Hi all !! New guy here....Need some tech help on my one owner (me) Tympani 1D's...Is it Normal for all enameled Aluminum magnet VC wire to erupt with crusty, whitish oxidation & suffer with resulting numerous electrical circuit opens over time ?? My 50+ yr old 1/4 lb spool of 32 ga copper enameled mag wire Still looks factory fresh with absolutely No signs of discoloration, corrosion or continuity failure !! ...Nor have Any of the many dozens of coils I made with it....Short of marine duty or water exposure, I've just never seen any enameled mag wire corrosion damage before...Can anyone explain why never flooded or physically damaged Aluminum mag wire should "dissolve" into white dust ?? ...Thx, ...tom..
It's a pretty common issue on old Magnepans. I assume there's a slow reaction between the glue and wire, but I'm speculating.
Thx,....The slow chemical glue reaction Is an interesting consideration.....Ironically,.....Aluminum magnet wire is advertised & claimed to have Superior antioxidation & corrosion resistance over Copper enameled magnet wire !!! ....Petroleum & solvent based adhesives complex insulation reaction attacks are usual # 1 suspects but any Water based adhesives Could possibly trap water moisture (a known metal corrosion initiator) long enough beneath the glue line Directly against the thin enamel coating to trigger the Deadly wire cancer, especially when No heat treatment is allowed to the delicate Mylar during the speakers manufacture....I'm trying to Reduce the same Corrosion issue during the upcoming VC rewiring....The relatively simple reglueing of Intact VC wire to intact Mylar is one thing but the total VC rewire job seems beyond Ridiculous & maybe oem preventable ???
There are quite a few threads here and pages on other sites that deal with total rewires of Magnepans. Making a fixture is typically required, but other than that it seems pretty straightforward. Magnepan will typically help with kits that provide the currently preferred wire and glue also.
While a failure like this can be annoying, it typically occurs after a lot of very good years of listening. For the price and performance, they still seem like one of the best things going as a step into high-end audio.
Long-term reactions like these are typically hard to simulate, especially when suppliers change formulations without your knowledge or when they change something that seems trivial at first glance. Accelerated testing often has blind spots you don't realize until one of them bites you. Some other threads indicate that Magnepan was quite worried about premature failures when they happened, as you would expect from a company that's been around as long as they have.
While a failure like this can be annoying, it typically occurs after a lot of very good years of listening. For the price and performance, they still seem like one of the best things going as a step into high-end audio.
Long-term reactions like these are typically hard to simulate, especially when suppliers change formulations without your knowledge or when they change something that seems trivial at first glance. Accelerated testing often has blind spots you don't realize until one of them bites you. Some other threads indicate that Magnepan was quite worried about premature failures when they happened, as you would expect from a company that's been around as long as they have.
Thx again Matt,.....I agree & realized at the purchase time (1977) the T-1D Was on the commercial fringe, extreme leading edge of novel speaker design & it's relatively Simple pm magnet, voice coil bonded to stable, chemical & heat resistant, high tensile strength space-age plastic was an updated improvement on longtime traditional p-m dynamic design with
Anyhow,....again, i'm just reaching out trying to avoid another post rebuild time bomb catastrophe with my T-1D's only failure VC wire corrosion issue in mind.....seems the original water based "Miloxane" adhesive-coating build componet was reported changed at some date to another water based "FastBond N30" adhesive-coating componet (why keep using a similar, suspect, metal oxidizing initating water based agent in close, intimate proximity sealed forever to the Aluminum VC wire ??) .....Does anyone know anything about the Aluminum VC corrosion issue (or any other) with the currently used rebuild kit or factory rebuild durability performance ??? ...Thx,...tom
Of course it's possible a long-term chemical reaction wasn't the key factor involved in the VC wire corrosion at all but rather the particular magnet wire insulation build performance rating (film thickness, # of layers, etc) as this would be a relatively Low voltage application not theoretically Requiring the thickest multilayer enameled insulation choice....Anyone aware of originally used mag wire insulation rating (BDV, pinholes) & rewire kit offering compared to today's best available mag wire possible better choice ??