
Tibeliusgatan 7 International Domestic
LUNDAHL
S-761 50 NORRTÄLJE Phone +46 - 176 13930 0176-13930
SWEDEN Fax +46 - 176 13935 0176-13935
TRANSFORMERS
Moving Coil Input Transformer
LL1933
LL1933 is a high performance moving coil step-up transformer. The transformer combines our dual coil structure with
Cardas high purity copper wire in an oversized design. The objective with LL1933 is to provide an alternative for the
successful amorphous core LL1931 for those who prefer a low distortion, linear magnetization curve nickel lamination
core transformer. The dual-coil structure greatly improves immunity to external magnetic fields from power supplies,
motors etc. The transformer is housed in a mu-metal can.
Turns ratio: 1 + 1 : 8 + 8
Pin layout (viewed from component
side) and winding schematics:
Dimensions (L x W x H above PCB, in mm)
47 x 28 x 24
Spacing between pins
5.08 mm (0.2")
Spacing between rows of pins
35.6 mm (1.4")
Rec. PCB hole diameter:
1.5 mm
Weight:
115 g
Static resistance of each primary:
1.5 Ω
Static resistance of each secondary:
85 Ω
Frequency response (serial connection, source 50 Ω,
no load / secondaries open):
8 Hz -- 100 kHz +/- 1.0 dB
Isolation between windings/ between windings and core: 3 kV / 1.5 kV
Connection alternatives:
R090209
Serial-serial connection 1 : 8
8
2
1
10
4
4
2
1
10
9
7
5
6
LL1933
Top view
7
8
Can + core
Parallel-serial connection 1:16
+
+
+
4
2
1
10
9
7
5
6
LL1933
Top view 8
+
10 5
9 4
2
1
7
6
LL1933
8
Top view
Cartridge is grounded through primary
center tap. If phono preamp input is
unbalanced, connect pins 9 and 8 to input
ground.
Cartridge is grounded through primary
“cold”. If phono preamp input is
unbalanced, connect pins 9 and 8 to input
ground.
If cartridge cable is unbalanced (such as
a coaxial cable), ground cartridge
through pin 2 and not through pins 1+4.