Headphones amplifiers — Violectric HPA V101

The HPA V101 is a headphone amplifier from the German company Violectric and the entry point into its hi-fi headphone amplifier range. Violectric is the hi-fi brand of Lake People Electronic, and the V101 puts the parent company's established amplifier circuitry, designed by chief engineer Fried Reim, into the most affordable chassis of the current line.

Key specs that matter

The V101 accepts signals through unbalanced RCA or balanced XLR connectors, one of each, selected with a toggle switch on the back panel. Two unbalanced 6.3mm headphone jacks on the front let two pairs of headphones be used at the same time. Frequency response runs from 5Hz to 250kHz within -0.5dB. Maximum output is 2050mW into 50 ohms, and 18.9V RMS is available into 600 ohms. The case measures 165 x 43 x 165mm and weighs 1,222g.

Engineering and use context

The internal supply rails run at 50V, an unusually high figure for a headphone amplifier. This voltage swing is what lets the V101 drive high-impedance headphones as well as low-impedance models with low efficiency, including planar magnetic designs. A seven-position Pre-Gain switch offers -18, -12, -6, 0, +6, +12 and +18dB, so the gain can be matched to a particular source and pair of headphones and the volume control works over most of its travel. The discrete transistor output stage keeps the two channels separate to reduce crosstalk. Volume is set with an Alps RK27 potentiometer turned by a 25mm knob milled from solid aluminium. The power supply uses a toroidal transformer, and the black anodised aluminium case runs only slightly above room temperature even after hours of continuous use.

Pairing

Thanks to the wide Pre-Gain range and the high rail voltage, the V101 covers most headphone types on its own, from hard-to-drive planar magnetic models to dynamic headphones with very high impedance, without any extra matching accessory. The balanced XLR input accepts sources with balanced connections, the RCA pair takes any standard line source, and the dual jacks make it practical for listening with a second person.