Date this 515B?

[bowtie427ss]

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.

"If" it's the original cone, i'm pretty confident that your 604E is 1974 vintage. 21184-3 would be a late, and perhaps the final revision of that cone.

[cradeldorf]

Thanks for the heads up on that Bowtie.

[GM]

I was not aware that they continued to make "B" models all the way into the 70's.

FWIW, the last ones I ordered was in either '85 or '86, though by then they were 'stupid' expensive, but it wasn't my money.

GM

[Altec Best]

Yes the 604E ended production in 1974 I'm pretty sure.It was no longer available after that when they started phasing in the 604G's with the new Tangerine phase plugs circa 1975..As for the 21184 cones there has been 5 revisions of that cone that I'm aware of but could be more.. 21184-2,3,4,8 AFAIK..

[bowtie427ss]

when they started phasing in the 604G's with the new Tangerine phase plugs circa 1975.

AFAIK, the majority of 604G's have annular steel phase plugs. The cost cutting plastic plug came along in '76 near the end of 604G's production. Ironically, about exactly the same time period Urei abandoned them because of QC problems. While they weren't cataloged, i'm pretty sure you could get new 604E's into the 2nd half of the 70's. I don't pretend to know if 604E and 604G were produced concurrently or not. But, i suspect they were for at least a short period. They were still offering 605B's and 604G's at the same time in 1974.

.As for the 21184 cones there has been 5 revisions of that cone that I'm aware of but could be more.. 21184-2,3,4,8 AFAIK..

I probably shouldn't have used the word "revision" as it implies a change was made. I think the cones are all essentially identical, and those suffix digits indicate manufacturing lots, time periods, and possibly even various suppliers.

IIRC, it was suggested to me that only the first few were used in production of drivers and cone kits, the remainders were in re-cone kits only.

It is certainly possible that cradledorf's E was an early one, and was re-coned at some point.

[magnarc]

Isn't 21092 the actual VC and former, being separate from the actual cone, which usually is 21184-x

[bowtie427ss]

Isn't 21092 the actual VC and former, being separate from the actual cone, which usually is 21184-x

Hmmmmmmm, a "full kit" versus just a bare cone?

Interesting.

Logical.

More confusing as the same kit number from different time periods could contain cones of different numbers. Kind of sounds like something Altec would have done.

[Altec Best]

AFAIK, the majority of 604G's have annular steel phase plugs. While they weren't cataloged, i'm pretty sure you could get new 604E's into the 2nd half of the 70's.

As were mine.My 604G's have the annular plugs.. Another change was the new 23744 diaphragm... I'm almost certain that production of the 604E ceased sometime in late 1974 to early 1975.. The production of the units changed significantly from the gray/white color to the gray metallic color.. You could be right though... It would be interesting to see some date codes from some of the 604E units.. That would be the only way to know for sure IMHO, if someone had a unit with a late 70's date code.

[Old Guy]

Newest E I saw was dated 1976...not sure, but I recall seeing a pair with tangerines, it may have been that pair. We are talking 30 years and many speakers ago....

[Cal Weldon]

I heard the end of the G's were the first with the Tangerine.