Here is a scan of the Tascam 644 Portastudio service manual in .pdf format for free download, about eleven megabytes
And here is the user manual, owner’s manual, Instruction manual, whatever you want to call it.
I ahven’t filmed any footage of this model yet, but I plan to, so please visit and subscribe to my portastudio-repair-themed Youtube channel;-
Tetrakan Supermonobloc 