SPL Tube Vitalizer

The Tube Vitalizer looks impressive, with a nod towards vintage valve equipment. It is a 2U steel box, with a bare metal front panel.
There are plenty of black knobs, and three grilles revealing glowing tubes. Actually, most of the glow comes from the lamps illuminating the little VU meters.
Below these, two old-fashioned black knobs are labelled "ATTENUATOR". Switches light up red when pressed in, apart from a couple of metal toggles, and there are blue LEDs to show High and Low frequency compression. When you switch on, your attention is drawn to two LEDs, proudly labelled "TUBE STATUS", with the "WARM UP" one glowing for 45 seconds before a relay kicks into "ACTIVE" mode. During this 45 second period the circuitry slowly builds up to 250 volts to increase the life of the valves.
 This is sensible, but I am not sure that the LEDs are really necessary.
 The back panel features XLR connectors and also plastic balanced jack sockets for inputs and outputs. The unit runs at +6dB instead of the more usual +4dB. Jack connectors are also set to +6dB operation, unfortunately without a switch to enable -10dB operation.