Seeking Advice: Best Preamp Design for Low-Noise, Balanced Microphones

[bigben83]

Hi everyone,

I'm currently designing a compact, low-noise 2-channel preamp module and could use some advice on the best preamp topology and components for the job. The module needs to support both microphone and line-level inputs, have balanced XLR outputs, and feature remote volume control via a 10k linear potentiometer. Selectable phantom power (24V) is also required.

Key Design Requirements:​

• Ultra-low noise performance for professional audio applications
• Flexible power: 12-24V DC or potentially phantom power
• Balanced XLR outputs (preferably electronically balanced)
• Remote volume control using a 10k linear potentiometer with a DC supply (Similar to this https://rdlnet.com/product/st-vca3/)
• Input gain range: -60 dB to +4 dB

I’ve been considering preamp ICs like INA163, ADA4627-1, THAT1583, OPA1656, but I'm open to suggestions on what would work best for ultra-low noise performance. Additionally, I’m weighing whether to go for active balancing or a transformer-based output stage—would love some input on the trade-offs for each approach.

Has anyone here worked on something similar or have recommendations on circuit design, component choices, or best practices for achieving low-noise, high-quality audio performance? Any insights on PCB layout techniques to reduce noise and interference would also be much appreciated.

This is for a specialised system used in a church setting.

Looking forward to your thoughts!

 

[gyraf]

Why would it have to be "ultra low noise" if used in a church setting anyway?

 

[bigben83]

Why would it have to be "ultra low noise" if used in a church setting anyway?

To be used in acoustically dead rooms. so I'm aiming for as low noise as possible

 

[gyraf]

Now you have me confused: acoustically dead rooms, in a church setting..?!?

Trying to figure out exactly what you are aiming for here, it's not clear at all yet..

 

[bigben83]

Ha Ha sorry to confuse you. Think modern church with carpet floor, accoustic ceiling tiles. dense foam padded seating. acoustic slat-style wall treatment.

All I am after is a really good quality balanced mic preamp. which I can possibly modify the volume control so it can be remotely controlled. via a small seat-mounted control.