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Rør - Nyheder

 
 
 
 
 
 
Håndlavet dansk rørluksus
Ny dansk rør-effektforstærker til monitorbrug og hi-fi.
 
Af John Alex Hvidlykke, Lyd & Billede
 
 
 
 
Det danske mærke Fairman er ikke så kendt i hi-fi-sammenhæng, men i lydstudier har deres produkter en tilhængerskare. Deres nyeste udspil kunne dog godt tænkes at finde vej til private lytterum.Imens de øvrige Fairman-konstruktioner er kompressorer og equalizere til brug i lydstudier, er nyeste skud på stammen nemlig en rør-effektforstærker.
 
Forstærkeren, der er håndbygget, er beregnet til at drive nærfelt-monitorhøjttalere, men ville lige så let kunne bruges til privat stereolytning.Fairman KT88 Tube Stereo Amplifier arbejder i en balanceret push-pull-konfiguration med radiorør.
 
Forforstærker og fasesplitter er DC-koblet for at undgå kondensatorer i signalvejen. Dog var fire kondensatorer nødvendige på indgangene på KT-88-rørene. De er af typen “Supreme Silver/Gold” fra tyske Mundorf. 
 
Udgangstransformerne er fra den legendariske svenske transformerproducent Lars Lundahl. Strømforsyningen er også bygget med Lundahl transformatorer på 250 W.
 
Forstærkeren arbejder i klasse AB. Der er en separat transformator til den stabiliserede biasspænding.
 
Forstærkeren leverer 2 x 40 W, og der er både balancerede og ubalancerede RCA-indgange. Prisen er 40.000 kroner, hvis man afhenter den hos producenten i Rødovre.
 
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                                                     Audio Reseach GSi75
 
A preamplifier, amplifier, phono stage, and digital to analog converter all in one chassis, the GSi75 combines with your favorite speaker to deliver a singular and simple solution to control your listening system. Unlike other integrated designs that make performance - sacrificing compromises to fulfill a price point or form factor, the GSi75 harnesses the power and technologies developed by Audio Research into an authoritative platform to reveal the performances in your media.Powered with the new KT150 output tube, the GSi75 supplies finesse and control that belies the 75-watt per channel power rating. The digital-to-analog converter will handle almost any sampling frequency including DSD. The phono stage and headphone amplifier round out the GSi75, providing total system control and integration. The elegant, understated industrial design will complement the rest of your system both visually and sonically.
               
POWER OUTPUT 75 watts per channel continuous from 20Hz to 20kHz.
1 kHz total harmonic distortion typically 1.5% at 75 watts, 0.5% at 1 watt.
Approximate actual power available at “clipping” 80 watts (1kHz). (Note that actual power output is dependent upon both line voltage and “condition” i.e.: if power line has high distortion, maximum power will be affected adversely, although from a listening standpoint this is not very critical.)
POWER BANDWIDTH (-3dB points) 12Hz to 70kHz.
FREQUENCY RESPONSE (-3dB points at 1 watt) 1.0Hz to 70 kHz.
INPUT SENSITIVITY0.55V RMS Single-ended for rated output. (32.5dB gain into 8 ohms.)
INPUT IMPEDANCE52.5K ohms Single-ended.
INPUTSSE1, SE2, SE3, Phono, S/PDIF digital (coax RCA and Toslink), USB MAXIMUM INPUT10V RMS (any input).
OUTPUT POLARITY Non-Inverting (any input). OUTPUT TAPS 8 ohms, 4 ohms.
OUTPUT REGULATIONApproximately 2dB 8 ohm load to open circuit (Damping factor approximately 4).
OVERALL NEGATIVE FEEDBACK 4dB
SLEW RATE10 volts/microsecond.
RISE TIME4 microseconds.
HUM & NOISELess than 1.0 mV RMS -88dB below rated output (IHF weighted, Vol down).
CONTROLSRotary volume (103 steps), Rotary input selector, Power, Mute, Bias.
DIGITAL SAMPLE RATES44.1kHz to 192kHz, SPDIF and USB 2.0 HS, DSD USB 2.0 HMASTER OSCILLATOR22.579mHz ±20Hz for 44.1, 88.2 & 176.4kHz. 24.576mHz ±20Hz for 48, 96 & 192kHz sample rates.
INTRINSIC JITTER < 10 Ps