD4093 for the start/stop issue, cut on frontpanel pcb side a trace add few R/Cs  (1M and 10nF  ?) - see this pics:

Mod: Clock Frequency (thanks to Ultravox)

source: https://www.muffwiggler.com/forum/viewtopic.php?t=138862&postdays=0&postorder=desc&start=25

I was able to get the Clock Freq slider to work full travel by increasing the resistance of R17 to approx 222.5k. I didn't have a resistor of that value so I put a 100k trimmer in series with R17 and adjusted it so that the clock will still operate when the slider is set to min. The Clock Freq slider now gives 1Hz - 100Hz from min to max travel.

Schematics (round 1)

ARP 1601 Sequencer - Schematic (round 1).pdf

Panel: