Audison HV venti Thesis - 2-Kanal Verstärker

Audison Thesis HV venti - 2-channel amplifier

Absolute luxury - High End 2-channel amplifier 2 x 400W

Maximum Performance

The main aim of the HV venti project was achieving maximum performance. The most important aspect is the complete avoidance of integrated circuits. By its structure, and the low-voltage level they can easily affect the signal.

Compliance with the optimum working temperature was a fundamental aspect of design. A sophisticated heat exchange system transfers the accumulated warm air from its center inside the amplifier to the lateral heat sinks.

The signal is exchanged via special relays. The entire front end is symmetrical, while the entire stage structure is built separately as "dual mono", so each channel.

To avoid electro-magnetic interference, no high currents by the motherboard / passed the motherboard, with the exception of the connection terminals. A second board under the mainboard contains the complete power supply for the output stage.

This is - as in the VRx series - from the PWM Syncro configuration (due to the fast response time), though due to four dual-mono power supplies were needed. Two other power supplies for the signal levels - one for each channel - give a highly efficient system.

The Dual Power function toggles between HiCurrent and HiVoltage. In the HV venti HiCurrent delivers 200 W at 4 Ohms,

380 W at 2 ohms and 650 W at 1 Ohm Stereo - 1300 W at 2 Ohm Mono

This setting is designed to tone, while in HiVoltage a slight reduction in sound is present and no mgl 1 ohm load:400 W at 4 Ohms,

700 W at 2 Ohm Stereo - 1400 W at 2 ohms mono.

Because of the considerable weight (15 kg) of HVventi was elected a particularly secure mounting. The amplifier is mounted on a second mounting plate, which is first screwed on a solid substrate.

Special visual feature is the transparent cover with different colored lighting effects. The white, red and blue LEDs and the blue backlit display is easy to ASC for demonstration purposes using a 12 volt switch input.

For an even more refined and more exclusive appearance and protect the surface was completely converted to galvanization, nothing has been painted.

Technical details:

a) preamplifier

consists of two groups:pre-and control unit (Control Unit ASC), the entire stage to the driver outputs is symmetrical separate power supply 90 volts

Preliminary stage

ABS balanced inputs / outputs (bypass) isolated input stage by two polypropylene - Kapazitoren per channel JFET - transistor input stage, two-stage input selector - set by "SET IN switch" balanced output buffer control unit for thermal stabilization

Controller

•  Sensitivity by I / O switch IN SET
• IN SET I:1 - 7 volts (0 dB gain / gain)
• 0:0.25 - 1.6 volts (13 dB gain / gain) and infinitely variable by ADJUST
•  L / R alignment

infinitely adjustable, raises the output level of the left or right channel by max. At 3 dB

•  IN Fashion:  I / O switch, input balanced or unbalanced
• Out Mode: stereo / mono output selector

In most conventional (stereo) amplifiers that can be bridged to mono, the subwoofer is out of phase. Is switched to mono, one activates a phase rotation of 180 °, the sub must then both (R + L) positive terminals.

Using the crossover module is in mono mode automatically activates 24 dB LP!

b) crossover

For mounting you only removed a small bridge, which is inserted in place of the FW module. If the HV is so driven active unnecessarily long signal paths are used, which may interfere with the signal. Therefore, the filter can not be adjusted continuously, but in the frequencies from 45 to 55 - 65 - 80 Hz HP / LP with a slope of 12 dB stereo and mono can be adjusted 24 dB. Even if it means a loss of comfort, making this version but had the greatest linearity.

c) Drivers

• separate power supply 150 V
• thermally stabilized
• Class A operation
• balanced inputs
• first stage:complementary JFET transistors
• second stage:complementary BJT transistors
• Output buffer drives the output stage

d) output stage

The output stage uses an innovative design that is similar to the IGB transistor (Insulated Gate Bipolar Transistor), but is composed of individual components.

The circuit consists of a complementary pair of Hitachi DMOS driver transistors (2SK1058/2SJ162), usually (as with the HR 100) as output stages used, which drive two pairs SANKEN BJT power transistors (2SA1295/2SC3264), and a maximum peak current of 30 A at 200 W power supply.

This solution allows the use of only two output transistors, the load current - turn in contrast to conventional amplifiers, the number of transistors in parallel - will be reduced to the extent that the operation of the amplifier in Class A mode is possible.

Class A mode is a spezial mode which requires special measures to cool. On the solution of this property will be discussed here later.

This configuration was found in terms of sound quality combined with high output power as specifically:the DMOS power transistor delivers enough power for the driver function BJT output transistor, the current gain of the output transistors is reduced in case of excessive load. This in turn ensures that the driver stage is not overloaded and a consistently low THD at each applied load is present

With respect to the output stage another innovative solution has been accepted.

In most high-power amplifiers generate the power output and the return flow electromagnetic interference that disturb our precise audio signal. To mitigate this, or to circumvent, compromise as coiled cable or similar is required.

Compromises are not accepted at the HVventi.

In the amplifier of each recycle stream passes through a thick 6-layer copper board, on which the lines of the return flow are very close to those of the feed. In this way, the electromagnetic interference out of phase and cancel each other:this solution could be described as "balanced power".

e) was summarized / omitted

f) ASC:Status Control Amplifier

to control all the configurable features, temperatures, functional status, volume level indicator, etc

Display ads:

• POWER ON: mode on / off
• HI POWER / VOLTAGE: dual power status HiPower / Voltage, when from the HiCurrent mode when the fuses are inserted incorrectly activated, Master Protection

FAN ON:  active cooling system

TEMP GOOD constant light: optimum temperature, flashing-wait

LEFT CH Flashing:l eft fan is running, flashing frequency corresponds to fan speed 3 speed possible, from:left channel in Protect

RIGHT CH:  above

PRT BATT voltage is below : 10 volts or above 16 volts

PRT THERM:  Thermal Protect active (above 90 ° C)

CHECK SPK:  ground fault of one speaker cable

SAFETY:  Protect PRT other active control LEDs

CHECK FAN:  fan defective, check fan and air routes

SERVICE:  the amplifier is faulty. Please contact the nearest service (-> automatic RMA - No - generation is sought)

LEFT:  volume meters left

RIGHT:  Volume Meter right

PEAK:  shows eventual clipping

g) Lighting

As stated above, there are three lighting colors

• Red: Parameters for THESIS logo & Glass
• Blue: Audison logo
• White: backlit interior

The glass lid can be lifted off without disconnecting plugs, the lighting has a spring contact.

The lighting can be switched on with a mass close to the power circuit connections, eg when the trunk is opened. Furthermore, there is also a 12 V 600 mA input to the HVventi bring on the demo for wall lights.