Click to enlarge
To avoid massive build errors, make sure the BOM Revision you follow matches the Revision of the PCB you are building!!
The VP312-VPR No Input/Output (Variable) is a kit comprised of every single part and component needed (sans opamp, input
transformer and output transformer) to complete a VP312 microphone preamplifier. The VP312 is a single stage mic preamp for the
500 series format and is fully VPR compatible. The aluminum faceplate is wet painted and the aluminum L-bracket is yellow
The idea behind this kit is for someone who has a vintage 312 card and wants to convert it to 500 series use. Besides the AP2622,
AP2503 and 2520, there is really nothing worth salvaging.
It should be noted that the original AP2622 is in an abnormally tall can. In fact it is too tall to be mounted standing up on
the PCB. The best thing is to lay it down and secure it with a plastic wire tie. You will have to strategically place and drill
holes for this but hey, it is DIY after all.
This kit includes a Bourns potentiometer for fully variable gain control. Kits using a Grayhill switch are also available for
stepped gain control.
Complete VP312 kits with reproduction transformers can be found
Cost of separate items: $138.24