New BARE BOARD For BA312 IC Chip Replacement uses easy through-hole parts

Description

Up for sale here is this brand new bare board to build a replacement for the BA312 IC chip.  This chip frequently goes bad in vintage receivers such as the Sansui 9090DB, Sansui 881, and Marantz 2275, and can cause you to have weak or distorted sound.  The chip has been discontinued for decades, and is difficult to find, but luckily some fine folks on Audiokarma designed a replacement for it.  This board will let you build that replacement!
While some boards are built with tiny SMD parts that are extremely difficult to work with, this board is designed to use through-hole parts that normal people can install.  The board itself measures 19.4mm x 15.3mm and is 1.57mm thick.  With all parts installed, if you mount the transistors as low as I did, it will be about 10mm thick, which includes the solder joints.
I have shown a picture of what this looks like once it's assembled, but this listing is just for the bare board, nothing else.
Assembly and installation is fairly easy--you will need a soldering iron and solder.  I would recommend a fairly fine-point soldering iron (and thin solder), as a wider "chisel tip" will make this difficult.  I used a Hakko iron with a 1mm tip and it worked well.  I would STRONGLY recommend you replace all the electrolytic and tantalum capacitors on the board that has the BA312, or at least replace the ones that are surrounding the BA312.  These chips sometimes go bad due to shorted or leaky capacitors, so you need to replace the bad caps so the new replacement doesn't have issues.
Assembly is fairly simple.  You will need four resistors and three transistors.  For resistors you can use 1/8W, 1/4W, or 1/2W, as long as they are small enough.  Any resistor whose body is 6.5mm or shorter will fit just fine.  You will need one 51-ohm resistor (R3), one 180-ohm (R4), one 5k or 5.1k ohm (R1), and one 10k ohm (R2).  You can use metal film, carbon film, or pretty much anything else, as long as the body size is correct.  For transistors I recommend KSC1845, but you can use other similar transistors.  The board is marked with resistor locations and transistor pinouts.  You can use the cut-off resistor legs in holes 1-7 to make the pins to connect to the receiver's circuit board.
This listing is just for the bare board, nothing else.  If you want to buy a kit that includes the board, all 4 resistors, and all 3 transistors, I have that
here
.  If you want a board that's already assembled, I have that available
here
.  If you want to buy a genuine NOS unused BA312 chip, I have that available
here
.
US shipping and handling is , and international is , no matter what quantity you buy.  All my small parts are set up for combined shipping, so just use the "add to cart" feature and then check out all at once, and it will combine shipping.  If you have any questions, please ask.
Looking for more parts?  I have
power switches
,
feet
,
pushbuttons
,
top case screws
,
bottom screws
,
faceplate screws
,
white LED fuse lamps
,
blue LED fuse lamps
,
6.3v bi-pin bulbs
,
8v bi-pin bulbs
,
12v bi-pin bulbs
,
wired 8v 60ma bulbs
,
new power cords
,
new main capacitors for the Marantz 1060/2230
,
wired Pioneer speaker plug replacements
,
new 630v yellow film capacitors at 38 different values
,
new 1200v yellow film capacitors at 15 values
,
a large variety of transistors for vintage stereo repair,
new Wima film capacitors for stereo repair
,
new 250v yellow film crossover capacitors,
and more.  Just use "add to cart" on everything you want and then check out for combined shipping.