Tannoy VLS SERIES Operation Manual - page 7
5. Wiring and connections
VLS Series Operation Manual rev 1.0.0
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superiortoalowerpoweramplifierrunningat100%.Anamplifierwithinsufficientdrivecapabilitywillnot
allowthefullperformanceortheloudspeakertoberealised.(Seetechnicalspecificationssectionfor
recommendedamplifierpower.)
Whenusingamplifiersfromdifferentmanufacturersinasingleinstallation,makecertainthatallamplifiershave
closelymatchedgains.(Variationshouldbelessthan+/-0.5dB.)Thisprecautionisimportanttotheoverall
system balance when only a single active crossover is being used with multiple cabinets. When possible, it is
recommendedthatthesameamplifiersbeusedthroughout.
Series/parallel connections - When running low-impedance loudspeakers in parallel, care must be
takennottoallowtheimpedancetodroptoolow,asdamagemaybesustainedbytheamplifier.Mostlow
impedanceamplifierswillbeabletohandleloadsof2ohmsto8ohms.Thismeansforexamplethatwhen
usinganamplifierwith2ohmloadrating,uptothreeVLS30orsixVLS7/15maybeconnectedinparallel
per output, although care should be taken as impedance varies with frequency and at some frequencies the
impedance will drop to below 2 ohms.
5.3 Constant voltage (70 /100 V) Mode
In constant voltage distributed systems, normally a number of loudspeakers are connected in parallel to a single
amplifieroutput.Connectthepositive(+)conductorfromtheamplifierorpriorloudspeakerinthesystemtoa
positive(+)barrierstripterminalandthenegative(-)conductortoanegative(-)terminal.Theotherparallel
barrier strip is available for connecting additional loudspeakers.
A multi-position rotary switch on the rear input panel selects either the low-impedance operating mode or the
high-impedancemodes(70Vor100V)withavailabletransformertaps.WhenusingVLSSeriesloudspeakersin
distributed line systems, the transformer can be tapped with available power levels shown in the table below:
70 V
100 V
5 W
9.5 W
9.5 W
19 W
19 W
37.5 W
37.5 W
75 W
75 W
150 W
150 W
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