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View Full Version : L-100 Restore?



ceedubbya
08-18-2010, 05:31 PM
Hello I am brand new JBL owner! I just snagged a pair of L-100's in relatively good condition for ~$150 and so far I love the speakers. They have excellent bass and I love their forward sound. Anyways I am wondering if I need to do any maintenance on these such as replacing the caps or other crossover repairs? I took the woofer out and took a look at the crossover to see if there was anything noticeably wrong. I didn't see any problems, the caps seem to be in good shape and I haven't had any problems with the pots. But I have posted a few pictures for y'all to take a look. Also, I am driving them with a sansui ca-f1 ba-f1 preamp/amp combo, is this a good match for these speakers?

Thanks

BMWCCA
08-18-2010, 06:21 PM
I did not realize that Japanese pots were standard in JBLs in the '70s. :dont-know:

jcrobso
08-19-2010, 12:33 PM
Welcome to the forum!!:applaud:
The POTS look very new so I'm guessing that they were replaced.
The caps look good, but you can't tell by looking, testing for the correct value is the best way.

ceedubbya
08-22-2010, 12:38 PM
Hello again, sorry for the late reply I haven't had access to a computer for the last few days.

It is strange that the pots are so new because the man I bought them from said they were in storage for the last 20 years. Maybe he had them replaced as an attempt to restore them but eventually gave up or something.

Well I have been listening to these for a few days now and they are turning out to be excellent speakers.

I have run into a problem with one of the speakers though. Sometimes when I am listening to them one of the speakers cuts out as if a connection in the crossover or something is bad. The cutout does not only occur in one driver of the speaker but in all of them. I don't think it's the amp because I am able to power any other speaker on the left channel (the one it's on) just fine. So, my question is how can I find out what the problem is and how do I fix it? Should I test the connections with an ohm meter or something? How do I do this exactly?

Thank you for all your patience and help as I am kind of a newb to all this stuff.

Once I have better access to a computer I plan to upload more pictures of the crossover, cabinet, drivers, etc. And ask what else I can do to get these babies to look and sound like new.

Thanks

BMWCCA
08-22-2010, 01:27 PM
Do yours still have the original lousy connectors at the back of the cabinet? Assuming you've swapped channels left-to-right with the problem following, and that you're talking about a problem only in one channel. :dont-know:

Wagner
08-22-2010, 02:58 PM
Find the loose connection and fix it.

Stop looking for problems that aren't there if you are happy with the way they sound.

Judging from your comments, you are.

Thomas

Wagner
08-22-2010, 03:11 PM
I did not realize that Japanese pots were standard in JBLs in the '70s. :dont-know:


The solder work looks very good.

Not to mention that the pots are ALPS.

Wouldn't lose any sleep over that one.

Thomas

Wagner
11-22-2010, 11:36 AM
I did not realize that Japanese pots were standard in JBLs in the '70s. :dont-know:

Don't know if they were "standard" but were used by JBL extensively.

The ones pictured in post #1 are correct.

Regards,
Thomas