Specifications

Australian Hi-Fi | 21
Brand: Manley Laboratories
Model: Stingray
Category: Valve Integrated Amplifier
RRP: $2,799.00
Warranty: Five Years (Valves: 6 months)
Distributor: Syntec International Pty Ltd
Address: 60 Gibbes Street
Chatswood
NSW 2067
T: 1800 648 628
T: [phone]
F: [phone]
E: [e-mail]
W: www.syntec.com.au
Manley Laboratories
between two common impedances makes
a lot more sense than picking a ‘standard’
impedance. In fact, the Stingray will drive
impedances of between 3 and 10Ω. It’s
not at all happy with an open circuit, so
you should never operate it without any
speakers connected. (This would not be
sensible with any valve amplifier, but in
this case the Owners’ Manual specifically
warns against it.)
The two controls on the front panel
are for channel balance (left) and volume
(right). In between is the backlit ‘Stingray’
panel that somewhat superfluously
indicates the amplifier power is ‘On.’ I
say superfluously because if the valves are
glowing red, then the amplifier is very
obviously on, irrespective of whether
the panel is illuminated or not! (Manley
makes exactly this point in its Owners’
Manual, pointing out that if the panel
isn’t glowing, it probably means the
lamp needs replacing, pointing out in
passing that although the lamp looks
like a fuse, it isn’t. I can’t remember ever
seeing a lamp like this before, so if yours
dies, I wouldn’t bother going down to
your local shop to try to locate one, but
would instead recommend going direct to
Manley’s Australian distributor, Syntec,
for a replacement. That said, I wasn’t that
keen on the look of the illuminated logo
anyway, so if the lamp on mine died, I’d
leave well enough alone.
It’s when you come to the input
source switching process that things
start to become very interesting. There
are TWO source switches: one for the
right channel and the other for the left
channel. These are located on opposite
sides of the amplifier, right around the
‘back’, on the two hindmost ‘wings’ of
the Stingray. Alongside each are four
RCA input terminals, so four source
components can be accommodated. This
is quite a problematical arrangement.
Firstly because it means that if you want
to switch sources, you not only have to
reach around the back of the amplifier
(making sure to keep your hand and arm
clear of hot valves), but you also have
to switch TWO source switches, rather
than just the one. Of this EveAnna says
‘We realise splitting left and right this
way with individual input select switches
may be a problem for some—sorry. We
did it this way because a good percentage
of people rely on only one source 95 per
cent of the time and because it provides
you with the maximum stereo separation
at the lowest cost. Yes it could have
been more convenient but it would have
cost more [if] we had to use 10 ‘runs’
of good shielded wire and it wouldn’t
have sounded quite as good.’ Secondly,
it means you’ll need to use custom
individual interconnect cables, because
the standard ‘paired’ types won’t fit.
Thirdly, it also means that one of each
pair of RCA interconnects will have to
run either over or under the power cord
unless you’re very inventive when it
comes to positioning the amplifier and
your source components.
Needless to say, the mains power
switch is also located behind the
amplifier, on the small ‘flat’ at the very
rear. Manley’s manual helpfully notes:
‘You should be able to ‘feel’ the rocker
switch located next to the AC power cord.
Flip the switch away from the power cord
to turn on the Stingray, or towards the
power cord to turn off the unit.’ Again,
if you’re turning the unit off, watch out
for hot valves! (I suspect most users may
find it easier to run the Stingray’s power
cord down to a switched power block or
mains power conditioner and turn the
amplifier on and off there instead.) As for
leaving the unit on, neither Manley nor
I advise it (at least not if you want your
valves to have a halfway respectable life).
Again in the words of the manual: ‘It is
not recommended that you leave your
Stingray stay permanently switched on
(sic). This only wastes electricity and tube
life. The Stingray reaches peak operating
condition in approximately 30 minutes.’
Connecting the speaker wires also
entails negotiating a hazard. The speaker
binding posts, although properly
insulated themselves, are fixed to the
stainless steel top plate immediately in
front of—and exceedingly close to—the
output transformers. If you use a long
banana plug, or don’t trim the ends of
your speaker cable, it’s possible that the
wires could touch the transformer case
and short out, with the potential of
damaging the amplifier. Indeed the plugs
I use on my cable did exactly this when
I connected up the amplifier, though
I realised the danger immediately, and
had not at that stage even connected
the mains power cable. To its credit,
the Owners’ Manual has a very large
and prominent warning to this effect,
complete with an illustration showing
the potential problem, with a large ‘NO!’
overprinted over the diagram.
As you can see, there are lots—and
lots!—of valves on the Stingray: eight
EL84s, two 12AT7s and two 6414s. There
doesn’t seem to be a lot of consistency
with the valves that ship as ‘standard’,
with Manley Laboratories saying it will
provide either EI6BQ5 or EL84M output
valves, GE or Raytheon JAN NOS USA or
6414W drivers, and 12ATWA or 12AT7
Large Plate Input valves. All the valves
on the amplifier provided for review were
unmarked except for the valve identifiers
and a label proclaiming they were ‘Made
in Yugoslavia.’ (Which, since Yugoslavia
hasn’t been a country for some time,
means the valves were very definitely
‘New Old Stock’ [NOS]!)
It’s important that the eight output
valves are correctly biased, which Manley
does at the factory, and for which
appropriate test points are provided
on the amplifier. However, a little to
my surprise, Manley doesn’t seem too
fussed about the need to bias the valves
regularly, saying that: ‘Some people
never do’—which seemed a little cavalier
to me. Further on in the manual I was
relieved to find the advice: ‘We suggest
you check every three months—that way
you are assured that the amp is running
optimally and will spot a tube on its way
out. Some check every month, once a
week is getting a little obsessive.’
The instructions for biasing are
excellent. They’re clear, lucid, to
the point and leave no room for
misinterpretation. They also say that
before you start, you’ll need to go out
and buy yourself a properly insulated
flat-bladed screwdriver and a multimeter
ManleylabHFSep06.indd 21 22/01/2009 1:55:46 PM