Violectric HPA V101

Features of the Violectric HPA V101

Handmade in Germany, the Violectric HPA V101 has two 1/4″ headphone sockets on the front panel, which are activated with a delay when the unit is switched on. The two outputs can also be used in parallel, although headphones of similar impedance are recommended, as the unbalanced jacks cannot be controlled separately. To the right is a combination power button and LED, which glows blue to indicate that the unit is on. On the left, volume control is provided by a 25mm all-aluminium rotary knob and an Alps RK 27 potentiometer with the same fine pitch as on the larger models.

The Violectric HPA V101 has an IEC/CEE socket for the power supply, as well as unbalanced RCA and balanced XLR inputs on the rear, which can be switched using the toggle switch. The headphone amplifier does not have a line output.

Switchable gain

The latest addition to the Violectric range also uses discrete output stages and a channel-separate design for low crosstalk. It also features an extended frequency response of 5Hz to 250kHz (-0.5dB), which the manufacturer claims ensures linear reproduction of the audible range. The overall gain of the model is +6 dB, which can be adjusted using the ‘Pre-Gain’ switch. A total of seven settings (-18/-12/-6/0/+6/+12/+18 dB) are available for additional gain or attenuation when using different sources and headphones. Ideally, the setting should result in a normal playback level at 12 o’clock, so that it can be easily adjusted in either direction as required.

The DIP switches on the Violectric HPA V101 are not accessible from the outside. While larger models such as the HPA V202 (review), HPA V222 (review) or DHA V226 (review) offer direct access via the back of the unit, the flat slide switches on the little brother are located on the PCB inside. This practice is reminiscent of the headphone amplifiers made by Lake People (reviews), the company’s original professional brand, and seems rather unusual in the hi-fi sector. However, it doesn’t take much skill to remove two screws on the front (2.5 mm Allen) and back (T10 Torx), allowing the top of the case to be removed. There is no doubt, however, that external adjustment is more convenient, especially if you have to change headphones or sources on a regular basis.

In practice: sensitive to demanding headphones in use

With an internal operating voltage of +/- 25 volts, generated by a toroidal transformer power supply, the HPA V101 can deliver an extremely high output voltage of up to 18.9 Vrms (600 ohms) for high impedance headphones. On the other hand, low to medium impedance models and magnetostats benefit from a high output of up to 2,050 milliwatts (50 ohms). Normally, the reserves are so generous that a Hifiman Sundara can be driven effortlessly in the factory setting (+/- 0dB) without the need for additional amplification. If, on the other hand, you are looking for an optimum control range for listening pleasure, an attenuation of -6 dB is recommended. This also applies to the Beyerdynamic DT 1990 Pro (review), Sennheiser HD 660S (review) and Focal’s Elegia. It is also worth noting that the headphone amplifier hardly gets warm even after several hours of use.

Thanks to its low-noise amplification, the Violectric HPA V101 is also suitable for sensitive IEMs. With an attenuation of -18 dB, a Sennheiser IE 100 Pro produces only minimal noise at 5pm (attack). However, this does not affect the usable range, as the control range is between 7:30 and 13:30 at the highest attenuation. In comparison to the HPA V202, the smaller model performs significantly better, but does not reach the top results of the HPA V222.

Sound quality

In terms of spatial imaging, the HPA V101 is undoubtedly superior to a high-end mobile solution such as the Apogee Groove (see review). Especially with live recordings, such as Gregory Porter’s interpretation of ‘It’s Probably Me’ (Polar Music Prize, Stockholm 2017), the display expands when switched on, placing the stage deeper in the room and creating a much more realistic concert atmosphere. Lehmann Audio’s Linear, on the other hand, gives an even more expansive impression than the HPA V101. A comparison of the two floorstanding units with the DT 1990 Pro shows that the Linear’s reproduction is more spacious and homogeneous. There is also a slight difference in the sound image, which tends to be warmer on the Linear. On the other hand, the Konstanzer’s sound is a little brighter, very clean and with excellent definition.

Differences can also be heard in studio productions such as ‘Anti Loudness’ from this year’s ‘Empor’ album by Hamburg-based techno marching band ‘Meute’, which the HPA V101 in combination with the Focal Elegia does not reproduce quite as vividly. It is also noticeable that when switching to linear there is a bit more sonority and substance in the lower bass range, which definitely adds to the listening pleasure. This is not to say that the HPA V101s are not fun to listen to. A studio headphone such as the H200 from Adam Audio in Berlin, for example, shines with impressive (low) bass reproduction on the test unit. On the contrary, the HPA V101’s amplification is extremely neutral and, for a hi-fi unit, very ‘clean’, making its professional origins unmistakable. This makes the HPA V101 an ideal headphone amplifier for unadulterated listening, as well as for critical evaluation, as it will mercilessly expose quality differences and manufacturing flaws.

The HPA V101 also harmonises perfectly with magnetostats. With Tracy Chapman’s ‘Give Me One Reason’ (LP version), from the album ‘New Beginning’, the Sundara is wonderfully powerful and responsive. Verve and enthusiasm are immediately apparent. The purity and freshness with which the HPA V101 reproduces the 1995 release is also remarkable. Compared to the Linear, the reproduction is brighter and tidier, and the recording is attractively illuminated.

The bottom line

Despite its handy size, the Violectric HPA V101 has considerable reserves (2,050 mW Pmax at 50 ohms and 18.9 V RMS at 600 ohms) for low to high impedance headphones and magnetostats, and hardly heats up over several hours of use. Low-noise amplification also makes this powerful headphone amp suitable for sensitive IEMs, whose control range can be extended thanks to the seven-stage ‘pre-gain’ setting. It should be noted, however, that the DIP switches are located on the inside of the circuit board and are not accessible from the outside as they are on the larger models.