Thursday, November 14, 2013

FM Acoustics 245 - pictures and specs

245 is like a 155 with balanced output, and with a better and internal PSU. And two of the inputs features switchable additional 6 dB/10 dB gain.

Proprietary discrete, enhanced Class A circuitry using hand-selected super-speed semiconductors. These are individually analysed, selected and are then subjected to FM ACOUSTICSí unique listening selection process. The FM 245 uses hand-calibrated enhanced Class A modules.

4 unbalanced HIGH LEVEL inputs.
1 precision Class A TAPE/ACCESSORIES loop.

Input features:
High level, earth-free unbalanced discrete Class A circuitry.

Input impedance:
50 kOhms, linear over full frequency range

Input Headroom:
+21 dBv (9V RMS)

Input Sensitivity:
100 mV for 100 mV out at tape output

Max. Gain:
Any Input to Tape output: 0 dB.
Any Input to Main output: 20 dB.

Frequency response:
20 Hz - 20 kHz +/- 0.03db

Without RF filter: 1 Hz - 2 MHz
With internal RF filter: 1 Hz - 100 kHz
The actual frequency response of the preamplifier, however, is intentionally attenuated above 100 kHz with a linear-phase antiRF circuit. For special application this can be bypassed.

Step response:
Perfect without any overshoot or ringing

Phase accuracy:
Without RF filter: better than -0 0 / +1 0 over full frequency range from 20 Hz - 20 kHz

Resolution of Output Level Control:
Better than 0.02 dB

Center Resolution of Balance Control:
Better than 0.02 dB

Rise time:
300 nanoseconds = 0,3 uSec. (capability of electronics, measured without RF filter)

Fall time:
300 nanoseconds = 0,3 uSec. (capability of electronics, measured without RF filter)

Hum and Noise:
Below full output: >120 dB, 20 Hz - 20 kHz
Below 0 dBv: > 95 dBV

Fully symmetrical, true balanced, discrete Class A circuitry. Drives any balanced or unbalanced load. Sensors automatically adjust output to optimal performance whatever type the connected equipment.
Short-circuit proof, the unit perfectly passes the true balanced pro float test.

Maximum output level:
+28 dBv (19,5 V RMS) into 4,7 kOhms balanced load

Recommended load Impedance:
600 Ohms

Stereo separation:
Better than 85 dB

Channel separation:
Better than 95 dB

Harmonic Distortion:
Over full frequency range 0,003% at 3V out. No higher order harmonics at all (up to clipping level).

Mains voltage:
115V / 230V, 45-66 Hz

Mains Overvoltage:
Maximum short-term =140% V nominal
Maximum long-term = 120% V nominal

Mains Undervoltage:
Maximum 80% V nominal before protection circuitry activates. Stable operation within a voltage range of
95V to 140V (in 115V setting)
190V to 280V (in 230V setting)

Power consumption:
15 W continuous

Operating temperature:
-20 to +40 C

Operating humidity:
Long-term: 0 - 85%
Short-term: 0 - 95%
continuous high humidity may shorten lifetime of certain components somewhat

Burn-in time at factory:
1000 thermal cycles, minimum 200 hours

Vibration test at factory:
50í000 vibration cycles, minimum 60 minutes

Average Live expectancy:
36 years (at 25 C ambient, 10 hours/day, 365 days/year)

Front panel:
5mm laser cut, brushed and then hand-polished 9000 aluminium, letters anodized so they can never wear off, precision hand-selected dust-proof OUTPUT LEVEL and BALANCE controls with dB calibrated scales. Precision, self-cleaning long-life switches, POWER switch, POWER ON indicator.

Back panel:
Brushed and hand-polished 9000 aluminium, lettering anodised so it can never wear off. All inputs and outputs are precision RCA- and XLR-connectors. To avoid ground loops electrical ground is lifted from chassis. Star grounding is ensured (provided that the connected equipment and cables are capable of this.)

Inputs: precision RCA-Phono recetables

balanced male XLR 3-pin or unbalanced, automatically optimizing connection
Pin 1: ground
Pin 2: (return) cold
Pin 3: (signal) hot

Spare parts availability:
Min. 10 years; Guaranteed ex stock availability of 99.8% of all parts.

446 mm wide / 44 mm high / 280 mm deep

Weight: 6 kg net / 8 kg packed