Introduction
Your JSS4-VC2 Speaker Selector-Volume Control is designed to operate ith up to 4 pairs of
loudspeakers of 4, 8, and 16 Ohms impedance in any combination. It can be used ith one or
t o stereo amplifiers, or ith 4 Channels of a surround-sound type sound system. Each of the
4 output Control channels can be individually s itched to the amplifier connected to A INPUT,
or one connected to the B INPUT. Thus it is convenient to listen to different program material
in different rooms, s ap front and rear channels in a surround-sound system, etc.
Impedance loading protection for the po er amplifier (s) is built-in, and fully automatic. Four
100 Watt AUTOMATCH attenuators are employed, pre-set so that the orst-case operating
condition (four pairs of-4 Ohm speakers operating simultaneously at maximum volume) ill
appear as a 4 Ohm load on the amplifier. Higher impedance speakers and/or lo er volume
settings of the controls ill reflect a higher impedance to the amplifier, so that safe operation
is assured.
Since impedance matching protection is achieved by use of AUTOMATCH transformers, there
is no heat generated in the matching process- this assures safe operation in a closed
environment. There are no extra buttons to operate that must be remembered to maintain
safe operation. An additional advantage is that there is no po er loss in the JSS4-VC2. There is
a level drop of -6 dB to the speakers at maximum volume settings of the JSS4-VC2 controls (at
the factory setting), but this is not a po er loss. When all 4 controls are set at maximum volume,
the full po er of the source amplifier is available, divided equally among each of the 4 speaker
pairs.
Both the A and B amplifier inputs are identical, and completely independent of each other.
Speakers selected for operation ith the A amplifier input ill have the same impedance
protection as those that may be operating ith the B amplifier. The number of pairs of speakers
in operation on either channel ill have no effect on any operating on the other.
Other JSS4-VC2 features include po er handling capability of up to 100 Watts RMS continuous
at 8 Ohms in any s itching mode. The LEFT and RIGHT channels are completely separate
to assure safe operation ith alt types of amplifiers, including those ith bridging outputs.
The volume attenuators are tapped auto-transformer type ith attenuation of 3 dB/step except
for the last 2, hich are 4 and 6 dB. These controls do not heat up in operation, nor do they
deteriorate over long time use.
Connecting
Connections to amplifiers and speakers are illustrated in the back of these instructions.
Remember that the LEFT and RIGHT circuits are separate, so connections must be made correctly
or the system ill not operate properly.
Heavy duty push-to-open connections are provided on the rear panel to insure positive, long
lasting, connections. To make connections, strip about 3/8" of insulation from the ire end.
Push the connector tab to ard the rear panel to open the hole. Insert the stripped ire end
into the opening , and release the tab. Make sure no loose ends stick out to cause problems.
Check that the bare ire, not the insulation, is connected to the hole.
If only one amplifier is to be used, connect it to the AMPLIFIER A terminals as sho n. Make
sure the + and -, and L and R channel connections are correct to avoid unsatisfactory operation
or dead channels.
The same precautions should be used hen connecting the speakers, crossed channels, polarity,
or grounds ill result in improper operation.