YORKVILLE AP1020 Owner's Manual

Also see for AP1020: Service schematics Service manual

Contents

YORKVILLE AP1020 Owner's Manual Manual pdf 4 page image

Stereo Mode• Channels A and B inputs areseparate.• Two independent amplifi-ers, Amp A and Amp B.• Two loads are driven.• Loads are connectedbetween the black and red posts on each channel.Bridge Mode• Channels A and B inputs are paralleled. Gain Bhas no effect.• Output signals are equal in amplitude but oppo-site in phase.• One load is driven.• The load is connected between the two red bindingposts. The black posts are not used.Subsonic Filter SwitchThe AP1020 features a specially designed sub-sonic filter, which effectively blocks potentiallydestructive energy in the band below 40 Hz.The filter provides a 12 dB/octave skirt below40 Hz. It is implemented with a two-pole net-work designed to minimize phase shift downto 40 Hz. We recommend using this filter inconjunction with some subwoofers and withall high power full range cabinets. With the fil-ter disabled, the AP1020 is flat down to 6 Hz,and rolls off at 12 dB/octave below that.Limiter SwitchWhen the internal limiters are activated,the AP1020’s gain is continuously self-adjusted to fit the signal within the avail-able dynamic range. Occasional clippingis permitted. The limiters will not onlyhelp to protect your system’s mid-hornsand tweeters, but will automatically makethe best use of the available dynamicheadroom. With the limiters activated, allyou need to do is turn up the signal leveluntil you start to see some clipping. Thelimiters will make sure that you are gettingthe maximum clean power output at alltimes. Setting the switch to the Out posi-tion completely disables both limiters.Protect LEDIn the event of a shorted load, or a load which is of too low animpedance for the amplifier to handle ,the Protect LED will flashalternately in about 7-second intervals. The sound may come onand off at ½-second. In this case, the fault is in the speakers or thespeaker cables and should be located and remedied. No reset ofthe AP1020 is required to restore proper operation. The Protect LEDwill stay on if the amplifier has overheated. Check the speaker loadimpedance, the position of the load select switch, and any restric-tions to air flow at the air intake or exhaust vents of the amplifier.Short-Circuit ProtectionThe AP1020 is fully protected against all possible passive loadconditions. It can operate with a dead short continuously withoutdamage. We don’t recommend that you short your AP1020 “justfor fun,” short-circuits create a lot of stress on the output devices.The output stage uses a unique triple-slope VL limiting schemethat is sophisticated enough to remain inert during transient cur-rents in excess of 40 Amperes and phase angles of more than 45degrees, yet is capable of protecting the output stage from damagedue to accidental short circuits and improper loads.DC ProtectionIn the unlikely event of the AP1020’s outputs “going DC,” a thy-ristor circuit will short the output terminals and divert all poten-tially harmful currents away from your speakers.Thermal ProtectionIn the unlikely event that the AP1020 overheats, the signal willbe sporadically cut off and the Protect LED will stay on. If furtherheating occurs, due to a malfunction, the internal thermal breakerwill interrupt the primary circuit. There is no visible indication ofthis rare condition. The AP1020 is designed and tested to operateunder “worst case” conditions without shutting down, check forblocked airflow if you experience a thermal shutdown.CoolingThe fan draws air inward from the front and expels hot air throughthe rear vents on the amplifier. This is compatible with otherYorkville power amplifiers (and with most installations). Since hotair rises, the heated air forcibly expelled from the back tends torise away from the equipment rack, this draws cool air from thefloor upwards into the front of the rack. In some cases, where therear of the rack is obstructed, it may be necessary to install fansin the rack to aid cooling. If there are no obstructions, secondarycooling is not required.Fan Filter MaintenanceThe AP1020 is factory equipped with a fan filter mounted on theair intake grill on the amplifier’s front panel. Regular cleaning ofthis filter will increase the amplifier’s long-term reliability. The fil-ter should be removed and washed at the first sign of visible clog-ging. This will typically occur every four to six weeks dependingon use and environment. Replacement filters are inexpensive andcan be ordered through Yorkville dealers. The foam filter shouldbe removed if a regular inspection schedule is not going to be fol-lowed. The amplifier can operate without the filter in place, butthe amplifier should be cleaned internally (by a qualified servicetechnician) when dust is visible on the heatsink fins.Note: In an unusually dusty location removing the foam fil-ter can extend the operating time before thermal shutdowncould occur. At that time, the internal heatsinks should becleaned thoroughly.CAUTION: The AP1020 can deliver over 800 Watts of power into a bridged load. Yorkville’s own high power speaker systems havecircuit-breaker protection built in. Although these speakers will protect themselves, they are unlikely to be damaged by a bridgedAP1020. However, many other speaker manufacturers make “high power cabinets” with no protection features at allYorkville Sound is not responsible for any damage, which may result as a consequence of exceeding such a speaker’s power handlingcapability. Yorkville’s two-year unconditional warranty does not cover any consequential damages to non-Yorkville equipment. Pleaseconsider these facts carefully before you choose to run your AP1020 in bridged mode!