TentLabs E-choke
“Quiet background, more details, incredible specs ”
DIY
The module comes fully assembled and tested. It can be used for the upgrade of an existing tube amplifier, or when building new. The E-choke is not suited as choke input filter, nor as active anode load, as it does not store energy.
General Description
Designer Menno Vanderveen set the concept for this DIY module. The E-choke replaces traditional chokes that generally work quite well, but suffer from serious disadvantages:
• high weight
• big size
• magnetic field radiation that induces hum in the circuit
The E-choke effectively solves all these issues, and offers up to 70dB supply ripple reduction at currents up to 500 mAdc. In addition, intermodulation distortion reduces dramatically, see the measurements and background articles below.
UL40-S2, triode, distortion no E-choke
UL40-S2, triode, distortion with E-choke
Look how effectively the choke removes the hum, but also dramatically reduces the intermodulation products of the signal (1 kHz) with power supply ripple (100 Hz)
Technical description
See the background articles by Menno Vanderveen:
• E-choke design (English)
Specifications
Electrical
• Imax out 500mAdc
• Vmax in 450Vdc (can be adapted to 600Vdc max when changing input capacitor to suitable working voltage)
• Vripple 15Vtt (maximum input ripple)
• Equivalent inductance 10H
• C-in 330uF/450V (included on module):
C-in may be reduced linearly when current consumption is lower than 500mA
C-in must be reduced when valve rectification is applied
• C-out 330uF/450V (externally required, recommended value)
• Voltage drop <17Vdc (in-out at 500mAdc load)
• Dissipation <5W
• Heatsink integrated, connected to ground
• Rejection :
>40dB, time modus off (mostly used with class AB amplifiers)
>60dB, time modus on (recommended for class A amplifiers)
• short circuit NOT protected, always include fuse at module output
Specifications
Mechanical
PCB size: 72*50*50 mm (W*L*H) (includes electrolytic, excludes standoffs)
Hole pitch: 63*41 mm (symmetrical). All hole diameters 3.2 mm
Manual
No manual yet. Connections are fairly straightforward, see example below:
Warranty
This module is warranted for 5 years, assumed all mounting instructions are followed