Fairchild 610 User manual


FAIRCHILD MODEL 610 10 WATT AMPLIFIER
GENERAL
The FAIRCHILD MODEL 610 amplifier is a fully siliconized, 10
watt rms monitor amplifier with short circuit and overload
protection. The amplifier features compact design, low dis-
tortion, flat response and low noise. It has bridging input,
transformerless output and an integrated power supply.
The complete amplifier, less line transformer, is on printed
circuit card. In this design, heat sink of the output stage
is coupled to the chassis of the amplifier, effectively in-
creasing heat radiating surface.
The MODEL 610 accommodates input levels from -10 dbm (.25V
bridging) and higher. Minimum level of .25V is required to
produce 10 watts rms power into an 8 ohm load, or 61/2 watts
power into a 16 ohm load.
The amplifier circuit consists of four directly coupled stages
of amplification, phase inversion and driving. DC feedback
loops stabilize the operating point over a wide range of oper-
ating temperatures with no degradation in performance of the
unit.
Instantaneous overload protection is obtained through current-
limiting transistors in the driving circuit of each half of the
output stage. As current through either of the output transis-
tors exceeds preset value (clipping point for 10 watts), output
stage is clamped down driving the output stage into non-conductive
state. Output stage is CTASS AB circuit, with maximum current
flowing through the transistors being .4 amps, and idling current
20 ma.
APPLICATIONS
The MODEL 610 amplifier is intended for professional use in systems
where moderate power levels are adequate. It is excellent for driv-
ing speakers with or without transformer isolation. 70 volt line
can be achieved b using appropriate step-up transformer with 1:8
ratio, primary being 4 or 8 ohms. The 610 can be used in cue
circuits, talkback and intercom systems where high quality and
high reliability are required. If the unit is used as a line
amplifier, a transformer may be used with sufficiently high power
rating and low distortion so that full use of available power can
be achieved.

INSTALLATION & OPERATION
- MODEL 610
The MODEL 610 amplifier may be rack mounted. A rack mounting
frame (MODEL 662RM) is available for this purpose. Five 610s
can be placed side-by-side in this frame, taking up 51/4" of
rack space. If less than five amplifiers are mounted in the
frame, either blank panels can be used to fill in or other
FAIRCHILD INTEGRA components can be mounted in the empty space.
CAUTION, however, must be exercised not to mount equipment with
mic transformers next to the amplifiers. The integral power
supply of the amplifier creates
AC
field capable of inducing
60 cycle hum into low level transformers.
ALTHOUGH the chassis of the 610 amplfier is made out of steel
for shielding purposes, it is recommended that the amplifier
be checked out for proximity interference before being mounted
next to other amplifiers.
The 610 will work off any impedance not exceeding 10,000 ohms,
and levels not lower than -10dbm (.25V). It has capacitive
input isolation. In order to run it off a balanced line, an
input transformer may be in order. However, direct operation
of the 610 from a balanced line is feasible provided that the
amplifier ground is a floating ground and the load is not
grounded (either transformer output or speaker).
CONNECTICNS
Input to the amplifier is
TERMINALS 1
and 2 -
TERMINAL 2
being
ground. Output of the amplifier is TERMINALS 3 and 4 - TERMINAL
4 being low side.
Care should be exercised in making appropriate grounding to the
load for if input and output grounds are interconnected to the
same terminal output, current could flow thioush the input
ground causing an unwanted feedback condition.
SHIELDS
If shielded wire is used for the input, shield can be tied to
either the case ground of the rack assembly, or to the low side
of the input, providing the other end of the shield is not tied
to ground and isfloating. Shield should be tied at one end only,
and it may be at the source end. Internal shielding of the
amplifier is tied to the chassis ground internally, and is auto-
matically grounded when the unit is mounted on the grounded rack.
PRECAUTIONS
The YODEL 610 amplifier is capable of taking abuse. However,
some operating precautions should be exercised. As stated in
the specifications, input level of -10 dbm will produce full
output into any load. Since the outut impedance is very low,
varying loads will not change the output level to any appreciable
degree. Short circuiting output will produce instantaneous turn
off of the output transistors. It is vfxtually impossible

damage the output stage. However, if excessively high levels
are fed into the input (in excess of 20 dbm or )0 db higher than
the specified -10) with the input gain control wide open,
power dissipation of the input stage will be excessive and
component damage may occur.
The power switch can be turned on or off at any time without
fear of damage to the circuit. If excessive levels hit the power
amplifier and the output stage goes into "blocked" state, turning
the unit off and on again will not remove the disable condition.
Protection of the output stage will continue as long as excessive
power is present in the unit. To remove the disable condition,
turn the input gain control down. Then turn the amplifier off
and then on again and increase input level for desired output.
If overload or momentary short occurs during operation of the
amplifier, the protection circuit will automatically disable it-
self as soon as dangerous transient has passed.
SPECIFICATIONS MODEL 610
POWER OUTZUT
lOW - 8 ohm load
6.5W - 16 ohm load
OUTPUT IMPEDANCE
.5 ohm
DAMPING FACTOR
Min. 16
INPUT IMPEDANCE
10K bridging
INPUT LEVEL
-10 dbm for full output (.25V)
POWER REQUIREMENT
117V AC
1
/
4
amp
FREQUENCY RESPONSE
+1 db 20 to 20KC
TED DISTORTION
Less than .4% at full power any
frequency. Less than .2% at 1
watt output
NOISE
-86 db below rated output
DIMENSIONS & WEIGHT
3"x51/4"x10"D - 4 lbs 8 oz
CONTROLS
ON/OFF switch. Input gain control
MODEL 610MI - mic or phono amplifier
The MODEL 610MI differs from the standard MODEL 610 in that it
has three added stages of amplification providing enough gain
to drive the power section of the circuit directly from micro-
phone or phono cartridge.
CONNECTIONS - same as MC_Td. 610 Terminal 1 - high side input
2 - low side input
3 - high side output
4 - low side output
The 610MI normally comes strapped for mic input and is provided
for phono input on special order. However, in order to select
the cover rrom
proper equalization for mic or phono inputs, remove

the amplifier and select position for the jumper on the printed
circuit card:
Jumper soldered to TERMINALS A and B provides
phono equalization with
3
my sensitivity at 1Khz
for full 10 watts of output power
Jumper strapped between TERMINALS B and C will
provide flat response for mic input with sensi-
tivity of -50 dbm for full 10 watts of output
power
Since gain control )f the amplifier is between the output of
the preamplifier section and the input to the power amplifier,
CAUTION should be exercised not to overload the input to the
preamplifier. Maximum levels are:
FOR MIC
- 20 dbm
FOR PHONO
- 25 dbm
Shield for the phono cable should be tied to TERMINAL 2, to-
gether with the low side of the cable. Double conductor cable
is recommended to be used with the micor phono sources. Mic
cable can be several feet long, but if long cables are antici-
pated, input transformer providing balanced input is recommended.
SPECIFICATIONS (Preamp)
INPUT IMPEDANCE
50K (input will accept any source re-
quiring loads 50K or lower)
EQUALIZATION
Flat ±1 db or phono NAB within 1 db
GAIN
40 db
NOISE & HUM
80 db below full power output
DISTORTION THD
.5%
or less
WARRANTY
See standard warranty policy. To validate warranty, complete
and return the warranty registration card included with this
manual. If there is any question on this or any other FAIRCHILD
professional product, please do not hesitate to contact our
CUSTOMER SERVICE DEPARTMENT, FAIRCHILD RECORDING EQUIE:IENT
CORPOiUTION, 10-40 45th Avenue, Long Island City, N.Y. 11101

5
i
4
32
3
610 MONITOR AMP
MOUNTING DIMENSIONS
A-96292

R3
100
cn
DI —D4
42VNL
36VFL
RIB
10K
610 AMP SCHEMATIC
fir
* —HEAT SINK
NOTES
I. ALL CAPACITORS IN MFD UNLESS
OTHERWISE SPECIFIED
2. ALL RESISTORS IN OHMS Ei I/4 WATT
UNLESS OTHERWISE SPECIFIED
3.* - TO BE SELECTED
R7
C2
220
001
RI6
Aeke
4.7K
•
4.
C6
TRIAD
F4OX
R20
120K
C5
5/25
C4
F
5/25
R19
I2K
R2I
150K
10K
02
2N3643
R6
120
RI
68
R2
68
R5
40251
RI2
I .2K
06
2N3565
R15
3.3K
01
2N3643
R17
4 7K
05
G 130
2.2K
RI3
C7
2000
/ 50V
* *
07
402 51
H25
H
22
16 5 620
2W
I/ 2W
/25V
2000
/25V
I
•
0
4
A-96235
2N3638
Q4
RII
470
R14
2.2K
I/2 AMP
110 VAC
03

09
SE4010
QII
R35
10K
R27
270K
3.3K
/
D6
1113023
C5
5/25
C8
C4
5/25
5/25
R38
10K
RI5
P
-
V V
v
A A
A_ _ _
3.3K
R7
C2
220
.001
R3
100
02
2N3643
R8
VVV
R6
A A
A
220
120
>
RI
R23
68
47
2W
C6
+
F
e_
2000
/25V
R25 <> R22
16
620
2W
I/2W
CI
/25V
1
/
2
AMP
110 VAC
03
) Q3
2N3638
RIO
VVV
DI -D4
42VNL
36VFL
ISSUE • I 7-10 -
.
68
2 12-26-68
R26
RI2
I.2K
L
0.A.0
4.7K
RI6
610MI AMP SCHEMATIC
!
t
t
JUMPER
INTERCONNECT
B - A RIAA PHONO EQUALIZATION
C - B MIC INPUT, FLAT RESPONSE
NOTES
I ALL CAPACITORS IN MFD. UNLESS
OTHERWISE SPECIFIED
2. ALL RESISTORS IN OHMS
a
I / 4 WATT
UNLESS OTHERWISE SPECIFIED
3.•-TO BE SELECTED
4.* *- HEAT SINK
•
o4
B - 96471
0
C9
.033
.0068
R30
R3I
R32
10K
33K
(.0
0
0
R20
120K
•
R2I
150K
470
01
2N3643
R24 4
2W
* *
40251
C7
2000
/50V
* *
07
402 51
2.2K
R13
TRIAD
F4OX
in
C)
RI8
10K
2N3565
C3
220PF
R4
100
Q6
2N3565
D5
GI30
* R28
220K
R29
100
RI9
I2K
NMI
R11
A A A
470
,
R34.
680.
RI4
5/25
Cl2
A A
v v v
100K
CIO
CII
2.2K
RI 7 .
>
4 .7K ">
Table of contents
Other Fairchild Amplifier manuals

Fairchild
Fairchild 870 User manual

Fairchild
Fairchild 692LA-30 User manual

Fairchild
Fairchild DA415/8 User manual

Fairchild
Fairchild 2N4123 User manual

Fairchild
Fairchild 692DCA User manual

Fairchild
Fairchild 610 User manual

Fairchild
Fairchild DA415/8 User manual

Fairchild
Fairchild 870 User manual

Fairchild
Fairchild Integra II Series User manual