Low impedance caps are required for the output capacitors of switcher power supplies. Sometimes the input capacitors, also. I've used those in three switcher power supplies I've repaired.
Solid state class AB amps with transformers were not designed to require low impedance caps. In the 400+ long service life caps I've installed since 2008, none has required replacing and none failed make the unit sound or perform better or at least as good as original.
I suspect a cap tested 2000 hours at 125 c should last at least twice those hours at 85 c more typically found in consumer hifi gear. 125 C is for engine compartment use in automobiles.
Solid state class AB amps with transformers were not designed to require low impedance caps. In the 400+ long service life caps I've installed since 2008, none has required replacing and none failed make the unit sound or perform better or at least as good as original.
I suspect a cap tested 2000 hours at 125 c should last at least twice those hours at 85 c more typically found in consumer hifi gear. 125 C is for engine compartment use in automobiles.
With that array of .01 and .1 uF bypass caps on there, one would not expect it to require main caps which have especially low impedance at high frequency. BUT those do tend to be the better ones which last longer even in 120 Hz application.
I just found this thread after posting to this thread - see post 24-26.
If anyone can provide some insight I would greatly appreciate it.
BTW, I bought another 2200 II as my "test mule" amp. It is in pretty good shape but not as pristine as the 1st one I bought.
I haven't made any mods to either unit yet - waiting on the feedback resistors to arrive from Taiwan. Hopefully someone can provide some guidance regarding all those film caps (3 different board locations) as I am confused about the various solutions others have tried.
If anyone can provide some insight I would greatly appreciate it.
BTW, I bought another 2200 II as my "test mule" amp. It is in pretty good shape but not as pristine as the 1st one I bought.
I haven't made any mods to either unit yet - waiting on the feedback resistors to arrive from Taiwan. Hopefully someone can provide some guidance regarding all those film caps (3 different board locations) as I am confused about the various solutions others have tried.
Started taking my 2200II apart and found this (see pics) on the left hand driver board. Most of these film caps I will be removing but what a mess the factory did with these caps. Looks like a trainee did this board. The other board (rh) looks OK.
Should I just try to clean this up the best I can (remove most of the excess solder)?
Should I just try to clean this up the best I can (remove most of the excess solder)?
I'd definitely wash that flux off with alcohol or something. Parasounds have resale value IMHO, check your local ebay craigslist or gumtree. I'd say it is worth the time to clean up. I wouldn't remove excess solder unless it makes traces too close together where they would short across in a humid salty environment (like an island).
Like all cap threads, this one also turned into a mess, straight from page 1 and solidly to the end 😉
Oh well.
Oh well.
Hi, sorry for kind of off topic, but I didn't find a better place to ask.
The Parasound HCA-2200ii has two inputs - RCA and XLR, and mechanical switches to choose which one to use.
Do the switches completely disconnect the unused input? So it is safe to have both inputs connected to the amp at the same time, all the time, and choose the needed source with the switches (with the amp turned off at the time of switching the input)?
Or even if the input is not selected, it could affect the input that is in use, if for example a second preamp is connected to the unused input?
The Parasound HCA-2200ii has two inputs - RCA and XLR, and mechanical switches to choose which one to use.
Do the switches completely disconnect the unused input? So it is safe to have both inputs connected to the amp at the same time, all the time, and choose the needed source with the switches (with the amp turned off at the time of switching the input)?
Or even if the input is not selected, it could affect the input that is in use, if for example a second preamp is connected to the unused input?