KRELLDIGITALSBP-64X DESIGNFEATURES
SoftwareBasedProcessingrequiresa perfectblendof exacting,multifaceted technologies,fromhightechdigital innovationto anultimaterefinementof analog circuitdesign.
Onthenexttwopages,wewill brieflypointout ourmethodsof addressingthese requirementsin the KrellDigitalSBP-64X.
INPUT
TheSBP-64Xwill accommodatebothCoaxialandFiberOpticalinputto insure compatibilitywithanydigitalsourcewithdigitaloutputs.
PROCESSING
The "WaveformReplicator"
TheKDISBP-64Xuses proprietary "WaveformReplicator"softwarewhich enablesourfour Motorolaprocessorsto performpolynomialcomputationsfor cal- culatingthe63additionaldatapointsto fill our64timesoversamplingrequirements. The Motorola DSP-56001
Wehavechosenthe MotorolaDSP-56001for tworeasonswhichmakethis pro- cessorclearly superiorto anyother for a similarapplication;DynamicHeadroom, andPrecision.
Dynamic Headroom
TheDSP-56001usesa 24bit data pathwhichrelates to a 48 dBincreasein dynamicheadroomover componentsusingdifferent processors.
Precision
Ofcritical importanceto anyprocessoris the sizeof its accumulator,for this
limitsthesizeof thecomputationalcoefficientsit canutilize. If thecoefficientis to 9
large it will overflowthe processor,forcingit to scalethe computationIn. audio processingthis is especiallydamagingbecausethe processorsperformmultiplecom- putationsbasedon onedata sample,so eachrepetitive computationis basedon a
scaledfigure whichcompoundsthe error oneachcomputationThus,.the size of the accumulatorlimitsthe potentialprecisionof a processor'scalculations.
TheMotorolaDSP-56001givesyourKDISBP-64Xsubstantiallyhigherprecision thanothercomponentsbasedon differentprocessors.
28 MHZclock speed
TheSBP-64Xis run at over28,000,000cycles per second.Thishighspeed, coupledwiththe DSP-56001'sability to performmultipleoperationsduringa single instructioncyclegivesthe SBP-64Xgreatercomputingpowerthanother, evenhigher speedprocessors.
DIGITALTO ANALOGCONVERSION
THEDACs
TheSBP-64Xutilizes twinBurrBrownPCM-6418bit DACsfor highspeedand superbaccuracy.
Parallel Data Into TheDACs
Unlikethe majorityof other processorsin the industry,the SBP-64Xruns parallel data throughthe DSP's,andinto the DACsBy. usingthese18 bit DACs,in parallel, weare ableto maintainthe incrediblespeedrequiredfor 64xoversampling withoutmultiplexing,andtl]~n, summingthe data.
NO"BRICKWALL"FILTERING
Theexactingnatureof ourdigital informationandthe extraordinarytechnique by whichour DACsperformtheir conversionsenableus to avoidanytypeof steep slopecut off (brick wall)filtering in the SBP-64XTherefore,.youexperiencethe benefitof absolutepurityin thesignalwithoutanyoftheundesirableeffectsof those filters.
DISCRETECURRENTTOVOLTAGE
Currentto Voltage(1iV)conversion,is performedin theanalogdomain,directly
after D/A.In mostprocessorsthis occurseither in theDACitself or in an external integratedcircuit op-ampAt.KrellDigital,wefeel that thesemethodsare unaccept- able. Therefore,wehaveengineereda 100%discreteCurrentto Voltagestagefor
