Page 8
Avalon Vt-747sp Operation Manual
AVA L O N D E S I G N
Quick Start-up
TSP
Twin Signal Path
Switch (in) swaps
three (3) tubes
into the audio
path from discrete
Class A amps.
F4
Boost-cut
sets amplitude
of mid-range
-4dB to +4dB
detent at 0dB
2kHz
peak-dip
FI
Boost-cut
sets amplitude
of low-bass
-24dB to +24dB
detent at 0dB
15Hz
shelf
F2
Boost-cut
sets amplitude
of mid-bass
-8dB to +8dB
detent at 0dB
125Hz
peak-dip
F3
Boost-cut
sets amplitude
of low-mid
-4dB to +4dB
detent at 0dB
500Hz
peak-dip
F5
Boost-cut
sets amplitude
of presence
-10dB to +10dB
detent at 0dB
5kHz
shelf
F6
Boost-cut
sets amplitude
of treble
-20dB to +20dB
detent at 0dB
32kHz
shelf
20
10
3
2
A
V
ALON
V
ACUUM
TUBE
-
7
5
3
1
0
1
2
d
e
c
i
b
e
l
s
V
U
+
IN
IN
IN
IN
IN
IN
IN
HF
v
747
sp
t
-
dB
+
-15
+15
-15
+15
0dB
+2
+6
+10
SIDE-CHAIN THRESHOLD
CONTOUR
GR
SC LISTEN
SIDE-CHAIN
CAL
GR
GAIN +10dB
60
100
80
160
250
300
400
1k
Hz
70
600
200
600
1k
800
1k6
2k5
3k
4k
10k
Hz
700
6k
2k
LF
TSP
EQ COMP
INPUT
0
20
8
32
4
6
6
10
1
1
FAST
SLOW
ATTACK
TUBE
SIGNAL
PATH
FAST
SLOW
RELEASE
GAIN
MAKE-UP
COMPRESSOR
METER
RATIO
COMPRESSION
12
0
47
8
3
10
2
6
5
-
dB
+
THRESHOLD
20
20
0
6
10
-
10
16
15
3
+2
DESIGN
AVA
L
O
N
0
1
2
3
3
2
1
+
-
CLASS
A
PROGRAM EQUALIZER
LEVEL
SIGNAL
-
dB
+
OUTPUT
0
20
6
22
3
4
4
8
1
1
EQUALIZER
R
dB
L
30
0
24
18
12
+
-
12
6
6
18
24
30
VT-747SP QUICK SET-UP OPERATING GUIDE
+10dB switch
Boosts input
amplifier by
+10dB for extra
tube over-drive
INPUT GAIN
Trims input level
-20dB to +8dB
detent at 0dB
(+18dB with +10dB IN)
LF and HF THRE
S
H
O
LD
Range -15dB to +15dB, detent at 0dB,
clockwise rotation raises the threshold
(less compression) and counter clockwise
rotation lowers the threshold (more compression)
at the frequencies set by the LF (low frequency)
and HF (high-frequency) spectral frequency
controls located directly below
THRESHOLD
Sets compressor
input threshold
from -30dB to
+20dB
COMPRESSION
Sets ratio of
compressor
from 1:1 to 20:1
COMPRESSOR
Switch (in) engages
compressor into
signal path
(hard-wire bypass)
SIX (6) BAND PASSIVE CLASS A, PROGRAM EQUALIZER
EQ to COMP
Inserts the
six (6) band
EQ pre the
compressor
Blue LED
Indicates
compressor
speed and
activation
SC Listen
Switch (in)
for Spectral EQ
into audio path
to monitor SC
ATTACK
Variable attack
time for the
compressor
2mS to 200mS
RELEASE
Variable release
time for the
compressor
100mS to 5S
SPECTRAL
Sweep frequency
for LF and HF
bands, used with
above threshold
controls
SIDE-CHAIN
Inserts spectral
EQ into side-
chain
METER
Recessed
screwdriver
adjust for 0dB
gain-reduction
meter trim.
AC POWER
Note: Check
rear power input
connector for
correct local
ac voltage. Allow
forty seconds for
the soft-start
procedure to
activate the
the audio
signal path.
A
V
ALON
Class
A
V
acuum
T
u
be
STEREO SPECTRAL
OPT
O-COMPRESSOR
WITH
TSP
POWER LED
Indicates ac
power is on
MAKE-UP
0dB to +10dB
variable gain on
opto-compressor
METER
High quality
VU meter
indicates
gain reduction
0dB to -20dB
VT
-747SP
Avalon Design is a division of Avalon Industries, Inc. 2001
c
OUTPUT METER
Fast LED meter
indicates both L-R
spectral content
and output level
-30dB to +30dB
OUTPUT LEVEL
Stereo output
level control
-20dB to +6dB
detent at 0dB
EQ
Switch (in)
activates 6 band
passive EQ into
audio path
(hard-wire bypass)
Note:
For the best sonic performance,
a
ll
o
w
thirty minutes for warm-up.
When not in use, turn the ac off. This will
extend the life of the electronics . . Enjoy!
Note:
Knob settings shown represent
starting positions only.
TSP
TWIN SIGNAL PATH
All units in dBu.
Figure 2.1 Quick Set-up Guide