Chokes, mostly used in tube amplifiers
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 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 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.
Very low current chokes, normally used as grid chokes
| Photo | Current | Type | Inductance | Winding resistance | Weight | Typical use |
|---|---|---|---|---|---|---|
 | 0.8 mA | LL1670 | 540 | 4.8k | 88 g | Grid choke |
Low current chokes, most often used as anode chokes
| Photo | Application current (mA) | Type | Configuration (serial or parallel) | Inductance (H) | Capacity (I * L) (Vs) | Winding resistance (ohm) | Weight (kg) | Typical use |
|---|---|---|---|---|---|---|---|---|
 | 5 – 40 | LL1667 | Serial | 800 – 100 | 4.05 | 2.4k | 0.75 | High impedance anode choke |
| 10 – 60 | LL1668 | Serial | 250 – 40 | 2.5 | 680 | 0.75 | Anode choke | |
| 10 – 100 | LL2743 | Serial | 440 – 44 | 4.5 | 400 | 1.35 | Anode choke |
Medium current chokes, most often used in anode voltage power supplies
| Photo | Application current (mA) | Type | Configuration (serial or parallel) | Inductance (H) | Capacity (I * L) (Vs) | Winding resistance (ohm) | Weight (kg) | Typical use |
|---|---|---|---|---|---|---|---|---|
 | 150 – 400 300 – 800 | LL1638 LL1638 | Serial Parallel | 10 – 4 2.5 – 1 | 1.5 0.8 | 36 9 | 1.35 1.35 | Power supply Power supply |
 | 100 – 200 200 – 400 | LL1673 LL1673 | Serial Parallel | 20 – 10 5 – 2.5 | 2 1 | 60 15 | 1.35 1.35 | Power supply Power supply |
 | 100 – 200 200 – 400 | LL1685 LL1685 | Serial Parallel | 17 – 9 4 – 2 | 1.7 0.8 | 130 32 | 0.75 0.75 | Power supply Power supply |
 | 100 – 300 200 – 600 | LL2742 LL2742 | Serial Parallel | 42 – 14 10 – 3 | 4.2 2 | 160 40 | 1.35 1.35 | Power supply Power supply |
| 500 – 1000 1000 – 2000 | LL2771 LL2771 | Serial Parallel | 6 – 3 1.5 – 0.7 | 3 1.5 | 11 3 | 4.9 4.9 | Power supply Power supply |
High current chokes, most often used in filament current supplies or for solid state applications
| Photo | Application current (A) | Type | Configuration (serial or parallel) | Inductance (mH) | Capacity (I * L) (Vs) | Winding resistance (ohm) | Weight (kg) | Typical use |
|---|---|---|---|---|---|---|---|---|
 | 1 – 2 2 – 4 | LL1694 LL1694 | Serial Parallel | 240 – 120 60 – 30 | 0.24 0.12 | 1.8 0.45 | 0.83 0.83 | Filament current supply Filament current supply |
 | 1 – 2 2 – 4 | LL2733 LL2733 | Serial Parallel | 700 – 350 170 – 80 | 0.7 0.35 | 3.4 0.9 | 1.35 1.35 | Filament current supply Filament current supply |
| 0.5 – 1 1 – 2 | LL2751 LL2751 | Serial Parallel | 200 – 100 50 – 25 | 0.11 0.05 | 1 0.25 | 0.44 0.44 | Small tube filament current Small tube filament current | |
| 1 – 3 2 – 6 | LL2772 LL2772 | Serial Parallel | 250 – 80 60 – 20 | 0.24 0.12 | 0.7 0.2 | 1.35 1.35 | Power supply (low voltage) Power supply (low voltage) | |
 | 2 – 5 4 – 10 | LL2773 LL2773 | Serial Parallel | 160 – 65 40 – 16 | 0.33 0.15 | 0.44 0.11 | 2.5 2.5 | Power supply (low voltage) Power supply (low voltage) |
