
High Level Audio Output Transformer
LL1585
LL1585 is a high level audio line output transformer for balanced or unbalanced drive. The transformer is built
from two three-section coils, with primaries and secondaries separated by electrostatic shields, and a audio C-
core of our own production. The transformer is housed in a mu-metal housing.
The LL1585 is (as all output transformers) ideally used with mixed feedback drive circuits. (See separate paper
for mixed feedback design principles).
Turns ratio: 1 + 1 : 1 + 1
Dims (Length x Width x Height above PCB (mm)): 47 x 34 x 21
Pin layout (viewed from component side) and winding schematics:
Spacing between pins:
5.08 mm (0.2")
Spacing between rows of pins:
35.56 mm (1.4")
Weight:
130 g
Core:
Audio C-core
Housing:
Mu-metal
Rec. PCB hole diameter:
1.5 mm
Static resistance of each primary:
64
Ω
Static resistance of each secondary:
64
Ω
Leakage inductance of secondaries (sec. in series): 0.4 mH
No-load impedance, typically (primaries in series):
8 k
Ω
@ 50 Hz, 15V RMS.
Optimum source impedance:
Minus 128
Ω
(Mixed feedback drv)
Balance of output (according to IRT, source < 10
Ω
, Load 600
Ω):
> 60 dB
Maximum output level before saturation (sec. in series, load 600
Ω
)
+ 28 dBU @ 20 Hz
Frequency response (source 10
Ω,
load 600
Ω
):
10 Hz -- 100 kHz +/- 0.3 dB
Loss across transformer (at midband with 600
Ω
load):
3 dB
Isolation between primary and secondary windings / between
windings and core:
4 kV / 2 kV
Suggested use
126
5
4
3
2
1
11
9
8
7
126
5
4
3
2
1
11
9
8
7
Tibeliusgatan 7 International Domestic
S-761 50 NORRTÄLJE Phone +46 - 176 13930 0176-13930
SWEDEN Fax +46 - 176 13935 0176-13935
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2
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5
9
4
12
11
LL1585
LL1585
R20001213
(top view)