Leitch DPS-475: Difference between revisions

Latest revision as of 21:14, 19 February 2026

Description

The Leitch DPS-475 is a broadcast-quality digital processing synchronizer designed for NTSC-only operation. Originally developed by Digital Processing Systems (DPS) and continued under the Leitch brand following the 2000 acquisition, the DPS-475 is hardware identical to its multi-standard sibling, the DPS-575, but is software-locked to operate only with NTSC signals.

The unit combines frame synchronization, time base correction, format transcoding, and audio/video processing in a single 1U rackmount chassis. It serves as a universal bridge between analog and digital video systems, accepting composite, S-Video, component analog, SDI, and optionally DV (IEEE-1394) inputs while providing simultaneous outputs in all formats.

A key innovation is the DigiDuplex mode, which enables bi-directional connectivity between analog tape machines and digital routing systems. This allows the SDI input to feed analog outputs (for recording to an analog VTR) while simultaneously accepting the VTR's analog output, processing it, and outputting via SDI—all in a single unit.

The DPS-475 employs a 12-bit adaptive 3-dimensional comb filter decoder featuring DPS's proprietary Phase Quadrature Mixing (PQM) technology, which virtually eliminates cross-luminance and cross-chrominance artifacts from composite sources. The integrated framestore supports still image storage with linear keying, enabling logo insertion and source identification.

Available in video-only (DPS-475) and audio/video (DPS-475AV) configurations, as well as "LC" variants without front panel controls for remote-operated installations.

Photos

Relationship to DPS-575

The DPS-475 is hardware identical to the DPS-575. The only difference is a software lock that restricts the DPS-475 to NTSC operation, whereas the DPS-575 supports auto-sensing dual-standard PAL/NTSC operation.

According to discussions in the laserdisc community, it is reportedly possible to convert a DPS-475 to a DPS-575 via firmware flashing, effectively unlocking PAL support. This involves uploading DPS-575 firmware to the unit. See this LDDB forum thread for details.

Specifications

Video Processing

Parameter	Specification
ADC/DAC Resolution	12-bit
Component Pipeline	10-bit YUV
Synchronizing Range	Infinite
Frequency Response (Sync Mode)	±0.25 dB (0–5.5 MHz), -1 dB (5.5–5.75 MHz)
Frequency Response (TBC Mode)	-3 dB (0–4.2 MHz, notch at 3.58 MHz)
Signal-to-Noise (TSG/SDI)	>75 dB luminance weighted
Signal-to-Noise (Sync Mode)	>70 dB luminance weighted
Signal-to-Noise (TBC Mode)	>60 dB luminance weighted
Differential Phase	<1° (modulated ramp)
Differential Gain	<1% (modulated ramp)
K-Factor (2T)	<0.5%
Luminance Jitter (TBC Mode)	<15 ns

Video Inputs

Input	Specification
Composite Video (BNC)	1V p-p, 75Ω
Component Y (BNC)	1V p-p, 75Ω
Component R-Y/B-Y (BNC)	0.7V p-p, 75Ω
S-Video Y (Mini-DIN-4)	1V p-p, 75Ω
S-Video C (Mini-DIN-4)	286 mV burst (NTSC)
SDI (BNC)	75Ω, auto EQ to 300m, reclocked/buffered loop output
DV (6-pin Molex, optional)	IEEE-1394
Genlock Reference (BNC loop)	1V p-p, 75Ω

Video Outputs

Output	Specification
Composite Video (BNC ×2)	1V p-p, 75Ω
Component Y (BNC)	1V p-p, 75Ω
Component R-Y/B-Y (BNC)	0.7V p-p, 75Ω
S-Video Y (Mini-DIN-4)	1V p-p, 75Ω
S-Video C (Mini-DIN-4)	286 mV burst (NTSC)
RGB (BNC)	1V p-p, 75Ω
RGBS Sync (BNC)	300 mV or 8V p-p (selectable)
SDI (BNC ×2)	75Ω
DV (6-pin Molex, optional)	IEEE-1394

Proc Amp Controls

Control	Range
Video Level	±3 dB
Setup Level	±20 IRE
Chroma Level	±6 dB
Hue Phase	±45°
Horizontal Genlock Timing	±6 µs
Subcarrier Genlock Timing	360°
Input Y/C Delay	-592 ns to +518 ns

Audio Specifications (DPS-475AV)

Parameter	Specification
Processing Resolution	24-bit
Analog Input Sampling Rate	32, 44.1, 48 kHz
Maximum Analog Level	+24 dBu
Analog Input Impedance	600Ω or 18kΩ
Operating Levels	+8, +4, 0, -4, -10 dBu
AES/EBU Resolution	24-bit, up to 96 kHz
SDI Embedded Resolution	20-bit, 48 kHz synchronous

General

Parameter	Specification
Dimensions (W × H × D)	17" × 1.75" × 20" (43.2 × 4.4 × 50.8 cm)
Rack Height	1U
Power	70W, 100–240 VAC, 50/60 Hz
Remote Control	RS-232/RS-422 (DB-9F), Ethernet 10Base-T (RJ-45), DCN (BNC)
GPI	2× input (on breakout cable), 1× output (on breakout cable)

Model Variants

Model	Description
DPS-475	Video-only synchronizer (NTSC only)
DPS-475AV	Integrated audio/video synchronizer (NTSC only)
DPS-475LC	Video-only without front panel controls
DPS-475LCAV	Audio/video without front panel controls

Options

Part Number	Description
AS-575	Four-channel digital audio synchronizer module (upgrades DPS-475 to DPS-475AV)
AS-575L	Audio synchronizer module with audio limiter
ASL-575	Audio limiter option (requires existing AS-575)
NR-575	Digital noise reduction and bandwidth filter
AL-475	Animated logo option (NTSC)
DVM-5010	DV I/O module (IEEE-1394)
RC-475	Multi-channel remote panel
RC-4000	Multi-channel remote panel with Ethernet
774-753	Video breakout cable
774-755	Audio breakout cable

Test Signals

The DPS-475 includes over 30 built-in 10-bit test patterns for NTSC:

SMPTE Bars
EIA Bars
Full Field Bars
Bars / Luma
Bars / Reverse
Bars / Red
Bars 100%
Super Black

(Plus additional multiburst, pulse & bar, and specialized test patterns)

Remote Control

The DPS-475 supports multiple remote control methods:

Serial — RS-232 or RS-422 via DB-9F connector at 9600 or 38400 bps
Ethernet — 10Base-T for LAN/WAN control via web browser or Leitch PILOT GUI software
DCN — Proprietary DPS serial control network (BNC)
GPI — Two TTL/contact closure inputs and one TTL pulse output (via breakout cable)

Multiple DPS-475 units can be networked and controlled from a central location using the optional RC-475 or RC-4000 remote panels.

Documents

DPS-475/DPS-575 Service Manual

@@ Line 6: / Line 6: @@
 |images=Leitch DPS-475 front angle.jpg,Leitch DPS-475 back.jpg,Leitch DPS-475 left side.jpg,Leitch DPS-475 right side.jpg,Leitch DPS-475 top.jpg,Leitch DPS-475 bottom.jpg
 |year_released=2000
-|signal_standard=NTSC
+|av_system=NTSC
-|video_inputs=Composite (BNC), Component Y/R-Y/B-Y (BNC), S-Video (Mini-DIN-4), SDI (BNC), DV/IEEE-1394 (6-pin Molex, optional)
+|frequency=50Hz,60Hz
-|video_outputs=Composite (BNC ×2), Component Y/R-Y/B-Y (BNC), S-Video (Mini-DIN-4), RGB/RGBS (BNC), SDI (BNC ×2), DV/IEEE-1394 (6-pin Molex, optional)
+|power_avg=70
-|audio_inputs=2× Stereo analog (balanced/unbalanced, barrier strip), 2× AES/EBU stereo (BNC via breakout), SDI embedded (2 stereo via SDI input)
-|audio_outputs=2× Stereo analog (balanced/unbalanced, barrier strip), 2× AES/EBU stereo (BNC via breakout), SDI embedded (2 stereo via SDI output)
 |features=12-bit video encoder/decoder, adaptive 3D comb filter with PQM technology, DigiDuplex bi-directional analog/digital interface, video framestore with linear keyer, 30+ test pattern generator, VITS/VIRS inserter, video AGC, audio test signal generator (4 channels), genlock with timing adjustment, proc amp controls, optional digital noise reduction, optional animated logo inserter, optional DV (IEEE-1394) I/O, optional audio limiter
 |description=The '''Leitch DPS-475''' is a broadcast-quality digital processing synchronizer designed for NTSC-only operation. Originally developed by [[Digital Processing Systems]] (DPS) and continued under the Leitch brand following the 2000 acquisition, the DPS-475 is '''hardware identical''' to its multi-standard sibling, the [[Leitch DPS-575|DPS-575]], but is software-locked to operate only with NTSC signals.
@@ Line 24: / Line 22: @@
 |width=17 in
 |depth=20 in
-|weight=
-|power_voltage=100-240V AC
-|power_wattage=70W
 }}
@@ Line 246: / Line 241: @@
 * [[Leitch]]
 * [[:Category:Time base correctors and frame synchronizers|Time base correctors and frame synchronizers]]
+{{AV TBC
+|type=Line TBC
+|buffer_size=Infinite window
+|notes=Full-range timebase correction with infinite correction window
+}}
+{{AV TBC
+|type=Frame synchronizer
+|buffer_size=1 frame
+|notes=12-bit processing, 10-bit YUV component pipeline
+}}
+{{AV input
+|label=Composite
+|signal=Composite (CVBS)
+|connector=BNC
+|count=1
+|audio=None
+|location=rear
+|notes=1V p-p, 75Ω
+}}
+{{AV input
+|label=Component
+|signal=Component (YPbPr)
+|connector=BNC
+|count=1
+|audio=None
+|location=rear
+|notes=3× BNC (Y/R-Y/B-Y). Y: 1V p-p, R-Y/B-Y: 0.7V p-p, 75Ω
+}}
+{{AV input
+|label=S-Video
+|signal=S-Video (Y/C)
+|connector=Mini-DIN-4
+|count=1
+|audio=None
+|location=rear
+|notes=Y: 1V p-p, C: 286mV burst (NTSC), 75Ω
+}}
+{{AV input
+|label=SDI
+|signal=SDI
+|connector=BNC
+|count=1
+|audio=None
+|location=rear
+|notes=75Ω, auto EQ to 300m, reclocked/buffered loop output. AV variant carries 2× embedded stereo audio (20-bit, 48 kHz).
+}}
+{{AV input
+|label=Genlock Ref
+|signal=Composite (CVBS)
+|connector=BNC
+|count=1
+|audio=None
+|location=rear
+|notes=Color black/burst reference, Hi-Z loop-through, 1V p-p, 75Ω
+}}
+{{AV input
+|label=Analog Audio
+|signal=Analog stereo
+|connector=Phoenix connector
+|count=2
+|audio=Stereo
+|location=rear
+|notes=Balanced/unbalanced on barrier strip terminal blocks. DPS-475AV only. +24 dBu max, 600Ω or 18kΩ impedance.
+}}
+{{AV output
+|label=Composite
+|output_type=Video
+|signal=Composite (CVBS)
+|connector=BNC
+|count=2
+|location=rear
+|notes=1V p-p, 75Ω
+}}
+{{AV output
+|label=Component
+|output_type=Video
+|signal=Component (YPbPr)
+|connector=BNC
+|count=1
+|location=rear
+|notes=3× BNC (Y/R-Y/B-Y). Y: 1V p-p, R-Y/B-Y: 0.7V p-p, 75Ω
+}}
+{{AV output
+|label=S-Video
+|output_type=Video
+|signal=S-Video (Y/C)
+|connector=Mini-DIN-4
+|count=1
+|location=rear
+|notes=Y: 1V p-p, C: 286mV burst (NTSC), 75Ω
+}}
+{{AV output
+|label=RGB
+|output_type=Video
+|signal=RGBS
+|connector=BNC
+|count=1
+|location=rear
+|notes=4× BNC (R/G/B/Sync). RGB: 1V p-p, Sync: 300mV or 8V p-p (selectable), 75Ω
+}}
+{{AV output
+|label=SDI
+|output_type=Video
+|signal=SDI
+|connector=BNC
+|count=2
+|location=rear
+|notes=75Ω. AV variant carries 2× embedded stereo audio (20-bit, 48 kHz synchronous).
+}}
+{{AV output
+|label=Analog Audio
+|output_type=Audio
+|signal=Analog stereo
+|connector=Phoenix connector
+|count=2
+|location=rear
+|notes=Balanced/unbalanced on barrier strip terminal blocks. DPS-475AV only.
+}}
+{{AV voltage range
+|voltage_min=100
+|voltage_max=240
+}}
 [[Category:Leitch AV devices]]
 [[Category:Time base correctors and frame synchronizers]]