[[email protected]]

On Jan 29, 9:00*pm, flipper wrote:
On Sat, 29 Jan 2011 06:17:26 -0800 (PST), wrote:
On Jan 28, 8:40 pm, Patrick Turner wrote:
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 -

- Show quoted text -

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.- Hide quoted text -

- Show quoted text -

Chances are, ARC may be doing just that ! *US-manufactured
transformers are ver-r-r-y dear these days . And besides, creeping AC
mains voltages are becoming a problem here , as well . What is
historically known as a ' 110 ' volts AC *slowly became 117,
120,125,128 ... I measured what is very close to 130 volts on some
occasions .

I'm not sure where this 'creeping AC' notion comes from but, as I
mentioned to Patrick, I can't find when U.S. power was actually spec'd
at "one ten," despite that being popular nomenclature, and my 1940
Sonora radio declares "117V AC/DC." (doesn't care about 'Hz', which
they would call 'cycles per second', because it's just a single
rectifier off the 'line'.)

With current line voltage being 120VAC a 2.6%, so called, 'creep' over
70 years hardly strikes me as a 'problem', especially since it isn't
really an operational creep as modern tolerances, generally +-5%, are
tighter than in 1940.

What may be the cause of the, so called, 'creep' notion is observing,
as you have done, socket voltage. Reason being, power companies like
to operate on the high side of the range for the obvious reason it's
downhill from there. I.E. You're not going to have more than what's at
the entry and then you have internal line losses. Second, the power
company believes a higher voltage is more efficient because of lower
current, for the same power (disputable), hence lower line losses. At
any rate, with tighter regulation one can operate closer to the
tolerance max (same reason nominal 'crept up' from 117VAC to 120VAC)
but the 120VAC nominal spec hasn't change for many decades.

Point is, simply observing 125VAC on your wall outlet doesn't mean the
'line voltage' spec has 'crept up' as it's still within the 120VAC
nominal +5%.

Having said that those are ANSI specs (C84.1) but utilities are
regulated by your local authority so things 'could' be different in
your locale, as in California where they require tighter regulation,
but local authorities are prone to simply adopt the ANSI standard as
there's little reason to reinvent the wheel (except in California).

ANSI also allows +5.8% under unspecified "short durations or unusual
conditions" for a max of 127VAC. Transients, sags, dips, or swells may
be higher and ANSI specifies that equipment should be able to tolerate
up to +-10% (longer than 10 seconds).

A conservative designer would likely shoot for +-10% continuous, if
you can achieve it without compromising other goals, but SPEC it +-5%
because there's no reason to 'guarantee' more than is required.

(As an original Star Trek fan I call this the "Montgomery Scott Rule:
A good engineer is always a wee bit conservative, at least on paper."

We should probably also note that the undefined quantity "wee bit" is
not a synonym for "arbitrarily large" and doesn't mean "zero sustained
damage from 10,385 direct photon torpedo hits with shields down but,
on paper, we'll spec level 1 hull breach from 2 with shields up.")

A good and serious manufacturer should have built his
equipment with proper VAC input settings in order to accomodate
variations anywhere in the entire world .

That's a wonderful sounding notion but you can't design for "anything
someone might do." You can only design to a SPEC and it isn't
necessarily 'worth it' to sell your product 'everywhere'.

You may also decide to 'regionalize' your products, as in a 'U.S.
model' and an 'E.U. model', instead of trying to make things
'universal' since it might make more sense to use a specific
transformer/power supply rather than incorporate the added expense of
multiple windings/taps, selection switches, and what not, plus the
associated size implications, into every one of them. But, as the
saying goes, "it depends."

Reality has a habit of
biting you . Better safe than sorry !

I could, of course, be wrong but since the unit Patrick mentions is
specifically labeled 220VAC I sort of imagined it might have been
designed and intended for 220VAC. Yeah, I know, silly me.

I sure wish someone would call TUV, UL, CE, et al, and get them to
drop these silly labeling regs because it's blindingly obvious no one
reads them and even when they do they declare it shouldn't matter what
the damn things say anyway. So what's the point? Just leave three
heavy duty wires hanging out the back and let 'em tap into a 10KV
distribution line or clamp them onto a car battery. 'Should work'
regardless, right?

Batteries are great. We still call the plate supply ' B+' ... don't
we ?