Abstrakt Instruments VS-1 DIY

Silkscreen wrong

check that your PSU is still modified with other regulators

my psu was still modified with the correct parts since it was bought as Partkit from Brian, back in 2020.

you have to respect that the MOLEX connectors on the Voice Motherboard and Voices have to installed in one step.

You cannot start with soldering the molex connectors at the pcb without align it against the opposite part.

do this: 

Voice Cards BOM lists 1.5M resistor for R7 and R45, but those are already filled with 49.9K resistors as per the BOM and the schematic

wait on validation, DO NOT INSTALL R7/R45

do not populate R7 and R45

On the Output board - R22 isn’t listed on the BOM, schematic says 2.2K

C22 is DNP - do not populate

Q15, 16, 17, 18 aren’t listed on the BOM

"Note that R140 and R141 are the preinstalled smt resistors on the back."

"Brian for some reason doesn't list parts that are back in the "Rare Parts" list, so A3 is an CA3086N; A10, A12, A13, A14, A15 are all AS3080E; and A18 and A19 are AS3310."

"There is one wrong sized hole on the bottom row of holes for the molex connectors. In one of the videos Brian suggests using a dremel tool to grind down the size of the affected pin, which I tried and it was relatively easy and worked well. I suppose you could also drill out the hole, but you would then also drill out the solder pad, and would need to run a wire jumper from the affected pin to one of the vias to make that work."

30k resistor bag is labeled with quantity of 32 - in Altium is 24.

100nF caps 20 in bag and labeled with quant. of 20, BOM is quant. of 18 and in Altium

don´t remove the pcb stripes (from pcb fab - panelized pcb) in case you use a solder frame. otherwise the traces can be damaged

use 1/4W 0.5W watt 0207 Format resistors for R66/R67 to improve thermal noise

U2 wrong silkscreen orientation

Install

R7, R11, R37, R41, R48 & R73

 with few millimeter distance against the PCB to avoid Thermal Issues

valid  

Yutube video

and build guide

Since we have to trim the Voices by Trimmers from Top, its not possible for 2 Trimmers when you have installed IC Sockets for A3 (Expo CA3086/CA3046)

valid  

Since we have to trim the Voices by Trimmers from Top, its not possible for 2 Trimmers when you have installed IC Sockets for A10

valid  

do not clean the Styrene Cap with Isopropyl - the Capacitor is glued and can be damaged

valid

Do not wash the Trimmers, install the Trimmers and styrene Cap on Voice Card at the end and 

valid

for better Installation and to avoid a broken capacitor due to mechanical stress bend the pins for C19 and C12

  valid

@Brian

change the Voicecard Pinout for C19/C12

from my experience it can happen under Mechanical stress situation that the Potentiometer Chassis/body comes in contact thru the PCB solderstop with the traces..

This was happen on TTSH, DDRM and other devices and the users wasn't able to Troubleshoot easily the root cause !

valid 

@Brian

change the routing of the trace

in the full kit comes for the Voice Pcbs only 6,8uf.

but no 10uF caps for the power rails.

6.8uF should be fine for the VCA out from the original schematic

@Brian please give an info about the 6.8UF caps - why are no 10uF caps in the Voicecard bag ?