Anyone know how to date a McIntosh using the serial number?

[jackevorkian]

Just picked up a nice 2505 and am curious when it was built. McIntosh said they don't keep records from back then and could only offer that it was built between 67-77.

Is there a reference anywhere? Is there any logic to their numbering system?

[JonnyBoy]

I dunno but you may be able to get a date of manufacturing off one of the components like a capacitor or something. And, I wouldn't know that code either, but I think some actually do that with the last 2 numbers or something. I could be wrong tho...