---
title: "AN-9 Land Line Telephone Interface Circuit"
description: "This land line analog interface circuit provides a higher quality signal compared to inductive or acoustic coupling methods. Its frequency response and low distortion are important as well as its ground-loop isolation between the phone line and your recording equipment.…"
url: "https://diamondcut.com/docs/an9-land-line-telephone-interface-circuit/"
updated: "2022-01-31"
category: Application Notes
---

# AN-9 Land Line Telephone Interface Circuit

This land line analog interface circuit provides a higher quality signal compared to inductive or acoustic coupling methods. Its frequency response and low distortion are important as well as its ground-loop isolation between the phone line and your recording equipment. Hum levels will be quite low using this interface circuit.

[Click here to view the PDF](https://www.diamondcut.com/AppNotes/AN9b.pdf) – Land Line Telephone Interface Circuit