Hello all,
so went from Antique Sound Lab 8W tube amp to a bigger one using 6550s in push-pull configuration, therefore higher power levels.
I am peacefully listening to the speakers...when suddenly I hear resonances and almost shattering from one. Upon closer inspection I find the diaphragm moves quite some on 4 sections. On these the aluminum crossbars are warming up against the environment and the other bars (so assuming a current here).
Is it possible that the silicone dots have lost their adhesion?
If so, how would you address that, i.e.
a) peel the old ones out (tweezers...this is a perfect scenario to rip the diaphragm), set new ones.
b) set new dots directly adjacent
c) set new dots on the opposite side, if they were non adhering they could still be good against push...
or am I wrong with my assumption, is there just not enough tension in the panels yet?
Cheers
brxl
so went from Antique Sound Lab 8W tube amp to a bigger one using 6550s in push-pull configuration, therefore higher power levels.
I am peacefully listening to the speakers...when suddenly I hear resonances and almost shattering from one. Upon closer inspection I find the diaphragm moves quite some on 4 sections. On these the aluminum crossbars are warming up against the environment and the other bars (so assuming a current here).
Is it possible that the silicone dots have lost their adhesion?
If so, how would you address that, i.e.
a) peel the old ones out (tweezers...this is a perfect scenario to rip the diaphragm), set new ones.
b) set new dots directly adjacent
c) set new dots on the opposite side, if they were non adhering they could still be good against push...
or am I wrong with my assumption, is there just not enough tension in the panels yet?
Cheers
brxl
Well I presume you can see if the dots are still attached to the Mylart by gently pushing the mylar.....I have never seen any adhesion problems with silicone dots myself ( I use 'new' Mylar which I clean very well). Nor did I see old audiostatics with this problem though I did not repair very much of them so maybe it is possible.
I am surprised by warming up of the aluminiumbar as the electrostatic current is in the order of micro-amps at best so has almost zero power......
I am surprised by warming up of the aluminiumbar as the electrostatic current is in the order of micro-amps at best so has almost zero power......
Thanks a lot for the answer.
I poked with a tiny paint brush, there is more travel in the diaphragm on the sections in questions. I cannot verify whether it is from having lost adhesion or missing tension. The space between the wires does not allow for good inspection...
Upon 2nd thought I want to recheck the temperature on the aluminum bars. Could also be they just sat more in the afternoon sun by coincidence. I am puzzled as they were warmer on both sides (I forgot to write that specifically)...which should not be the case if the adhesion is lost to one side....because then the dots still work in the push direction...I am about to answer myself it is missing tension and flapping to both sides...but I can observe and recheck the temperature rise in the evening.
Cheers
brxl
I poked with a tiny paint brush, there is more travel in the diaphragm on the sections in questions. I cannot verify whether it is from having lost adhesion or missing tension. The space between the wires does not allow for good inspection...
Upon 2nd thought I want to recheck the temperature on the aluminum bars. Could also be they just sat more in the afternoon sun by coincidence. I am puzzled as they were warmer on both sides (I forgot to write that specifically)...which should not be the case if the adhesion is lost to one side....because then the dots still work in the push direction...I am about to answer myself it is missing tension and flapping to both sides...but I can observe and recheck the temperature rise in the evening.
Cheers
brxl
After many runs I find that it does not heat up, those bars may just have been sitting in the afternoon sunlight.
Using a hair dryer I was able to increase tension, travel is now almost equal between both panels. I did several short cycles to come (asymptotically) close to the other panels,
cheers
brxl
Using a hair dryer I was able to increase tension, travel is now almost equal between both panels. I did several short cycles to come (asymptotically) close to the other panels,
cheers
brxl
- Status
- This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.