The HPA V181 was developed with the target to enable ultimate transmission quality for low- , medium- and high-impedance headphones. These may also be balanced versions !!! So, the HPA V181 is the first balanced headphone amp manufactured in Germany!

LOW-NOISE because of low internal gain. Therefore the self generated noise from the amplifier is not audible.

HIGH OUTPUT VOLTAGE in balanced mode !

HIGH OUTPUT POWER because of powerful amplifiers able to deliver much more current headphone needs. Therefore best suited for low impedance headphones and even magnetostatic cans !!!

HIGH DAMPING FACTOR through lowest output impedance. Therefore best suited for full control even over critical headphones with the guarantee to have flattest possible response.

The four built-in amplifiers provide balanced operation of headphones. Connection is made via 4-pol Neutrik XLR connector. Two “standard” headphones may be connected via 1/4" jacks on the front panel. Case and back panel are made of aluminium and are Nextel coated. The 8 mm frontpanel is black. The labeling is laser engraved.

Our Technique

There are "all-balanced" headphone amps on the market. Some accepting only balanced inputs, some also unbalanced inputs. The "all-balanced" amps must have 4-section volume control. As we come from the professional industry, in our opinion a balanced signal has its advantages because of its immunity to hum and pick-up noise with long cables. For that purpose the so called CMRR (Common-Mode-Rejection-Ration) should be in a range far beyond 40 dB, better 60 to 80 dB. This cannot be made with capacitors and their tolerances or quad pots with 4 specific tolerances in the signal path! There are very expensive ALPS 4-channel pots on the market. Using digital 4-channel pots might be a solution, but the sound will definately suffer.

The benefits of a balanced headphone connection include other reasons: In single ended amps and headphones the signal is returned in one cable for left and right channel through the phones socket. It is connected to the ground of the amp where it runs to its endpoint, the transformer. As the cables to the headphone and the ground from the socket to the transformer have specific resistances, you can easy imagine that the ground level - that should remain quiet - is now "polluted" with energy from the right and left channel simultaneously. The amount of the "pollution" is proportional to the resistances. With balanced amplifiers the ground level remains totally clean, as all energy flows only between both supply voltages! The practical (hearable and measurable) result is better crosstalk ( = channel separation) in a region of +15 to +30 dB !!

For the above reasons, it is not neccessary to have an "all-balanced" signal flow thru the entire amp. It is sufficient to design only the balanced push-pull amp. The advanges are: - Compatible with balanced AND unbalanced input signals - more precise lo-cut filters because there is only an unbalanced signal path with specific tolerances - higher sound quality - less cost for quad pots and other components.

HPA V181 Features

- Balanced inputs with gold-plated Neutrik XLR connectors
- Unbalanced inputs with gold-plated ALPS cinch connectors
- Switchable unbalanced outputs with cinch connectors
- OPTIONAL USB input 16 Bit / 48 kHz or 24 Bit / 96 kHz
- PRE-GAIN = switchable input gain in five steps
- Independent-channel design
- DC-coupled (switchable)
- ALPS RK27 High-Grade volume control
- High-Quality op-amps in the signal path
- High-quality MKP capacitors in the signal path
- 0.1 and 1% metal film resistors throughout the unit
- 4 amplifiers with BUF634
- 1 balanced headphone output, Neutrik 4-pin, gold plated
- 2 silver-plated Neutrik headphone outputs
- Relay-based headphone output cutoff
- Toroidal transformer
- Large filtering capacitors in the power supply
- Switchable ground lift
- Rugged aluminium case with Nextel coating
- Solid, laser-engraved aluminium front panel

Technical Data

	HPA V100	HPA V181	HPA v200

Unbalanced Inputs	2	2	2
Balanced Inputs	(2)	(2)	(2)
Impedance	10 kOhms	10 kOhms	10 kOhms
Unbalanced Outputs	(2)	(2)	(2)
Balanced Outputs	0	0	0
Number of Channels	2	4 (2 x Balanced)	2
Nominal Input Level	+6 dBu	+6 dBu	+6 dBu
Amplifier Gain	8 dB	8 dB	8 dB
... with Pre-Gain	-4/+2/+8/+14/+20 dB	-4/+2/+8/+14/+20 dB	-4/+2/+8/+14/+20 dB

Frequency Range (-0,5 dB)	5 Hz 60 kHz	5 Hz 60 kHz	5 Hz 60 kHz

USB Input	N/A	Optional 16/48 or 24/96	16/48

Damping Factor (in 50 Ohm Load)	400	250	800
Dynamic Range (A-wtd)	128 dB	128 dB	128 dB

Noise (A-wtd)	-100 dB	-100 dB	-100 dB
THD+N @ 10V / 100 Ohms (1W)	-109 dB	-108 dB	-110 dB
THD+N @ 4V / 32 Ohms (0,5W)	-103 dB	-109 dB	-103 dB
Crosstalk @ 1 kHz	-115 dB	-115 dB	-110 dB
Crosstalk @ 15 kHz	-95 dB	-100 dB	-95 dB

Max Output Voltage in 600 Ohms	19,6 V	20,2 V	18,5 V
Max Output Power in 600 Ohms	640 mW	680 mW	570 mW

Max Output Voltage in 100 Ohms	14,5 V	14,4 V	14,8 V
Max Output Power in 100 Ohms	2100 mW	2050 mW	2200 mW

Max Output Voltage in 50 Ohms	10,5 V	10,2 V	11,6 V
Max Output Power in 50 Ohms	2200 mW	2100 mW	2700 mW

Max Output Voltage in 32 Ohms	7,4 V	7,9 V	8,0 V
Max Output Power in 32 Ohms	1700 mW	1950 mW	1700 mW

Max Output Voltage in 16 Ohms	3,5 V	4,5 V	4 V
Max Output Power in 16 Ohms	780 mW	1250 mW	1000 mW

Number of Outputs SE	2	2	2
Number of Outputs Balanced	N/A	1	N/A

Power Supply	230 / 115 V	230 / 115 V	230 / 115 V
Power Consumption	10 VA	10 VA	10 VA

Dimensions (WxHxD) mm	170x49x225	170x49x225	170x49x225

Violectric HPA V181 Balanced Headphone Amp

OPTION - USB Input DAC 16 bit /48 kHz

OPTION - USB Input DAC 24 bit /96 kHz

OPTION - Digital COAX Input DAC 24 bit /96 kHz

OPTION - OPTICAL Input DAC 24 bit /96 kHz (Toslink)

Neutrik 4 Pin XLR to WW L/R Female 3 Pin XLR Adapter

The HPA V181 was developed with the target to enable ultimate transmission quality for low- , medium- and high-impedance headphones

Balanced or Single Ended Headphones!!!

Our Technique

HPA V181 Features

Technical Data

HPA V100

HPA V181

HPA v200