
Moving Coil Input Transformer
LL1681
The LL1681 is a large core moving coil input transformer with a mu-metal core.
The LL1681 consists of two coils, each with a two-sectioned primary winding and one high level secondary
winding (with paper insulation) separated by electrostatic shields.
The transformer is magnetically shielded by a mu metal housing.
Turns ratio: 1 + 1 : 13 + 13
Dims (Length x Width x Height above PCB (mm)): 48 x 29 x 20
Pin layout (viewed from component
side) and winding schematics:
Spacing between pins:
5.08 mm (0.2")
Spacing between rows of pins:
35.56mm (1.4")
Weight:
90 g
Rec. PCB hole diameter:
1.5 mm
Static resistance of each primary:
4.8Ω
Static resistance of each secondary:
820Ω
Distortion
(Transformer connected 1:26, source impedance 40 ohms)
< 0.15% at –10 dBU, 50Hz
(typically 0.1%)
< 1% at +5 dBU, 50Hz
Frequency response, balanced input
(Transformer connected 1:13, source 50Hz, sec. level +10dBU)
7Hz – 70 kHz +/- 1dB
Frequency response, Unbalanced input
(Transformer connected 1:13, source 50Hz, sec. level +10dBU)
7Hz – 40 kHz +/- 1dB
Isolation between primary and secondary windings/ between
windings and shield:
4 kV / 2 kV
R020924
Tibeliusgatan 7 International Domestic
SE-761 50 NORRTÄLJE Phone +46 - 176 13930 0176-13930
SWEDEN Fax +46 - 176 13935 0176-13935
5
4
1
10
9
6
7
5
4
2
1
10
9
7
6
LL1681
(Top view)
8
Indicates phase
5
4
2
1
10
9
7
6
LL1681
(To
view)
8
5
4
2
1
10
9
7
6
LL1681
(To
view)
8
Connection for turns ratio 1 : 26 Connection for turns ratio 1 : 13