Right, my '55s are black crinkle.
GM
Printable View
'73 as evidenced by the square QC/inspector's stamp.
What about the early cone part number then?
Most 515B are 21184.
Works for me since a NIB matched pair of '71 421-8H [391142] have this version of the stamp.
WRT any diaphragm assy. anomalies, no clue about this one, but do know from experience that if a new driver was spec'd to either replace an earlier version and/or to match up with a very high output impedance system there was no telling what was required to get the right 'balance' of specs with then available parts.
GM
I have a square QC stamp on my 64 604E, but mine doesn't have a line through the middle of it.
Is the cone number 21184 with no additional revision numbers(without -2 or -3 after it)?
Out of curiosity, how do you know it's '64 and not '74?
Mid 60's(nobody seems to know exactly when they started) thru 1980-81.Quote:
What time period was the square stamp used ?
You are assuming it is early. It likely is not. The 75 cone number I posted above is almost the same. 21090 for this one. 21092 on the 1975 sheet.
http://www.hostboard.com/forums/hbmc.../2011/02/2.jpg
I guess I automatically assumed that as they progressed through the years that they no longer made the old models. That's why I figured that a 515 B was an early driver. I was not aware that they continued to make "B" models all the way into the 70's. I was wrong my 604 does have a line through the QC mark. and the cone number appears to be followed by a 3. I do not know whether it's a 64 or 74 other than I figured once they started making the g's h's and k's that they no longer made the E models.