QS-LV – Quiet Supply for Low-Voltage Tube Amps

CAD $58.00CAD $88.00


The London Power Quiet Supply for Low-voltage Tube Amps (QS-LV) provides a significant reduction of supply-borne noise and hum – typically 60dB from 50Hz to 120Hz. Supply noise is especially problematic for single-ended amps, but the QS-LV will make an SE amp as quiet as a well-balanced push-pull amp. Quiet that Champ, Valve Jr., GA-3/4/5/6 and all the clones.

Push-pull amps benefit from QS-LV’s hum reduction, too. Switching to triode mode in most amps causes an increase in hum, but with QS-LV installed the supply will be QUIET and so will both triode and pentode operating modes. Tame the noise of your clipped plexi, Trainwreck, Komet or other non-master-volume amp.

Supply voltages up to 500Vdc are accommodated, and amplifier power up to 120Wrms, limited by the filter cap voltage. For supplies up to 950V, see QS-HV Quiet Supply for High-voltage.    On-board current limiting protects both QS-LV and your amp. QS-LV is typically placed after the main filter cap for “whole amp” quieting, but can be placed further down the supply chain as required. Or use QS-LV in a preamp power supply for critical applications, such as for microphone preamps, reverb units, or high-gain instrument preamps.

Proper heat sinking is required. In most amps, the chassis will suffice as the heat sink. In amps over 100W, or that are cathode biased for 30W and over, it is best to add a fan to cool the chassis. An aluminum heat sink is also a good idea on larger amps. The mosfet supports the PCB in normal mounting. Mounting hardware and thermal pad are included.

Installation of QS-LV will bring your amp one step closer to achieving the noise performance of London Power’s amp line.

If you are building a stand-alone preamp, achieve world-class performance by adding the QS-LV to our PSU-PRE Power Supply Kit for Tube Preamp.

PCB dimensions: 1.4 x 1,4″, 36 x 36mm
Height when mounted in standard orientation: 1.4″ 36mm

QS-LV-COMP requires assembly and installation. Notes and mounting hardware are included.

QS-LV-BLT requires installation. Notes and mounting hardware are included.

Kit includes notes with installation tips + layout and schematic diagrams of the kit.

Questions or comments about this product? Email London Power directly. See our forum and join the discussion about the Quiet Supply for Low Voltage Tube Amps at The Ultimate Tone Forum!

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