Universal balanced receiver preamp based on THAT1200 1203 1206 open source PCB

[pbilous]

While designing LM3886-based amplifier I desired to have balanced inputs. Few options were considered, but I ended up going with balanced input line receiver based on THAT chips. Below are attached schematics and gerber files for those interested.

PCB has a dedicated space for the XLR / TRS combo connector by Neutric - Mouser part # 568-NCJ9FI-H.
Another cool feature of the board is that both chips are bypassed by both ceramic and by aluminum organic polymer capacitors.

There is no power regulators included on the board - it will need regulated dual +/- 15V power.

Parts list:

• C1 - C4 are 470pF - space is provisioned for poly caps - something like WIMA FKP2 - Mouser part number 505-FKP2C04701D0MC0
• C5, C6 are 100pF - TDK C0G - 810-FG18C0G1H101JNT6
• C7, C8 - 220uF - Panasonic Aluminum Organic Polymer Capacitors - 667-16SEPC220MD+S
• C9 - C12 - 0.1uF - TDK X7R - 810-FG18X7R1H104KNT6
• C13 - C16 - Panasonic Aluminum Organic Polymer Capacitors - 667-25SEP10M+TSS

 

[jan.didden]

One point to watch out for is the absence of series output resistors on the opamp outputs.
Most designers know that that is inviting instability once you put on output cabling (and possibly load) capacity.
Something like 47 or 100 ohms output series R is normally used to isolate the opamp from capacitive load.

Jan

 

[pbilous]

THAT120x receivers are able to drive up to 300 pF capacitive loads according to the datasheet. However, attached is the rev1.1 with output resistors. 🙂

 

[pbilous]

Fixed vias' locations for rev1.1. Attached is updated gerber file.

 

[feovo]

hi.
just want to know its works fine for you? can i go with your pcb. THANKS

 

[tomchr]

You might want to space the terminal blocks out a bit. They often have keys that protrude and are intended for daisy-chaining multiple terminal blocks. They'll probably get in the way if you place the connectors tight side-by-side.

Tom