MyTek DDD-603 User manual

Reference
Manual
Revision 7/96
(V.3.3 & V.1.3)
MYTEK USA
DDD-603
DIGITAL AES/EBU/SPDIF METER
MYTEK USA
DDD-603
PK+VU
0
-
0.5
1
2
3
4
5
6
7
8
9
10
OVER
OVERLOAD
COUNTER
+
IN OK
ADJUST
CALREF
CLEAR
12
13
14
15
16
17
18
19
20
25
30
35
40
85
80
75
70
65
60
50
21
22
23
24
25
50
30
29
28
27
26
21
22
23
24
25
50
30
29
28
27
26
11
12
13
14
15
16
17
18
19
20
25
30
35
40
85
80
75
70
65
60
50
11
POWER OFF
NONE
CALREF
HOLD
1SEC
SIMPLE
PEAK
PK+VU
CAL PHASE
DIGITAL AES/EBU METER

2
Operation: Normal peak mode:
Note:
No phase meter in basic
software version V1.3
(only V3.3-"full mastering")
1
"Over" l.e.d. shows true digital overload (after 3
subsequent samples exceed max. range). It can be set to
display just the 0 dB level or overs of different sample
Overload counter counts every time the "over" l.e.d. is
lit. The counter counts up to 10. "E" reading means 10
or more. The counter can be cleared by "clear" button. It
also can have other functions- See "Software versions"
Mytek supplies various rackmounting hardware for the DDD-603
meter. Contact your dealer or Mytek for more info.
The highest lit l.e.d. (including "over" l.e.d.) can be held
for 1 sec., memorized or immediately turned off. These
functions are controlled by switch A. Memorized
segment can be cleared by "clear" button.
The middle small bargraph has two functions controlled
by switch C. In the "phase" mode it serves as a phase
correlation meter
. In the "0 VU ref" mode the bar shows 0 VU
reference level. -See "Calibration mode".
(only in the "full" version of
software)
"In OK" l.e.d. shows presence of input AES/EBU signal
i.e. indicates proper digital connection.
Position "simple" of the switch C leaves active the L
and R bargraph only. The overload counter and the
middle bargraph are turned off. This feature facilitates
equipment operation during long hours of studio work.
The L and R bargraph indicates peak value of the signal.
The meter ballistics are carefully managed by internal
software to naturally represent incoming sound.
ACTUAL SIZE
1.425" wide
12 units fit
into 19" rack
5.25" high (3U), 5.50" deep
Contents:
Operation: Normal peak mode.....................................................2
Operation: Peak + VU mode........................................................3
Operation: Calibration mode........................................................4
Operation: What you see is what you get....................................5
Setup: Connections......................................................................7
.......................................8
.....................................................................................12
Additional features- Software versions
Warranty
For technical support in the US call
212-388 2677
Overseas contact your dealer.
Manufactured by Mytek,
PO. Box 1023, New York, NY 10016, USA
tel. [phone] fax. [phone]
Internet: http://www.mytekdigital.com
MYTEK USA
MYTEK USA
DDD-603
PK+VU
0
-
0.5
1
2
3
4
5
6
7
8
9
10
OVER
OVERLOAD
COUNTER
+
IN OK
ADJUST
CALREF
CLEAR
12
13
14
15
16
17
18
19
20
25
30
35
40
85
80
75
70
65
60
50
21
22
23
24
25
50
30
29
28
27
26
21
22
23
24
25
50
30
29
28
27
26
11
12
13
14
15
16
17
18
19
20
25
30
35
40
85
80
75
70
65
60
50
11
POWER OFF
NONE
CALREF
HOLD
1SEC
SIMPLE
PEAK
PK+VU
CAL PHASE
DIGITAL AES/EBU METER

MYTEK USA
DDD-603
PK+VU
0
-
0.5
1
2
3
4
5
6
7
8
9
10
OVER
OVERLOAD
COUNTER
+
IN OK
ADJUST
CALREF
CLEAR
12
13
14
15
16
17
18
19
20
25
30
35
40
85
80
75
70
65
60
50
21
22
23
24
25
50
30
29
28
27
26
21
22
23
24
25
50
30
29
28
27
26
11
12
13
14
15
16
17
18
19
20
25
30
35
40
85
80
75
70
65
60
50
11
POWER OFF
NONE
CALREF
HOLD
1SEC
SIMPLE
PEAK
PK+VU
CAL PHASE
DIGITAL AES/EBU METER
MYTEK USA
DDD-603
PK+VU
0
-
0.5
1
2
3
4
5
6
7
8
9
10
OVER
OVERLOAD
COUNTER
+
IN OK
ADJUST
CALREF
CLEAR
12
13
14
15
16
17
18
19
20
25
30
35
40
85
80
75
70
65
60
50
21
22
23
24
25
50
30
29
28
27
26
21
22
23
24
25
50
30
29
28
27
26
11
12
13
14
15
16
17
18
19
20
25
30
35
40
85
80
75
70
65
60
50
11
POWER OFF
NONE
CALREF
HOLD
1SEC
SIMPLE
PEAK
PK+VU
CAL PHASE
DIGITAL AES/EBU METER
4
Operation: Calibration mode:
3
This mode is used to set the A/D converter input levels or to fine adjust the levels
of a digital attenuator, digital mixer or other digital equipment.
The VU (integrated) level (unlike the peak level) represents the perceived
loudness of the program.
"Over" l.e.d. shows the overload of the peak value,
exactly as in NORMAL PEAK MODE. The "1 sec." and
"hold" functions are disabled i.e. the position of switch
A is not important.
The overload counter works normally.
The middle bargraph shows selected 0 VU level
reference. It is selected using "0 VU adjust" trimpot.
The reference can be set in 1 dB steps between -12 dB
and -20 dB level. In other words it represents how much
headroom you have left. The choice depends on type of
music, recording method and type of the A/D converter
used. In most situations a level between -14 and -16 dB
works well. On this drawing the reference level is set at
-17 dB.
The "floating dot" segment represents the peak value of
the signal. The resolution of the bargraphs L and R is
increased to 0.2 dB per step versus the selected "0 VU
reference level". In this example the reference level is
set at -14 dB below full scale. The segment "14" of the
L/R bargraph means -14 dB, segment "15" means now -
14.2 dB, segment "13" is -13.8 dB and so on.
Operation: VU+peak mode:
"Over" l.e.d. shows the overload of the peak value,
exactly as in NORMAL PEAK MODE.
Scale is different to that of the peak mode. In order to
correspond visually to an analog VU meter scale is
linear (1 dB steps) all the way down. Last segment of -
50dB functions as "signal present" indicator. Lower
segments values in VU mode are these on the inner
side of the bargraphs.
The L and R bargraph represent the VU (integrated)
value of the signal. By definition it is always lower
than the peak value. The VU value represents the
perceived program volume.
All other functions work as in NORMAL PEAK
MODE.
The "floating dot" segment represents the peak value of
the signal. If switch A is set to "none" the dot just
moves according to the actual peak value. If "1 sec." or
"hold" is selected it is held appropriately

Operation:Whatyousee iswhatyouget!
65
There aretwoimportant thingsabout theDDD-603 meter:
1.Thestandard overloads shown(3samples)are exactlytheseseenlateron 1630
mastering tape-you can besureyourmasterisCD- ready.
2.Themeterisfully digital.It isDSP basedand noteven onesampleisevermissed or
misinterpreted-everything is shownwith 0.00003%accuracy(1/2exp15 ).The
numberson thescale areroundedtothenearest integer.
In otherwords-you canalwaystrustit-Whatyou see iswhatyou get!
Asyou usethemeteryou will find it extremely usefulforvariety ofthings-it will warn
you immediately ofany strangebehaviorofyourdigitalequipmentand showyou the
quality ofyour recordings: thenoiseorhumand thedynamicsofthemusic.
Theoperation oftheDDD-603 isveryeasy,but theinterpretation ofsomereadings
requireslittle experience.Wehaveshown heresome examplesof"strange"readings:
Noisefloor:whitenoiseorhum:
Inmoststudiosituationstherewill besomenoisefloorshowing up at the analog input
ofyourdigitalsystem(A/Dconverter).Ideallyit should bebelow-80dBbut inmany
largemixing setupscan bequitehigh-asmuchas-70 dB.If you see excessivenoise
tryto determineitscharacterby turning up thevolume and listening.If you hearhum,
you shouldlook forground loopsand eliminatethem.If thereistoo much broadband
noisetrytocutunusedconsole channels,reverbreturnsetc.Pleasetry"Extended
bottomofthescale"mode.
DCoffset:
All ofA/Dconverters(including DATmachinesetc.,)produce socalledDCoffset.DC
offset isaverysmall DCvoltagepresent inthedigitalaudiosignal.It isinherent to
digitalsystemsbecausetheyare"DCcoupled",in otherwordshavefrequencyresponse
from0Hzup.IdeallytheDCoffset iszero,but inareal lifeit sometimescan bevery
high.MostA/Dconvertersproduce an offsetof fewLSBswhichisnegligible.
Occasionally howeveryou can getastrangereading ofalevelyou can'thear.It is
probablytheDCoffset.You can'thearit becauseit is0Hz.Toeliminatetheoffsetyou
should disconnect theinputsoftheA/Dtomakesurethisistheproblem.Connect the
inputsback,thentryresetting theA/Dby turning thepoweroff/on.Sometimesthe
offsetmay originatefromthe consoleoutput,butmostconverterswill compensatefor
that.Some equipmentcan produce small DCoffsetafterwarming up becauseofthe
termaldrift.It isagood practice toalwayswarmdigitalequipmentfor fewhoursand
thenresetitbeforeuse.ExcessiveDCoffsetdoesnotaffect thesound quality,butcan
cause edit "clicks"iftheprogramislaterdigitallyedited.TheDCoffsetcan be
eliminatedfromexisting recordingsby DSP filtering withahigh-pass digitalfilterset
forexample at1Hzorby using specialDC-shiftmethod available atsomemastering
labs.Thesecond method isbetterbecauseit doesnotalterthesonicquality ofthe
program.
Notethat thelevelofDCoffsetand noise alwaysadd together.Pleasetry"Extended
bottomofthescale"mode.
Ideal(low)noisefloor.
Low DCoffset.
Maximumacceptable
noisefloor.
Maximumacceptable
DCoffset.

Setup:Connections:
7
TheDDD-603 meteriscapableof reading bothAES/EBUand S/PDIFsignals.Two
XLRconnectorson theback oftheunit arewiredaccording toAES/EBUspecsand
anadaptordescribed belowshould beusedforS/PDIFsignals.Themeterinput is
high impedance withminimaleffecton the clockjitter.Wefound thistypeofin/out
superiortoaregular110 Ohmbufferedin/out.Inmostsituationsthemetercan be
daisy-chained,but injittercriticalapplications(suchasDACinputs)it should be
connectedat the end ofthesignalchain.TheDDD-603 input/output iswiredas
below:
TheDDD-603 meter requiresregulated+5Vsupplywithmin.of1.5Acapacity.
Everymeteris suppliedwithsuchapoweradaptor.Using differentpowersupply
maydamagetheunitand voidswarranty.
S/PDIFadaptor
Power supply
Internal in/outwiring
2
3
1
2
3
1
digital input
high
impedance
meterinput
+
_
digital throughput
1
3
2
XLRRCAjack
GND
+5V(+/-5%)
Additionalfeatures
andsoftware versions:
"Basic"version V1.3
"Full mastering"version V3.3
TheDDD-603 meteris softwarebased.Mytekmanufacurestwo versionsofthe
meter:"basic"-V1.3and "full mastering"-V3.3.Thefeaturesdescribed previously
are"basic"features."Full mastering"softvareV3.3
providesextrafeatureswhichcan be enabledbysetting theDIPswitchontheback
paneloftheunit.Theswitchworksonlyifsoftwareversion V3.3 orhigheris
installed(it isdisabledinthe"basic"version V1.3).Version V3.3 hasalsoa
function selectable at thefrontpanel.Foradditionalcostownersofthe
"basic"version can upgradeto"full"version by exchanging theinternalcustom
memorychipatyourdealerorMytek.
(except forthephasemeter)
phase
meter
All basicfeaturesenabled(asinV1.3)plusthephase
meter.Oversof3samplesormore asin1630.
Basicfeatures,TheDIPswitchis
disabled.nophasemeter. Oversof3samplesormore asin1630.
V3.3-7segmentdisplayshows
.Emeans10 ormore.Useit
to determinehowbadtheoverloadisand totrack overs.
The countercannotberesetmanually,it will reset itself
everytimetheoveroccurs.
number ofsamples
overloadedinlastovershoot
V3.3-Overloadledislit if
.Thisfeature aswell as4and 5 can beused
whenan"overloadstandard"otherthanisused.
1 ormore samplesare
overloadedSony 1630
V3.2-Overloadledislit if
.2 ormore samplesare
overloaded
V3.3-Overloadledislit if
.4 ormore samplesare overloaded
ON1 43 5 6 72
OFF
ON1 4
35 6 7 2
OFF
ON 1 43 5 6 72
OFF
ON 1 4
35 6 7 2
OFF
ON 1 4
35 6 7 2
OFF
ON 1 43 5 6 7
2
OFF
meanseitherposition
1
3
2
4
5
8

These are "Extended Top" values in dB's
below the full scale.
The middle bargraph shows -3dB level
and cannot be adjusted unless in
calibration mode.
The middle bargraph shows -60dB level
and cannot be adjusted unless in
calibration mode.
These are "Extended Bottom" values in
dB's below the full scale.
V3.3- - Top of the scale is
extended as shown below. Functions 3,4 and 5 are disabled
(overloads of 3 or more samples as in basic version or the
1630).
This function is usefull to check the master tape before
sending it out to a CD plant. It may not be practical for
mixing or tracking.
Extended Top of the scale V3.3- : Bottom of the scale
is extended as shown below. Functions 3,4 and 5 are
disabled (overloads are of 4 or more samples- (we had to do
it this way)). This function is designed to allow the user to
check any potential problem in the digital audio signal such
as noise floor or DC offset.
Extended bottom of the scale
ON 14
3
567
2
OFF
ON 14
3
567
2
OFF
67
910
0.05
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
0.9
1.0
OVER
1.4
1.6
1.8
2.0
2.2
2.4
2.6
2.8
3
4
6
10
14
85
80
70
60
40
30
20
1.2
0.5
1
2
3
6
10
14
20
30
40
50
OVER
60
61
62
63
64
65
66
67
68
69
70
71
72
90
84
80
78
76
74
73
55
MYTEK USA
DDD-603
PK+VU
0
-
0.5
1
2
3
4
5
6
7
8
9
10
OVER
OVERLOAD
COUNTER
+
IN OK
ADJUST
CALREF
CLEAR
12
13
14
15
16
17
18
19
20
25
30
35
40
85
80
75
70
65
60
50
21
22
23
24
25
50
30
29
28
27
26
21
22
23
24
25
50
30
29
28
27
26
11
12
13
14
15
16
17
18
19
20
25
30
35
40
85
80
75
70
65
60
50
11
POWER OFF
NONE
CALREF
HOLD
1SEC
SIMPLE
PEAK
PK+VU
CAL PHASE
DIGITAL AES/EBU METER
MYTEK USA
DDD-603
PK+VU
0
-
0.5
1
2
3
4
5
6
7
8
9
10
OVER
OVERLOAD
COUNTER
+
IN OK
ADJUST
CALREF
CLEAR
12
13
14
15
16
17
18
19
20
25
30
35
40
85
80
75
70
65
60
50
21
22
23
24
25
50
30
29
28
27
26
21
22
23
24
25
50
30
29
28
27
26
11
12
13
14
15
16
17
18
19
20
25
30
35
40
85
80
75
70
65
60
50
11
POWER OFF
NONE
CALREF
HOLD
1SEC
SIMPLE
PEAK
PK+VU
CAL PHASE
DIGITAL AES/EBU METER

Warranty
12
11
THIS PRODUCTWASMADEBYMYTEK A COMPANY SPECIALIZING IN
HIGH END STUDIOEQUIPMENT.OTHERMYTEKPRODUCTSINCLUDE
AD2021 AND D-DAC20 20 BITCONVERTERS,WORKSTATION 20 BIT
AD/DA INTERFACE,8X20 SERIES20 BITCONVERTERS FORADATAND
TASCAM,THEPRIVATE QMULTICHANNEL HEADPHONESYSTEM,A
SONY-SSL-LYNX TRANSPORTINTERFACE,THEDIGIPOT-DIGITAL
MOTORIZED OPTICALPOTENTIOMETERAND OTHERPRODUCTS.PLEASE
CALL MYTEK AT212-388 2677,FAX TO:212-686 4948 ORWRITE TO:PO
Thisdigitalmeteriswarranted by Mytektotheoriginalpurchaser,againstdefectsin
workmanshipand materialsusedinmanufactureforaperiod ofoneyear,fromthedate
ofshipment.
Faultsdueto purchasermisuse,unauthorizedmodificationsoraccidentsarenot
coveredbythiswarranty.
No otherwarrantyisexpressed orimplied.
Any faulty unit should besent,shipping prepaid,tothemanufacturer.theserialnumber
oftheunit shouldaccompany any requestforservice.
Thisdigitalmeterser#___________________________was soldto:
_____________________________________________________________________
on_______________________________
authorizedsignature________________________
Fortechnicalsupport intheUScall:
212-388 2677
oremail: [e-mail]
Overseascontactyourdealer.
V3.3-OVERlightas0dB- InthismodetheOverlight is
alwaystriggeredwhenONEormoresamplesareover
(=7FFF).The counterhoweveris still triggered depending
on howyou set theswitches5and 6.Thismode allowsyou
to pushtheprogramlevelup abit becausenowmeter
recognizesthedifference between overand 0 dB.Nowyou
can usethe counterasan overloadindicatorand overledas
a0 dBlevel indicator.
ON 1 43 5 6 72
OFF
6