How reliable is a chinese electrolytic used to fake a japanese brand capacitor ? In Elna datasheet you find different color, no 3000uF value and both 2700uF and 3300uF 35V in datasheet have bigger cans than these you bought. You thought of fake capacitors until you decided to buy these that have more than one reason to be possible fakes. How can you buy these after considering fakes ?
True, but there is also some personal pride in that my diy builds or repairs hardly fail. Nowadays lots of consumer products look like the are engineered to fail after warranty.
I like these amps very much and use 1 as my main amp with a test setup of drivers with 4 Visaton frs 8m 3.3" in pvc pipes. 2 On each side in a 120degree angle and a Dayton PTmini-6 planer tweeter in the middle.
I Still have to build the final speaker boxes for them and use them with 2 jbl804 closed car subs; but I am amazed at how much I love the sound from this simple and cheap setup. I'm actually a bit worried that the final box is going to sound less good, so I'm looking more into why it's sound so good at the moment.
As I'm writing and reading this, this might just be a lame excuse for not having them build yet....
I know that feeling: when being an electrical engineer goes beyond strict rationality and becomes a devotion. This is why you are excellent engineers. You not only solve the task well - it still lives on in your mind as topic for analysis and improvement. Continue doing it the way that brings you pleasure.
It was when I noticed you discussing expected lifetimes of 8000hours at 105 degrees Celsius, I thought "is this realistic?", or at least get the circuit out of the sauna.
Good point; there seem to be a lot of 'original brand caps' which don't show up in the spec sheets of the manufacturers.
So many even that this almost can't be a correct indicator for real or imitation. Why would imitators use the strange and very recognizable colors? This does not make sense to me.
Maybe these are oem series, custom orders, or something like that. Might be old stock, might be the latest advancement which they first roll out in small quantities to see if they hold up in the real world. If anyone has knowlegde about this, please share.
Size was mentioned earlier in this threat and can could be the result of more advanced production.
I really don't know; but had a good 'feeling' about these, so I bought them. Maybe they are fake but if they are good enough they won't die on me anymore; they are fine to me.
I just had an other look at the 2 left over new caps and the 2 old ones which came off the boards an noticed that the bulged cap has a bit less weight so I put the 4 on a scale and measured them precisely:
# 1 - removed bulged 'Nichicon 6800uF' - 8.83g it does not look like it has vented; it has just a slightly (~1mm) bulged 'x' op top. Measured without the bulge 37.2mm x 18.1mm
#2 - removed ok 'Nichicon 6800uF' - 10.21g the jacket looks ok but there is a 1mm slit on the bottom side, like it's to large. 35.8mm x 18.1mm If the jacket would fit it would be even shorter; about 34.8 - 1.5/2.5mm shorter then the other one and has 1.38g (15.6%) more weight.
#3&4 - 2 new 'Elna 3000uF - 6.40g and 6.45g and both measure the same 21.3 x 18.2mm
Based on this my suspect about the original 'Nichicons' being fake, got stronger. Can you put some of your 'Nichicon 6800uF' caps on a precision scale any have a look if they are all the same height/length and have nice fitting jackets?
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