"
http://i10.tinypic.com/2zfsff8.jpg
http://i7.tinypic.com/4htbcbp.jpg
http://i15.tinypic.com/29bgglt.jpg
http://i15.tinypic.com/40ljq53.jpg
http://i15.tinypic.com/44rdbuv.jpg
http://i15.tinypic.com/2nbepw9.jpg
Proof QSC is using single sided phenolic paper PCBs.
Phildo "
The poster 'Phildo' a sound mixing engineer who mixes sound on cruise
liners and posts in alt.audio.pro.live-sound is apparently under the
impression that one of the products above contains phenolic-paper
pcbs.
Apparently my word that it's not isn't good enough for him.
Have you actually peeked under the sheet metal of the
QSC yourself, first-hand?
Else, based on nothing but the photos cited above, I'd have
to agree that the QSC sure looks like it is using phenolic
circuit boards.
As others have observed, at audio frequencies the dielectric
properties aren't really an issue. But the mechanical strength
is. And the reputation/prestige of the vendor.
As you can see from the photos, the larger QSC board
requires many more standoffs to support the larger size
and/or lower strength of the phenol-paper board
I grew up associating phenolic-paper which cheap, mass-
produced for pennies, consumer stuff including throw-away
things like even greeting cards, etc.
And the jumper wires (and just the size of the boards) are a
very strong indicator of single-sided, another sign of cheaped-
out production design. I should know, I've done it myself.
From those photos, the QSC looks like the original design
which has been "cost engineered" to stay competitive, and
the Europower example looks like a 2nd or 3rd generation
version (albeit an obvious clone).
Behr may deserve strong criticism for not doing their own
designs, but they (or perhaps their Chinese contractor?)
appear to have brought the design up to date with better
materials/manufacturing.
Of course, it doesn't take Behr to clone a successfull design
and run with it, the Chinese have a reputation for doing it
all by themselves, sometimes off-shift on the same assembly
line as the original. And sometimes even with the same
sequence of serial numbers.