M405M — Extended Range VU Monitoring System
| Type | module |
| Category | METER |
| Try it | simulator & front panel · download package (zip) |
| Earliest dated evidence | 1995|28 — manual issue date |
| Evidence | "Issue #1 March 20, 1995" in WBSps Engineering from H drive-20261018T013433Z-1-001/WBSps Engineering from H drive/WBSps - Word Perfect Manuals/M405M.WP |
| Confidence | high |
| All years found | 1995|28 |
| Variants | M405, M405C, M405D, M405F, M405P, M405PSS |
| Folder | Modules/METER/M405M |
Connections
What it is made of and what it is part of.
Pictures
1995 - M405M - Archived - M405M - METER - MONITOR 001.jpg
1995 - M405M - Archived - M405M - METER - MONITOR 002.jpg
1995 - M405M - Archived - M405M - METER - MONITOR 003.jpg
1995 - 405-03-082 - M405M PCB CONNECTOR BRACKET - DRN DRG - ISS 1.jpgDates found in the documents
| Year | Kind | Text | File |
|---|---|---|---|
| 1995|28 | manual issue date | Issue #1 March 20, 1995 |
1995 - M405M - 14-292-02-003 - 3 P1 CONNECTOR 3-1 - LAYOUT.wp |
Documents (1)
| Year | File | |
|---|---|---|
| 1995|28 | 1995 - M405M - 14-292-02-003 - 3 P1 CONNECTOR 3-1 - LAYOUT.wp | note |
Photos & scans (3)
Sub-assemblies & parts used (1)
| Item | What | Family | Year | How we know |
|---|---|---|---|---|
| SA14-292 | 3 P1 CONNECTOR 3-1 - LAYOUT | Circuit boards (SA14-nnn) | its circuit board |
Parts list — board 14-292 (17 parts)
From 14-292#2.WP; also in timelines/data/bom.csv.
| Ref | Part | Value | Manufacturer | Mfr part no. |
|---|---|---|---|---|
| C1 | Capacitor | 10 uF/25 V | ITT | 10M25 |
| C10 | delete | |||
| C11 | Capacitor | 1 uF/35 V | ITT | 1M35 |
| CR1 | Diode | Motorola | 1N4148 | |
| P3 | Connector, 2 Pin Bergstik | Berg | 65645-202 | |
| Q1 | Transistor | National | 2N3906 | |
| R1 | Resistor | 1/4W 5% | 47K | Philips CR25 |
| R11 | Resistor | 1/4W 1% | 9K09 | Philips MRS 25F |
| R16 | Resistor | 1/4W 5% | 43K | Philips CR25 |
| R17 | Potentiometer | 50K | Piher | PT10V 50K |
| R18 | Resistor | 1/4W 5% | 22K | Philips CR25 |
| R29 | Resistor | 1/4W 5% | 4K7 | Philips CR25 |
| R33 | delete | |||
| R34 | Potentiometer | 20K | Piher | PT10V 20K |
| R35 | Resistor | 1/4W 5% | 47K | Philips CR25 |
| U1 | Integrated Circuit | National | LM833N | |
| U1, U3 | 8 Pin Dip Socket | AMP | 640463-3 |
Parts list — board M405M (8 parts)
From M405M.WP; also in timelines/data/bom.csv.
| Ref | Part | Value | Manufacturer | Mfr part no. |
|---|---|---|---|---|
| A1 | VU Meter Amplifier | WBS | SA14-292B | |
| A2 | Intercom pre and Output Amplifier | WBS | M703C | |
| F1 | 314 Amp fast blow fuse | Buss | AGC0.75 | |
| J1 | Jack 1/4" headphone | Switchcraft | NL-11413 | |
| LS1 | Speaker | Misco | DC22S | |
| M1 | Vu Meter | Bach-Simpson | 544WL | |
| R1 | Speaker Level | Clarostat | WBS 10-073 | |
| SW1-SW7 | Switch | Schadow | 2CF-GHT-AA |
Named in other drawings & documents (4)
| File | Page |
|---|---|
| 1995 - 405-03-082 - M405M PCB CONNECTOR BRACKET - DRN DRG - ISS 1.jpg | 1 |
| 1995 - M405P - ITEMIMP(1).TXT (2).docx | 1 |
| 1995 - M405P - ITEMIMP(1).TXT.docx | 1 |
| 1995 - M405P - ITEMIMP.TXT.docx | 1 |
From the manuals
Each manual split into its sections. Text that is the same in many Ward-Beck manuals (warranty, address, standard notes) is kept once on the Boilerplate page and linked.
Specifications (1)
Technical Data — 301 words · 1995 - M405M - 14-292-02-003 - 3 P1 CONNECTOR 3-1 - LAYOUT.wp, page 1
M405M EXTENDED RANGE VU MONITORING SYSTEM
Range: -10 dBu to +10 dBu in five steps.
Input Selection: Pushbutton select between two sources.
Source Impedance: 600 ohms or less, balanced.
Input Impedance: Greater than 20K ohms.
Attenuator Tracking: ±0.25dB per step, non-cumulative.
Meter Ballistics: Complies with ANSI C16.5.
Frequency Response: ±0.25 dB 30 Hz to 15 kHz.
Monitor Output: ±1 dB from 100 Hz to 5 kHz.
Total Harmonic Distortion Headset Output: Less than 1%, from 50 Hz to 10 kHz. Speaker Output: Less than 1%, 50 Hz to 10 kHz
Noise: 40 dB below 0 VU reference. GENERAL
M405M EXTENDED RANGE VU MONITORING SYSTEM
The M405M has been designed to measure and monitor the average level of an audio signal. This instrument is self-contained and mounts in an EIA standard 19" equipment rack. It is powered by a 24 volt DC wall mount power supply.
A "range" attenuator, providing 5 steps (-10, 0, +4, +8, +10 dBu), accommodates audio input levels from -10 to +10 dBu for a 0 meter reading. The M405M accepts two inputs (A or B) at the rear of the instrument. Selection between the A or B inputs may be made by a pushbutton selector on the front of the unit.
An internal speaker, complete with level control, is mounted in the front panel to permit the user to listen to the source being metered. A headset jack is also provided on the front panel for headphone monitoring. A1 VU Meter Amplifier WBS SA14-292B
A2 Intercom pre and Output Amplifier WBS M703C
F1 314 Amp fast blow fuse Buss AGC0.75
J1 Jack 1/4" headphone Switchcraft NL-11413
LS1 Speaker Misco DC22S
M1 Vu Meter Bach-Simpson 544WL
R1 Speaker Level Clarostat WBS 10-073
SW1-SW7 Switch Schadow 2CF-GHT-AA
M405M
EXTENDED RANGE VU MONITORING SYSTEM Issue #1 March 20, 1995 MW94002/M405M.WP