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Control Room to Machine Room Connections

Path: Studio Guides/Studio A/Patches/Control Room to Machine Room Connections.mdUpdated: 2/3/2026

Control Room to Machine Room Connections

Overview

Studio A control room patchbay connects to the machine room patchbay via DB25 snakes and XLR trunks. This article maps where each patch point in the control room terminates in the machine room.

Related articles:

  • Studio A Patchbays - Control room and credenza patchbay layouts
  • Studio A Signal Flow - Circular Perspective - Complete signal flow from mic to DAW

DAW Outputs (Control Room β†’ Machine Room)

Console Patchbay: DAW Outputs Section

Control room patch points:

  • DAW Out 1-2 (Stereo mix left/right)
  • DAW Out 3-4
  • DAW Out 5-6
  • DAW Out 7-8
  • DAW Out 9-10
  • DAW Out 11-12
  • DAW Out 13-14
  • DAW Out 15-16

Continues through:

  • DAW Out 17-18
  • DAW Out 19-20
  • DAW Out 21-22
  • DAW Out 23-24
  • DAW Out 25-26
  • DAW Out 27-28
  • DAW Out 29-30
  • DAW Out 31-32

Machine Room Termination

Location: Machine room patchbay [TBD - Add photo]

Physical connection:

  • DB25 snake from control room β†’ Machine room patchbay
  • 8 channels per DB25 (4Γ— DB25 snakes for 32 channels)

Machine room patch points:

  • DAW Out 1-32 (top row, machine room patchbay)
  • Connects to: REDNET 2 inputs (analog to Dante conversion)
  • Or: Patch to outboard gear inputs (compressors, reverbs, etc.)

Signal flow:

ProTools DAW β†’ HDX/REDNET PCIe outputs β†’ Control room patchbay DAW Outs β†’ 
DB25 snake β†’ Machine room patchbay β†’ REDNET 2 inputs β†’ Dante network

Common patches:

  • DAW Out 1-2 β†’ REDNET 2 In 1-2 (main mix for monitoring)
  • DAW Out 3-8 β†’ Outboard compressor inputs (parallel processing)
  • DAW Out 9-16 β†’ External reverb/delay sends

DAW Inputs (Machine Room β†’ Control Room)

Console Patchbay: DAW Inputs Section

Control room patch points:

  • DAW In 1-2 (Channel strip outputs)
  • DAW In 3-4
  • DAW In 5-6
  • DAW In 7-8
  • DAW In 9-10
  • DAW In 11-12
  • DAW In 13-14
  • DAW In 15-16

Continues through:

  • DAW In 17-18
  • DAW In 19-20
  • DAW In 21-22
  • DAW In 23-24
  • DAW In 25-26
  • DAW In 27-28
  • DAW In 29-30
  • DAW In 31-32

Machine Room Termination

Location: Machine room patchbay [TBD - Add photo]

Physical connection:

  • DB25 snake from machine room β†’ Control room patchbay
  • 8 channels per DB25 (4Γ— DB25 snakes for 32 channels)

Machine room patch points:

  • DAW In 1-32 (bottom row, machine room patchbay)
  • Receives from: REDNET 2 outputs (Dante to analog conversion)
  • Or: Patch from outboard gear outputs (compressors, mic preamps, etc.)

Signal flow:

Mic β†’ REDNET 2 preamp β†’ Dante network β†’ REDNET PCIe β†’ Machine room patchbay 
β†’ DB25 snake β†’ Control room patchbay DAW Ins β†’ SSL channel strips β†’ ProTools

Common patches:

  • REDNET 2 Out 1-16 β†’ Machine room patchbay β†’ DAW In 1-16 (mic inputs)
  • Outboard compressor outputs β†’ Machine room patchbay β†’ DAW In 17-24
  • External reverb returns β†’ Machine room patchbay β†’ DAW In 25-32

Track Bus Outputs (SSL Console β†’ Machine Room)

Console Patchbay: Track Bus Section

Control room patch points:

  • Track Bus 1-2
  • Track Bus 3-4
  • Track Bus 5-6
  • Track Bus 7-8
  • Track Bus 9-10
  • Track Bus 11-12
  • Track Bus 13-14
  • Track Bus 15-16

Continues through:

  • Track Bus 17-18
  • Track Bus 19-20
  • Track Bus 21-22
  • Track Bus 23-24

Machine Room Termination

Location: Machine room patchbay [TBD - Add photo]

Physical connection:

  • DB25 snake from control room β†’ Machine room patchbay
  • 8 channels per DB25 (3Γ— DB25 snakes for 24 channels)

Machine room patch points:

  • Track Bus 1-24 (machine room patchbay)
  • Connects to: REDNET 2 inputs (for recording console mixes)
  • Or: Patch to outboard summing mixers, tape machines, etc.

Signal flow:

SSL channel faders β†’ Track Bus (stereo pairs) β†’ Control room patchbay β†’ 
DB25 snake β†’ Machine room patchbay β†’ REDNET 2 inputs β†’ ProTools

Common patches:

  • Track Bus 1-2 β†’ REDNET 2 In 33-34 (stereo mix from console)
  • Track Bus 3-4 β†’ REDNET 2 In 35-36 (drum bus)
  • Track Bus 5-6 β†’ REDNET 2 In 37-38 (instrument bus)

Use case:

  • Mixing on SSL console (analog workflow)
  • Record console mix stems to ProTools via Track Bus β†’ REDNET 2 β†’ DAW
  • Or: Send Track Bus to outboard summing (Dangerous Music 2-Bus+)

Monitor Inputs (Machine Room β†’ Control Room)

Console Patchbay: Monitor Inputs Section

Control room patch points:

  • Monitor In 1-2 (External sources for monitoring)
  • Monitor In 3-4
  • Monitor In 5-6
  • Monitor In 7-8
  • Monitor In 9-10
  • Monitor In 11-12
  • Monitor In 13-14
  • Monitor In 15-16

Machine Room Termination

Location: Machine room patchbay [TBD - Add photo]

Physical connection:

  • DB25 snake from machine room β†’ Control room patchbay
  • 8 channels per DB25 (2Γ— DB25 snakes for 16 channels)

Machine room patch points:

  • Monitor In 1-16 (machine room patchbay)
  • Receives from: REDNET 2 outputs (Dante playback sources)
  • Or: External playback devices (CD player, media server, etc.)

Signal flow:

REDNET 2 outputs β†’ Machine room patchbay β†’ DB25 snake β†’ 
Control room patchbay Monitor Ins β†’ SSL monitor section β†’ Studio monitors

Common patches:

  • REDNET 2 Out 33-34 β†’ Machine room patchbay β†’ Monitor In 1-2 (main playback)
  • Media server outputs β†’ Machine room patchbay β†’ Monitor In 3-4
  • Bluetooth receiver β†’ Machine room patchbay β†’ Monitor In 5-6

Use case:

  • Listen to external audio sources through SSL monitor section
  • A/B compare mixes from different sources
  • Reference tracks from media server

DB25 Snake Pinouts

Standard Tascam/Yamaha Pinout

DB25 Pin β†’ Audio Channel:

Pin 1-2:   Channel 1 (balanced)
Pin 3-4:   Channel 2 (balanced)
Pin 5-6:   Channel 3 (balanced)
Pin 7-8:   Channel 4 (balanced)
Pin 9-10:  Channel 5 (balanced)
Pin 11-12: Channel 6 (balanced)
Pin 13:    Ground
Pin 14-15: Channel 7 (balanced)
Pin 16-17: Channel 8 (balanced)
Pin 18-25: Ground

Each DB25 carries 8 balanced channels (16 conductors + ground)

Studio A DB25 Snake Count

DAW Outputs (Control Room β†’ Machine Room):

  • 4Γ— DB25 snakes (32 channels)

DAW Inputs (Machine Room β†’ Control Room):

  • 4Γ— DB25 snakes (32 channels)

Track Bus Outputs (Control Room β†’ Machine Room):

  • 3Γ— DB25 snakes (24 channels)

Monitor Inputs (Machine Room β†’ Control Room):

  • 2Γ— DB25 snakes (16 channels)

Total: 13Γ— DB25 snakes between control room and machine room

XLR Trunk Connections

Studio A Wall Panels β†’ Machine Room

Main tracking room wall panel (Mic Lines 1-16):

  • 16Γ— XLR female wall jacks
  • XLR trunk cable (16 channels) β†’ Machine room patchbay
  • Terminates at: Machine room mic input patchbay

Iso booth wall panel (Mic Lines 17-32):

  • 16Γ— XLR female wall jacks
  • XLR trunk cable (16 channels) β†’ Machine room patchbay
  • Terminates at: Machine room mic input patchbay

Machine Room Mic Input Patchbay

Location: Machine room patchbay [TBD - Add photo]

Patch points:

  • Mic Line 1-32 (top row)
  • Connects to: REDNET 2 mic preamp inputs
  • Or: Patch to external mic preamps (Neve 1073, API 512c, etc.)

Signal flow:

Mic β†’ Wall panel XLR β†’ XLR trunk β†’ Machine room mic input patchbay β†’ 
REDNET 2 mic preamps β†’ Dante network β†’ REDNET PCIe β†’ ProTools

Machine Room Patchbay Layout (TBD)

Top section:

  • DAW Outputs 1-32 (from control room)
  • Track Bus Outputs 1-24 (from control room)
  • Mic Line Inputs 1-32 (from wall panels)

Middle section:

  • REDNET 2 Unit 1 Outputs 1-16
  • REDNET 2 Unit 2 Outputs 17-32
  • REDNET 2 Unit 3 Outputs 33-48

Bottom section:

  • DAW Inputs 1-32 (to control room)
  • Monitor Inputs 1-16 (to control room)
  • REDNET 2 Unit 1 Inputs 1-16
  • REDNET 2 Unit 2 Inputs 17-32

[Add photo of machine room patchbay when available]

Common Patching Scenarios

Scenario 1: Tracking Session

Goal: Record 16 mics β†’ ProTools

Patches (Machine Room):

  1. Mic Line 1-16 (wall panels) β†’ REDNET 2 Mic Inputs 1-16
  2. REDNET 2 Outputs 1-16 β†’ DAW Inputs 1-16 (to control room)

Patches (Control Room):

  1. DAW In 1-16 β†’ SSL Channel Strips 1-16
  2. SSL Channel Outputs β†’ Track Bus 1-2 (stereo mix)
  3. Track Bus 1-2 β†’ DAW Out 1-2 (back to machine room for monitoring)

Result: 16 mic channels routed through SSL, recorded to ProTools

Scenario 2: Mixing with Outboard Gear

Goal: Send ProTools tracks to external compressor, return to console

Patches (Machine Room):

  1. DAW Output 3-4 (from control room) β†’ Distressor inputs
  2. Distressor outputs β†’ DAW Input 17-18 (to control room)

Patches (Control Room):

  1. ProTools track outputs β†’ DAW Out 3-4
  2. DAW In 17-18 β†’ SSL Channel Strips 17-18
  3. Process on console, mix to main output

Result: Parallel compression workflow (ProTools β†’ Outboard β†’ Console)

Scenario 3: External Reverb Send

Goal: Send console channels to external reverb, return to console

Patches (Machine Room):

  1. DAW Output 9-10 (from control room) β†’ Lexicon 480L inputs
  2. Lexicon 480L outputs β†’ Monitor Input 7-8 (to control room)

Patches (Control Room):

  1. SSL channel Aux Sends β†’ DAW Out 9-10 (reverb send)
  2. Monitor In 7-8 β†’ SSL Aux Returns
  3. Blend reverb return with dry signal

Result: Hardware reverb on console channels

Cable Management Best Practices

DB25 Snake Labeling

Label both ends:

  • Control room end: "DAW OUT 1-8 β†’ Machine Room"
  • Machine room end: "DAW OUT 1-8 ← Control Room"

Use color-coded labels:

  • Blue: DAW Outputs
  • Red: DAW Inputs
  • Green: Track Bus Outputs
  • Yellow: Monitor Inputs

XLR Trunk Labeling

Label at wall panel:

  • "Mic Line 1-16 β†’ Machine Room"

Label at machine room patchbay:

  • "Mic Line 1-16 ← Main Tracking Room"
  • "Mic Line 17-32 ← Iso Booth"

Cable Routing

Keep snakes organized:

  • Bundle by function (all DAW snakes together, all Track Bus snakes together)
  • Use cable raceways between control room and machine room
  • Leave service loop (extra cable length) for re-patching flexibility

Troubleshooting

No signal from machine room to control room

Check:

  1. DB25 snake properly seated at both ends
  2. Correct patchbay routing (REDNET 2 outputs β†’ DAW Inputs)
  3. Dante network routing (Dante Controller shows connections)

Intermittent crackling on specific channels

Check:

  1. DB25 pins not bent or damaged
  2. XLR trunk cables not pinched or damaged
  3. Patchbay jack contacts clean (use DeoxIT contact cleaner)

Hum or ground loop on channels

Check:

  1. Ground lift switches on patchbay
  2. Audio cables not running parallel to power cables
  3. All equipment on same electrical phase

Photos and Diagrams

[Add photos when available:]

  • Machine room patchbay overview
  • Control room patchbay DAW Outputs section
  • Control room patchbay DAW Inputs section
  • DB25 snake connections at machine room
  • XLR trunk connections from wall panels
  • Cable management raceway routing

[Add diagrams when available:]

  • Complete signal flow: Control room ↔ Machine room
  • DB25 pinout reference
  • XLR trunk routing schematic