Lundahl Transformers - General purpose audio transformers

General purpose transformers
General purpose audio transformers for ground isolation, for splitting and for low turns ratio microphone input.

General properties:

Many different connection alternatives possible
Moderat copper resistance (50 ohms per section typically)
Medium level capability (Max 10 dBU at 50 Hz per section typically)
Excellent magnetic and electrostatic shielding
High mu cores (mu metal or amorphous strip core)

Type Turns Ratio Size (LxWxH mm) Max Prim. Level.
1% dist, 50Hz (Prim. in series) Applications

LL1527 1+1 : 1+1 38x24x17 +16 dBU The "standard" problem solver. Ground isolation, MS decoding,
splitting 1 direct + 1 isolated outputs. Mic input 200:800 ohms.

LL1527XL 1+1 : 1+1 38x24x20.5 +19 dBU As LL1527,
but with + 3 dB level capability compared to the LL1527

LL1527A 1+1 : 1+1 38x24x17 +16 dBU As LL1527.
Secondary shields available individually on connector pins.

LL1532 1+1 : 2 28x17x15 +10 dBU A small size audio transformer.
For isolation, microphone input (200:800 ohms) and bridging input.

LL1570 1+1 : 1+1 38x24x17 +16 dBU Splitting 1 direct + 1 isolated outputs. High fidelity isolation and microphone input (200 : 800 ohms)

LL1570XL 1+1 : 1+1 38x24x20.5 +19 dBU As LL1570,
but with + 3 dB level capability compared to the LL1570

LL1581XL 1+1 : 1+1 38x24x20.5 +13 dBU
(Prim in parallel) Splitting 1 direct + 2 isolated outputs.
Very high immunity to external magnetic fields and to large ground differences.

LL1583 1 : 1+1 28x17x15 +8 dBU
(Prim in parallel) Splitting 1 direct + 2 isolated outputs.
Small size mic. level transformer with the same excellent noise immunity as the LL1581XL.

LL1588 1+1 : 1+1 47x28x24 +28 dBU High level isolation applications
1:2 microphone input. Phase splitting.

LL1684 1+1 : 1+1 42x28x22 +25 dBU Amorphous core version of LL1588.
High level isolation applications
1:2 microphone input. Phase splitting.

LL7902 1+1+1+1 : 1+1+1+1 66x32x21 +28 dBU High level high quality general purpose transformer for very demanding applications.
"When only the best is good enough".

LL7904 1+1: 1+1 66x32x21 +23 dBU
(Prim in parallel) Very high level splitting transformer for 1 direct + 2 isolated outputs.
Very high immunity to external magnetic fields and to large ground differences.

Type	Turns Ratio	Size (LxWxH mm)	Max Prim. Level. 1% dist, 50Hz (Prim. in series)	Applications
LL1527	1+1 : 1+1	38x24x17	+16 dBU	The "standard" problem solver. Ground isolation, MS decoding, splitting 1 direct + 1 isolated outputs. Mic input 200:800 ohms.
LL1527XL	1+1 : 1+1	38x24x20.5	+19 dBU	As LL1527, but with + 3 dB level capability compared to the LL1527
LL1527A	1+1 : 1+1	38x24x17	+16 dBU	As LL1527. Secondary shields available individually on connector pins.
LL1532	1+1 : 2	28x17x15	+10 dBU	A small size audio transformer. For isolation, microphone input (200:800 ohms) and bridging input.
LL1570	1+1 : 1+1	38x24x17	+16 dBU	Splitting 1 direct + 1 isolated outputs. High fidelity isolation and microphone input (200 : 800 ohms)
LL1570XL	1+1 : 1+1	38x24x20.5	+19 dBU	As LL1570, but with + 3 dB level capability compared to the LL1570
LL1581XL	1+1 : 1+1	38x24x20.5	+13 dBU (Prim in parallel)	Splitting 1 direct + 2 isolated outputs. Very high immunity to external magnetic fields and to large ground differences.
LL1583	1 : 1+1	28x17x15	+8 dBU (Prim in parallel)	Splitting 1 direct + 2 isolated outputs. Small size mic. level transformer with the same excellent noise immunity as the LL1581XL.
LL1588	1+1 : 1+1	47x28x24	+28 dBU	High level isolation applications 1:2 microphone input. Phase splitting.
LL1684	1+1 : 1+1	42x28x22	+25 dBU	Amorphous core version of LL1588. High level isolation applications 1:2 microphone input. Phase splitting.
LL7902	1+1+1+1 : 1+1+1+1	66x32x21	+28 dBU	High level high quality general purpose transformer for very demanding applications. "When only the best is good enough".
LL7904	1+1: 1+1	66x32x21	+23 dBU (Prim in parallel)	Very high level splitting transformer for 1 direct + 2 isolated outputs. Very high immunity to external magnetic fields and to large ground differences.

Per Lundahl, email: web_master/AT/lundahl/DOT/se

Lundahl Transformers AB
Tibeliusgatan 7
SE-761 50 Norrtälje
SWEDEN
Phone: +46 - 176 139 30
Fax: +46 - 176 139 35
Email: office/AT/lundahl/DOT/se