gdsmith1144
11-28-2017, 01:55 AM
Lansing Heritage Forum is new to this writer as it is rare or unlikely that previous participation has occurred in open website discussions other than through professional discourse. However, after some lengthy interactions yesterday with an old acquaintance who is now an emeritus physicist professor (his focus is/was electron behavior in exotic environs, e.g. < 1.0K), our conversations have stimulated an entrance onto this forum given a recent doorstep arrival from e-bay of two (2) LE 25 units, formerly from L-100 speaker cabinets. These are not designated as LE 25-2 or LE 25-4 as typically found in a stamped letter/number format on back side of speakers. On the contrary, original JBL LE 25 8 ohm labels are affixed on the back side which presumably should indicate age of units. Photos of these units are purposely not provided in this beginning thread with consideration of keeping thought open as discussion progresses.
A goal is to "bring life back" to these aged agile transducers (comment on e-bay was "one works, other is questionable) as each needs significant attention (dust covers are severely indented, and one is torn). New circular disk dampening "foam" needs replacement as well. Resistance tests have not been performed, but will be forthcoming this AM. In its ideal since, an attempt will be made to retain all surface originality (i.e. return dust covers to convex shape and glue torn portions).
In reading other Forums which apply to LE 25's, it is understood by this writer that replacement copies of LE 25's are readily available and will not incur the time and effort needed in this restoration. Having said that, and retrospectively considering yesterday's conversations about ancient Asian ceramics (some being restored), the thought of exploring into late 1960's audio engineering technology is fascinating. Recollection of Ampex applications of Lansing-based audio technology in the late 1950's bring back sound memories (pun intended) from this writer's adolescent youth as the Ampex tape unit had replaced a Webcor wire recorder for taping blues radio broadcasts. Sound emanating from the detachable speaker boxes was clear and pure and brought attention to product inscriptions on this unit, i.e. "James B/ Lansing".
Now with retired time as a disposable luxury, and access to a multitude of technical resources, resurrecting LE 25's is akin to tying that elusive adult insect which so tastefully attracts marine or freshwater finned species. With a limited experience base in speaker restoration, not withstanding a recently completed crack repair of two 8 ohm LE 8-T's acquired in 1975 ("Lansalloy" sp?) surrounds plus phenomenal aid from white colored 3M Fast Cure 5200 Marine Adhesive Sealant- a one-part polyurethane which chemically reacts with moisture and retains flexibility/available through West Marine, creating this thread for the LE 25 project is essential. Hopefully, there will be those who will join in thinking about restorative steps.
First will be to test resistance. Are their methods for determining positive and negative terminals? It is assumed that this is not necessary for this initial test, but it may be necessary as the project progresses. Please join with your contributions, and there will be more concise discourse from this writer. Photos will be included upon request and to provide context.
A goal is to "bring life back" to these aged agile transducers (comment on e-bay was "one works, other is questionable) as each needs significant attention (dust covers are severely indented, and one is torn). New circular disk dampening "foam" needs replacement as well. Resistance tests have not been performed, but will be forthcoming this AM. In its ideal since, an attempt will be made to retain all surface originality (i.e. return dust covers to convex shape and glue torn portions).
In reading other Forums which apply to LE 25's, it is understood by this writer that replacement copies of LE 25's are readily available and will not incur the time and effort needed in this restoration. Having said that, and retrospectively considering yesterday's conversations about ancient Asian ceramics (some being restored), the thought of exploring into late 1960's audio engineering technology is fascinating. Recollection of Ampex applications of Lansing-based audio technology in the late 1950's bring back sound memories (pun intended) from this writer's adolescent youth as the Ampex tape unit had replaced a Webcor wire recorder for taping blues radio broadcasts. Sound emanating from the detachable speaker boxes was clear and pure and brought attention to product inscriptions on this unit, i.e. "James B/ Lansing".
Now with retired time as a disposable luxury, and access to a multitude of technical resources, resurrecting LE 25's is akin to tying that elusive adult insect which so tastefully attracts marine or freshwater finned species. With a limited experience base in speaker restoration, not withstanding a recently completed crack repair of two 8 ohm LE 8-T's acquired in 1975 ("Lansalloy" sp?) surrounds plus phenomenal aid from white colored 3M Fast Cure 5200 Marine Adhesive Sealant- a one-part polyurethane which chemically reacts with moisture and retains flexibility/available through West Marine, creating this thread for the LE 25 project is essential. Hopefully, there will be those who will join in thinking about restorative steps.
First will be to test resistance. Are their methods for determining positive and negative terminals? It is assumed that this is not necessary for this initial test, but it may be necessary as the project progresses. Please join with your contributions, and there will be more concise discourse from this writer. Photos will be included upon request and to provide context.