--- title: "ADDAC System: ADDAC219IN Stereo > Dual Mono | Takazudo Modular" url: "https://takazudomodular.com/en/products/addac219in-stereo-mono-intro/" language: en description: "An introduction to the ADDAC219IN Stereo > Dual Mono. The ADDAC219IN Stereo > Dual Mono is an interface module that separates external line-level stereo signals into individual left and right mono outputs. It accepts a 3.5mm stereo TRS jack input, internally splits the signal into left and right mono, and outputs each through independent 3.5mm mono output jacks. It also boosts line-level signals to Eurorack level. With two conversion sections, this module serves as a bridge between external gear and your Eurorack system." alternate_ja: "https://takazudomodular.com/products/addac219in-stereo-mono-intro/" source: "Takazudo Modular" --- ![ADDAC System: ADDAC219IN Stereo \> Dual Mono](https://imgs.takazudomodular.com/images/p/addac219in-product-img-1__og/revisions/production/r1-7d5be71a262e0f0ee6658adb4521f3ab25eb9444f2f2c699025e5b4f5c187282/1200w.webp) # ADDAC System: ADDAC219IN Stereo \> Dual Mono Author: Takazudo | Published: 2025/05/26 - [# ADDAC System](https://takazudomodular.com/en/tags/addac/) - [# Modular Synthesizer](https://takazudomodular.com/en/tags/modular/) - [# Utility](https://takazudomodular.com/en/tags/utility/) - [# Audio I/O](https://takazudomodular.com/en/tags/audio-io/) This is an introduction to the **ADDAC219IN Stereo \> Dual Mono** by ADDAC System, available at Takazudo Modular. The ADDAC219IN Stereo \> Dual Mono is an interface module that **separates external line-level stereo signals into individual left and right mono outputs**. It accepts a 3.5mm stereo TRS jack input, internally splits the signal into left and right mono, and outputs each through independent 3.5mm mono output jacks. It also **boosts line-level signals to Eurorack level**. With two conversion sections, this module serves as a bridge between external gear and your Eurorack system. This product is available for purchase below. [![ADDAC System: ADDAC219IN Stereo \> Dual Mono](https://imgs.takazudomodular.com/images/p/addac219in-product-img-1__og/revisions/production/r1-7d5be71a262e0f0ee6658adb4521f3ab25eb9444f2f2c699025e5b4f5c187282/2000w.webp) SOLD ADDAC System: ADDAC219IN Stereo \> Dual Mono 13,800 yen (tax & shipping included) You can set up restock notifications on Mercari Shops.](https://jp.mercari.com/shops/product/ct6B9YPXA9SM338xqbz2D9) You can set up restock notifications on Mercari Shops. - [Buy this item via Buyee (International shipping)](https://buyee.jp/mercari/item/ct6B9YPXA9SM338xqbz2D9) ## Product Photos ![Product photo](https://imgs.takazudomodular.com/images/p/addac219in-product-img-1__og/revisions/production/r1-7d5be71a262e0f0ee6658adb4521f3ab25eb9444f2f2c699025e5b4f5c187282/2000w.webp) ![Product photo](https://imgs.takazudomodular.com/images/p/addac219in-product-img-2/revisions/production/r1-8eb07662332f6f90a17a097223e39ca340916c28240780bd8945b13bb08094c8/2000w.webp) ![Product photo](https://imgs.takazudomodular.com/images/p/addac219in-product-img-3/revisions/production/r1-dcb788d95229baf33507d62baa26695d23772ab3039e44e4c065af3e6aa0cd16/2000w.webp) ## Manuals and Guides Takazudo Modular publishes manuals and guide articles for this product. Please see below. - [ADDAC219IN Stereo \> Dual Mono: DIY GuideJapanese translation included](https://takazudomodular.com/manuals/addac219in-stereo-diy/) ## Splitting Stereo Into Dual Mono This module's function is straightforward -- exactly as described above: **Split stereo into dual mono. Boost the level and output it ready for modular use!** Even when building a Eurorack system, you will often want to use other gear alongside it. For example, our shop carries the following as standalone audio devices: [Meng Qi: Wingie2 An introduction to the Meng Qi Wingie2. The Wingie2 is a standalone resonator. It is an instrument capable of applying various resonance processing to ambient sounds and audio input.](https://takazudomodular.com/en/products/wingie2-intro/) [Recovery Effects And Devices: The Mystic An introduction to the Recovery Effects And Devices The Mystic. By intentionally not supporting 1V/Oct, The Mystic directs the performer's attention to the act of synthesis itself. A standalone semi-modular synth with a 2-operator FM configuration and analog delay, capable of generating sustained, organic drone and noise textures.](https://takazudomodular.com/en/products/recovery-mystic-intro/) The latter, The Mystic, has a mono output and can be connected directly to a Eurorack system. However, Wingie2's output is stereo -- audio out via a TRS cable carrying combined L/R signals. To connect this to a Eurorack system, you need to convert it to mono. In such cases, you would need a cable that splits stereo into two mono signals, but having a dedicated module pre-installed in your setup keeps things tidy. ## Adjusting Audio Level Differences The ADDAC219IN does not just convert stereo signals to mono -- it also adjusts audio signal level differences. Audio signals exchanged between Eurorack modules are around +/-5V, while other gear typically operates at +/-2V or less. In short, the signals exchanged between Eurorack modules are a bit too hot for most electronic instruments. This is due to historical differences in how instruments evolved -- most electronic instruments handled audio waveforms at +/-2V or less, while Eurorack modules adopted +/-5V. Because of this voltage difference, you may notice that audio from external music gear sounds too quiet when brought into a Eurorack system. This is where the ADDAC219IN's ability to **boost the level of audio imported from external gear** comes in handy. This module handles the level adjustment simultaneously -- a welcome convenience. ## Examples of Gear With 3.5mm Stereo TRS Audio Output Music gear that outputs audio via a 3.5mm stereo TRS jack includes products such as: - [Teenage Engineering: OP-1 Field](https://teenage.engineering/products/op-1) - [Korg: Volca series](https://www.korg-volca.com/) - [Bastl Instruments: Kastle](https://bastl-instruments.com/instruments/kastle) Devices with 3.5mm stereo TRS jacks tend to be smaller, gadget-style instruments. Additionally, since standard small headphone jacks are 3.5mm stereo TRS, this module could also be useful when you want to quickly bring audio from a PC or smartphone into your Eurorack system. So whenever you want to bring something from outside your modular into the system, this is a great module to have on hand. ## Related Products The reverse of this module -- one that combines dual mono into stereo -- is also available from ADDAC System, and we carry it as well. [ADDAC System: ADDAC219OUT Dual Mono \> Stereo An introduction to the ADDAC219OUT Dual Mono \> Stereo. The ADDAC219OUT Dual Mono \> Stereo is a passive 3HP module that provides a simple way to send signals from your Eurorack system to external stereo gear. It combines two mono inputs (left/right) into a single TRS stereo output, attenuates the modular synth level down to line level, and outputs through a 3.5mm TRS stereo jack. With three independent sections, it can send multiple outputs to external gear at once.](https://takazudomodular.com/en/products/addac219out-mono-stereo-intro/) Please check that out as well. ## Technical Specifications - Width: 3HP - Depth: 40mm - Power consumption: 20mA +12V / 20mA -12V / 0mA +5V ## Included Accessories - Power ribbon cable - Screws ## Product Warranty This product carries a 2-year manufacturer warranty covering normal use under typical operating conditions. Please contact us if you notice any issues with the product. --- About the Brand ## About ADDAC System ADDAC System is a modular synthesizer maker based in Portugal. Their lineup is built on solid, no-nonsense modules that make the most of analog character. At the same time, they have released plenty of inventive modules that bring digital technology into the mix in a tasteful way — flexible CV-to-MIDI converters, deeply controllable granular processors, and more. - [ADDAC System Website](https://www.addacsystem.com/) - [Instagram: addacsystem](https://www.instagram.com/addacsystem/) - [X: @ADDACSystem](https://x.com/ADDACSystem) - [YouTube: ADDAC System](https://www.youtube.com/@addacsystem6002) ![Logo: 電氣美術研究會](https://imgs.takazudomodular.com/images/p/denbi/revisions/production/r1-c35cb4eaf5f608733e69add54a5d951fcd8e67a5b52edf89e605c75dd0a0fd42/820w.webp) ## Bonus: Modular Accessory Set by 電氣美術研究會 (Denki Bijutsu Kenkyukai) Included In the hope that more people will get hands-on with modular synths, we have teamed up with 電氣美術研究會 to bundle a modular accessory set with this product. The contents vary by season — patch cables, power cables, a dress-nut sample set, a mono splitter, and more. The set is included with the product, so please give it a try! - [電氣美術研究會](https://ears-modular.com/) That concludes the introduction to the ADDAC219IN Stereo \> Dual Mono. [![ADDAC System: ADDAC219IN Stereo \> Dual Mono](https://imgs.takazudomodular.com/images/p/addac219in-product-img-1__og/revisions/production/r1-7d5be71a262e0f0ee6658adb4521f3ab25eb9444f2f2c699025e5b4f5c187282/2000w.webp) SOLD ADDAC System: ADDAC219IN Stereo \> Dual Mono 13,800 yen (tax & shipping included) You can set up restock notifications on Mercari Shops.](https://jp.mercari.com/shops/product/ct6B9YPXA9SM338xqbz2D9) You can set up restock notifications on Mercari Shops. - [Buy this item via Buyee (International shipping)](https://buyee.jp/mercari/item/ct6B9YPXA9SM338xqbz2D9) We hope you found this helpful. ## Product information (catalog snapshot) This is the catalog information published on the site when it was built. It is not a guarantee of live Mercari Shops inventory; check the purchase page for current availability. ### ADDAC219IN Stereo \> Dual Mono - Brand: ADDAC System - Price: ¥13,800 (JPY) - Status: Sold out - Width: 3HP - Purchase page: - Purchase page: