Dating a Mark I

[sfarnell]

Becauase the serial number on the early Mark I is on a platic label affixed to the chassis and not directly on the chassis, is there another way to date a Mark I?

What are the inclusive serial numbers for the original Mark I?

Also, how does one determine if a hardwood cab is an original Mesa or an after market cab?

Thanks!!!

 

[nagshay1818]

I could use this too. Someone let us know

 

[jonarobb]

If the Dyno-label has fallen off, there are still several ways to date it....

Most chassis have a handwritten date on the underneath when it was at it's final inspection

Transformer codes are another, although Mesa often used transformers spread out over a long manufacturing run in some early Mark series amps. Example being a 1979 Mark IIA I have here at the shop with a power transformer from 1977 and a reverb transformer from 1978. The number directly after the EIA code (606) is the year.

Potentiometers.... All pots have a date code on them. Mesa used CTS pots back then with an EIA code of 137. Right after that number will be a another series of numbers. The first number in that series is the year and week of year. If you have pots with inconsistent dates, the most recent original pot becomes the controlling date for the so called model year.

Lastly, the original Sprague and Mallory Electrolytics Capacitors are all date coded too.

Hope this helps....