Hello
I thought I would share my experiences with building the op sound cards. I had all the parts for a while before I decided to brave the build. I read many articles and watched a lot of you tube videos about using an oven for the reflow process. I did try to build a soundcard with a teensy and a cheap chinese 10 watt amp module-- which did work but very noisy and a bit of a mess with wiring etc. So that is when I committed to building the OP sound card and it was a big project for me as I intended to build 15 sound cards.
I bought the boards and a stainless steel stencil from OSH and all the other parts from various suppliers. Being in Australia the freight costs have been costly but just couldn't get everything from the one supplier as stocks weren't always available, some items being last time buy ie the SD card reader for example.
I have a pretty good workbench setup with various soldering iron stations, hot air rework system and also a desoldering vacuum pump station and being a retired comms technician I know my way around electronic circuits etc.
So to the build. I use a ice cube tray to put the components for one board in it as I found it easy to get the components out and have it close by the board. I set the pcb up on a wooden bread board and stick it down with the supplied aids that OSH provided. The stainless steel stencil is easy to clean which is something very important as the amp chip is the problem device to get right with the reflow process. This component is the only item that has caused me problems. Getting the spread of solder on the board is not to hard but the amp chip is really a bit hit or miss. The main thing is not too much solder on it and maybe very little in the centre of the chip and then cross your fingers and hope for the best.
So I have had a 20 % failure rate as three of the 15 boards have no sound working. All the other functions work as per the LEDs but no sound. I did remove the chip from a board using my reflow hot air, then used the vacuum desoldering gun to clean the excess solder then fitted a new chip and reflowed with the hot air gun , but the device still didn't work. I checked all the supporting circuitry and everything buzzed out ok so just can't tell what is going on underneath the chip !!
I did look at making an arduino control heating unit for the oven so it would follow the reflow curves for the solder, however I watched a video where someone was just using a timer and a temperature probe and turning the oven off and on manually and they got good results. So this is what I did and got good results for 80% of the time!! So I have three dead boards which are not repairable so I will strip what parts are reusable and throw the rest in the bin.
So was it worth it??
YES it sounds fantastic. I have been using the sound files from this site and with a decent speaker in a good box the tank roars to life!! Luke has done a great job with this device as it has loads of potential for you to customise your tank models. Just a bummer about the amp chip-- I think with more practice I could get better with the solder placement etc-- you really need to be precise when you drop the device onto the board. You can't push it around too much as you will create shorts under the chip.
So I am short a couple of boards for my TCB units however I have got a few Taigen sound modules so I will use these in my Panzar 3's and also fit these with a Sabretooth serial dual motor drive units (5amp) as these should be ok for the smaller tanks.
cheers and happy tanking.