TentLabs filament supply is designed to heat DHT’s the cleanest way possible, without affecting the music currents generated inside the tubes’ heater. The supplies generate a very low noise output, while maintaining its’ high output impedance. Result areas are:
• Bigger soundstage
• Better focus
• Cleaner tone
• Better resolution
A typical example is shown below:
Each tube needs its own filament supply, in turn fed by a separate winding from the power transformer. The whole supply then is floating, and only has one connection to ground, as shown above. This example above shows the DHT in fixed bias mode. When using cathode bias, the grounded leg has to be connected to the top of the cathode resistor instead.
These are the only connections to the filament, so no caps, no hum-bucking pot, no nada!
The total output current is limited, depending on the version, but they all start-up slowly. Especially when the tube is cold, this is a nice feature. Cold tubes, when heated with traditional supplies, draw currents up to ten times their nominal current. Using TentLabs heater supply will gently switch on your tubes.
The units are factory adjusted at your order. After installation, the supply needs minor DC adjustment, to compensate for possible voltage losses in the wiring (some 100 mV are easily lost at high currents). During use, no adjustments are needed anymore, not even after changing the tubes !
The new generation filament supplies has an over temperature indicator and shutdown, in case the heatsink-temperatue exceeds 90C. The LED and wiring is supplied separately with the modules.
• Output Voltage adjustable between 1.5V and 9V, specify when ordering.
• Higher output voltages available on special order
• Output current: automatically adapts to required level to reach voltage specified above.
• Input voltage should not exceed 1 V above specification (see application info).
• Output noise < 20 uVrms (1 Hz – 20 kHz).
• Output hum < 200 uVpeak at 100Hz / 120Hz.
• Output impedance 10 mOhm at 0Hz.
• Output impedance 10kOhm > 5Hz.
• The heatsink is electrically isolated from the circuit and can be attached to a chassis
• Over-temperature shutdown with LED indication
• Total size 50*90*40mm (W*L*H, heatsink included, standoffs excluded).
• Weight each 90 gram (each, excluding packaging)
• Hole pitch 41* 81mm.
• Needs 10mm stand-offs to mount on chassis, supplied with modules.
5 years of warrantee is provided by Tentlabs (the Netherlands), assumed the products are build in according application information.
As this is a true DIY product, so no additional support can be given, more infortmation can be found in Tentlabs website.
TentLabs heater supply is designed to supply the heaters of indirectly heated tubes. Its’ main use is feeding phono and linestage tubes, to keep the hum levels down. The module can also be applied to feed other circuits, like the CDpro CD driver.
More tubes can be connected in parallel, assumed their respective heaters are at equal potential. If heater potentials are different, separate modules (and transformer windings for each module) are required. The heater reference needs to be connected close to the tube The total output current is limited to 1.5Adc, mainly due to heat dissipation. The units are factory adjusted at your order. After installation, the supply needs no adjustment.
• Output adjustable between 2.5V and 13V, specify when ordering
• Output current maximum 1.5A
• Input voltage should not exceed 1 V above specification (see application info – to be written)
• Minimum input voltage 4 Vac
• Output noise < tbd uVrms (10Hz – 20kHz)
• Output hum < tbd uVpeak at 100Hz / 120Hz
• Output impedance < tbd mOhm
• Fast switch-off function available on request (required if used to supply 9V section of philips CDpro CD drive)
• The heatsink is not electrically isolated from the circuit and should be isolated from the chassis
• The output is not short circuit proof
• Total size 40*60*40mm (W*L*H, heatsink included, standoffs excluded).
• Weight each 60 gram (excluding packaging)
• Hole pitch 31* 51mm, hole diameter 3.5mm
• Needs 8mm stand-offs to mount on chassis, supplied with modules.
PRICING & WARRANTEE
5 years of warrantee by Tentlabs (the Netherlands), assumed they are built in according application information.