Manley Stingray II - Manual (Page 8)

LOOP RETURN: This input comes in after the Input Selector and just before the Stingray II’s Balance and Volume
controls. If you have all your sources going into another external preamplifier, or even a Home Theater surround proces-
sor, then you could plug that preamp’s outputs here and let the Stingray II just function as a stereo power amplifier when
the Loop is active (see the previous page for more information). The Volume and Balance controls still function in this
mode. The REC OUT and LOOP RETURN function as an insert point or effects loop, meaning you can insert something
like a crossover, equalizer, or you can even monitor off your tape deck’s 3rd head using the INSERT button on your
remote as a tape monitor.
SUB OUT: This is a line level output after the Stingray II’s volume control. Use this output to feed the input of your
subwoofer amplifier. The signal level of the output follows the main volume control in the Stingray II so that if you
change the volume control on the Stingray II, your external powered subwoofer amplifier will also track and change
volume. Remember this is a LINE LEVEL output, not a speaker output. If your subwoofer only has speaker level inputs
on it, then you need to drive it with the speaker outputs on the Stingray II. Use of the headphone jack mutes this output.
*NOTE: Do not use a Y-cable to connect a mono subwoofer to the subwoofer outputs. This will mono the main output
from the amplifier. Instead, just use a single channel to drive a single powered subwoofer input, or use the speaker level
inputs off the Stingray binding posts. Alternately, you could use an external Stereo to Mono combiner such as the RDL
TX-LC2 Audio Combiner. This would sum both Left and Right signals and provide a Mono balanced output to drive a
powered subwoofer input. If you need to drive an unbalanced input, use the (+) and Ground outputs.
TRIODE / ULTRALINEAR SWITCH: Located on top of the unit, just above the speaker posts. This switch changes
the configuration of the output tubes and how the screen grids drive the output transformer. Triode mode hooks the
screen grids up to the output tubes’ anodes and will give you around 20 watts. UltraLinear, also known as “Partial Tri-
ode”, connects the screen grids to the UL taps on the output transformer’s primaries and will yield around 40 watts of
output power. Triode mode tends to give you a more etheral and delicate sound while the UL mode has a more aggres-
sive or punchy sound. Feel free to experiment and pick whatever operating mode you like the sound of best in your sys-
tem. What will “sound best” really depends on your system and your room and your speakers and your tastes and what
you are looking for. We do not suggest you play with this switch all the time. You should never switch up and down
rapidly as there are high voltages on this switch, and you’ll blow something up quickly by nervously fidgeting with it.
We strongly suggest you pick the setting you like best and just leave it there.
B+ FUSE HOLDER: Should you need to replace this fuse, simply insert a flat-head screwdriver in the slot (after mak-
ing sure the unit is powered down completely, of course) and turn it counterclockwise. The fuse holder should pop out
with the fuse. Replace the old fuse with new one, push the holder back in, and turn the screwdriver clockwise to lock.
SPEAKER POSTS: The speaker connection posts are on the back side panels. The RED is positive and WHITE (or
black) is negative (ground). Be sure you have speakers (or a 4 to 10 ohm load resistor) connected to these terminals
before powering on the Stingray II. Tube amps (unlike solid state) require a speaker if there is any chance there will be a
signal applied.
Watch out for reversing the positive and negative wires either at the amp or speakers (unless you want to simulate
a record company executive’s office hi-fi). The lows get lost, and the image is very weird. If in doubt, try reversing one
channel, the way with the most bass is correct.
These terminals will accommodate most thicknesses of bare speaker wire and most U shaped terminals or banana
plugs. The only thing that they don’t like is thin wire. You should avoid thin wire for speaker cables in general. Use at
least 18 gauge (18AWG) or heavier. Bigger wire has smaller AWG numbers. Be sure that the top bolts are tight, but
avoid over-tightening that might be difficult to undo or may damage the posts. In other words, firm as “strong finger
tight” but less than “big wrench tight”.
These outputs are appropriate for speakers rated between 3 and 10 ohms which includes all those 4 and 8 ohm
speakers. For reference, the amp design and output transformers were optimized for 5 ohms. You’ll get a little less
maximum power on either side of 5, but don’t forget that your speaker manufacturer is giving you a nominal impedance
figure when he tells you that you have “an 8 ohm speaker” which means your speaker’s actual impedance swings wildly
vs. frequency all over the place. In real life, we have found 5 ohms to be a good place to be for most people. If you have
some wacky speakers that hit strange extremes, then you might be a good candidate to order some custom other-imped-
ance output trannies from our in-house magnetics department.
HEADPHONE JACK: Located on the Right-Front panel. Plugging headphones in will mute the speaker and subwoof-
er outputs.
1/8” INPUT (Input 4): Located on the Left-Front panel. Accepts standard 1/8” cables.
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