User guide

8
ENGLISH
Performance specications
Headphone Outputs (Outputs 1-2)
• Outputimpedance:<10Ohms
• Poweroutputinto150R:15mV
• Poweroutputinto50R:30mW
• THD+N:-100dB(0.001%)(-1dBFSinput,20Hz/22kHz 
bandpasslter,150Rload)
• SignaltoNoiseRatio:>105dB
S/PDIF Digital Input
• AutomaticSampleRateconversion
• Supportedsamplerates:continuousfrom32kHzto192kHz
• THD+N:<-110dBanysamplerate
Crosstalk (Channel Isolation)
• Anyoutputtooutput:>100dB
Digital Performace
• D/ADynamicRange:120dB(A-weighted)
• MeasuredD/ADynamicRange:108dB(A-weighted)
• ClockSource:InternalClockonly
• Clockjitter<250picoseconds
• SupportedSampleRates:44.1kHz&48kHz.
• 2inputchannelstocomputer:S/PDIF(2).
• 2outputchannelsfromcomputer:Headphones(2).
Connectors and Controls
• StereoS/PDIFinputonRCA
• StereoHeadphoneOutputon¼”TRS
• HeadphoneOutputLevelcontrol(analogue)
• 4-pinUSB2.0compatiblesocket
Indicators
• 1GreenLEDIndicator:
  Flashing:Unitnotinstalledcorrectlyonhost
  Off:VRMeffectsturnedoff
  On:VRMeffectsturnedon
Power
• BuspowerfromUSBbus.
Weight and Dimensions
• Dimensions:68mmx25mmx68mm(WxHxD)
• Weight:123g
Latency and CPU information
TheVRMBoxprocessingtakesplaceatadriverlevelonyourcomputer.
Thisprocessincursa64samplelatency(about1ms).TheVRMprocessing
alsousesacertainamountofCPUresources.
The VRM Box driver will also add additional latency. This latency will
dependonhowyouusetheVRMBox:
WhenusingtheVRMBoxasyouraudiointerfaceinyourDAW,thelatency
youexperiencewillbedependantontheaudiobuffersizeyousetin
yourDAW,andinmostDAWstheactuallatencygureisdisplayedinthe
preferences.Iftheaudiobuffersizeissettolessthan64samples,thenthe
VRM processing does not have enough time to do the processing and no
audiowillpass.VRMCPUrequirementsaremuchhigherwhentheaudio
buffersizeissettoolow,soitisrecommendedthatabuffersizeof512
samples(Mac)or10ms(Windows)shouldgivethebeststartingpoint.
WhenusingtheS/PDIFinput(receivingaudiofromanotheraudiointerface),
thelatencygurewillbedependantontheaudiobuffersizeyousetinyour
DAWforthatinterface,PLUSadditionallatencyfromtheVRMBox.Inthis
case,therewillbelatencyincurredfromthetransferofS/PDIFaudiosent
fromtheVRMBoxviaUSBusingtheVRMaudiodriver,throughtheVRM
processing,thenbacktotheVRMBox.Thetotalroundtriplatencyislikely
tobeintheregionof20ms(dependingoncomputerspecs).
FormoredetailedinformationpleaserefertotheFocusriteanswerbase:
www.focusrite.com/answerbase
Copyright
FocusriteisaregisteredtrademarkofFocusriteAudioEngineeringLimited.
TheFocusritelogo,VRMVirtualReferenceMonitoringandtheVRMlogo
aretrademarksofFocusriteAudioEngineeringLimited.
Allotherproductnames,trademarks,ortradenamesarethemarksoftheir
respectiveowners,whichareinnowayassociated,connectednorafliated
with Focusrite or its VRM Box product. These other product names, trade
marks,andtradenamesareusedsolelytoidentifyanddescribethethird
partyloudspeakersystems,thesonicbehavioursofwhichwerestudiedfor
the VRM technology incorporated within the VRM Box, and to accurately
describeanelementoffunctionalitywithintheVRMBox.
The VRM Box is an independently engineered technology which utilises
Focusrite’sVRMVirtualReferenceMonitoring(Patentappliedfor)toac-
curatelymeasureexamplesofthesonicimpactoforiginalloudspeaker
systemsuponanaudiostream,soastoelectronicallyemulatetheperform-
anceoftheoriginalproductstudied.Theresultofthisprocessissubjective
andmaynotbeperceivedbyauserasproducingthesameeffectsasthe
loudspeakersystemsstudied.
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