
Audio Transformer/Moving Coil Input Transformer
LL9206
LL9206 is an input audio transformer for moving coil pickups. The transformer is built up from two coils, each
coil with one secondary winding surrounded by two primary windings. This structure results in an excellent
frequency response. All winding ends are available on the pins. Thus, the transformer can be used with a set of
different turn’s ratios.
The LL9206 is made with amorphous core material. As this type of core does not store energy (unlike e.g.
conventional mu-metal cores) the low frequency resonance with external series capacitors is practically
eliminated.
Turns ratio: 1 + 1 + 1 + 1 : 10 + 10
Dims: (Length x Width x Height above PCB (mm)) 30 x 22.5 x 14.5
Pin Layout (viewed from pins
side) and windings schematics:
Spacing between pins: 2.54 mm (0.1")
Spacing between rows of pins: 22.86 mm (0.9")
Weight: 27 g
Rec. PCB hole diameter: 1.5 mm
Static resistance of each
primary (average): 10
Ω
Static resistance of each
secondary (average): 395
Ω
Self resonance point : > 250 kHz
Frequency response (@ -10 dBU, all in series. Source 50Ω , load 100 kΩ) :
10 Hz -- 25 kHz +/- 1 dB
10 Hz -- 90 kHz +/- 1.5 dB
Distortion (primaries connected in series, source impedance 50Ω ): < 0.5% @ -2 dBU, 50 Hz
Primary no load impedance @ 0 dBU, 50 Hz, all in series: 8 kΩ typically
Core / Can: Amorphous Strip Core / Mu metal can
Isolation between windings / between windings and core: 3 kV / 1.5 kV
Turns ratio and possible use at different termination alternatives.
Termination alternatives are shown on the next page
Termination
Alternative
Turns
ratio
Copper Resistance
prim/sec
Possible Use
A 1:5 40Ω / 790 Ω 400Ω / 10 kΩ
B 1:5 10Ω / 200 Ω Not recommended
C 1:10 10Ω / 790 Ω 100Ω / 10kΩ
D 1:10 2.5Ω / 200 Ω Not recommended
E 1:20 2.5Ω / 790 Ω 25Ω / 10kΩ
1 9
2
3
4
5
6
7
8
10
11
13
14
15
16
4
3
2
1
5
6
7
8
15
16
10
9
Can + Core 13, 14
Tibeliusgatan 7 International Domestic
S-761 50 NORRTÄLJE Phone +46 - 176 13930 0176-13930
SWEDEN Fax +46 - 176 13935 0176-13935
R020201
When the LL9206 is used in
MC pickup applications,
please note that the primary
side of the transformer must
have a ground reference.