Ask to check which one has the 2213H
That is the later version but l would request to see what drivers are in there as it may not be a first owner pair
Ask to check which one has the 2213H
That is the later version but l would request to see what drivers are in there as it may not be a first owner pair
schematics/tech info dated as late as 1994, show the LE25 remained in the L100A. Your first post captures the rest.
This is not a setup I have made. It is published on this page somewhere.
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Last edited by Odd; 09-18-2017 at 11:50 AM. Reason: More info
43XX (2235-2123-2450-2405-CC 3155)5235-4412-4406-4401-L250-18Ti-L40-S109 Aquarius lV-C38 (030) 305P MkII
Odd, I think your chart is correct except for the tweeters. Only the earliest L100s with the vertical driver arrangement used the LE20.
To follow up on the LE26 question, I'm sure that if there are L100s out here with LE26s in them, this was done years after leaving the factory. The L26 is the tweeter used in the Decade series.
Widget
I really wish our resident expert Bo could chime in. He collects these........mic drop
Yep,
The O'l Tin ear is around somewhere.
http://www.audioheritage.org/vbullet...3A-1-vs-123A-3
Thanks grumpy, I had studied this technical manual several times but I wasn't sure that it applies to both versions of L100A(Late Model)...Now after gathering these useful info from all my dear new friends in audioheritage(including you), I'm sure that high and mid freq drivers remained the same in both versions, but I can't say that about the woofers yet...Did they eventually change 123A-3 to 2213H?(I think Ian thinks so...)If not,then the both versions of L100A(Late Model) are 100% similar except for their crossover network control scales!(What is the point in that,JBL?!
)
The confusion/issue may be vs non-identical pro versions (e.g., 4310, 4311, 4311A/B...) which continued to be developed during and after the switch to ferrite magnets.
I don't have various L100 versions in-hand to back this up, and (perhaps predictably) my interest is waning. If I wanted a museum piece, I'd be striving for accuracy... but for listening? I think
I'd (personally) be more interested in the 2213H (newer, fits, recommended for replacement, same cone kit as 123A-3, and no need for re-charge). I'm sure there are those
who would disagree and only Alnico and exact specs will do... we're talking about a 40 year old driver though, so good luck with that, and your potential purchase.
Hello Y'all !,
First of all, I wanted to thank all my dear friends(Including: grumpy,Mr.Widget,script56,JPW Retired,odd,Ian Mackenzie and...)who helped me with my questions...May God bless you all!For my first question(which was the correct order of L100 versions),I've found a great post by a great user called "VSN" in a thread on this great site(!) that I think it can help many others with the same question...Here it is(All credits go to "VSN"
) :
((There were four versions of the L100:
1) The very first model was the L100 Century made from 1971 to 1974. This model is very unique in many ways from the vast majority of L100’s found for sale today. Some call this model ‘rare’, yet in actuality it had the longest production run of all the models and many thousands were made. The main reason you do not see this version as much is they were far outnumbered by the enormous volume produced as the later models gained popularity. The most notable difference of this early model is the drivers are in a straight vertical row. Other differences exist in the crossover network, phasing of the transducers, and the cabinet bass port. Lower value capacitors and the use of an inductor in the LX12-10 network produced crossover points of 2.5K Hz & 7.5K Hz. All the drivers were in phase with each other, unlike the later models where the woofer and midrange are 180 out of phase. The bass port was only a small hole in the cabinet without an internal tube, and the tweeter was the LE20 round, not the LE25 square.
2) The second model released was the L100A Century which was made from 1974 to 1976. The most notable difference was the midrange driver became offset from the bass and tweeter axis. The circuitry changed to higher value capacitors and eliminated the inductor shifting the crossover points to 1.5K Hz and 6K Hz and became the N100 network which remained the same in all future models. The woofer phasing was changed to be 180 out from the midrange to cancel out the duplicated tones where the 123A-1 and LE5-2 overlapped. The bass port diameter was enlarged along with adding the internal tube to enhance the low frequency response, and the LE25 square tweeter replaced the LE20 round tweeter.
3) The third model was the orange label L100A Late which was made from 1976 to 1977. This model was virtually identical to the black label L100A Century excluding the foilcal label dropped the word Century and a polarity change occurred to the woofer. Up until this point all previous models had used the 123A-1 positive firing woofer which was now replaced with the 123A-3 negative firing woofer. As the new -3 woofer fired in the opposite direction as the previous model, it was required to be wired backwards inside the cabinet to maintain the correct polarity as the network circuitry remained unchanged. This means the positive input wire now went to the negative woofer terminal to maintain the out of phase relationship with the midrange. JBL did not want to confuse the service centers by suddenly changing the internal wiring of the well established L100.
4) There is really a fourth L100A “Late-Late” model yet JBL does not identify this as a separate model even though the internal wiring changed to the studio monitor color code, the face of the cabinet got a slight groove around the face perimeter plus the presence and brilliance controls went from a +/- 3 scale to a 0 to 10 scale. Somewhere in those last few years, the rear input connectors changed from the metal spring loaded style to the plastic twist-lock style which were used on many other late 70’s models such as the L112 & L150, plus they were relocated higher up toward the middle of the cabinet rather than offset near the woofer end.))
Pretty well-explained, huh?And for my last question(It's really the last one
and will hopefully clear all my confusions about L100
):
Was the LX12-10 crossover really better than the N100? and thus making the "original" L100 sound more musical(or better(?))than the later ones?(I've read these in some posts on AH,but highly doubt it...)
Thanks again!![]()
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Last edited by Koosha9876; 09-26-2017 at 12:40 PM. Reason: typos
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