Sound quality differences among the same models
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It's probably just suffered from use and time. It might be interesting to pull it apart for a look see but I don't think you're going to be 'fixing' anything.ScareDe2 said:I got a second DT680 for $15 it has a weird quiet hum and an inferior sound than the first I purchased. I tried with the other pair of speakers with same result, still a great sounding machine, but I can't crank it full volume it distorts and the woofer is not pounding with the same movements. I know it's the central unit maybe the amplifier. When I get those long screwdrivers I will finally be able to open it and carefully look at the circuitry. Maybe someone dropped it othrwise the cosmetic is great, cd player working but skipping at full volume (first DT680 plays CD without any problem) and the tape deck A is working tape deck B not working. Very decent condition only problem is the slightly inferior sound. I wish I can fix it.
ScareDe2
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i finaly got a long screwdriver and I opened it and I saw some sign of burning below the capacitor 25v 4700uf 85degree celcius japan. I am sure if I change that the sound will improve. Do I have to get the exact same capacitor or any 25v 4700uf will do?jimmyjimmy19702010 said:
BoomboxLover48
Boomus Fidelis
So do l!jimmyjimmy19702010 said:
I am taking a few of my favorite boxes to my grave! So I don't care much!
BoomboxLover48
Boomus Fidelis
I've never seen another person that would go to the innermost depth and detail to answer a question. 
So blessed to have him on this beautiful and friendly site!
Stay blessed NORM (superduper)
So blessed to have him on this beautiful and friendly site!
Stay blessed NORM (superduper)
Pics?ScareDe2 said:
Sounds like one of the main filter caps in the power supply maybe? I haven't had one of my 680s apart for a while.
If the capacity and voltage of the cap is correct (minimum of 25V), then you're good to go.
I doubt its burnt. Rather all large caps are glued down with caramel colored glue. Bet that's it but like its already been said, lets see a pic.
ScareDe2
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thank for that info I did not know the caramel colored glue was normal. But the capacitor shows a cavity and one small hair-line cracks. Also I interchanged component from my working panasonic with the defective one to isolate the problem, not 100% sure yet but it seems that part is the problem.
BoomboxLover48
Boomus Fidelis
That is a very healthy cap! If you see a bulge on the top cross cut.... health might be questionable.ScareDe2 said:
BoomboxLover48
Boomus Fidelis
That Caramel pee is spilled on the left side also.... ...looks like someone got so pissed off!ScareDe2 said:thank for that info I did not know the caramel colored glue was normal. But the capacitor shows a cavity and one small hair-line cracks. Also I interchanged component from my working panasonic with the defective one to isolate the problem, not 100% sure yet but it seems that part is the problem.
My best guess is that it is some varnish, wax or glue spilled during the assembly process. In some cases they glue the cap in place too...That don't look like leaked electrolyte at all. See that bubble entrapped in the glue. Manufacturers put glue to reduce shock and vibration damage from shipping long distances. It was a common practice in old electronics for components that can vibrate.
Vintage Man
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Ghettoboom767
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This is just an amazing thread! Norm is so great in his knowledge,I've read every bit of this!
I've restored boomboxes from the shell up with complete disassemble but have not replaced caps yet,most all of my boxes perform quite good that's not to say they may not need it.
I just loved reading this as it does explain age on electronics,Thank-You so much Norm.
I have a Pioneer SX-V90 digital receiver that has a bad cap that is quite bad,failing and hissing a bit,almost a little smoke.Unit will still turn on but I don't want to hurt it anymore until I can get it fixed. I'm hoping to get it fixed by winter.
Great information!!😋😎📟💳
I've restored boomboxes from the shell up with complete disassemble but have not replaced caps yet,most all of my boxes perform quite good that's not to say they may not need it.
I just loved reading this as it does explain age on electronics,Thank-You so much Norm.
I have a Pioneer SX-V90 digital receiver that has a bad cap that is quite bad,failing and hissing a bit,almost a little smoke.Unit will still turn on but I don't want to hurt it anymore until I can get it fixed. I'm hoping to get it fixed by winter.
Great information!!😋😎📟💳
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