17 Nov
2016
17 Nov
'16
5:37 a.m.
On 2016-Nov-16, at 8:44 PM, Jon Elson wrote:
On 11/16/2016 10:10 PM, drlegendre . wrote:
(tending off-topic . . )
As long as one is being careful about the size (capacitance) of the replacements.
IME, I've found limited benefit in trying to use/source/scavenge switching-supply caps
for tube gear.
The mains-side filter caps for switching supplies tend to be large in capacitance (100-200
and > uF), and typically are not suitable for replacing the ~ 8-40uF B+ filter caps in
vintage tube electronics that have tube rectifiers.
Maybe there are smaller ones in the smaller switching supplies around these days, I
haven't looked at those recently.
"Note the "tube audio" folks
gravitate to that stuff and tend to cause
seriously sick prices, because tubes."
FYI - I've installed dozens of the new-production CE / Mallory caps, all of
them in the 350-525V range. Zero complaints, zero comebacks, in as long as
I've installed them. For those of us in that field, they're like a gift
from the gods.
Vintage tube audio doesn't need to get involved, except for the old-style
twist-lock Mallory cap design.
All the off-line switching supplies use either 250 V (120 supply only) or 400+ (120/240
supply) capacitors as the main input filter. So, at least, capacitors in that voltage
range are STILL being made, and are in all computers, TVs and other home appliances.
(Yes, I know the OP needed a 30 V cap.)
So, some other tube gear replacement parts may be scarcer than hen's teeth, but the
HV caps are easily available.