The FM Plus 557 assisted listening system – now with integrated Wi-Fi – has replaced the existing 457 systems for public venues. The Williams AV FM 557 PRO D Dante Assistive Listening System offers both FM and Wi-Fi transmission from the same box for nearly the same cost as traditional FM systems.

This system features the cutting edge PPA TT55 transmitter (replacing the T45 FM transmitter) with multiple digital audio input options and an OLED display with easy-to manage navigation, and network control features.

This complete turnkey solution includes 4 PPA R37N receivers, each featuring seekbutton channel selection with access to 17 selectable wideband frequencies between 72.1-75.9MHz. The bundle includes a coax cable and rack panel kit for professional installation. The system is expandable, accommodating any number of listeners. This system complies with 2010 ADA guidelines for hearing assistance and is covered by Lifetime PLUS limited warranty.

The PRO D version features Dante input, coaxial cable and rack panel kit for professional installation.

Williams AV FM 557 PRO D Dante Assistive Listening System Features

Assisted listening system
Integrated WiFi
Offers FM and WiFi transmission
Complete turnkey solution

FM T55 D transmitter1
PPA R37N receivers4
EAR 022 surround earphones4
NKL 001 neckloops2
BAT KT6 two-bay chargers and rechargeable batteries2
ANT 005 remote coaxial antenna1
IDP 008 ADA wall plaque1
RPK 005 rack panel kit1

FM 557 PRO
- NOTES:
  - The FCC requires this device to be used with approved, FCC 15.203 compliant antennas and be professionally installed. Refer to Williams AV’s Antenna Selection Install Guide for compliant antennas for this product.
  - The FM + connects to the installation location’s Wi-Fi Network. It does not provide a network on its own. The Wi-Fi network will need to be installed and established before the FM + can be used.
- Dimensions: 8.45″ W x 8.25″ D x 1.72″H (21.5 cm x 21 cm x 4.4 cm)
- Weight: Transmitter: 3.2 lbs (1.45 kg)
- Color: Black/Silver with silver legends on the front, white legends on the back
- Rack Mount
  - Standard 19” Rack, one EIA rack space high, 1/2 space wide
  - 1–2 units can be mounted in a single rack space with optional RPK 005 (single) or RPK 006 (double) Rack Mount Kits
- Power Supply
  - Desktop Style Transformer (TFP 062); Input: 100-240 VAC, 50/60 Hz. IEC Line
  - Cord; Output: 24 VDC, 750 mA, 18W. 2.5mm ID center positive barrel connector
- Power ON Indicator: Push On/Push Off latching power button, backlit green indicates power ON, backlight off indicates power OFF, fading from bright to dark indicates Sleep Mode.
- Temperature Range Operating: +32° F to +122° F (0° C to 50° C); Storage: -4° F to +158° F (-20° C to 70° C)
- User Interface: 3.12” High Resolution OLED display with selections via buttons. Hosted Web page. Remote control and monitoring.
- Dante: Only available on FM T55 D
- Ethernet: RJ-45 on back of unit supports CAT 5e cable lengths up to 328 feet (100 meters); 10/100 Base-T IEEE 802.3 compliant, unique MAC address
- RF Section: Operating Frequencies: 72.1-75.9 MHz , 17 wideband channels (selectable)
- Frequency Accuracy: ± 2 ppm stability, 0-50˚ C
- Deviation: ± 75 kHz maximum
- Pre-Emphasis: 75 microsec
- RF Field Strength: Does not exceed 80 mV/m at 3 m
- Compatible Antennas: ANT 005, ANT 021, ANT 024, or ANT 025 (Refer to Williams AV’s Antenna Selection Install Guide for FCC-compliant antennas for this product.)
- Transmission Range: Up to 1000 ft (304 m) with ANT 005 coaxial antenna mounted on rear chassis connector
- RF Outputs
  - (1x) #10-32 stud connector in center of unit (pcb mounted)
  - (1x) F-connector on rear chassis
- RF Transmit Indicator: 1 Green LED On Air Indicator
- RF Power: Full, Medium, Low or OFF indiacted by menu icon.
- RF Time Out (sleep mode): 30 min. duration, 4 hr. duration, or Always On selected via menu. Starts when audio is below -18 dB level with no button pressed for selected duration.
- Audio Section: Audio Processor Functions: DSP based; Compression: 1:1, 1.5:1 or 2:1; High-pass and Low-pass Filter Frequency control
- Frequency Response: 31-16000 Hz, ±3 dB (re: 1 kHz, ±3 dB) (“Music” Audio Preset)
- Signal-to-Noise Ratio: 67 dB (typical) Transmited RF
- Total Harmonic Distortion: Less than 0.25% @ 1 kHz (RF output)
- Common Mode Rejection: Greater than 57 dB @ 1 kHz, Mic or Line
- Audio Inputs: (1x) Combination 3-pin XLR, 1/4″ (TRS) jack for balanced or unbalanced line level, or balanced or unbalanced microphone with selectable phantom power
- Audio Input Gain Adjust: In menu, adjustable to 0 to -50 dB, in 1dB steps
- Phantom Power: 14.4 VDC applied through 2.2 kOhms resistors to analog combo jack: Pin 2 and Pin 3 on XLR jack, or tip and ring on 1/4″ TRS jack
- Audio Level Indicators: 10-LED array that reads -18 to +9 dB at 3 dB intervals. 7 Green, 2 Amber, and 1 red LED. Green LEDs indicate normal operating audio level peaks, Amber LEDS indicate close to overload peaks, Red LED indicates overload peaks
- Headphone Output: 1/4″ TRS stereo jack, mono signal, 14.85 mW at +9dB, maximum in 33 Ω (level adjustable in menu 0 to -40 dB in 2 dB steps)
- Line Output: RCA jack (black), -10 dBV (.32 VRMS); Output impedance 100 ohms at +9dB
- Input Levels (Bal or Unbal) (at Audio Input Gain = 0dB)
  - Nominal (1st Amber + 3dB LED)
  - Overload Warning (Displayed on Screen)
  - Absolute Max. Rating (Stresses above these ratings may cause permanent damage or degrade reliability.)
- Microphone: -55 dBV (1.7 mV RMS) -22 dBV (80 mV RMS) +20 dBV (10.0 V RMS)
- Line: -25 dBV (55 mV RMS) +16 dBV (6.3 V RMS) +20 dBV (10.0 V RMS)
- Approvals: FCC, RoHS3, WEEE, Industry Canada
- Warranty: 2-year parts and labor
ANT 005
- Use with: PPA T45, PPA T55, PPA T55C, PPA T27 Transmitters
- Connector type: F-connector
- Cable type: RG 59 coax
- Nominal Impedance: 75 Ohm
- Total Cable Length: 22 ft
- Active Antenna Length: 80 in
NKL 001
- Color: Black
- Weight: 1.5 oz
- Length: 18.5” cord
- Connector: NKL 001: 3.5 mm mono plug NKL 001-S: 3.5 mm stereo plug with ring disconnected
- Impedance: 8-16 Ohms
- Input Power: 500 mW max
PPA R37N
- Dimensions: 4.1" x 2.85" x 1.38" (104 x 72 x 35mm)
- Weight: 4.6oz (130g) with batteries. 2.6oz (73g) without batteries
- Color: Black
- Battery Type: (2) AA Alkaline or 2 x AA NiMH
- Battery Life:
  - Two (2) AA non-rechargeable alkaline batteries (BAT 001), approx. 50 hrs
  - (2) AA rechargeable NiMH batteries (BAT 026), 1500 mAh, approx. 32 hrs
- Current Consumption: 52mA nominal
- Temperature Range: – 0 to 50C
- Channels 17, accessed via seek button in battery compartment
- Operating Freq.: 72.1, 72.2, 72.3, 72.4, 72.5, 72.6, 72.7, 72.8, 72.9, 74.7, 75.3, 75.4, 75.5, 75.6, 75.7, 75.8, 75.9 MHz*
- Intermediate Freq.: 75 kHz
- FM Deviation: 75 kHz
- De-Emphasis: 75 µS
- LED Indicator: Power: Green; Low Battery: Flashes Green
- AFC Range: ± 120 kHz
- Sensitivity: 2 µV at 12 dB Sinad with squelch defeated
- Input Overload: 100 mV
- Frequency Response: 200 – 15 kHz
- Modulation: FM, +/- 75 kHz peak deviation
- Signal-to-Noise Ratio: 65 dB min @ 100 uV
- Receive Antenna: Integral with earphone/headphone cord
- Audio Output: 35 mW max, peak into 16 ohms
- Output Connector: 3.5 mm stereo/mono phone jack
- Earphone: Earbud-type with foam cushion, 3.5 mm plug, 32 Ω
- Auto Shut-off: Enters sleep mode after approx 6 mins of no RF signal
- Approvals: FCC, Industry Canada, RoHS, WEEE
- Warranty: Lifetime PLUS Limited Warranty, 90 Days on most accessories.
IDP 00810-3/8" (L) x 6-¼" (W) x 1/8" (H)