Chokes
We have a wide range of chokes and inductors for tube amplifiers, ranging from anode choke LL1667 (operating current from 5 mA) to filament current choke LL7233 operating at 3.4 A
Our chokes are built to order in our dual coil single C-core style. The use of C-cores with well-defined air-gap results in an almost constant inductance throughout the whole operating voltage range.
Most of our chokes can be ordered for operating current within about 10% of desired value (within a reasonable current range), even if this value is not presented in the data sheet. The column “Capacity” can be used to calculate the estimated resulting inductance for undocumented versions. For available sub-types of chokes, please click here.
For example the LL1638/300mA in serial connection will have an inductance approx. 1.5Vs / 0.3A = 5H.
When measuring/verifying the inductance in this type of chokes, make sure to use conditions similar to the operating conditions.
When calculation the signal headroom in a power supply choke, the ripple voltage from a rectified sinus signal is approx. 42% of original RMS voltage. As long as max voltage ratings are not exceeded, all our power supply chokes can be used in choke input configurations. In applications where the current consumptions is almost constant (such as a class A amplifier), the input current spikes will be significantly less compared to a capacitor input supply.
High current chokes, mostly used for filament supplies or for solid state application
|
Model
|
Current (A)
|
Configuration
series or parallel
|
Inductance
mH
|
Capacity
(I*L) (Vs)
|
Winding resistance
(ohm)
|
Weight
kg
|
Typical use
|
Price
USD
|
|
1 - 2
|
series
|
240 -120
|
0.24
|
1.8
|
0.83
|
Filament supply
|
89.00
|
|
|
2 - 4
|
parallel
|
60 - 30
|
0.12
|
0.45
|
0.83
|
Filament supply
|
89.00
|
|
|
1 - 2
|
series
|
700 - 350
|
0.7
|
3.4
|
1.35
|
Filament supply
|
114.00
|
|
|
2 - 4
|
parallel
|
170 - 80
|
0.35
|
0.9
|
1.35
|
Filament supply
|
114.00
|
|
|
0.5 - 1
|
series
|
200 -100
|
0.11
|
1
|
0.44
|
Small tube filament supply
|
88.00
|
|
|
1 - 2
|
parallel
|
50 - 25
|
0.05
|
0.25
|
0.44
|
Small tube filament supply
|
88.00
|
|
|
1 - 3
|
series
|
250 - 80
|
0.24
|
0.7
|
1.35
|
Low voltage power supply
|
127.00
|
|
|
2 - 6
|
parallel
|
60 - 20
|
0.12
|
0.3
|
1.35
|
Low voltage power supply
|
127.00
|
|
|
2 - 5
|
series
|
160 - 65
|
0.33
|
0.44
|
2.5
|
Low voltage power supply
|
164.00
|
|
|
4 - 10
|
parallel
|
40 - 16
|
0.15
|
0.11
|
2.5
|
Low voltage power supply
|
164.00
|
Very low current choke, normally used as a grid choke
|
Model
|
Current (A)
|
Inductance
H
|
Winding resistance
|
Weight
grams
|
Typical use
|
Price
USD
|
|
0.8mA
|
540
|
4.8K
|
88
|
Grid choke
|
70.00
|
|
|
|
1.8
0.45
|
series 25Ω
parallel 6.2Ω
|
68
|
extremely low current choke
replaces LL4611
|
92.00
|
|
|
|
0.18
45mH
|
series 25Ω
parallel 6.2Ω
|
68
|
extremely low current choke
replaces LL4611
|
92.00
|
Low current choke, normally used as anode chokes
|
Model
|
Current (mA)
|
Configuration
series or parallel
|
Inductance
H
|
Capacity
(I*L) (Vs)
|
Winding resistance
|
Weight
kg
|
Typical use
|
Price
USD
|
|
5 - 40
|
series
|
800 - 100
|
4.05
|
2.4K
|
0.75
|
High impedance anode choke
|
118.00
|
|
|
10 - 60
|
series
|
250 - 40
|
2.5
|
680Ω
|
0.75
|
Anode choke
|
113.00
|
|
|
LL1668AM
|
10 - 60
|
series
|
250 - 40
|
2.5
|
680Ω
|
0.75
|
Anode choke, amorphous core
|
280.00
|
|
LL1668Ag
|
10 - 60
|
series
|
250 - 40
|
2.5
|
680Ω
|
0.75
|
Anode choke, silver wire
|
2173.00
|
|
LL1668AgAM
|
10 60
|
series
|
250 - 40
|
2.5
|
680Ω
|
0.75
|
Anode chokem silver wire and amorphous core
|
2424.00
|
|
10 - 100
|
series
|
440 - 44
|
4.5
|
400Ω
|
1.35
|
Anode choke
|
128.00
|
|
|
LL2743AM
|
10 - 100
|
series
|
440 - 44
|
4.5
|
400Ω
|
1.35
|
Anode choke, amorphous core
|
328.00
|
|
LL2743Ag
|
10 - 100
|
series
|
440 - 44
|
4.5
|
400Ω
|
1.35
|
Anode choke, silver wire
|
3334.00
|
|
LL2743AgAM
|
10 - 100
|
series
|
440 - 44
|
4.5
|
400Ω
|
1.35
|
Anode choke, silver wire and amorphous core
|
3644.00
|
|
Model
|
Current (mA)
|
Configuration
series or parallel
|
Inductance
H
|
Capacity
(I*L) (Vs)
|
Winding resistance
(ohm)
|
Weight
kg
|
Typical use
|
Price
USD
|
|
150 - 400
|
series
|
10 - 4
|
1.5
|
36
|
1.35
|
Power supply
|
118.00
|
|
|
300 - 800
|
parallel
|
2.5 - 1
|
0.8
|
9
|
1.35
|
Power supply
|
118.00
|
|
|
100 - 200
|
series
|
20 - 10
|
2
|
60
|
1.35
|
Power supply
|
118.00
|
|
|
200 - 400
|
parallel
|
5 - 2.5
|
1
|
15
|
1.35
|
Power supply
|
118.00
|
|
|
100 - 200
|
series
|
17 - 9
|
1.7
|
130
|
0.75
|
Power supply
|
108.00
|
|
|
200 - 400
|
parallel
|
4 - 2
|
0.8
|
32
|
0.75
|
Power supply
|
108.00
|
|
|
100 - 300
|
series
|
42 - 14
|
4.2
|
160
|
1.35
|
Power supply
|
125.00
|
|
|
200 - 600
|
parallel
|
10 - 3
|
2
|
40
|
1.35
|
Power supply
|
125.00
|
|
|
500 - 1000
|
series
|
6 - 3
|
3
|
11
|
4.9
|
Power supply
|
200.00
|
|
|
1000 - 2000
|
parallel
|
1.5 - 0.7
|
1.5
|
3
|
4.9
|
Power supply
|
200.00
|
Medium current choke, normally used in anode power supplies
To place an order, please send your inquiry with your complete shipping address to erhardaudio@gmail.com, thank you.
An import tariff of 15% will be added to ALL Lundahl transformers and accessories, until further notice.