On Jan 29, 7:27*am, flipper wrote:
On Fri, 28 Jan 2011 12:03:55 +0100, "GRe"
wrote:
"Patrick Turner" wrote in message
....
[...]
The vast majority of users are technically illiterate, through no
fault of their own.
They cannot be blamed for buying ARC and other major "reputable" brand
names of audio gear while thinking they can use it without special
mains arrangements to get reliability if the mains voltage is 13.7%
above the labelled input mains voltage on the unit they buy, ie,
252Vrms instead of the labelled 220Vrms.
Obviously (on paper) ARC's operate within spec even at .au supply.
VT200 Power requirements: 105-125VAC, 60Hz (210-250VAC, 50Hz);
990W at rated output; 1200W maximum; 680W at idle.
(not from the manufacturer's site)
VT200 MKII Power requirements: 105-125VAC, 60Hz (210-250VAC, 50Hz);
990W at rated output; 1200W maximum; 680W at "idle".
Complete spec, see:http://www.audioresearch.com/vt200.html
VM220 Power requirements: 105-125VAC, 60Hz (210-250VAC, 50Hz);
620W at rated output; 900W maximum; 400W at "idle".
Complete spec, see:http://www.audioresearch.com/VM220.html
Those specs are technically 'not quite right' as 'harmonization'
specifies 230VAC +- 10% for a range of 207VAC-253VAC. In the former
240VAC countries the spec is 230VAC +10% -6% and in the 220VAC
countries it's 230VAC +6 -10, so they didn't have to change a blessed
thing, which results in the same 'fully harmonized' 230VAC +- 10% spec
as far as equipment manufacturers go. Maybe ARC is using 'round
numbers'.
Further, country power specs are 'on the grid' and not your wall
outlet. "Service voltage" (outlet) can be down to 85% of nominal,
which is why design engineers see operating specs that don't 'match'
the country power spec. I mean as far as steady state voltage goes.
The 'every day' problems are transients and brownouts.
To cover operating conditions the amp should cover 185VAC to 253VAC
but you might put the 'country power' range on the label to avoid
confusion.
Something doesn't jive, though, because Patrick says the amp's label
states 220VAC and that isn't consistent with the above spec. That
leads me to believe it might be a 'pre harmonization' amp that was
intended for 220VAC continental Europe use.
And therein lies a problem because harmonization only 'pretends' to
harmonize by inventing a new spec that's simply wide enough to
encompass the existing power systems but it didn't actually change a
blessed thing on the ground. In theory that's 'not a problem' for
*new* designs, which should take into account the extended +-10%
range, but it leads to a perception problem that "we're all on the
same power now so what works in France should work in the U.K." Except
(for the most part) France was and is still 220VAC +-6% while the U.K
was and is still 240VAC +-6% so what was 'once upon a time' built for
220VAC is over voltaged on 240VAC.
All 'harmonization' did was to 'force' manufacturers into making
equipment that works in both 220VAC and 240VAC countries, which they
could and usually did do on their own by either complying with both
specs (one means being transformer taps as Patrick mentioned) or
making models specific to the export region, but, in the process, it
created confusion by pretending something changed. It's also a pain in
the butt for manufacturer's because they can no longer 'fine tune' a
product for the actual mains power as it has to be the mythical, and
wider (more difficult to design for), 'harmonized' voltage of 230VAC
+-10%.
The damn hi-brow makers AND low brow makers SHOULD ensure that users
are made aware of the pitfalls of incorrect mains voltages. But they
all know any mention of anything technical or of any possible negative
outcomes is detrimental to sales figures. They think its better users
burn their gear to bits, with an attitude of utter carelessness about
their customers.
A bit hard to find but ARC actually say something about it, quote:
"Factors which can shorten tube life include inadequate
ventilation, overdriving loudspeakers at continuously high
volume levels, severely fluctuating A.C. line conditions (e.g.
sagging line voltage during summer peaks of air-conditioning
demand), or severe interference pulses or electromagnetic
interference. Power-conditioning products such as line filters,
isolation transformers and the like may or may not help sonic
performance, particularly when used with power amplifiers;
contact your dealer for professional advice. A dedicated 15-amp
or 20-amp A.C. circuit for your power amplifier is the most
effective solution for power-starved audio systems".
[...]
Regards,
Gio- Hide quoted text -
- Show quoted text -- Hide quoted text -
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I suspect ARC may have switched to 220V chinese made power trannies.
All I do know is that ppl here buy ARC stuff and don't care about the
mains voltage and then smoke happens.
It is insanely stupid to expect a large heavy box full of very hot
vacuum tubes to last well when the mains voltage is too high, and the
biasing method is so stupid, and there is no active protection if one
or more tubes goes into thermal run-away.
As long as ppl here in Oz understand that there can be problems and
that there are solutions, I have done all I can.
Patrick Turner.