Vacuum HE1 SE (unbalanced)

Vacuum HE1 XLR (balanced)

Built-in regenerative power supply

Purest 8-tube unbalanced preamp and 10-tube balanced preamp

Power supply filtered entirely with SOLEN capacitors

AC supply for all tube filaments,

Vacuum tube rectification, vacuum tube power supply and amplifier circuitry without transistor rectification or regulation

Full function remote control

User adjustable tones:

For balanced versions, the user can connect the preamp output to a true XLR output, or to the SE output for a very different sound and listening experience.

For both balanced and unbalanced versions, the user can also swap the internal A and B tubes for each channel to obtain a different tone.

Pre-buy warning:

The bile tube is guaranteed for 3 months as it only lasts for a few thousand hours. All other components are guaranteed for 10 years according to the Rexchip warranty policy.

For sound quality reasons, we recommend that you replace all tubes after 5000 hours of use (3 hours a day, approximately 5 years). After replacement the new tubes need 150 hours to age.

This unit is powered by a fully analogue regenerative power supply. The full analogue technology is pure in sound but less efficient than the digital technology, so it is recommended that the maximum continuous or cumulative power on time is no more than 8 hours per day.

The design and build of this unit may be different.

This machine is the purest of the bilevels, with only resistors, capacitors and tubes in the power and signal circuits of the bilevels.

There is no regulated power supply for the filament or signal circuit, the filament is powered by AC.

No chokes or electrolytic capacitors are used in the power supply circuit, only small capacity film capacitors and electronic tubes are used for rectification and filtering.

This unit has been specially designed to achieve a high signal-to-noise ratio of 98DB at everyday listening volumes.

For example, when listening to vocals, you will not hear the so-called "thick sound" of a singer with an olive in his mouth, nor a thick, warm and slow bile, but a thick, clear sound with high resolution, high dynamic reproduction, and a slightly softened and warm sound.

The difference between balanced and unbalanced versions.

The unbalanced version is an amplifier with two channels built in to provide signal amplification for the left and right channels.

A balanced version is an amplifier with four built-in channels, providing balanced signal amplification for the left and right channels.

In order to maintain maximum musicality, the four channels of the amplifier are completely independent of each other and are not designed to offset each other's distortion, so that the balanced version can be used with balanced or unbalanced outputs when the inputs are balanced, whereas the unbalanced version can be used with balanced outputs, but there is no output signal at the cold end of the balance. There is no output signal.

To allow users of balanced systems to experience the tonal changes between balanced and unbalanced, the outer pair of XLR output sockets are unbalanced and the inner pair of XLR sockets are true balanced outputs, allowing users to connect the different sockets directly with the original XLR cables and experience the balanced and unbalanced tones for fun.

Distortion reduction :

Electronic tubes are non-linear devices. The characteristic is that the greater the input signal amplitude, the greater the distortion. The lower the amplitude of the output signal and the higher the amplitude, the higher the distortion will be.

The volume system consists of two parts, one placed at the input to limit the amplitude of the input signal, and the other at the output of the amplifier to intercept the low and flat part of the output characteristic distortion. To enhance the overall output drive, there is a two-tube parallel cathode output after the volume control at the output.

Volume control characteristics :

The volume control characteristics of this unit have been calculated and verified over a long period of time and have a control range of 95DB, with a rapid increase of several DB per step below 15 steps, and a 0.75DB increase per step above 15 steps. Perfect for making fine adjustments on a daily basis.

To reduce noise induction, the volume module is shielded using a pure copper box.

Please note:

For sound quality reasons, this unit does not use an output delay circuit. When the power switch is pressed, the display will flash for about half a minute. We recommend that you wait until the display stops flashing before switching on the amplifier.

If you find it troublesome to use, you can add an output delay circuit when ordering (only available for unbalanced versions).

About the XLR output of this unit:

Unbalanced version.

To accommodate users with existing balanced amplifiers, this unit has a set of XLR outputs in addition to the RCA outputs, which can be connected to a balanced amplifier via a balanced signal cable.

Balanced version.

In order to allow users of balanced systems to experience the tonal variations between balanced and unbalanced, facing the faceplate, the outer pair of XLR output sockets are unbalanced outputs and the inner pair of XLR sockets are true balanced outputs, allowing users to connect the different sockets directly with their existing XLR cables and experience the balanced and unbalanced tones for fun.

Automatic switch-off of the display:

When the input channel is set to 5 and the volume is 0, the volume knob is turned once in the off direction and the second position of the display shows "1", indicating that the display auto-off function is activated and the display will automatically go off after about 10 seconds without any operation, leaving only a "- " indicates that the machine is switched on. To cancel the function, turn the volume knob to the direction of OFF when channel 5 is entered and the volume is 0. The second position shows "0".

Display functions:

The first position is the input selection display.

The second position is the automatic switch-off display.

The third and fourth digit is the volume display, the higher the value the higher the volume.

The active devices are all non-linear and it is impossible to achieve everything.

Given that the input sensitivity of most post-amplifiers is around 1V, we decided that the best performance would be in the 2V output range.

As for the frequency response, we did not seek to achieve a wide range, but rather to determine the parameters to be used through actual listening and tuning.

The following illustrations are based on the unbalanced version (unless otherwise stated)