Nakamichi T-100 User manual

yo
a
*
100
Audio
Analy

CALITION -
RISK OF ELECTRIC
SHOCK. DONOTOPEN |!
CAUTION-———
TO REDUCE THE RISK OF
ELECTRIC SHOCK, DO NOT
REMOVE COVER (OR BACK). NO
USER-SERVICEABLE PARTS INSIDE.
REFER SERVICING TO QUALIFIED
SERVICE PERSONNEL.
The lightning flash with arrowhead
symbol, within an equilateral! triangle, is
intended to alert the user of the presence
of uninsulated “dangerous voltage”
within the product's enclosure; that may
be of sufficient magnitude to constitute a
risk of electric shock to persons.
The exclamation point within an
A equilateral triangle is intended to alert
the user of the presence of important
operating and maintenance (servicing)
instructions, in the literature
accompanying the appliance.
WARNING
TO PREVENT FIRE OR SHOCK
HAZARD, DO NOT EXPOSE THIS
APPLIANCE TO RAIN OR MOISTURE.
Please record the Model Number and Serial
Number in the space provided below and
retain these numbers.
Model Number and Serial Number are
located on the rear panel of the unit.
Model Number: Nakamichi T-100
Serial Number :

The
Nakamichi
T-100
Audio
Analyzer
is
a
powerful
diagnostic
instrument
which
enables
you
to
get
the
optimum
performance
from
your
audio
system.
Originally
conceived
as
a
tool
for
the
serious
recordist,
the
Analyzer
also
provides
valuable
information
about
preamplifiers,
amplifiers,
turntables,
phonograph
cartridges,
loudspeakers,
and
microphones.
The
T-100
incorporates
the
functions
of
an
oscillator,
a
vacuum
tube
volt
meter
(VTVM),
a
distortion
meter,
and
a
wow
&
flutter
meter
ina
compact,
portable
form.
The
oscillator
provides
21
different
frequencies
and
pink
noise
for
accurate
frequency
measurements
from
20
Hz
to
20
kHz.
The
pink
noise
generator
is
particularly
useful
for
subjective
testing
of
tape
decks,
loudspeakers,
and
microphones.
The
400
Hz
oscillator
can
be
used
with
the
built-in
distortion
analyzer
to
measure
the
harmonic
distortion
of
tape
decks
and
amplifiers.
The
3
kHz
oscillator
allows
you
to
test
a
tape
deck’s
record/play
wow
&
flutter.
(You
have
a
choice
of
weighted
or
unweighted
readings.)
With
a
3
kHz
test
tape,
you
can
measure
playback-only
tape
speed
deviation
and
wow
&
flutter.
With
a3
kHz
test
record,
you
can
measure
turntable
wow
&
flutter.
The
T-100
also
provides
A-Weighted
noise
readings
of
inputs
down
to
10
xV.
Finally,
the
Analyzer
provides
extremely
accurate
peak
or
average
level
indication.
You
can
use
the
Analyzer
to
supplement
the
VU
meters
of
your
tape
deck
and
avoid
tape
saturation
when
you
record.
By
connecting
the
Analyzer
in
parallel
with
your
speakers,
you
can
avoid
amplifier/speaker
overload
when
you
play
back.
The
controls
and
features
of
the
T-100
may,
at
first,
be
unfamiliar.
But
despite
its
sophisticated
functions,
the
T-100
Audio
Analyzer
is
,
relatively
simple
to
connect
and
use.
The
procedures
and
charts
in
this
manual
have
been
designed
to
help
you
make
the
fullest
use
of
the
T-100
in
the
shortest
possible
time.
Nakamichi Corporation

Contents
CONTENTS:
1. Tape Decks
1.1 Frequency Response
1.11 Line Amplifier .--.-----1+:--sse0
1.12 Record Amplifier .-.- o |
1.13 Test Tape Playback «+++... 6
1.14 Record/Playback se eseeeacnseccencere 7
1.2 Total Harmonic Distortion
1.21 Line Amplifier --------:s:--seece 8
1.22 Record/Playback «s+ 8
1.23 Record/Playback Level
Versus Distortion -----sceeseeeeee 9
1.3 Record/Playback Saturation......... 10
1.4 Noise Level
1.41 Mic Input dveseatadgadeucaccancdeascedes 11
1.42 Lime Input ----s--seccesesceetseeteees 11
1.43 Playback -srsesseeceeressersessreeeenseees Wi
1.44 Record/Playback — «+--+: 12
1.5 Tape Speed, Wow & Flutter
1.51 Test Tape Playback «---+--.-+.--.- 13
1.52 Record/Playback ----++-+----+ss+ 13
1.6 Volume Indication
1.61 Peak Metering ---------------+se+e 14
1.62 VU Metering -sc--eeceseereseeee 14
2. Transducers
2.1 Output Level
2.11 Cartridge
2.12 Microphone
2.13 Loudspeaker
2.2 Frequency Response
2.21 Cartridge wetusasleceasitesctccavesccausests 18
2.22 Microphone 18
2.23 Loudspeaker —----secseesscseeeee 18
3. Amplifiers
3.1 Frequency Response
3.11 Tone Controls
3.12 Loudness Contour Controls --20
3.13 Equalizers, Filters,
CLOSSOVELS vovessecseescesssessensenseeee 21
3.2 Phono Preamplifier Overload ------- 22
3.3 Noise Level
3.31 Phono EAPUt -e-sereeereeeeoeseesseeeee 23
3.32 Phono Input with Moving
Coil Booster -ecceressssresssrenreereres 23
3.33 Aux, Tape Input —-r-erscsecessesees 23
3.4 Volume Indication
3.41 Power Amplifier Peak
Metering Ssaascencses vavecaaksscocavecsses 24
3.42 Power Amplifier VU
Metering Wedacsecdens soguaadecssecdécceses 24
4. Turntable Wow & Fultter --+++--+:eeee0 25
5. Pink NOs --cssssecscrecsscscenscececeseecsecrenes 26

Functions and Features
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M& Nakamichi Audio Analyzer T-100
Voltage 2 3 1
78910
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{ol Peguiny ot a
} D
Wattage 1 2 5 1 2 5 10 20 50 100 WwW
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(Bonm = fy | toil toptit tried
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1 7 tree T t
Voltage 1 2 3 4 30 OV
PWnakamichi Wattage Scale
With the Meter Range switch in the 494"
position, the scale reads from 0.1% to 3%.
With the meter range switch in the
“0.1%” position, the scale reads from
0.01% to 0.3%. This scale also provides
voltage readings in certain modes.
When the Function control i is S set to
“Speed Cal” this control calibrates the
top indicator to zero speed deviation.

7 Function Control
Speed Cal: calibrates top indicator
for zero speed deviation.
Speed Unweighted: selects speed
deviation in the top indicator and
unweighted wow & flutter peak on
the bottom indicator.
Speed Wow/Flutter: selects speed
deviation on the top indicator and
weighted wow & flutter peak on
the bottom indicator.
Level T.H. Dist L: selects left channel
level on the top indicator and left
channel total harmonic distortion
on the bottom indicator.
Level T.H. Dist. R: selects right
channel level on the top indicator
and right channel total harmonic
distortion on the bottom indicator.
Level: selects left channel level on the
top indicator, right channel! level on
the bottom indicator.
Level —20dB: decreases oscillator
output by 20dB while
simultaneously making the
indicators 20dB more sensitive.
Selects left channel level on the top
indicator, right channel level on the
bottom indicator.
Noise —40dB: displays left channel
A-weighted noise on the top
indicator, right channel A-weighted
noise on the bottom indicator.
Makes the display 40dB more
sensitive.
Peak: selects peak-reading ballistics
for the level display. Selects left
channel level on the top indicator,
right channel level on the bottom
indicator. When the left and right
input level controls are turned to
maximum, the sensitivity of the
display is the same as when the
function control is set to “Level.”
However, by turning the input level
controls counterclockwise, you can
reduce the sensitivity to any
intermediate value.
Selects one of 21 oscillator frequencies or
8 Meter Range Switch
Selects the meter range for the bottom
indicator when the function control is set
to “Speed Unweighted,’’ “Speed
Wow/Flutter,” “Level T.H. Dist. L,’’ and
“Level T.H. Dist. R."” With the Meter Range
switch in the ‘1% position, the scale
reads from 0.1% to 3%. With the switch
in the 0.1%" position, the scale reads
from 0.01% to 0.3%. With the function
control set to “Level,” ‘Level —20dB,”
“Noise ~40dB,” or “Peak,” the Meter
Range switch changes the sensitivity for
both indicators by 20dB.
9 Input Level Switch
Controls the sensitivity of the top
indicator when the Function control is set
to “Level T.H. Dist. L.” and ‘Level T.H.
Dist. R.“* Controls the sensitivity both
indicators when the Function control is set
to “Level,”” “Level —20dB,” ‘Noise
—40dB,” or ’’Peak.’”’
,10Input Level Controls;
Adjust the sensitivity of the indicators
when the Function control is set to
“Peak.” With these controls turned fully
clockwise, the sensitivity will be the same
as when the Function control is set to
“Level.”’ Turning these controls
counterclockwise wil! lower the
sensitivity to any intermediate value.
1 Oscillator Control
pink noise. When the Function control is
set to Level T.H. Dist. L” or Level T.H.
Dist. R.” the oscillator will produce a
400 Hz tone regardless of the position of
the Oscillator control. Similarly, when
the Function control is set to “Speed Cal,’
“Speed Unweighted,” or ‘Speed Wow/
Flutter,” the oscillator will produce
a3 kHz tone regardless of the position of
the Oscillator control. Setting the
Oscillator control to the unmarked detent
between “Pink Noise” and “20K” will
turn off the oscillator.
12 Osciltator Output Control
13 Power Switch
14 AC Cord Connector
15 Input Jacks
16 Oscillator Output Jacks
‘17 Scope Jacks
These jacks allow you to connect the
Analyzer output to an oscilloscope.
Warning: Do not under any
circumstances connect the ‘’Scop:’’
output jacks (17) to any input of
your preamplifier, amplifier or
receiver. In certain situations the
T-100 will produce a D.C. signal
through the scope output which may
cause serious damage to your
loudspeakers and other components.
8 Wattage Scale
This scale, included as an accessory, fits
over the display portion of the analyzer
and provides direct wattage and voltge
readings for power amplifier
measurements.
CAUTION
Although the T-100 can be used from the
moment it is turned on, it is recomminded
that you allow the Analyzer to “‘warm up”
for at least ten minutes before perforning
any critical measurements where maximum
accuracy is required.

‘ Indicator Status Charts
Before you use the analyzer, take some time to familiarize yourself with the Indicator
Status Chart. The Chart will help you understand the logic of the T-100’s layout. It
helps explain some of the apparent inconsistencies of the display (for exam-
ple: although the top indicator usually displays the left channel level, when the
function switch is set to “Level T.H. Dist. R,’ the indicator shows the right channel
level}. And it helps you to take advantage of the wide range of sensitivity. The following
meter
voltage
chart
can
be
used with
the
indicator
status
chart
to
calibrate
inputs
and
outputs for a variety of applications.
CONTROL SETTING INDICATOR STATUS
METER | INPUT
FUNCTION) RANGE | LEVEL | TOP INDICATOR ao
SWITCH | swiTcH
a
CONTROL SETTING INDICATOR STATUS
METER | INPUT
FUNCTION BOTTOM
RANGE | LEVEL | TOP INDICATOR
SETTING = cwitcH | SWITCH INDICATOR
Speed Deviation
Speed Cal. (any) fany)}
ne ony any —3 to +3%
Speed Unweighted
Unweighted Speed Deviation Wow/Flutrer
(peak)
1% —3 to +3% 0.1 to 3%
0.1% —3 to +3% 0.01 to 0.3%
Speed Weighted
Wow/Flutter Speed Deviation Wow/Flutter
(peak)
1% —3 to +3% 0.1 ta 3%
0.1% —3 to +3% 0.1 t0 0.3%
OdB = 1V OdB = 1V
OdB = 0.1V OdB = 0.1V
OdB = 10mvV OdB = 10mV
0dB = 0.1V 0dB =0,1V
OdB = 10mV OdB = 10mV
OdB = ImV OdB = Imv
Right
Left A- ,
A e A-Weighted
Weighted Noise Noise
OdB = 0.1V 0dB = 0.1V
0d8 = 10mV OdB = 10mV
OdB = imV OdB = ImV
OdB = 10mV OdB = 10mV
OdB = Imv OdB = ImV
Od8 = 0.imV OdB =O.1mVv
Right Inpu
Left Input Level
a
Lor
R
Total
a
LorR
i
T.H,
Dist.
Distortion
Distortion
0.1 t0 33%
0.1 10 3%
0.1 to 3%
0.01 10 0.3%
0.01 to 0.3%
0.01 to 0.3%
Right Input
OdB = 10V OdB = 10V
OdB = 1V OdB = 1V * With the Function control set to “Peak”, the Input Level controls
OdB = 0.1V OdB =0.1V . peN eis
OdB =1V OdB = 1V (10) can be used to adjust the sensitivity of the indicators to any
OdB =0.1V 0dB = 0.1V intermediate value. Hence these 0 dB values only apply when the
OdB = 10mv Og8 = 10mV input level controls are turned fully clockwise.
Meter Voltage When Voltage When Voltage When Voltage When Voltage When Voltage When Mee '
Reading OdB = 10V OdB = 1V OdB = 0.1V QdB = 10mV OdB = I1mV OdB = 0.1mV Reading
0.3162V 31.62mV 3.162mV 0.3162mV
0.2818V 28.18MV 2.818MV 0.2818mV
0.2512V 25.12mV 2.512mMV 0.2512mV
0.2239V 22.39mV 2.239mV 0.2239mV
0.1995V 19.95mV 1.995mV 0.1995mV
0.1778V 17.78mV 1.778mV 0.1778mV
0.1585V 15.85mV 1.585mV 0.1585mV
0.1413V 14.13mV 1.413mV 0.1413mV
0.1259V 12.59mV 1.259mV 0.1259mV
0.1122V 11.22mV 1.122mV 0.1122mV
0.1000V 10.00mV 1.000mV 0.1000mV
0.0891V 8.91mV 0.89imV 0.089 1mV
0.0794V 7.94mV 0.794mV 0.0794mV
0.0708V 7.08mV 0.708mV 0.0708mV
0.0631V 6.31mV 0.631mV 0.063 1mV
0.0562V 5.62mV 0.562mV 0.0562mV
0.0501V 5.01mV 0.50imV 0.0501mV
0.0447V 4.47mV 0.447mV 0.0447mV
0.0398V 3.98mV 0.398mV 0.0398mV
0.0355V 3.55mV 0.355mV 0.0355mV
0.0316V 3.16mV 0.316mV 0.0316mV
0.0282V 2.82mV 0.282mV 0.0282mV
0.0251V 2.51mV 0.251mV 0.0251mV
0.0224V 2.24mV 0.224mV 0.0224mV
0.0200V 2.00mV 0.200mV 0.0200mV
0.0178V 1.78mV 0.178mV 0.0178mV
0.0158V 1.58mV 0.158mV 0.0158mV
0.0141V 1.441mV 0.141mV 0.0141mV
0.0126V 1.26mMV 0.126mV 0.0126mV
0.0112V 1.12mV 0.112mV 0.0112mV
0.07100V 1.00mV 0.100mV 0.0100mV
ttt eee eget
ive}

1. Tape Decks
1.1 Frequency Response
Line Amplifier
Tape Deck
Line Amp
1.11 Line Amplifier (of a
three-head deck)
1.111 Connect the Output jacks (16) to
the line input jacks of the tape deck.
Connect the line output jacks of the
tape deck to the Input jacks (15).
1.112 Set the Function control (7) to
“Level.”
1.1 13 Set the Oscillator contre! (11) to
your reference frequency (usually 400
Hz or 1 kHz).
1.114 Set the tape deck’s ‘‘monitor”’
switch to ‘‘source.”
1.115 Adjust the tape deck’s line input
level controls so that the tape deck’s
meters indicate 0 dB (0 VU). If you
find that you cannot get a 0 dB reading
on the tape deck’s meters even when the
tape deck’s line input controls are
turned all the way up, turn the
Oscillator Output control (12)
clockwise until the tape deck meters
read 0 dB.
1.116 Adjust the line output level of the
tape deck so that the top (2) and
bottom (4) indicators read 0 dB or any
other convenient level you wish to
use as a standard.
1.117 Set the Function control (7) to
“Level —20dB.” This will reduce the
Oscillator Output by 20 dB while
simultaneously
increasing
the
sensitivity
of the indicators by 20 dB, so that the
indicator level remains unchanged.
(You can verify the reduction in
oscillator output by checking the tape
deck’s meters.)
1.118 Set the Oscillator contro! (11) to
20
Hz.
Make
a
record
of
the
top
(2)
and bottom (4) indicator readings.
Repeat for each frequency up to 20 kHz.
You can plot the output levels against
frequency to make a curve representing
the line amplifier frequency response.
.12 Record Amplifier
If you are capable of locating circuit
parts and making internal probes and
disconnections in your tape deck, then
you can measure the frequency
response characteristics of the record
amplifier. Note that many tape deck
manufacturers’ warranties are voided
when the user modifies or abuses the
deck. Consequently, any damage to
the tape deck resulting from the
improper execution of this procedure
may void your tape deck warranty.
Note that it is not sufficient to merely
measure the voltage across the record
head terminals. Since the record head
impedance varies with frequency, this
method will result in an inaccurate
measurement of the record amplifier
frequency response (generally,
exaggerated lows and highs). In order
to obtain accurate readings, your must
disconnect the negative (return) lead
from the record head and insert a 100
Ohm series resistor. You can then
measure the voltage drop across the
resistor (the difference in voltage
between one side of the resistor and
the other). Many tape decks provide a
built-in series resistor with charly
marked test points precisely for this
purpose, If you are unsure about your
deck, consult the unit’s service rnanual
or check with its manufactur before
proceeding.
It will also be necessary to diicoonnect
the bias oscillator from the record
head in order to make an accurate
measurement of the record anp lifier.
Again, many tape decks provde a
simple means of disconnectirg the
bias oscillator, such as with ajusnper
cable, in order to facilitate ths procedure.

oy
—_
oy vary
=
Record Amplifier
Bas ———————
Signal
Here, too, it is best to study the deck’s
service manual carefully.
Remember to re-connect the bais
oscillator and restore the record head
connections (if they were modified}
when you have completed the
measurements.
-121 Connect the Output jacks (16) to
the line input jacks of the tape
recorder. Connect either end of the
record head series resistor to the Input
jacks (14).
-122 Set the Function control (7) to
“level.”
-123 Set the Oscillator control (11) to
your reference frequency (usually
400 Hz or 1 kHz).
.124 Set the tape deck in the record
mode. (If you are measuring a cassette
deck you will have to load a cassette.)
-125 Adjust the line input level of the
tape deck so that the tape deck meters
read 0 dB (0 VU). If you find that you
cannot get a 0 dB reading on the tape
deck’s meters even when the tape
deck’s line input controls are turned
all the way up, turn the Oscillator
Output control (12) clockwise until
the tape deck meters read 0 dB.
1.126 Set the Meter Range (8) and Input
Level (9) switches so that the top (2)
and bottom (4) indicators read at a
convenient standard level.
1.127 Set the Function control (7) to
“Level —20dB.” This will reduce the
oscillator output by 20 dB while
simultaneously increasing the
sensitivity of the indicators by 20 dB,
so that the indicator level remains
unchanged. (You can verify the
reduction in oscillator output by
checking the tape deck’s meters.)
1.128 Set the Oscillator control (11) to
123)
Nakamichi
Measuring obj: ~=°
20 Hz. Make a record of the top (2)
and bottom (4) indicator readings.
You may have to increase the indicator
sensitivity by 20 dB in order to obtain
a reading of the lowest frequencies. To
increase sensitivity, move either the
Meter Range (8) or the Input Level
(9) switch down one step. You will
then bring the indicator sensitivity
down one 20 dB step for the middle
frequencies. You may also need to
bring the sensitivity down an
additional step to measure the high
frequencies. You can plot the output
levels against frequency to make a
curve of the record amplifier
frequency response and equalization.
But remember to add and subtract
20 dB where appropriate to
compensate for the difference in
indicator sensitivity ranges. If the tape
deck offers switchable equalization,
you can test the record amplifier at
each setting.
=
CURRENT
“Rowan
RE SPUNSS
Date:
10 20 50 100 200
S00 1K 2K 5K 10K 20K30K
Frequency (Hz)

1.2 Total Harmonic Distortion
1.21 Line Amplifier
(of a three-head tape deck)
1.21 Connect the Output jacks (16) to
the line input jacks of the tape deck.
Connect the line output jacks of the
tape deck to the Input jacks (5).
1.212 Set the tape deck’s “monitor”
switch to “source.”
1.213 Turn down the Oscillator Output
control (12) to minimum. Turn up the
tape deck’s line input controls to
maximum. Slowly advance the
Oscillator Output control until the tape
deck’s meters read 0 dB (0 VU).
Line Amplifier
1.214 Set the Function control (7) to
“Level T.H. Dist. R.”
1.215 Set the tape deck’s output control
to maximum. Adjust the Input Level
switch (9) so that the top indicator
reads between —10 and +10 dB. Read
the right channel distortion on the
“oo ee al
Tape Deck
Line Amp
Line output
bottom indicator. Remember that the
distortion readings vary according to the
position of the Meter Range switch (8).
1.216 Set the Function control (7) to
“Level T.H. Dist. L" and read the
distortion of the left channel on the
bottom indicator.
1.22 Record/Playback
1.221 Connect the Output jacks (16) to
the line input jacks of the tape deck.
Connect the line output jacks of the
tape deck to the Input jacks (15).
1.222 Load a tape into your tape deck and
make the appropriate bias and
equalization adjustments. Put the tape
deck into the record/pause mode.
1.223 Set the Function control (7) to
“Level T. H. Dist. R.”
1.224 Turn down the Oscillator Output
control (12) to minimum. Turn up the
tape deck’s line input controls to
maximum. Slowly advance the
Oscillator Output control until the
tape deck’s meters read 0 dB (0 VU).
1.225 Record about one minute of the
400 Hz oscillator tone.
T-100 Tape Deck
4600Hz
ew
Tape
Total Harmonic Distortion
Tape Deck T-100
se Es gy DO
{
1
$
j
400Hz |
1.226 Rewind the tape and play back the
tone.
1.227 Set the tape deck’s line output
control to maximum. Adjust the Input
Level switch (9) so that the top
indicator reads between —10 and +10
dB. Read the right channel distortion
on the bottom indicator. Remember
that the distortion readings vary
according to the position of the Meter
Range switch (8).
1.228 Set the Function control (7) to
“Level T.H. Dist. L’’ and reacd the
distortion of the left channel on the
bottom indicator. Note tha witha
three-head tape deck you am read
the record/playback distorion as
you record by switching the ‘monitor’
switch to “tape” as you reiosd.

1.23 Record/Playback Level Record /Plavback Level Vs. Distortion :
Versus Distortion
(> (> :
T-100 Tape Deck | Tape Deck T-100
1.231
Follow
steps
1.221
through
1.228.
=<
:
|
<2,
We
5
ee
1.232
Connect
the
Output
jacks
(16)
sos
e
rr
oe
to
the
Input
jacks
(15).
Tape
sei
1.233 Set the Function control (7)
to “Level.” 1.238 You can plot the distortion
readings against the tape deck input
level. When the input level is low, the
analyzer reads mostly noise
components. As the input level
increases, the distortion reading will
tend to decrease. At very high input
levels, tape saturation distortion sets
1.234 Move the Meter Range switch (8)
and the Input Level switch (9) until
the oscillator output level is indicated
on the top (2) and bottom (4)
indicators.
1.235 Make a note of the position of the
Meter Range and Input Level switches,
and the dB reading of the oscillator
output. Then use the Oscillator
Output control (12) to decrease the
reading by two dB,
in and the distortion readings will
increase rapidly. You may notice a
decrease in distortion if you make
measurements using high-cut filters,
noise reduction systems, etc. These
will tend to reduce the noise
components which reach the Analyzer.
1.236 You are now ready to measure
record/playback distortion at —2 dB
(—2 VU). You have used the analyzer’s
own meters to calibrate the oscillator
output rather than the tape deck’s
meters, To make the measurement,
follow steps 1.221, 1.223, and 1.225
through 1.228.
Record/Playback Level vs. T.H.D.
+14
+10
1.237 In the same manner, recalibrate
the Oscillator Output for -4, —6, —8,
—10, +2, +4, +6, +8, and +10 dB and
@ +2 10
measure
the
distortion
at
these
levels.
ae
;
Remember
that
to
obtain
an
accurate
&
a
6.
distortion
reading,
you
must
adjust
°
a
the Input Level switch (9) so that the otk 2z
level
read
between
~—10
and
+10
dB.
0
Remember that the distortion readings
vary according to the position of the
Meter Range switch (8).
Input (dB)

1.44 Record/Playback
1.441
Connect
the
Output
Jacks
(16)
to
the
line
input
jacks
of
the
tape
deck.
Connect
the
line
output
jacks
of
the
tape
deck
to
the
Input
jacks
(15).
1.442 Set the Function control (7) to
“Level’’. Set the Oscillator control
(11) to 400 Hz.
1.443
Load
a
fresh
tape
into
your
tape
deck
and
select
the
appropriate
bias
and
equalization
positions.
Put
the
tape
deck
into
the
record/pause
mode.
1.444
Adjust
the
tape
deck’s
line
input
level
controls
so
that
the
tape
deck’s
meters
indicate
0
dB
(0
VU).
If
you
find
that
you
cannot
get
a
0
dB
reading
on
the
tape
deck’s
meters
even
when
the
tape
deck’s
line
input
controls
are
turned
all
the
way
up,
turn
the
Oscillator
Output
control
(12)
clockwise
until
the
tape
deck
meters
read
0
dB.
1.445
Record
about
30
seconds
of
the
400
Hz
tone.
Then,
while
the
tape
deck
is
recording,
change
the
Function
control
(7)
setting
to
“Noise-A
(-40dB)".
This
will
disconnect
the
oscillator
and
short
the
tape
deck
line
inputs.
Record
for
about
30
seconds
to
get
a
sample
of
tape
noise.
1.446
Return
the
Function
control
(7)
to “Level’’. Rewind the tape and
play back. Adjust the line output
levels
of
the
tape
deck
so
that
the
top
(2) and bottom (4) indicators read
OdB or any other convenient level
you wish to use as a standard. Make a
note of the indicator readings, and do
Record/Playback Noise Level
T-100
Tape
Deck
OSC Output
not
alter
the
tape
deck
line
output
levels
for
the
rest
of
this
procedure.
1.447
When
you
have
reached
the
end
of
the
recorded
400
Hz
tone,
set
the
Function
control
(7)
to
“Noise-A
{-40dB)’’.
The
IHF
A-Weighted
noise
level
should
appear
on
the
indicators,
(If
necessary,
move
the
Meter
Range
(8)
or
Input
Level
(9)
switch
to
geta
reading.)
The
signal-to-noise
ratio
wil!
be
the
difference
in
dB
between
the
level
of
the
400
Hz-tone
and
the
noise
level.
Remember
that
setting
the
Function
control
to
“Noise-A
{-40dB)"’
automatically
makes
the
display
40 dB
more
sensitive.
For
example,
if
the
400
Hz
tone
read
at
O
GB
and
the
noise
level
reads
-18
dB,
the
signal-to-noise
ratio
is
58
dB.
(Remember
to
account
for
each
20
dB
change
you
make
in
either
the
Meter
Range
(8)
or
Input
Level!
(9)
switches.
For
example,
if
the
400
Hz
tone
read
at
0
dB
and
if
you
have
moved
either
switch
down
one
step,
and
the
noise
level
reads
-2
dB,
the
signal-to-noise
ratio
is
62
dB.)
1.448
This
signal-to-noise
ratio
is
referenced
to
0
dB
(0
VU)
and
is
IHF
A-Weighted.
Note
that
some
tape
deck
manufacturers
specify
with
different
weighting
curves,
filters,
with
a
3%
distortion
level
reference,
or
with
the
tape
deck’s
noise
reduct
J eee Input
Tape
Deck
T-100
reduction
system
switched
on.
The
signal-to-noise
ratio
you
measure
may
be
different
from,
yet
consistent
with
the
manufacturer's
specification.
If
your
tape
deck
has
a
noise
reduction
system,
you
may
wish
to
measure
signal-to-noise
with
the
system
off
and
with
it
on.
If
you
want
to
refer
your
measurement
to
the
3%
distortion
level,
you
can
use
procedure
1.23,
Record/Playback
Level
Versus
Distortion,
to
determine
the
difference
between
0
dB
(0
VU)
and
the
3%
distortion
level.
For
example,if
you
find
that
3%
distortion
occurs
at
+3
dB,
and
the
signal-to-noise
ratio
referenced
to
0
dB
was
58
dB,
then
the
signal-to-noise
referenced
to
3%
distortion
will
be
61
dB.
IHF
A-Weighted
Curve
Response (dB)
Frequency (Hz)
12

13
1.5 Tape Speed, Wow & Flutter
There are two methods of measuring tape
tape wow & flutter. One, playback-only,
uses a 3 kHz test tape of presumed
accuracy. The other, record/playback,
uses the tape deck itself to make a
3 kHz tape and play. the tape back.
Obviously, the record/playback method
results in higher figures. Record/playback
readings are roughly 1.414 times
playback-only readings. Inversely,
playback-only readings are roughly
0.707 times record/playback readings.
Tape speed, it should be noted, can
only be verified during playback using
a standard pre-recorded 3 kHz test tape.
1.51 Test Tape Playback
1.511 Set the Functicn control (7) to
“Speed Cal.””
1.512 Adjust the Speed Cal control (6)
so that the top indicator (2) reads zero
on the speed deviation scale (1).
1.513 Set the Function control (7) to
“Speed Wow/Fiutter”.
1.514 Play back the 3 kHz test tape.
1.515 The top indicator (2) shows speed
Test Tape Playback Method
Test Tape
3KHz ¥
Tape Deck
deviation. The bottom indicator (4)
shows weighted wow & flutter.
Remember that the wow & flutter
reading varies according to the position
of the Meter Range switch (8). You
can expect the wow & flutter reading
to fluctuate. Read the center value.
1.516 For unweighted wow & flutter
readings, set the Function control (7)
to ‘Speed Unweighted.”’
1.52 Record/Play
1.521 Connect the Output jacks (16) to
the tape deck’s line input jacks.
Connect the tape deck’s fine output
jacks to the Input jacks (15).
1.522 Set the Function control (7) to
“Speed Cal." The oscillator output
will be a 3 kHz tone regardless of the
position of the Oscillator control (11).
1.523 Turn the Speed calibration control
(6) so that the top indicator (2) reads
zero on the speed deviation scale (1).
1.524 Set the Function control (7) to
“Speed Wow/Flutter.”
1.525 Set the tape deck’s line input
level controls and/or the oscillator
output control so that the tape
deck’‘s meters read in the range
Record/Playback Method
Tape Deck
between —10 and 0 dB (VU).
1.526 Record the 3 kHz test tone.
1.527 Follow steps 1.514 through 1.516,
but remember that you can measure
only wow & flutter using this
record/play method.
1.528 You can connect an oscilloscope
to the right channel Scope jack (17)
to see the waveform of the
demodulated signal.
Tape Deck

1.6 Volume Indication
You can use the extreme accuracy and
‘ange of the T-100 indicators to
supplement the meters of your tape deck
as you record. Without manipulating
the Meter Range (8) and Input Level (9)
switches, you can read volume indication
from —20 to +10 dB. By changing the
indicator sensitivity, you can extend the
range even further. You can calibrate the
peak indication so that 0dB on the T-100
corresponds exactly to 0 dB (0 VU) on
the tape deck’s meters. This will enable
you to use the indicators on the T-100
exclusively, with the assurance that
you are getting accurate input readings.
1.61 Peak Metering
1.611 Connect the line output jacks of
the tape deck to the Input jacks (15).
Connect the Output jacks (16) to the
line input jacks of the tape deck.
1.612 Set the Oscillator control (11) to
400 Hz. Set the Function control (7)
to “Peak.”
1.613 {f the tape deck is a two-head
machine, put the deck into
record/pause mode. If the deck is a
three-head machine, set the “monitor”
switch to “source.”
1.614 Adjust the tape deck line input
level controls and/or the Oscillator
Output control (12) so that the tape
deck meters read 0 dB (OVU).
1.615 Set the tape deck line output level
controls to a convenient point, i.e.
where you normally set them for tape
playback. A long as you will be using
the T-100 for peak metering, do not
alter the output level control settings.
1.616 Set the Meter Range (8) and Input
Level (9) switches so that the
indicators read slightly above 0 dB.
1.617 Turn the Input Level controls (10)
counterclockwise until the indicators
read 0 dB.
14
Peak/VU Metering
Calibration
T-100 Tape Déck
Line Line
tnput input | output
(-—n
1.618 Disconnect the Outputs (16) from
the tape deck line inputs. Connect the
source to be recorded to the tape
recorder. !f you wish to monitor the
tape recording through an audio system
system (as opposed to a pair of
headphones) you will need “Y”
connectors so that both the Analyzer
and the audio system receive signal
from the tape deck’s line output jacks.
CAUTION
Under certain circumstances in the peak
metering mode, it is possible to overload
the input section circuitry of the T-100.
Overioad results in inaccurate readings and
is indicated by arrested movement of the
bar-graph display (the indicators will never
“move” beyond a certain point). In such
instances turning down the Input Level
controls (10) will not help (electrically,
they are positioned after the input
circuitry). What does help is increasing the
input Level switch (9) setting (moving it
up one step). A complementary decrease
of the Meter Range switch (8) (moving it
down, if it is not down already) will
restore input sensitivity of the T-100 to
the original level.
Monitoring Audio System
Tape Deck Line
output
*Y* connector
1.62 Average (VU) Metering
1.621 Set the Function contro! (7) to
“Level.”
1.622 Connect the line output jacks of
the tape deck to the Input jacks (15).
Connect the Output jacks (16) to the
line input jacks of the tape deck.
1.623 Set the Oscillator control (11) to
400 Hz.
1.624 Follow steps 1.613 and 1.614.
1.625 Set the tape deck line output level
controls so that the indicators read
0 dB. You may have to manipulate the
Meter Range (8) and Jnput Level (9)
switches to achieve this. Once the tape
deck line output levels are set, do not
change them as long as you will be
using the T-100 for average metering.
1.626 Follow step 1.618.

2.12 Microphone
Microphone output information is useful
in judging the compatibility of a
microphone with console and tape deck
mic inputs. You may discover that the
output is high enough to require
attenuation, or low enough to require an
outboard preamplifier and connection to
a line-level input. In order to test a
microphone, you need a “known”
speaker. Specifically, you need to know
the speaker sensitivity, usually measured
in terms of sound pressure level (SPL) at
one meter, on axis, with a 1-watt input.
' You must set out to reproduce these
“ conditions. First you use the analyzer to
calibrate a 1-watt input at 1 kHz. To
do this, you must know the speaker
” impedance. Position the microphone
one meter from the speaker, on axis. Then
take measurements,
2.121 First calibrate a 1-watt input for
the speakers. Connect the Output jacks
(16) to the preamplifier “aux” input
jacks. Connect the Input jacks (15)
to the power amplifier speaker output
terminals, in parallel with the speakers
themselves.
2.122 Set the Function control (7) to
‘Nevel —20dB.” Set the Oscillator
control (11) to “1K.” Set the Meter
Range switch (8) to 1%,’ and the
input level switch to “10V.” With
these settings, zero dB equals 1 volt
and maximum indication is 3.162 volts.
Calibration ~
input T-100
Amp Ww
ee ee es
2.123 Set the preamplifier balance control
control so that only the speaker you
will use to perform the test will play.
Slowly advance the preamplifier
volume control until the appropriate
indicators read the proper voltage for
1 watt. This voltage is the square
root of the speaker’s impedance at 1
kHz, If your preamplifier volume
control is a stepped attenuator, you
will probably need some “fine turning”
to get the proper output voltage
reading. Use the Oscillator Output
control (12) if necessary. Once the
proper voltage is calibrated, do not
touch the preamplifier volume control
or the oscillator output control.
2.124 Turn off the power to the
preamplifier and power amplifier.
Disconnect the Inputs (15) from the
amplifier’s speaker output terminals.
Position the microphone one meter
from and directly in front of the
loudspeaker.
2.125 Connect the microphone output
to the left Input jack (15).
Measurement
Microphone 7-100
<—<e—[]
2.126 Turn on the system and play the
calibrated 1 kHz test tone through the
loudspeaker. Set the Meter Range
switch (8) to “0.1%."’ Set the Input
Level switch (9) to “O.1V." Zero dB
will equal 1 millivolt. Read the
microphone output voltage in dB
from the top (2) indicator. You can
also read millivolts directly by using
the THD/Wow & Flutter scale (5).
Remember that any change in the
meter range (8) or input level (9)
settings will result in a different 0 dB
reference. Refer to the Indicator
Status Charts on page 3,
if there are any doubts as to
scale reference. This is the output at
the speaker’s rated sound pressure
level for these conditions. Microphone
sensitivity is frequently expressed in
millivolts per microbar (onemmicrobar
is approximately 74 dB SPL).

Loudspeaker
T-100 Amp
HSH]
OSC Output
2.13 Loudspeaker
Speaker output level is useful in selecting
a compatible amplifier for the room and
desired sound pressure levels. In order to
test a loudspeaker, you need a “’known”
microphone. Specifically, you need to
know the-microphone sensitivity, usually
measured in terms of millivolts per
microbar. You can also modify this
procedure to measure sound pressure
level of stereo pair at any listening
position.
2.131 Calibrate a 1-watt input to the
speakers by following steps 2.121,
2.122, and 2.123.
2.132 Connect the microphone according
to steps 2.124 and 2.125.
2.133 Turn on the system and play the
calibrated 1 kHz test tone through the
loudspeaker. Set the Meter Range
switch (8) to “0.1%.” Set the Input
Level switch (9) to “0.1V.” Zero dB
will equal 1 millivolt. Read the
microphone output voltage in dB from
the top (2) indicator. You can also
read millivolts directly by using the
THD/Wow & Flutter scale (5).
Remember that any change in the
meter range (8) or input level (9)
settings will result in a different 0-
GB reference. Refer to the Indicator
Status Charts on page 3,
if there are any doubts as to
scale reference.
Use the microphone sensitivity
rating to calculate the speaker’s sound
pressure level. For example, if the
microphone is rated at 0.5 millivolts
per microbar, and the speaker causes
the microphone to produce 2 millivolts,
the speaker output is 86 dB SPL. (2
millivolts is 12 dB higher than 0.5
millivolts. 1 millibar is approximately
74 dB SPL. 74 + 12 = 86).

2.2
Frequency
Response
RIAA Characteristics Chart
2.21
Cartridge
Frequency
'
Recording!
Playback
Frequency
‘
Recording
Playback
Frequency
‘Recording
Playback
|
(Hz).
(dB):
(dB):
(Hz):
(a)
(dB)
||
(Hz)
+
(dB)
(dB)
2.211 Connect the cartridge output
cables to the Input jacks (15).
2.212 Set the Function control (7) to
“Level —~20dB,” the Meter
Range switch (8) to “0.1%,” and the
Input Level switch (9) to either “1V”"
or
“0.1V”
as
appropriate.
the
bass
and
cuts
the
treble
of
the
NOTE:
Although
this
chart
provides
cartridge
output.
The
unequalized
values
over
an
extended
range
2.213
Play
the
test
record
and
record
cartridge
output
will
have
a
rising
of
20Hz
to
20,000Hz,
the
the
cartridge
output
level
in
dB
for
frequency
response
characteristic,
official
RIAA
equalization
is
each
frequency.
Remember
that
where
the
phono
preamplifier
output
defined
only
from
30Hz
to
RIAA
playback
equalization
boosts
will
havea
flat
characteristic.
15,000Hz.
2.22 Microphone
Microphone
2.221
Follow
steps
2.121
through
2.125.
100
Te30
4
—— 1m ———
2.222
Set
the
Oscillator
control
(11)
to
CHES
=
|
eae
|
20
Hz.
Turn
on
the
system
and
OSC
Output
ve
H
play
the
tone.
Record
the
microphone
2020,000te
;
output level in dB, as read from the
top indicator (2). Repeat the
procedure
for
each
frequency
up
to
frequency,
Remember
that
this
is
not
section
(2.
Transducers)
if
yo:
have
20
kHz.
You
can
use
the
data
to
plot
an
absolute
measurement
—
re-read
any
questions
regarding
this
a
curve
of
output
levels
against
the
introductory
paragraphs
for
this
Procedure.
2.23 Loudspeaker
Loudspeaker
2.231
Follow
steps
2.121
through
2.125.
T-100
|
2.232
Set
the
Oscillator
control
(11)
to
[HS
x
ap
. 20 Hz. Turn on the system and play OSC Output
the
tone.
Record
the
microphone
20~20,000H:
t
i
output level in dB, as read from the
top indicator (2). Repeat the
procedure
for
each
frequency
up
to
response
of
a
stereo
pair
at
any
determine
the
advantages
of
df-ferent
20
kHz.
You
can
use
the
data
to
plot
listening
position.
You
can
measure
speaker
positions
and
orientaions,
a
curve
of
output
levels
against
the
affects
of
manipulating
the
not
to
mention
of
different
sje
akers,
frequency.
You
can
also
measure
the
speaker’s
crossover
controls.
You
can