Lundahl output transformers.

Recommendations by tube type

Tube

Ra @ Plate to Cathode Voltage
Transformer
Order Nr
Primary
Secondary Output Power

Low Freq.
Response
Notes

1605

SE

110mA@580V
Ra=861Ω
218-111-49

3kΩ
24Henry

Alt.B = 4Ω
Alt.C = 8Ω
Alt.D = 16Ω
22Watt
16Hz @1.5dB
 

2x 1605

PSE

220mA@580V
Ra=430Ω

218-269-58

1k6Ω
13H
Alt.C = 4Ω
Alt.D = 8Ω
Alt.E = 16Ω
44Watt
15Hz @1.5dB
 

4x 1605

PSE
440mA@580V
Ra=215Ω

218-179-91

600Ω
8H
(in parallel)
Alt.C = 4Ω
Alt.D = 8Ω
Alt.E = 16Ω
91Watt
15Hz @1.5dB

2A3
2A3-mesh
AD1

SE

60mA @250V
Ra=800Ω
218-109-00
3kΩ
46H

Alt.B = 4Ω
Alt.C = 8Ω
Alt.D = 16Ω
3.5Watt

8Hz @1.5dB
 

2A3
2A3-mesh
AD1

SE

60mA @250V
Ra=800Ω

218-134-09
3kΩ
29H

3.5Watt
12Hz @1.5dB
 

2x 2A3
2x 2A3-mesh
2x AD1

PSE

each tube
60mA @250V
Ra=400Ω

218-107-95
1k2Ω
12H
Alt.B = 4Ω
Alt.C = 8Ω
Alt.D = 16Ω
7Watt
16Hz @1.5dB
2A3-S
75mA @375V
Ra=745Ω
218-110-72
3kΩ
30H
Alt.B = 4Ω
Alt.C = 8Ω
Alt.D = 16Ω
9Watt
5Hz @1.5dB
 

2x 2A3-S

PSE

each tube
75mA @375V
Ra=373Ω
218-108-27
1k2Ω
9H
Alt.B = 4Ω
Alt.C = 8Ω
Alt.D = 16Ω
20Watt
10Hz @1.5dB
 

20B

SE

42mA @420V
Ra=3k4Ω
218-143-29

16k
17H


8Watt

19Hz @1.5dB

 

300B-mesh

SE

60mA@365V
Ra=700Ω

218-134-09
3kΩ
29H
7Hz @1.5dB
 

300B-mesh

SE

60mA@365V
Ra=700Ω
218-109-00
3kΩ
46H
Alt.B = 4Ω
Alt.C = 8Ω
Alt.D = 16Ω
7Watt
3Hz @1.5dB
 
300B
80mA@400V
Ra=790Ω
218-110-72
3kΩ
30H
Alt.B = 4Ω
Alt.C = 8Ω
Alt.D = 16Ω
5Hz @1.5dB
 

300B-XLS

SE

80mA@450V
Ra=700Ω
218-135-90
3kΩ
22H
Alt.B = 4Ω
Alt.C = 8Ω
Alt.D = 16Ω
15Watt
5Hz @1.5dB
 
300B-XLS
80mA@450V
Ra=700Ω
218-110-72
3kΩ
30H
Alt.B = 4Ω
Alt.C = 8Ω
Alt.D = 16Ω
15Watt
5Hz @1.5dB
 

300B-XLS

SE

110mA@457V
Ra=670Ω
218-251-91
3k
23H
Alt.B = 4Ω
Alt.C = 8Ω
Alt.D = 16Ω
20Watt
7Hz @1.5dB
 
45 or 45 Mesh
34mA @250V
Ra=1750Ω
218-114-48
6kΩ
60H
Alt.B = 4Ω
Alt.C = 8Ω
Alt.D = 16Ω
1.5Watt

13Hz @1.5dB

 

45 or 45 Mesh

SE

36mA @275V
Ra=1670Ω
218-114-48
6kΩ
60H
Alt.B = 4Ω
Alt.C = 8Ω
Alt.D = 16Ω
1,8Watt

12Hz @1.5dB

 
45 Mesh only
39mA @300V
Ra=1600Ω
218-114-48
6kΩ
60H
Alt.B = 4Ω
Alt.C = 8Ω
Alt.D = 16Ω
2,5Watt

12Hz @1.5dB

45 or 45 Mesh

SE

36mA @275V
Ra=1670Ω

LL1663-039mA

218-258-83
5kΩ
45H

2Watt

17Hz @1.5dB

45 or 45 Mesh

SE

34mA @250V
Ra=1750Ω

LL1663-039mA

218-258-83
5kΩ
45H

1.6Watt
17H @1.5dBz
45 Mesh only
39mA @300V
Ra=1600Ω

LL1663-039mA

218-258-83

5kΩ
45H


2.9Watt
17Hz @1.5dB

2x45 Mesh only

PSE

2x39mA @300V
Ra=800Ω
218-131-76
3kΩ
29H

5.2Watt
10Hz @1.5dB

50

SE

55mA @450V
Ra=1800Ω
Custom made. Price is same as normal LL1679
4k3Ω
51H
Alt.B = 4Ω
Alt.C = 8Ω
Alt.D = 16Ω
4.3Watt

16Hz @1.5dB

520B

SE

120mA@500V
Ra=500Ω
218-111-49
3kΩ
24H
Alt.B = 4Ω
Alt.C = 8Ω
Alt.D = 16Ω
17Watt
8Hz @1.5dB

520B

SE

120mA@500V
Ra=500Ω
218-268-19
2k2Ω
23H
Alt.C = 4Ω
Alt.D = 8Ω
Alt.E = 16Ω
20Watt
8Hz @1.5dB
 

2x 520B

PSE

240mA@500V
Ra=250Ω
218-268-19
1kΩ
16H
Alt.B = 4Ω
Alt.C = 8Ω
Alt.D = 16Ω
41Watt
7Hz @1.5dB
 

Note 1) Note, EML Mesh Version can do higher power than solid plate version. This is NOT so with China tubes. gst other this will give better bias stability of the tube, some protection against accidental overload, and better linearity of tube curves.

Note 2) Application for ultra low distortion.

Note 3) These two transformers are simply point to point connected in parallel. Thought it may seem hard to believe, primary and secondary impedance will stay the same this way, because the windings ratio will not chance. The total configuration, so two transformers in parallel, behave like this: Maximum Ouput=140Watt. Inductance= 8H. Maximum DC current=460mA. Primary 600Ω. Secundary: ALT-C= 4Ω. ALT-D=8Ω. Alt-E=16Ω.