I'm doing some research on the capacitor power supply needed for the F5 build,
Papa uses 8x 15,000uf caps, is it overkill to think of using 18,000uf or 22,000uf instead? I plan on using a soft start device and a 400va transformer.
What is the consensus on temp. ratings, 85* or 105*?
Longevity the reason?
Thanks,
Ron
Papa uses 8x 15,000uf caps, is it overkill to think of using 18,000uf or 22,000uf instead? I plan on using a soft start device and a 400va transformer.
What is the consensus on temp. ratings, 85* or 105*?
Longevity the reason?
Thanks,
Ron
Renron said:
According to manufacturers' tech reports, life of electrolytic capacitor is mainly depending on the working temperature (the life doubles for each 10 degC lower working temp) while the operating voltage has almost no influence to the life.
For example, Panasonic spec. of 15,000uF/35V says that it has life of 3,000 hours at 85 degC. Then it's life is estimated as follows at different working temps:
- at 75 degC, life = 2*3,000 = 6,000 hours
- at 65 degC, life = 4*3,000 = 12,000 hours
- at 55 degC, life = 8*3,000 = 24,000 hours
- and, so on . . .
If the spec says 3,000hours at 105 degC, it has longer life than the above.
vdi_nenna said:
Too much?
No, but maybe no improvement either
One pair of BIG ones will do, but those are costly
Multiple small ones may be mounted on a board with the bridge, and looks more tidy
Less wires could be an improvement
BIG short wirres could be an improvement
BUT, some may have found that smaller sound better
Others find that a single pair sounds better
Normally classA would need tougher caps than AB
But the F5 is on the small side, so maybe not
Well, we know the 8watt Monster and Hiraga
Battery power, and HUGE caps
But I guess those times are over
One single pair of tough caps or multiple pairs of smaller ones?
Its tricky
Babowana said:
For example, Panasonic spec. of 15,000uF/35V says that it has life of 3,000 hours at 85 degC. Then it's life is estimated as follows at different working temps:
BC claims 12000 hours at 85 degree
And 210000 hours at 40 degree
And they dont even cost very much
Well, I am thinking about a way to shield the caps from the heat from heatsink and trafo
We know the heatsink may be 60 degree or so
Question is, have anyone measured the air inside the box?
What will it?
Like 40 degree?
Looking at BHC
It seem life time doubles when can size doubles
Evox Rifa, up to 25000 hours at 105 degree
Renron said:
Definitely need a soft start.
I dont on mine with 2 off 10,000uF but I cant get away with less than 13 amp mains fuse ! The start up surge is massive even with my tiddly capacitors.
As a previously pro enginneer I came from the class of minimal cost but good performance hence 2 off 10,000uF.
vdi_nenna said:
I believe that the design filter capacitance is decided mostly with respect to the "adquate" ripple voltage for the amplifier under development. As far as I understand, Papa has decided his design filter capacitance with F5 also in this regard, based on his professional experience.
So, your 8* 39,000uF will provide your F5 with further reduced ripple voltages, reverse-linearly to the originally designed value. The sound improvement? I have no idea . . .