Tascam MH-8 User Manual

Page 1
MH-8
Headphone Amplifier
OWNER'S MANUAL
D01098720A
Contents
IMPORTANT SAFETY INSTRUCTIONS ........2
1 − Introduction .........................................4
Features ........................................................... 4
Included items ................................................. 4
About this manual .......................................... 4
Trademarks ...................................................... 4
Precautions and notes for placement
and use ............................................................ 4
Cleaning the unit ............................................ 4
Front panel ...................................................... 5
Rear panel ....................................................... 6
Audio inputs and outputs .............................. 8
Audio performance ....................................... 8
Dimensional drawings .................................... 9
Block diagram ............................................... 10
Level diagram ................................................ 11
Page 2
2
TASCAM MH-8

IMPORTANT SAFETY INSTRUCTIONS

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 equilateral triangle, is intended to alert the user to 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 equilateral triangle is intended to alert the user to the presence of important operating and maintenance (servicing) instructions in the literature accompanying the appliance.
This appliance has a serial number located on the rear panel. Please record the model number and serial number and retain them for your records.
Model number
Serial number
For U.S.A.
TO THE USER
This equipment has been tested and found to comply with the limits for a Class A digital device, pursuant to Part 15 of the FCC Rules. These limits are designed to provide reasonable protection against harmful interference when the equipment is operated in a commercial environment. This equipment generates, uses, and can radiate radio frequency energy and, if not instal led and used i n accordance with the instruction manual, may cause harmful interference to radio communications. Operation of this equipment in a residential area is likely to cause harmful interference in which case the user will be required to correct the interference at his own expense.
CAUTION
Chang es or modifications to this equipme nt not expressly approved by TEAC CORPORATION for compliance could void the user's authority to operate this equipment.
WARNING: TO PREVENT FIRE OR
SHOCK HAZARD, DO NOT EXPOSE
THIS APPLIANCE TO RAIN OR
MOISTURE.
CE Marking Information
a) Applicable electromagnetic environment: E4 b) Peak inrush current: 9.124 A
Norwegian: Produkter med Klasse I konstruksjon er utstyrt
med en ekstern strømforsyning med en 3-pins tilkoblingskontakt. Det er viktig at denne kontakten tilkobles en jordet stikk-kontakt.
Swedish: Produkter med Klass 1 konstruktion är utrustad
med strömförsörjning med jordad 3 stifts strömad­apter. Sladdkontakt till denna måste kopplas till en AC adapter med skyddande jord.
Finnish: Tuotteen suojausluokka on I (suojamaadoitettu).
In North America use only on 120V supply.
Tuote on kytkettävä suojamaadoitettuun pistora­siaan.
Page 3
TASCAM MH-8
3
IMPORTANT SAFETY INSTRUCTIONS
1 Read these instructions.
2 Keep these instructions.
3 Heed all warnings.
4 Follow all instructions.
5 Do not use this apparatus near water.
6 Clean only with dry cloth.
7 Do not block any ventilation openings. Install in
accordance with the manufacturer's instructions.
8 Do not inst al l nea r any he a t sou r c es su c h
as radiators, heat registers, stoves, or other apparatus (including amplifiers) that produce heat.
9 Do not defeat the safety purpose of the polarized
or grounding-type plug. A polarized plug has two blades with one wider than the other. A grounding type plug has two blades and a third grounding prong. The wide blade or the third prong are provided for your safety. If the provided plug does not fit into your outlet, consult an electrician for replacement of the obsolete outlet.
10 Protect the power cord from being walked on
or pinched particularly at plugs, convenience receptacles, and the point where they exit from the apparatus.
11 Only use attachments/accessories specified by
the manufacturer.
12 Use only with the cart, stand, tripod, bracket, or
table specified by the manufacturer, or sold with the apparatus. When a cart is used, use caution when moving the cart/apparatus combination to avoid injury from tip-over.
Do not expose this apparatus to drips or splashes.
Do not place any objects filled with liquids, such
as vases, on the apparatus.
Do not install this apparatus in a confined space
such as a book case or similar unit.
The appar a tu s draws nominal non-op e r ating
power fr o m th e AC outlet with its POWER or
STANDBY/ON switch not in the ON position.
The apparatus should be located close enough
to the AC outlet so that you can easily grasp the
power cord plug at any time.
The mains plug is used as the disconnect device,
the di sc onn ect d e vi ce sha ll re mai n re adil y
operable.
Products with Class I construction are equipped
wi th a power su p p ly cord tha t has a 3-prong
grounding plug. The cord of such a product must be plugged into an AC outlet that has a protective grounding connection.
If the product uses batteries (including a battery
pack or installed batteries), they should not be
exposed to sunshine, fire or excessive heat.
CAUTION for products that use replaceable lithium
batteries: there is danger of explosion if a battery
is replaced with an incorrect type of ba t tery. Replace only with the same or equivalent type.
Caution should be taken when using earphones or
headphones with the product because excessive
sound pressure (volume) from earphones or head­phones can cause hearing loss.
If you are experiencing problems with this product,
contact TEAC for a service referral. Do not use the
product until it has been repaired.
RACK-MOUNTING THE UNIT
ª
Use the supplied rack-mounting kit to mount the unit in a standard 19-inch rack, as shown below.
13 Unplug this apparatus during lightning storms or
when unused for long periods of time.
14 Refer all servicing to qualified service personnel.
Servicing is required when the apparatus has been damaged in any way, such as power-supply cord or plug is damaged, liquid has been spilled or objects have fallen into the apparatus, the apparatus has been exposed to rain or moisture, does not operate normally, or has been dropped.
Remove the feet of the unit before mounting.
NOTE
Leave 1U of space above the unit for ventilation.
Allow at least 10 cm (4 in) at the rear of the unit for
ventilation.
Page 4
4
TASCAM MH-8

1 − Introduction

Thank you for your purchase of the TASCAM MH-8 Headphone Amplifier.
Before connecting and using the unit, please take time to read this manual thoroughly to ensure you understand how to properly set up and connect the unit, as well as the operation of its many useful and convenient functions. After you have finished reading this manual, please keep it in a safe place for future reference.
You can also download the Owner's Manual from the TASCAM web site (http://www.tascam.com).

Features

Rack-mountable 1U size
8 headphone outputs
Maximum output of 250 mW + 250 mW (at 32Ω)
2 pairs of inputs
INPUT 1 on XLR connectors or TRS phone jack inputs
INPUT 2 on XLR connectors or RCA pin jack inputs
Each headphone output channel also has direct inputs
Every input and output channel has an overload indica-
tor and a signal indicator
Ground lift switch allows signal grounding to be turned
ON or OFF for all channels at the same time
NOTE
Explanation of actions in special situation and supplement.
CAUTION
Instructions that should be followed to avoid injury, damage to the unit or other equipment.

Trademarks

TASCAM is a trademark of TEAC Corporation, regis-
tered in the U.S. and other countries.
Other company names, product names and logos in this document are the trademarks or registered trademarks of their respective owners.

Precautions and notes for placement and use

The operating temperature should be between 5°C and
35°C (41°F and 95°F).
Make sure that the unit is mounted in a level position for
correct operation.
Do not place any object on the unit for heat dissipation.
Avoid installing this unit on top of any heat-generating
electrical device such as a power amplifier.

Included items

The included items are listed below.
Take care when opening the package not to damage the items. Keep the package materials for transportation in the future.
Please contact the store where you purchased this unit if any of these items are missing or have been damaged dur­ing transportation.
Main unit (MH-8)• ............................................................1
Power cord• .......................................................................1
A rack-mounting screw kit• ..............................................1
A warranty card• ..............................................................1
Owner's manual (this manual)
........................................1

About this manual

In this manual, we use the following conventions:
The names of keys and controls are given in the follow-
ing typeface: POWER.
Additional information is introduced in the styles below
when needed:

Cleaning the unit

To clean the unit, wipe it gently with a soft dry cloth. Do not wipe with chemical cleaning cloths, benzene, paint thinner, ethyl alcohol or other chemical agents to clean the unit as they could damage the surface.
Page 5
TASCAM MH-8
5

2 − Names and Functions of Parts

Front panel

POWER switch and indicator

Press to turn power ON or OFF. The indicator lights when the power is ON.
Overload (OL) indicators

These light if the level input to this device is too high (overloading with a clipping level of –3 dB or higher).
Signal (SIG) indicators

These light when a signal (–20 dBu or greater) is detected at an input jack.
Input LEVEL knobs

Use to adjust the input levels.
INPUT 1 and 2 activation buttons

Select which of the two inputs (INPUT 1 or 2) to output to the headphones.
Overload (OL) indicators

These light if the level input to the channel is too high (overloading with a clipping level of –3 dB or higher).
Signal (SIG) indicators

These light when a signal (–20 dBu or greater) is detected at a direct input for the channel.
DIR buttons

Press to output the signal from the corresponding
DIRECT INPUTS to the headphones.
MONO buttons

Make the headphone output function as a monaural output.
PHONES jacks
Connect headphones.
PHONES knobs
Adjust the headphones output levels.
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TASCAM MH-8
2 − Names and Functions of Parts

Rear panel

DIRECT INPUT jacks
These direct input connectors provide direct line inputs for each channel.
FOLDBACK output connectors
These output the input signals (INPUT 1 and 2) unchanged.
NOTE
When input is through INPUT 2’s unbalanced RCA pin jacks, the nominal output level is converted to balanced +4 dBu.
INPUT 2 XLR connectors
These XLR connectors are balanced line inputs for INPUT 2.
(1: GND, 2: HOT, 3: COLD)
INPUT 2 RCA jacks
These RCA pin jacks are unbalanced line inputs for INPUT 2.
Power connector
Use the included power cord to connect the power source.
CAUTION
When using this unit, always use the included power cord. Moreover, do not use the included power cord with any other equipment. Misuse of a power cord could cause malfunction, fire or electric shock.
Ground lift (GND LIFT) switch
Even when the ground connector is used to ground the unit, this ground connection can be interrupted (ground lift) by setting the GND LIFT switch to the left.
NOTE
Signals should not be input to both the XLR and the RCA connectors at the same time. Use either the XLR or the RCA connectors for input.
INPUT 1 XLR connectors
These XLR connectors are balanced line inputs for INPUT 1.
INPUT 1 TRS jacks
These TRS jacks are balanced line inputs for INPUT 1.
NOTE
Signals should not be input to both the XLR and the TRS connectors at the same time. Use either the XLR or the TRS connectors for input.
Signal ground (SIGNAL GND) connector
Use a commercially available PVC-covered cord to connect this connector to the signal ground. Note that this is NOT an electrical safety ground (earth).
Page 7
TASCAM MH-8
7
If you are having trouble with the operation of this unit, please try the following before seeking repair. If these measures do not solve the problem, please contact the store where you bought the unit or a TASCAM Service Center.
Power will not turn ON.
ª
Confirm that the power plug is securely inserted.
No sound is output.
ª
Are the headphones connected correctly?
Are the input sources connected correctly?
Are the input selections correct?
Are the input
Are the headphone output (
There is noise.
ª
Check the connecting cables for incomplete connec-
tions.
LEVEL knobs minimized?
PHONES) knobs minimized?

3 – Troubleshooting

Page 8
8
TASCAM MH-8

4 – Specifications

Audio inputs and outputs

INPUT 1 and 2
Connector XLR-3-31
(1: GND, 2: HOT, 3: COLD)
Input impedance 56 kΩ
Nominal input level +4 dBu (1.23 V)
Maximum input level +24 dBu (12.3 V)
INPUT 1
Connectors 6.3 mm (1/4”) TRS Standard
phone jacks (Tip: HOT, Ring: COLD, Sleeve: GND)
Input impedance 56 kΩ
Nominal input level +4 dBu (1.23 V)
Maximum input level +24 dBu (12.3 V)
INPUT 2
Connectors RCA pin jacks
Input impedance 22 kΩ
Nominal input level –10 dBV (0.3 V)
Maximum input level +10 dBV (3.16 V)
DIRECT INPUT
Connectors 6.3 mm (1/4”) TRS Standard
phone jacks (Tip: HOT, Ring: COLD, Sleeve: GND)
Input impedance 56 kΩ
Nominal input level +4 dBu (1.23 V)
Maximum input level +24 dBu (12.3 V)

Audio performance

Frequency response 20 Hz - 50 kHz/100 mW 32Ω,
±3 dB (PHONES outputs)
10 Hz - 100 kHz, ±3 dB (FOLDBACK outputs)
S/N ratio 85 dB or greater (PHONES
outputs, A-WTD, 20 kHz LPF)
90 dB or greater (FOLDBACK outputs, A-WTD, 20 kHz LPF)
THD 0.05% or less (PHONES outputs,
when outputting 100 mW + 100
mW (32 Ω), 20Hz HPF and 20
kHz LPF)
0.007% or less (FOLDBACK outputs, 20 Hz HPF and 20 kHz LPF)
Channel separation 50 dB or greater (Within a
channel, PHONES outputs, A-WTD, 20 kHz LPF,1 kHz
nominal input, 32Ω termination)
90 dB or greater (FOLDBACK outputs, A-WTD, 20 kHz LPF,
1 kHz nominal input, 600Ω
termination)
Crosstalk 65 dB or greater (PHONES
outputs, A-WTD, 20 kHz LPF,
1 kHz nominal input, 32Ω
termination)
Power AC 100-240V, 50-60 Hz
Power consumption 36 W
Dimensions (mm) 482 (width) x 44 (height) x 280
(depth)
Weight 3.8 kg
FOLDBACK outputs
Connectors 6.3 mm (1/4”) TRS Standard
phone jacks (Tip: HOT, Ring: COLD, Sleeve: GND)
Output impedance 94Ω
Nominal output level +4 dBu (1.23 V)
Maximum output level +24 dBu (12.3 V)
PHONES outputs
Connectors 6.3 mm (1/4”) Standard
stereo phone jacks
Maximum output 250 mW + 250 mW (32Ω)
Page 9
TASCAM MH-8
9

Dimensional drawings

10.5 mm
280 mm 14 mm
31.8 mm
432.6 mm
41.1 mm
0.9 mm
44 mm
434.2 mm
482.6 mm
465 mm
4 – Specifications
Illustrations and other depictions may differ in part from the actual product.
Specifications and external appearance may be changed without notification to improve the product.
Page 10
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TASCAM MH-8
-2dBu+4dBu
-10dBv
-2dBu
MAX +8dBu
MAX +8dBu
+4dBu
-2dBu
INPUTS 2
INPUTS 1
FOLDBACK 1
FOLDBACK 2
GND LIFT
CIRCUIT GROUND
CHASSIS GROUND
TRS-L(MONO)
TRS-R
INPUT 1
DIR 1
INPUT 2
DIRECT INPUTS 1
TRS-L(MONO)
TRS-R
INPUT 1
DIR 8
INPUT 2
DIRECT INPUTS 8
...
...
INPUTS 1 L
INPUTS 1 R
INPUTS 2 L
INPUTS 2 R
INPUTS 1 L
INPUTS 1 R
INPUTS 2 L
INPUTS 2 R
DIRECT INPUTS 2 - 7
R
L
L
R
XLR - L
TRS-L(MONO)
1/2
U107
TRS - R
XLR - R
1/2
1/2
1/2
1/2
1/2
U101
U101
U107
U108
U108
U103
U104
INPUT 1 LED
OL
SIG
1/21/2
COMPARATOR
U105U106
LOGARITHMIC
AMP.
LEVEL - L
LEVEL - R
1/2
1/2
INPUT 1
INPUT 1
U102
U102
INPUT 2 LED
OL
SIG
1/21/2
COMPARATOR
U105U106
LOGARITHMIC
AMP.
RCA - L
1/2
U201
1/2
1/2
1/2
1/2
U201
U208
U208
LEVEL - L
LEVEL - R
1/2
1/2
INPUT 2
INPUT 2
U203
U203
1/2
U202
RCA - R
1/21/2
U202
U204
U205
1/2
1/2
1/2
1/2
LEVEL - L
PHONES 1
LEVEL - R
OL
SIG
1/21/2
LOGARITHMIC
COMPARATOR
1/2
1/2
1/2
1/2
PHONES 1
PHONES 1
U303
U303
U301
U301
U304
U305
AMP.
Max +22dBu
Max 250mW@32 OHM
LEVEL - L
PHONES 8
LEVEL - R
OL
SI
G
1/21/2
LOGARITHMIC
COMPARATOR
1/2
1/2
1/2
1/2
PHONES 8
PHONES 8
U904
U905
AMP.
Max +22dBu
Max 250mW@32 OHM
U003
U003
U001
U001
J101
J102
J103
J104
J105
J106
J204
J205
J303
J001
J301
J302
J003
J002
U302
U302
U002
U002
PHONES 1 LED
PHONES 8 LED
J205
J204
J203
XLR - L
XLR - R
...
...
PHONES 2 - 7
4 – Specifications

Block diagram

Page 11
TASCAM MH-8
11

Level diagram

-2dBu
-2dBu
-2dBu
MAX +8dBu
MAX +8dBu
+4dBu
+4dBu
-2dBu
-2dBu
+4dBu
-10dBv
XLR - L
TRS - L
INPUT 1 LED
INPUT 1
LEVEL - L
PHONE 1-8
LEVEL - L
FOLDBACK - L
INPUTS1/2
(250mW@32 OHM)
INPUTS 1 XLR
(+4dBu)
INPUTS 2 RCA
(-10dBv)
INPUTS 1 TRS
INPUTS 2 XLR
FOLDBACK 1
FOLDBACK 2
PHONES 1-8
(-2dBu) (-2dBu)
DIRECT INPUT 1-8
INPUTS1/2
DIRECT INPUT 1-8
(+4dBu)
OL
SIG
1/2 1/2
COMPARATOR
1/2
U107
(dBv)
+5
0
-5
-10
-20
NOTE: 0dBv=2.218dBu
LEVEL - R
LEVEL - L
LEVEL - R
INPUT 2 LED
OL
SIG
1/2 1/2
COMPARATOR
1/2
U201
1/2
U302/U402/U502/U602
INPUT 2
DIR
LEVEL - R
TRS - R
XLR - R
FOLDBACK - R
INPUTS 1
DIRECT INPUTS
1 - 8
RCA - L
XLR - L
FOLDBACK - L
XLR - R
RCA - R
FOLDBACK - R
INPUTS 2
OL
SIG
1/21/2
LOGARITHMIC
COMPARATOR
1/2
1/2
1/2
1/2
1/2
1/2
1/2
1/2
1/2
1/2 1/2
1/2
1/2 1/2
1/2
1/2
1/2
1/2
1/2
PHONES 1-8
PHONES 1-8
INPUT 1
INPUT 1
INPUT 2
INPUT 1
U101
U202
U107
U108
U108
U103
U104
U202
U202
U201
U204
U205
U702/U802/U902/U002
U303/U403/U503/U603
U703/U803/U903/U003
U303/U403/U503/U603
U703/U803/U903/U003
U102
U102
U203
U203
U301/U401/U501/U601
U701/U801/U901/U001
U301/U401/U501/U601
U701/U801/U901/U001
U105 U106
U105 U106
U304
U504
U704
U904
U305
U505
U705
U905
AMP.
LOGARITHMI
C
AMP.
LOGARITHMIC
AMP.
Max +22dBu
Max 250mW@32 OHM
U206
U206
TRS - R
TRS - L
PHONES 1-8 LED
(-8dBu)
(-12dBu)
4 – Specifications
Page 12
MH-8
TEAC CORPORATION
Phone: +81-42-356-9143 1-47 Ochiai, Tama-shi, Tokyo 206-8530, Japan
TEAC AMERICA, INC. www.tascam.com
Phone: +1-323-726-0303 7733 Telegraph Road, Montebello, California 90640 USA
TEAC CANADA LTD. www.tascam.com
Phone: +1905-890-8008 Facsimile: +1905-890-9888 5939 Wallace Street, Mississauga, Ontario L4Z 1Z8, Canada
TEAC MEXICO, S.A. de C.V. www.teacmexico.net
Phone: +52-55-5010-6000 Río Churubusco 364, Colonia Del Carmen, Delegación Coyoacán, CP 04100, México DF, México
TEAC UK LIMITED www.tascam.co.uk
Phone: +44-8451-302511 Suites 19 & 20, Building 6, Croxley Green Business Park, Hatters Lane, Watford, Hertfordshire, WD18 8TE, UK
TEAC EUROPE GmbH www.tascam.de
Phone: +49-611-71580 Bahnstrasse 12, 65205 Wiesbaden-Erbenheim, Germany
www.tascam.jp
Printed in China
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