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
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Wattage 1 2 5 1 2 5 10 20 50 100 WwW
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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.