Lab Gruppen fP 6400
Overall efficiency and heat dissipation always have been fundamental problems in extremely high power amplifiers such as the fP 6400. As early as 1990, Lab.gruppen had achieved a breakthrough with a patented a high efficiency amplifier that represented a major evolution beyond typical Class D approaches. Designated Class TD®, this technology obtains the same high efficiency as Class D, but avoids the inherent drawbacks. For example, a typical Class D topology employs Pulse Width Modulation (PWM) to achieve high efficiency, but this requires a steep recovery filter between the output stage and the loudspeaker. In contrast, Lab.gruppen’s Class TD design keeps the audio signal within the analog domain, eliminating the need for filtering and therefore offering the same sonic quality as a traditional Class AB amplifier.
In addition to traditionally superb Lab.gruppen sonic performance, fP 6400 offers a full line of important features: Regulated Switch Mode Power Supply (R.SMPS™)
Switch-mode amplifiers are commonplace in today’s amplifier market. However, Lab.gruppen’s unique Regulated Switch-mode Power Supply (R.SMPS) technology offers a number of essential advantages that make it superior to other, seemingly similar power supply designs. The most important features are the precise regulation and the extreme power efficiency. The regulated power supply easily deals with high variations in the AC mains voltage: it can drop by up to 20% below its nominal level (e.g. to 180 V instead of 230 V) without affecting audio performance. The power supply is also exceptionally efficient, with only a fraction of the energy from the AC mains is turned into heat. A regulated power supply also affords other sonic advantages, including better cone control while retaining the same fast response as a conventional power supply.
Multiple Position Gain Switch (M.PGS)
To meet the demand for a flexible gain structuring in various system configurations, Lab.gruppen’s fP Series offers a multiple position gain switch. The maximum amplifier gain can be set to all industry standards: 20, 23, 26, 29, 32, 35, 38 and 41 dB.
Sophisticated protection circuitry, combining:
DC protection – Blocks infrasonic signals due to fault conditions
VHF protection – Protects the loudspeakers from sustained (non-musical) very high frequency signals above the audible range.
Thermal protection – Protects the amplifier from overheating. The protection warning indicators on the front panel illuminate before the protection process is initiated.
AC protection – Shuts down the power supply if the line voltage is outside the operating voltage.
Clip limiter – Prevents severely clipped waveforms from reaching the loudspeakers while maintaining full peak power.
|Number of input channels||2|
|Number of output channels||2|
|Peak output voltage||149 V|
|8 ohms load||104 Vrms|
|Max output power (all channels driven)|
|8 ohms 1||1300 W|
|4 ohms 1||2300 W|
|2 ohms 1||3000 W|
|Max output power bridged|
|8 ohms||4600 W|
|4 ohms||6000 W|
|THD + N 20 Hz – 20 kHz for 1 W||0.1 %|
|THD + N at 1 kHz and 1 dB below clipping||0.04 %|
|DIM 30 at 3 dB below clipping||0.06 %|
|Hum and noise||< -110 dB|
|Output impedance||60 mΩ|
|Slew rate||20 V/μsec|
|Common mode rejection||50 dB|
|Connectors and Buttons|
|Gain selectable [dB] 5) 2||20, 23, 26, 29, 32, 35, 38, 41|
|Gain controls||31 pos detent|
|Output headroom indicators||5 green LED’s|
|Over temperature||Yellow LED|
|Back panel user interface|
|Link connectors||XLR male|
|Clip limiters||On/Off, each ch.|
|MLS switch [dB]||0, -2, -4, -5|
|corresponding to [Vrms]||104, 84, 70, 62|
|when bridged [Vrms]||208, 168, 140, 124|
|Link switch||Ch. A-B|
|Soft start / Inrush power||Yes / max. 5 A|
|Full output power at 4 ohms, 230V/115V||180-265V/90-130V|
|Minimum start-up voltage, 230V/115V||175V/95V|
|230 V or 115 V versions||Yes|
|Current draw at 4 ohms and 230V/115V|
|Idle, no load at output||1.0/2.0 Arms|
|1/8 of full power (-9 dB)||6/12 Arms|
|1/3 of full power (-5 dB)||14/28 Arms|
|At full power (0 dB) at 1 kHz 1% THD||16/32 Arms|
|Weight||10.0 kg (22 lbs)|
|Approvals||CE: Immunity: EN 55 103-2, E3, with S/N below 1 % at normal operation level Safety: EN 60 065, class 1 ETL listed: Conforms to ANSI/UL STD 6500 and Certified to CAN/CSA E60065-00 FCC: Complies with Class B digital device, Part 15 of the FCC Rules|