Specifications
INFO@APART-AUDIO.COM
7
1)Volumepotmeterchannel1:usethispotmetertopresetthevolume.Incasetheamplierhas
been switched to bridge mode, this potmeter sets the level for bridge operation.
2)Signalledchannel1:thisledlightsupgreenwhenasufcientlystrongsignalispresentonthe
left channel, after passing the input level control. At startup, the led will light up red during a
few seconds, this is perfectly normal. When it lights up red during use, the power transformer
orpoweramplierisoverheatedorinprotectmodeandisshutdown.Turnoffthepower.The
amplier will not turn on automatically after most error conditions. In some cases, the
user MUST turn off power and remove the overload and then power on again ! More
details can be found in the table below.
3)APCactivityledleftchannel:thisledlightsupwhentheAPCcircuitryisactive.TheAPC
circuitry reduces the gain at the inputs to guarantee the full dynamic range of the power
ampliercircuits.
4)Clipledchannel1:thisledlightsupwhenevertheamplierclips.Thisisawarningsign:you
are pushing things a little too far or you are overloading the amp. Reduce the input level by a
few dB so that this led never lights up anymore ! Don’t ignore this!
5)Templedleftchannel:thisledlightsupwhentheamplierisoverheated.Outputpower
willautomaticallybecutbytheAPCcircuitry.Thispartoftheprotectioncircuitresetsitself
automaticallywhentemperaturehasnormalized.Whenbothsignalled(2)andtempled(5)are
red,thepowertransformer’sthermalprotectionisactiveandtheamplierisshutdown.Turn
off the power and let it cool down. The amplier will not turn on automatically after the
transformer has cooled down, the user MUST turn off the power, remove the cause of
the fault condition, wait for cooling down and then power on again!
6)Bridgeled:thisledlightsuptoindicatethattheamplierisinbridgemode.
7)Powerswitchandpowerled:iptheswitchtopowerontheamplier.Theblueledwilllightup
to indicate that mains power is present.
3. Inputs and outputs
Frontpanellayout:
1 2 3 4 75 6 8 9 10 11 12










