PPA 377

Personal PA® FM Assistive Listening System

Product Highlights

  • Microprocessor controlled
  • T35 professional transmitter
  • Up to 1000’ operating range




The Personal PA® 377 ensures people in your facility receive direct, clear communication of your message. Push-button menu controls make the system easy to set up and use. With professional sound features and an operating range of up to 1000 feet, the PPA 377 is ideal for large venues where superior coverage is essential. This complete turnkey solution includes four PPA Select receivers (PPA R37), each featuring seek-button channel selection with access to 17 pre-set wideband frequencies between 72-76 MHz. 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.

NOTE: The Personal PA® FM Listening System is approved by the FCC for operation in U.S. markets. The system cannot be used in all countries. Check with your government radio regulations for 72-76 MHz operation.

Disclaimer: FCC rules limit use of this equipment to auditory assistance.



System Includes

(1) T35 Transmitter

(4) PPA Select™ Receivers (PPA R37)

(2) NKL 001 Neckloops

(4) EAR 013 Earphones

(1) ANT 025 Whip Antenna

(1) WCA 013 Audio Cable

(1) TFP 016 Power Supply

(1) IDP 008 ADA Wall Plaque

(8) BAT 001 AA Alkaline Batteries

Optional 8-channel receivers (PPA R35-8N) are available for multi-channel applications.

All items can be purchased separately. Earphones sold separately. See accessories.

Ppa 377


  • T35 professional transmitter
  • Up to 1000’ operating range
  • LCD display, push-button menus
  • Microprocessor controlled
  • Accommodates any number of listeners
  • Adjustable power output
  • Combo XLR, ¼" TRS inputs
  • Meets ADAAG guidelines
  • Lifetime PLUS Limited Warranty. 90 days on accessories.
  • Made in the USA


PPA R37 Architectural and Engineering Specifications

  • The PPA R37 receiver shall be encased in black, PC/ABS impact-resistant plastic with a hinged battery door. The receiver shall be a body-pack style and include a detachable belt-clip for hands-free operation. The receiver shall have a 3.5mm stereo/mono jack to accommodate stereo or mono low impedance earphones, headphones and neckloops. The receiver shall have a combination volume control with power on/off rotator dial. It shall have a green LED indicating battery and system status codes. The R37 shall have access to 17 preset wideband channels between 72-76MHz. Channel selection shall be made by pushing the seek button inside the battery compartment. The receiver shall have channel-lock capability.
  • The receiver shall have a slide switch inside the battery compartment to select disposable Alkaline or NiMH rechargeable battery operation. It shall have charger contacts on the bottom of the receiver for use with Williams Sound drop-in chargers CHG 3512 and CHG 3502. The R37 shall operate up to 50 hours with two disposable AA Alkaline batteries and up to 32 hours with two AA NiMH rechargeable batteries (BAT 026).
  • The receiver shall provide a maximum out of 35mW at 16ø with an earbud type earphone. The systems audio frequency response shall be 200Hz to 15kHz ± 3dB and the signal to noise ratio shall be 65dB min. The receiver sensitivity shall be 2μV or better at 12dB Sinad with squelch defeated. The R37 shall accept up to ±75kHz FM deviation and have a 75 μ s de-emphasis time constant.
  • The R37 shall have FCC, Industry Canada approvals and be compliant with RoHS and WEEE regulations. The receiver shall be covered by a Lifetime PLUS Limited Warranty, excluding earphones, headphones and batteries.
  • This receiver model shall be the Williams Sound model PPA R37.


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.

PPA T35 Architectural and Engineering Specifications

  • The PPA T35 transmitter shall be microprocessor controlled with push button configuration. It shall have an operating range of up to 1000 feet. It shall have 10 wideband and 7 non-standard wideband channels operating on 72.1–75.9 MHz. It shall have 77 narrowband channels operating on 72.025–75.975 MHz.

Front Panel:

  • The PPA T35 shall have a push button controlled LCD digital display. There shall be three pre-configured (selectable) application presets: Hearing Assist, Music and Voice. Configurations for Bandwidth, Frequency, Audio Input Source (Microphone, Line, Simplex), High Pass Filter, Low Pass Filter, Compressor Slope, Compressor Gain and RF Output Power shall be push button controlled. The audio level shall be adjustable by push button control. There shall be a 10 LED array showing +9 to -18 at 3dB intervals. The PPA T35 shall have a 1/4" phone jack with push button volume control. It shall have push button control for monitoring source audio or transmitted audio. It shall have an input overload indicator. It shall have an “on" indicator and power button.

Rear Panel:

  • The PPA T35 shall be powered by 24 VAC power supply via a 3-pin Molex® connector. It shall have a 75 ohm
  • F-connector antenna. It shall have an ANT 025 whip antenna on the top panel directly connected to the circuit board. The transmitter shall have an RCA line output jack. It shall have a combination 1/4" phone/XLR audio input jack. It shall have an RF “Off" timer that turns off RF signal after 1 hour of no audio activity.
  • The PPA T35 shall have FCC, RoHS, and WEEE approval and be powered by UL and CSA power supply. It shall have a Lifetime PLUS Limited Warranty. It shall be compatible with Williams Sound FM equipment operating on 72-76 MHz. The transmitter shall be a Williams Sound. model number PPA T35.


Dimensions, Weight:

8.45" (21.5 cm) W x 8.18" (20.8 cm) D x 1.72" (4.4 cm) H, 3.1 lbs (1.4 kg)


Black with white legends

Rack Mount:

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


Wall mount Class II transformer (TFP 016)

Input: 120 VAC, 60 Hz, 17 W

Output: 24 VAC, 500 mA with 3-pin Molex® plug


UL, CSA listed

Temperature Range:

Operating:0° C to 40° C (+32° F to +104° F)


Storage:-20° C to 70° C (-4° F to +158° F)

Operating Freqs:

72.1-75.9 MHz* , 10 wideband channels (selectable), 7 non-standard wideband channels (selectable) OR 72.025-75.975 MHz, 77 narrowband channels (selectable)

Frequency Accuracy:

±.005% stability, 0-50˚ C


Wideband: ± 75 kHz maximum. Narrowband: ± 5 kHz maximum.


Wideband: 75 µsec. Narrowband: 300 µsec

RF Field Strength:

Does not exceed 80 mV/m at 3 m

Nominal Range:

Up to 1000 ft (304 m) Note: Maximum transmitter range is achieved using the ANT 005 coaxial antenna

Audio Proc. Functions:

Reduced or Normal Compressor Gain

Compression Slope Control

High Pass and Low Pass Filter Frequency control

Frequency Response:

22 – 16000 Hz, +1, -3 dB (adjustable)

Signal-to-Noise Ratio:

74 dB transmitted

Audio Level Control:

Push-button audio level controls, adjustable to 0 to -50 dB

Audio Level Indicators:

10 LED array that reads +9 to -18 at 3 dB intervals

Power On Indicator:

Green LED indicates power on

Phones Output:

Mono signal, 1/4" TRS stereo jack, 67 mW, maximum in 50 ohms (adjustable 0 to -40 dB)

Audio Input:

Combination 3-pin XLR, 1/4" TRS jack

Line Output:

RCA jack, -10 dBV (.32 VRMS) output, impedance 100 Ω

LCD Menu Controls:

Applications Presets (Music, Voice, Hearing Assist)

(Push-Button Selection)

Bandwidth, Frequency, Audio Input Source (Microphone, Line, Simplex), High Pass Filter, Low Pass Filter, Compressor Slope, Compressor Gain, RF Output Power

Input Levels (Bal or Unbal):

Nominal (1st Amber LED)

Maximum (Input Overload LED)

Absolute Maximum Ratings**

Microphone Simplex-Mic:

-60dBV (1 mV RMS)

-20 dBV (100 mV RMS)

+20dBV (10.0 V RMS)


-8dBV (400 mV RMS)

+16 dBV (6.3 V RMS)

+20 dB V (10.0 V RMS)

Simplex Mode:

12 volts simplex power (DIN 45596) on the 3-pin XLR connector

RF “Off" Timer:

Turns off RF signal after 1 hour of no audio activity

Common Mode Rejection:

> 57 dB @ 1 kHz, Mic or Line

Total Harmonic Distortion:

< 0.25% @ -10 dB V audio line output, 1 kHz




Lifetime PLUS Limited Warranty, 90 Days on most accessories.

Other Models

PPA 377 Personal PA® FM Listening System
PPA 377 PRO Personal PA® FM Listening System

Accessories for PPA 377 FM Listening System

All Williams Sound headphones and earphones are compatible with this product.

ANT 005 Remote Coaxial Antenna

BAT 001 AA Alkaline Battery

CHG 3512 Body-pack charger, 12 bay

RPK 005 Single rack mount kit

RPK 006 Dual rack mount kit

Products compatible with PPA 377 FM Listening System


Download/View Name Type Language
FM Brochure - Low Res Brochures English
Client Profile - Palm Beach County Schools Client Profiles English
Client Profile - Grace Church Client Profiles English
PPA 377 Specifications Specifications English
PPA T35 Manual Español Manuals Español
PPA 377 Sell Sheet Sell Sheets English
FM Brochure - High Res Brochures English
PPA T35 Manual Manuals English


Name Description Duration
Williams Sound: FM Listening Systems (PPA T35)

General information on how FM listening systems work.  Specific product information on the Williams Sound PPA T35 base station transmitter and complete line of FM assistive listening systems.