Brands Guides About
Monoprice 107128 3.5mm Mono to Stereo Adapter 3-Pack — main product image
Monoprice

Monoprice 107128 3.5mm Mono to Stereo Adapter 3-Pack

Gold-plated 3.5mm mono-to-stereo adapter 3-pack for quick audio connection compatibility.

View price on Amazon
Affiliate Disclosure: As an Amazon Associate, Studio Supplies earns from qualifying purchases made through links on this page, at no additional cost to you. This helps support our editorial team.

Notice a mistake? Let Us Know

Overview

The Monoprice 107128 is a simple but essential audio adapter that bridges the gap between mono output devices and stereo input equipment. The adapter features a 3.5mm mono plug on one end and a 3.5mm stereo jack on the other, allowing you to connect mono-output devices — such as certain microphones, instruments, or legacy audio equipment — to stereo headphones, speakers, or recording inputs. Without this adapter, a mono plug inserted into a stereo jack would typically only produce sound on one channel, making this small accessory a practical fix for an annoying and common audio compatibility issue.

Gold plating on both connectors ensures clean signal transfer and long-term durability by preventing the oxidation that can degrade cheaper nickel or tin contacts over time. The passive design means there are no batteries, circuits, or signal processing involved — the adapter simply routes the single mono channel to both stereo channels mechanically. Sold in a three-pack, these adapters are ideal for keeping spares in equipment bags, studio drawers, or at multiple workstations where mono-to-stereo conversion is frequently needed.

Specifications

Brand
Monoprice
Model
107128
Connector 1
3.5mm Mono Plug
Connector 2
3.5mm Stereo Jack
Plating
Gold Plated
Quantity
3-Pack

Frequently Asked Questions

It routes a mono (single-channel) signal from a mono plug device into both the left and right channels of a stereo jack, so you hear the same audio in both ears or both speakers instead of only one side.
Yes, plugging stereo headphones into the stereo jack end will output the mono source signal to both ear cups, though the audio will be identical in both channels rather than true stereo.
The 3-pack provides spares for multiple setups or replacements, which is useful since small adapters are easily misplaced or left connected to different devices.
Yes, both the mono plug and the stereo jack feature gold-plated contacts, which resist corrosion and maintain reliable signal transfer over time.

Related Products