This is the construction and application thread for the Stereo Insert Switcher.
Mastering Stereo Insert Switcher PC Board: https://ka-electronics.com/shop/index.p ... rch=insert
Features
• Full bypass with fully-balanced hot/cold switching. Fully passive.
• Two Inserts with Flip. (14 relays total.)
• PC board can also be loaded and jumpered for single insert or two inserts without flip. (Single Insert uses four relays; Two Insert uses 8 relays.)
• Backbone signal flows through the connections on the left to the right. Insert connections are on the 25 pin D in a modified Tascam format.
• Normal signal flow is Left/Right Backbone In > Insert 1 > Insert 2 > Backbone Left/Right Out.
• When Flip is engaged signal flow is Left/Right Backbone In > Insert 2 > Insert 1 > Backbone Left/Right Out.
• Cascadable using aditional boards in series for more inserts .
• Current-limited LED tally outputs are available.
• Isolated audio and relay grounds.
• Series-parallel coil connection to reduce switching currents. (Coils are 12V, control supply is 24V.)
• Powerable from +/-15V supplies using an external 7824 or LM317 regulator.
• Ideal for MS Matrix Insert/Bypass.
Bill of Materials
The insert switcher can be built as a two insert switcher with flip, an insert switcher without flip a single insert/bypass or two independent insert/bypass..
The bill-of-materials is for a two insert with flip.
The Mouser BOM cannot be edited.
To edit, load it into the shopping cart.
Remove the number of relays as needed.
A fully-configured switcher uses 14 relays.
Without flip 8 relays are required.
A single insert uses only 4 relays.
For XLR I/O or hardwired applications do not install the 25 pin D connector and wire directly to the board.
A Mouser bill-of-materials with 14 Omron relays is here: https://www.mouser.com/ProjectManager/P ... 446ab230fc
Stereo Mastering Insert Switcher PC Board, Fully Balanced, Passive, Two Insert with Flip.
Schematic
Mastering Insert Switcher Schematic, Audio Flow, Sheet 1
Larger Image: https://www.proaudiodesignforum.com/ima ... heet_1.png
Mastering Insert Switcher Schematic, Relay Coil Wiring, Sheet 2
Larger Image: https://www.proaudiodesignforum.com/ima ... heet_2.png
V1.2 Board
Mastering Insert Switcher Schematic, Relay Coil Wiring, Sheet 3
Larger Image: https://www.proaudiodesignforum.com/ima ... heet_3.png
A note about relays
The relay coil requirements are 12V.
The control supply is 24V: A series/parallel connection is used to reduce current.
The Mouser BOM specifies Omron G5V-2-H1-DC12 "H1" high-sensitivity relays.
With all relays engaged the 24V supply current is about 135 mA.
Panasonic DS2Y relays are polarity sensitive.
On boards before V1.2:
Do not use Panasonic relays unless you intend to reverse the control supply, diode and LED polarity.
Omron, Fujitsu, Takamisawa etc. do not have a coil polarity requirement.
On V1.2 boards Panasonic DS2Y relays may be used.
Two Inserts with Flip
Stereo Mastering Insert Switcher PC Board Stuffing Diagram.
DB-25 Insert Connector Pinout
Stereo Mastering Insert Switcher PC Board, Tascam DB-25F Breakout Cable Pinout
You can get breakout cables here:
The insert switcher uses a female DB-25.
Planet Waves provides breakout cables which are also DB-25F.
To use the breakout cables male-to-male snakes are available in various lengths from 5-25 feet.
Female DB25F to Stripped Ends: http://www.amazon.com/Planet-Waves-PW-C ... B001PGXIUM
Male DB25M to DB25M 5' Snake: http://www.amazon.com/Planet-Waves-Modu ... B001G7J2EG
Relay and LED Connections
Stereo Mastering Insert Switcher PC Board, Relay Control and LED Connector Pinout
Other Configurations
To eliminate the Flip function do not install six relays.
The normally-closed contacts of the flip relays are jumpered (shown in pink).
The relays that are used are RE3, 6, 9, 10, 11, 12, 13 and 14.
The relays that are not used are RE1, 2, 4, 5, 7, 8.
Two Inserts without Flip
Stereo Mastering Insert Switcher PC Board Stuffing Diagram without Flip.
Single Insert or Full Bypass
The normally-closed contacts of the Insert 2 and flip relays are jumpered.
Install relays at RE3, 6, 10, 13.
The relays that are not used are RE1, 2, 4, 5, 7, 8, 9, 11, 12, 14.
Split Backbone. Two Independent Full Bypass.
I/O points are at the flip relays.
Stereo Mastering Insert Switcher PC Board Stuffing Diagram for Split Backbone. Useful for Two Independent Full bypass.
Larger version: https://www.ka-electronics.com/images/j ... _Large.jpg
