Restoring/Upgrading L200 Studio Master

[colbysolomon]

Looking to update my favorite pair of loudspeakers. They still sound like a dream, but were a damaged by the previous owner. The terminal button is missing, and seems to have been jerry-rigged to work, but I think it might be best to upgrade them to something with a more secure connection, like a banana plug or similar. In looking up how to disassemble the component, I discovered that JBL recommended that the unit be converted to an LX-16A configuration, though I'm not sure what all that entails. Other L200 owners, what might you suggest I do, and where do I start? I would love to keep these as original looking as possible, but I know these things need some care and attention after 40 years.65634

[BMWCCA]

Welcome.
What a coincidence that we have two new members within an hour both from NC!

[Mr. Widget]

Welcome to the Lansing Heritage Forum. There are quite a few threads discussing modifications, updates, and restorations of their L200s. Here are a couple. Heather's begins life as the 4320 which was the original professional speaker that the L200 is based.


http://www.audioheritage.org/vbulletin/showthread.php?9796-4320-Project

http://www.audioheritage.org/vbulletin/showthread.php?32595-New-cabinet-for-L200

http://www.audioheritage.org/vbulletin/showthread.php?33625-L200-Restore

[hjames]

A big part of my L200 thread is here -
but - I did do some mods over the 7+ years I owned them ..

http://www.audioheritage.org/vbulletin/showthread.php?15317-Looky-What-I-just-got-Those-Darned-L200-Cabs-%28from-Aberdeen%29/page9

[kelossus]

How longs a piece of string?

There is a lot of modding potential in these beasts, I picked up a set here in Australia for an ABSOLUTE steal. Paid under 1k. Bought them from an EX US-Military guy who ended up in Australia as he met his Australian wife while stationed in Germany. Safe to say these speakers have been around the block as he bought them new in the States. Was happy to let them go to an enthusiast who was less than half his age but could tell I wasn't gonna flip them, I am very grateful I ended up with these.

Not the first set of 15 inch JBL's I have heard but the first pair I owned, I must admit I was very surprised how they lacked deep bass. I ended up selling the LE15B's for pretty much the price I paid for the speakers. My 4315's have more growl than these and punch a bit harder too. They have a nice hit in the mid-bass though and a fatter sound. Driving them with an MC275 for references sake.

In the process of converting these to quasi-L300's very similar to Heather, I have read her whole journey and taken a great deal from it.

This is what I did:

- Bought a set of 2225H's and reconed them with the Genuine 2235 kits got some Genuine 2421 diaphragms while I was at it.
- Got a set of 2405H slot tweeters
- Built Nelson Pass' L300 crossovers using Janzten Silvers, Superiors and Crosscaps. Wax Coils everywhere including the bass circuit.
- Got a replacement set of Crenalex foam grilles from the States

To do

- Bump out the back for the larger 2312 horn and call it a day

I will never sell these.

[kelossus]

The terminal button is missing, and seems to have been jerry-rigged to work, but I think it might be best to upgrade them to something with a more secure connection, like a banana plug or similar. In looking up how to disassemble the component, I discovered that JBL recommended that the unit be converted to an LX-16A configuration, though I'm not sure what all that entails..65634

They are LX-16A's from what I can see, the only difference was a change to a larger Cap from memory. They are very simple crossovers to begin with and I wouldn't bother with them.

If you want to leave them as is and replace the binding posts with banana plugs just remove the crossovers, drill out the rivets, remove the old posts and put in some news ones.

Will probably have to widen the hole to fit the new posts as they tend to be a bit thicker.

Let us know how you go mate.

[colbysolomon]

Thanks everyone for the suggestions... I didn't realize adding the banana plugs would be that straightforward. does anyone have any pictures of the insides of these crossovers so I know what to expect? Also, is http://amzn.com/B00JC19TI2 an acceptable binding post?

Just thought about this, how should I reassemble the crossover once I'm done? screws? Should I find a way to re-rivet them?

After removing the screws for the crossovers, I notices they were rather stripped, is there a way to fix this?

[Ed Zeppeli]

There are a few ways to fix the stripped screw holes that I know of. A simple method is to just take a few toothpicks, break them to hole depth and put one or two in the hole before re-assembly. This will give the screw something to bite into. Another more permanent fix would be to drill out the holes to the next size up dowel; glue it in and trim it flush.

Good luck,

Warren

[kelossus]

Thanks everyone for the suggestions... I didn't realize adding the banana plugs would be that straightforward. does anyone have any pictures of the insides of these crossovers so I know what to expect? Also, is http://amzn.com/B00JC19TI2 an acceptable binding post?

Just thought about this, how should I reassemble the crossover once I'm done? screws? Should I find a way to re-rivet them?

After removing the screws for the crossovers, I notices they were rather stripped, is there a way to fix this?

I tried searching on google for a picture of the crossover internals but couldn't find one unfortunately.

That link for the binding post doesn't seem to work but something to bear in mind is most modern binding posts are longer than the factory JBL ones and will more than likely stick out a tad on the back.

Are you talking about the screw heads being stripped or the holes in the particleboard?

I would re-rivet them preferably with black rivets to match the originals.

[Odd]

Inside http://www.audio-teams.com/webboard/img-lib/webboard/wba_114247607081.jpg http://www.audio-teams.com/webboard/img-lib/webboard/wba_114247610311.jpg

[kelossus]

Inside

Legend! Not much in em' eh?

Would definitely consider adding a slot tweeter and building either 4313b's 4333 Crossovers or Nelson Pass' L300 crossovers.

Will be a huge improvement.

[martin2395]

If you don't mind it, you can always just disconnect the old network, build a new external one and route the cables through the bass reflex port. It's the least intrusive manner and 100% reversible. :D


Those old Electro-Cap capacitors may still be within spec, I've measured some of them with a good LCR meter en they were OK. Not juding the sound of course.

[colbysolomon]

Next question, the manual says i need to removing a retaining nut to remove the high frequency control... Where is this thing?6572665725

[Ed Zeppeli]

Probably under the foilcal on the front. On my JBLs the foilcal is a fairly thick plate and would come off by gently applying heat with a blow dryer and prying up with a very thin blade; careful not to bend it.

I have no idea how fragile yours are but search around here. You'll find it.


Cheers,
Warren

[colbysolomon]

Probably under the foilcal on the front. On my JBLs the foilcal is a fairly thick plate and would come off by gently applying heat with a blow dryer and prying up with a very thin blade; careful not to bend it.

I have no idea how fragile yours are but search around here. You'll find it.


Cheers,
Warren
Is there any other way without mangling the foilcal?

[hjames]

Is there any other way without mangling the foilcal?
No - the screws into the remote board the pots are mounted on are hidden under the foilcal.
You always take a chance on bending the foilcal -
how badly depends on how gently you work it.

[colbysolomon]

No - the screws into the remote board the pots are mounted on are hidden under the foilcal.
You always take a chance on bending the foilcal -
how badly depends on how gently you work it.
thanks, I'll give it my best, or attempt to open the crossovers without completely disengaging. Wish me Luck!

[hjames]

thanks, I'll give it my best, or attempt to open the crossovers without completely disengaging. Wish me Luck!
Good luck.
Don't forget to use a heat gun or very high temp hairdryer (gun) to to heat up the foilcal
and soften the glue so its easier to pry it apart without damage. The heat is important.

But not a bernzamatic propane torch or anything like that -
thats too hot and will burn the paint or melt the foilcal.

Patience will win out ...

[martin2395]

A hair dryer works perfect, confimed on 4343 foilcals (after already bending one...) ;)