Download line input/output transformers

PRE AMP
AND LINE
AMP
PRODUCTS
"600 OHM" BALANCED LINES are used almost universally in
recording, broadcasting and most large installations where
analogue signals need to be fed from one piece of equipment to
the next. The balancing virtually eliminates ground noise and
unwanted signals which can be induced into cables. Transformers
are a very effective means for converting unbalanced signals to
balanced as well as providing almost complete isolation from
ground noise. A further benefit of using balanced lines is the
elimination of unwanted "pops" and "bangs" when signals are
switched. Many HiFi enthusiasts are now using 600 ohm lines as
their equipment becomes more complex.
WHY 600 OHMS? There is a lot of history and some confusion
here. The ideal impedance for driving an audio line is zero ohms
and the ideal input impedance for connecting to it is infinity. The
actual wire does not need to have any particular "characteristic
impedance" nor does it need to be terminated like radio frequency
cable. 600 ohms is a nominal value used to describe an
environment.
In summary it could be said that a line driver should have an
impedance no more than 600 ohms and a receiver should have an
impedance no less than 600 ohms. If both driver and receiver
were both 600 ohms however, half the signal would be lost in the
driver. In a small system the designer may try to make the receiver
impedance a factor of 5 greater than the driver but in a large or
very noisy environment a factor of 10 might be attempted.
NEW SOWTER PRODUCTS We are introducing several new
products for developers of studio compressors, pre-amplifiers etc
using tubes or transistors. Also for converting computer sound
cards, home cinema, DVD systems or most power amplifiers to
balanced inputs. The list below includes some new and some
existing products.
VINTAGE STUDIO EQUIPMENT We have a number of
transformers availalble for vintage studio equipment repair or
recreation. See our pro-vintage page
CUSTOM DESIGN SERVICE We are extending our custom
design service to include this type of transformer. We will not
make a charge for the design provided we accept the requirement
as being of general interest. We can work from circuits, actual
transformers loaned to us or from specifications. We may offer the
service on a "best efforts" basis if we cannot be sure of meeting a
particular performance.
PRE AMP AND LINE AMP PRODUCTS
100% Mumetal cores except where noted
Type
9041
9042
Description
General
purpose
output
8650
9050
High perf
output
8940
Application
Voltage
ratio
Z ratio
Total
Max level
DC res at 50 Hz
ref secy (dBu)
ohms
Max
Package
level at /core
50 Hz size/style
(V
rms)
Unit Price
(UK
Pounds)
PP triode
5CT:1
15k / 600
39
+23
(output)
11
j open 70%
Mumetal
28.50
AC coupled
Cathode
follower
3CT:1
5k / 600
39
+23
(output)
11
j open 70%
Mumetal
28.50
PP triode
9CT:1
15k / 600
81:1
14
+28
(output)
19
k open 50%
37.08
Mumetal
As 8650
reduced ratio
6CT:1
15k / 600
36:1
31
+32
30
k open 50%
37.08
Mumetal
AC Coupled
Cathode
follower
3:1
5k / 600
17
+28
(output)
19
k open 50%
37.08
Mumetal
9040
SE output
SE 45 mA 50H 5:1
25:1
65
+30
(output)
24
F+ 100% M6 57.13
3575
Input
Isolating,
Unbal/Bal
conversion
Amp or PC
card to bal
input
1:1CT
10k/10k
1300
+26
15
e (Mumetal
can)
8875
Very high perf
1:1CT
20k/20k
1300
+26
15
8920
Input phase
splitter.
1:1+1 Full
geometric
balance
10k/10k+10k
3200
+28
19
23.54
ex (Mumetal
29.03
can)
f (Mumetal
can)
36.90
3603
PC card or CD
player to bal
1:1CT
output
600/600
150
+17
5.5
e (Mumetal
can)
23.54
8540
600 ohm input
phase splitter
1:4CT
600/10k
47k load ok
112
ref pry
+16
4.9
e (Mumetal
can)
23.54
4383
600 ohm to
grid
1CT:4
600/10k
47k load ok
112
ref pry
+16
4.9
e (Mumetal
can)
23.54
4935
200 ohm to
grid
1CT:7
200/10k
47k load ok
50
ref pry
+12
3.1
e (Mumetal
can)
23.54
9045
50/200 ohm to
grid(s)
1+1:5CT
Line and mic geometric
etc input
balance
200/25k
45
ref pry
+18
6.2
j(Mumetal
can)
41.93
9062
High level 600
ohm to grid(s)
geometric
balance
1CT:4+4
600/10k+10k
103 ref
pry
+42
100
j(Mumetal
can)
49.50
9063
High level 600
ohm to grid(s)
geometric
balance
1CT:2+2
600/2k5+2k5
102 ref
pry
+36
50
j(Mumetal
can)
49.50
n/a
+/- 2
mA
f (Mumetal
can)
8347
DAC to tube
amplifier
interface
Requires 25
1:18.7
ohm I/V
resistor across
pry.
E A Sowter Ltd. The
Boatyard, Cullingham Road
IPSWICH IP1 2EG England
25/47k
4 ref
pry
34.43
Tel: +44(0)1473 252794
Fax: +44(0)1473 236188
E-Mail [email protected]