Violectric HPA V281 Service Manual

1 HEADPHONE AMPLIFIER HPA V281 USERS MANUAL

10GENERAL INFORMATION The HPA V281 is a stereophonic headphone amplifier designed to drive low-, medium- and high-Z loads (16...600 ohms) as usually

11With its small dimensions, the HPA V281 ensures optimum flexibility combined with high output power. During design, high emphasis was put on operat

12MAINS FUSE The 0.25A time-lag fuse is soldered in place on the circuit board. In case, it must be replaced with a fuse of the same type only. C

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14POWER SWITCH The unit is put into operation by means of the power switch. Power-on status is indicated by the blue LED below. The power-on proced

15UNBALANCED INPUTS For the use with unbalanced signals, gold plated premium RCA sockets are provided. They are labelled as "UNBAL IN LEFT"

16NOTES: - After inserting the USB connector, it may be necessary to close and restart running media applications on the host computer. - Volume of

17THE VOLUME CONTROL The desired volumes for left and right channel are set simultaneously by means of the “VOLUME“ control. Volume can also be set v

18Too loud ? Too soft ? The PRE-GAIN method The V281 is specially designed to drive headphones. Headphones however can present load impedances from 8

19DE- / ACTIVATING THE HEADPHONE OUTPUTS The headphone outputs can be activated or deactivated by pressing the “HEAD“ button on the front panel. The

2Content Theme Page About Violectric 3 Safety Instructions 5 The Earth / Grounding Concept 7 Connection / Connectors 9 General 10 Block Circuit

20On power-up and power-down, the outputs are cut from the amplifier circuitry by relay. THE BALANCED LINE OUTPUTS are located on the rear panel of

21THE UNBALANCED LINE OUTPUTS are located on the rear panel of the unit and are marked as “UNBAL OUT LEFT” and “UNBAL OUT RIGHT”. Gold-plated premium

22PLEASE NOTE: It is generally possible to use the unbalanced and balanced outputs simultaneously, but slight sound deterioration might occur dependi

23Muted status is indicated by the red “MUTE“ LED. The activated / de-activated status of the amp´s outputs however - as indicated by the green LEDs

24Things to know … Why makes it sense to make such huge efforts ? A headphone amplifier is a device designed to condition audio signals with regard

25difference between the interference contents: (s) – (s) = 0. Thus - in an ideal situation - all interference on the signal path is eliminated. Why

26reduced by 12 dB (a fourth), with 0,5 V instead of 2 V input as the result. This 0,5 V is again amplified by 4.5, then equalling 2.25 V. Now the vo

27Conductive-plastic resistive tracks, high-quality multi-tap wipers and separated chambers for the individual sections are highly desirable for soph

28“standard” amps. Why does a relay make sense when switching power ? Amplifiers generate unwanted output signals when applying or removing power, w

29Why does 100% host volume setting make sense ? Volume control within the host is always accomplished digitally, i.e. bits are removed from the dat

3Cordial thanks for your decision in favour of a product ! is a trademark and product line of Lake People electronic GmbH. Lake People electronic

30TECHNICAL DATA HPA V281 All Measurements RMS unwtd., 20 Hz - 20 kHz, Pre-Gain set to 0 dB Inputs: 2 x XLR female, balanced, 2 x RCA, unbalance

31Dismantling / Jumper Setings Please note: In the following, the internal settings of the HPA V281 are discussed. For changing these, a TORX T10 s

32JUMPER SETTINGS HPA V281

33JUMPER SETTINGS HPA V281

34EU CONFORMITY STATEMENT: We herewith declare that the following unit Name: VIOLECTRIC HPA V281 Serial No. : -all - is in conformity with t

35WARRENTY Since 1986 we are constructing and manufacturing sophisticated electronics for ambitious customers. Since the early beginnings we are try

36Additional gear from HEADPHONE AMPLFIERS: HPA V90 HPA V100 HPA V181 HPA V200 HPA V220 HPA V281 D/A CONVERTER: DAC V800 PHONO PRE-AMPLIFIER: PPA

4How do devices get to the customer ? devices can be obtained from respective specialist suppliers. If there is none such accessible regionally, t

5General Safety Instructions WARNING For your protection, please read the following: Water, Liquids, Moisture: This appliance should not be used

6Mains Fuse: The mains fuse of this appliance is soldered in place and accessible from the inside only!! A blown fuse may indicate an internal proble

7The Earth / Grounding Concept General GROUND-LIFT Jumper ( accessible from the inside. Mind the SECURITY INSTRUCTIONS !! ): Ex-works this jumper

8hum or jitter caused by different ground/earth potentials. Of coarse full electrical protection is granted as the case is always connected to ground

9Connection / Connectors for Analog Signals