FM ACOUSTICS FM155
750,000 (released in 1998)
¥ 750,000 (around 2001)
¥ 880,000 (around 2002)
¥ 930,000 (around 2004)
¥ 970,000 (around 2005)
¥ 1,390,000 (around June 2007)
Commentary
A preamplifier designed for line stage, incorporating ideas gained from the development of the Resolution Series preamplifier.
It uses a unique enhanced class A circuit and does not use any overall feedback / feed-forward.
A specially designed bias circuit prevents the distortion form and tone from changing after warm-up and ensures that the operating temperature is reached very quickly without the need for long warm-up periods.
The circuit configuration is a full discrete configuration and uses only semiconductors that have undergone curve tracer analysis and trial listening of characteristics.
The tape monitor circuit of a typical amplifier uses only a passive switch. However, since the input / output impedance and the characteristics of the input / output circuit of the equipment using the monitor loop differ from each other, the sound quality may be inconsistent and the playback sound may not be satisfactory. Therefore, the tape input / output of the FM155 includes a discrete Class A buffer circuit to isolate the high-level output from the subsequent load. This provides constant sound quality and high signal quality regardless of load or source type. It also eliminates frequency non-linearity, distortion, sound compression and clogging.
There is no wiring material for signal transmission inside the FM155, and the performance does not vary from unit to unit.
The power level and balance control are specially designed for the FM Accor Stix and hand selected by a special machine.
The transformer uses a special dual shield to prevent stray magnetic fields.
DIN, IEC, and MIL standard parts are used and hand selection and hand matching are done thoroughly.
The four contact ultra-precision relay manufactured in Switzerland is hermetically sealed to prevent the contacts from being affected by the surrounding environment, and the four contacts with a special coating can withstand tens of millions of switching operations.
It has a fully modular design.
All output circuits are protected from short circuit.
The FM155 uses a delay type switch ON. When the switch is ON, the signal flow diagram is sent to the output. After self-diagnosis, the control circuit starts the output when each part is in the complete state. It takes approximately 10 seconds to reach the complete operating state.
The FM155 can be connected to any balanced or unbalanced device. The necessary cables, RCA / phono and XLR connectors are available from Precision Interface Technology.
Other types of connectors, such as Fisher and Camac, are available on special order.
The minimum guaranteed specifications are attached to the user's manual for each product to be shipped.
Model Rating
| Type | Stereo preamplifier | ||||||
| Circuit | Discrete enhanced class A circuits using ultra-high-speed hand-select semiconductors. The circuits are individually analyzed and selected, and carefully selected through listening tests unique to FM Accor Stix. The whole unit consists of an enhanced class A module by hand calibration made by FM Accor Stix. |
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| Input impedance | Line : 33k Ω Tape : 100k Ω Absolutely linear for the entire playback band |
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| Input headroom | +21dBv(9VRMS) | ||||||
| Input sensitivity | 100 mV per 100 mV tape output | ||||||
| Maximum gain | 0 dB for all inputs at the tape output 20.5 dB at main output for all inputs |
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| Frequency characteristic | 20 Hz to 20 kHz ± 0.03 dB | ||||||
| Playback bandwidth | Without RF Filter : 2 Hz to 2 MHz Built-in RF filter : 2 Hz to 100 kHz * The actual frequency characteristics are attenuated above 100 khz by the linear phase anti-RF circuit (bypass is possible depending on the purpose). |
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| Phase accuracy | -0 ゜ / + 1 ゜ (without RF filter, 20 Hz to 20 kHz) | ||||||
| Step characteristic | No overshoot or ringing | ||||||
| Rise time | 200 nanoseconds = 0.2 μ sec (electronics capability, measured without RF filter) | ||||||
| Drop characteristic | 200 nanoseconds = 0.2 μ sec (electronics capability, measured without RF filter) | ||||||
| Hum and noise | 0 dBv or Less = -93dBV or Less -110dB or More (20 Hz to 20 kHz, full output) | ||||||
| Output | Single-ended discrete Class A circuit Drives all unbalanced / balanced loads Built-in short-circuit protection |
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| Output impedance | 10 Ω or less | ||||||
| Stereo separation | 78 dB or more | ||||||
| Channel separation | 92 dB or more | ||||||
| Harmonic distortion factor | 0.03% or more (at 3 V output) in the entire playback band No higher order harmonics until the clipping level is reached. |
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| Power supply voltage | 115V/230V Internal Switching, 50Hz/60Hz | ||||||
| Voltage range capable of stable operation | 95 V ~ 135 V (115 V Setting) 190 V ~ 270 V (230 V Setting) |
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| Power consumption | Continuous 10W | ||||||
| Operating temperature | -20 ° C to + 40 ° C | ||||||
| Operating humidity | Long-term : 0 to 85% Short time : 0 to 95% * If high humidity continues for a long time, the life of some parts will shorten. |
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| Shipping burn-in time | Temperature test 1000 cycles (minimum 200 hours) | ||||||
| Vibration test at time of shipment | Vibration test 50,000 cycles (minimum 60 minutes) | ||||||
| Front panel | Hand polished after brushing 4 mm laser-cut aluminum 9000. No wear as the lettering is treated with oxidation anode. High-precision output level and balance control with hand select, dust-proof treatment and dB scale. Switches have high-precision self-cleaning and long life specifications Power switch, power on indicator |
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| Rear panel | Aluminum 9000 is hand polished after brushing. The lettering is oxidized and anodized so there is no wear. Input / output terminals are high-precision RCA and XLR connectors. Electrical ground is lifted from the chassis to avoid ground loops. Star-ground system is possible depending on the connected equipment. |
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| Functions | Line input selector switch Tape monitor switch Stereo / mono selector switch -20dB mute switch Volume control Power switch |
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| Input-output | Four single-ended line inputs (RCA) Single Ended Loop Input / Output (RCA) Single ended pre-output (RCA) system |
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| External dimensions | Width 245x Height 62x Depth 290 mm | ||||||
| Weight | Body : 2.2 kg Packed : 5.5 kg |
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| Standard number of parts used |
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