Microphone Transformers
Microphone transformers are normally used for impedance matching:
At mic preamp input circuits to match microphones to preamp.
In tube microphones for matching high impedance tube circuits to normal output impedance.
In ribbon microphones to transform very low voltage, very low impedance ribbon motors to normal microphone output levels.
 
General properties of Lundahl microphone transformers :
 
PCB mount style (with exceptions)
High level capability
Excellent magnetic and electrostatic shielding
High mu cores (mu metal or amorphous strip core)
 
For Breakout PCB's, check here
 
 
 
Microphone Transformers
 Model
Turns
Ratio
Size
LxWxH mm
MAX
Prim Level
Comments
Price
USD
1+1:1+1
38x24x17
+16dBU
The "standard" problem solver. Ground isolation, MS decoding,
splitting 1 direct + 1 isolated outputs. Mic input 200:800 Ω.
67.00
1+1:2.5+2.5
38x24x17
+10dBU
200:5kΩ
68.00
1+1:3.5+3.5
38x24x17
+10dBU
200:10kΩ Also used in DI boxes 10k : 200Ω
68.00
1+1:5
38x24x17
+10dBU
200:5kΩ Probably the best 1:5 microphone input transformer available
77.00
1+1:1+1
38x24x20.5
+13dBU
200:5kΩ High level version of the LL1538
Larger core to the LL1538, able to handle higher signal levels.
89.00
1+1+1+1:4+4
30x23x14.5
+13dBU
200:3.2kΩ if used 1:4. Many other connections possible
88.00
1+1:1+1
38x24x17
+10dBU
200 : 200 Ω or 200 : 800 Ω. For low impedance input mic preamps such as
Jensen JE-990
74.00
 1+1:1+1
 38x24x20.5
 +10dBU
 200 : 200 Ω or 200 : 800 Ω. For low impedance input mic preamps such as
Jensen JE-990. Larger core to the LL1570, able to handle higher signal levels.
85.00
1+1:1.75+1.75
38x24x17
+10dBU
200:2.5kΩ
77.00
1+1:7
38x24x17
+10dBU
200:10kΩ Same pinout as the LL1538
77.00
1+1:14
38x24x17
+10dBU
50:10kΩ Same pinout as the LL1538. For low impedance source.
77.00
1+1:10
38x24x17
+10dBU
50:5kΩ Same pinout as the LL1538. For low impedance source.
77.00
1+1:10
38x24x20.5
+13dBU
50:5kΩ Same pinout as the LL1538. For low impedance source.
Larger core to the LL1578, able to handle higher signal levels.
89.00
1+1:4
26x17x12
+2dBU
200:3.2kΩ Small size
62.00
1+1+1+1:10+10
30x23x14.5
+14dBU
Mic input. DI-box. Moving coil input
92.00
1+1+1+1:4+4
37x23x12
+7dBU
50:3.2k if used 1:8 Many other connections possible
77.00
1+1:55+55
30x23x14.5
  
Ribbon microphones (used 1:110) Amorphous core. For active output stage
91.00
1+1:5+5
38x23x16
+7dBU
DI (direct input) used 10:1 Mic input 200:20k
71.00
(2+1)+(2+1):4+4
48x29x20
+14dBU
Can be connected for 75,150,300 and 600Ω microphones into 1200Ω
98.00
9:1+1
31x25x16
  
Tube microphones. Silicon-iron C-core, which results in a transformer
with more "transformer sound character", compared to a classic mu metal
lamination transformer. PCB mount style.
60.00
1+1:14
37x22x17
+10dBU
Compatible with LL1577, but with reduced internal capacitance
68.00
2:1
25x15.8x14.5
+15dBU
Output transformer for solid state microphones
62.00
1:37
27x18.8 diam
  
Ribbon microphones. Amorphous core. Flying leads. No housing
78.00
1+1+1+1:37
30x22.5x14.5
  
Ribbon microphones. Amorphous core. PCB version of LL2912.
With mu metal housing.
78.00
1+1+1+1:37
38x24x17
  
Ribbon microphones. Mu metal core version of the LL2913
67.00
1:37
36x22 diam
  
Ribbon microphones. Mu metal lamination core. Flying leads. No housing
71.00
LL2916
1+1:55+55
38x23x26
  
Mu metal lamination core version of the LL1927A
80.00
1+1+1+1:2+2+2+2
66x32x21
+16dBU
200:313kΩ (used 1:8) This is the ultimate microphone input transformer, designed for high quality tube equipment
143.00
LL7903Ag
            "
        " 
      "
As per the LL7903 above but wound using silver wire
639.00
1+1+1+1:5.6+5.6
66x32x21
+16dBU
improved version of the LL7905
143.00
LL7906Ag
            "
        "
      "
  As per the LL7906 above but wound using silver wire
639.00
To place an order, please click here
Breakout pcb's for Lundahl audio transformers