Sir Michael
With your past exhibited proclivity towards packaged power amps, I was figuring that to be your amps sole device of choice.
Now as far as the exploding of tantalum foil electrolytic caps, that tends to be suggestive of improper polarization in their installation…or a possible bipolar power mode operation of the unit in the designed circuit….or over voltage operation of those devices. With their inherent very low ESR, thin oxide dielectrics and active capacitance surface area they are much less forgiving than common electrolytics.
I know for a fact that some manufacturer’s modes of their polarity marking can prove somewhat small and cryptic. I am frequently just pulling
out my Triplett 630NA VOM set in its 10K ohms range, along with also previously knowing the meter leads true voltage polarity. It is then easy to take a reading and watch the caps initial fast charge up surge accumulate and then gradually drop back ever so closer to zero and then discharge the cap (now, that was one healthy high current spark from such a low capacitance unit, wasn't it !) and reverse the leads to recharge up again and see the same initial surge but this time with the meter hanging up and not doing that previous full drop as was experienced when the caps polarity and applied charge are in accordance.
Also, when you need tantalum foil voltage ratings in excess of 35VDC, you are getting into rare territory.
I tend to only see that availability being offered in Mil Spec or NASA qualified devices and in the ultra sealed / ultra reliable wet tantalum slug type of construction .(10-25 years longevity)
Considering those amps to be adequately heatsinked for their cooling, I would have the highest respect of those 3886’s internal design in proper self protection via their continual sampling loops of their operating thermal and power characteristics,
as well as detection of any DC offset voltage showing up on their speaker output lines. As far as you pumping that continuous RMS power level into a set of speakers, I don’t think that your ears, nerves or speakers ( Sniff…sniff…do I detect the acrid odor of Phenol wafting from those speaker cone spider bobbins ?) could tolerate it.
Considering your two 3886 power amp blocks and their power limiting specs on that described system, my choice of fusing, being a 3A standard line fuse, unless your raw DC power supply has an inordinate high value of filtering capacitance being utilized, where I would shift towards a slow blow version, from the aspect of initial turn on surge.
73's de Edd
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Alternatively speaking……. I wonder, if young Chinese piano players have to learn to play "Knife and Fork".
. I'm trying to figure out the correct fuse size for an amplifier I just finished. After having a nice fireworks display last week when some tantalums blew up (last time I use those!), I decided I need a fuse before something expensive blows up - like my speakers or the amp itself.
so cannot even check my current setup for details.
