{"id":15142152,"url":"https://github.com/futuresharks/preamp-two","last_synced_at":"2026-03-04T21:34:49.274Z","repository":{"id":46193587,"uuid":"73574899","full_name":"FutureSharks/preamp-two","owner":"FutureSharks","description":"An digitally controlled hi fi preamplifier 🔈🎵","archived":false,"fork":false,"pushed_at":"2022-11-20T20:03:21.000Z","size":104588,"stargazers_count":41,"open_issues_count":2,"forks_count":9,"subscribers_count":6,"default_branch":"master","last_synced_at":"2024-10-09T22:41:40.069Z","etag":null,"topics":["audio","circuitpython","hifi","kicad","micro-controller","neopixel","preamplifier","schematics"],"latest_commit_sha":null,"homepage":"","language":"Python","has_issues":true,"has_wiki":null,"has_pages":null,"mirror_url":null,"source_name":null,"license":"gpl-3.0","status":null,"scm":"git","pull_requests_enabled":true,"icon_url":"https://github.com/FutureSharks.png","metadata":{"files":{"readme":"README.md","changelog":null,"contributing":null,"funding":null,"license":"LICENSE","code_of_conduct":null,"threat_model":null,"audit":null,"citation":null,"codeowners":null,"security":null,"support":null}},"created_at":"2016-11-12T19:53:03.000Z","updated_at":"2024-06-18T12:07:29.000Z","dependencies_parsed_at":"2023-01-23T12:15:19.433Z","dependency_job_id":null,"html_url":"https://github.com/FutureSharks/preamp-two","commit_stats":null,"previous_names":[],"tags_count":2,"template":false,"template_full_name":null,"repository_url":"https://repos.ecosyste.ms/api/v1/hosts/GitHub/repositories/FutureSharks%2Fpreamp-two","tags_url":"https://repos.ecosyste.ms/api/v1/hosts/GitHub/repositories/FutureSharks%2Fpreamp-two/tags","releases_url":"https://repos.ecosyste.ms/api/v1/hosts/GitHub/repositories/FutureSharks%2Fpreamp-two/releases","manifests_url":"https://repos.ecosyste.ms/api/v1/hosts/GitHub/repositories/FutureSharks%2Fpreamp-two/manifests","owner_url":"https://repos.ecosyste.ms/api/v1/hosts/GitHub/owners/FutureSharks","download_url":"https://codeload.github.com/FutureSharks/preamp-two/tar.gz/refs/heads/master","host":{"name":"GitHub","url":"https://github.com","kind":"github","repositories_count":219867955,"owners_count":16555810,"icon_url":"https://github.com/github.png","version":null,"created_at":"2022-05-30T11:31:42.601Z","updated_at":"2022-07-04T15:15:14.044Z","host_url":"https://repos.ecosyste.ms/api/v1/hosts/GitHub","repositories_url":"https://repos.ecosyste.ms/api/v1/hosts/GitHub/repositories","repository_names_url":"https://repos.ecosyste.ms/api/v1/hosts/GitHub/repository_names","owners_url":"https://repos.ecosyste.ms/api/v1/hosts/GitHub/owners"}},"keywords":["audio","circuitpython","hifi","kicad","micro-controller","neopixel","preamplifier","schematics"],"created_at":"2024-09-26T09:23:48.743Z","updated_at":"2025-10-23T19:31:13.427Z","avatar_url":"https://github.com/FutureSharks.png","language":"Python","funding_links":[],"categories":[],"sub_categories":[],"readme":"# Preamp Two\n\n[![](images/page-break-1.png)](#)\n\n![complete](enclosure/enclosure-11.png)\n\nHere is my Hi-Fi preamplifier project. In this repository you can find schematics, PCB layouts, CircuitPython code, BoMs, measurements and photos.\n\nFeatures:\n\n* MDAC volume controller\n* 6 way relay based input selector\n* High performance design with measurements\n* Quality components and modular design\n* Completely digitally controlled\n* All open source and written in Python\n\n## Components and code\n\nThe preamplifier is made up of a number of connected components:\n\n* MDAC attenuator ([PCB](PCBs/mdac-attenuator), [code](code/modules/mdac_attenuator.py)): Controls the volume\n* Input selector ([PCB](PCBs/input-selector), [code](code/modules/input_selector.py)): Selects the input\n* Encoder panel ([PCB](PCBs/encoder-panel), [code](code/modules/encoder_panel.py)): Holds rotary encoder and LED indicator ring\n* Power Supply 5V ([PCB](PCBs/psu-digital)): Power supply for digital components.\n* Power Supply +/- 15V ([PCB](PCBs/psu-analog)): Analog Power supply for MDAC attenuator\n* Micro controller board ([PCB](PCBs/mcu-board), [code](code/main.py)): Holds the [Itsy Bitsy M4 Express](https://learn.adafruit.com/introducing-adafruit-itsybitsy-m4?view=all) and other connectors\n* RCA panel ([PCB](PCBs/rca-panel)): For the RCA sockets and connectors\n\nThe PCBs and schematics were created in [KiCad](http://kicad.org/) and the code that runs on the micro controller is [CircuitPython](https://circuitpython.org/).\n\n## Enclosure\n\nDiagrams, CAD files and other information can be found here: [enclosure](enclosure)\n\n## Measurements\n\nTHD, S/N ratio and power consumption: [measurements](measurements)\n\n## Prototypes and testing\n\nSee here for a number of different [prototypes](prototypes). All PCBs were made by [OSH Park](https://oshpark.com/).\n\n## Photos\n\n[![photos](images/gallery.png)](images#images)\n\n---\n\n\u003ca href=\"https://circuitpython.org/\"\u003e\u003cimg src=\"https://raw.githubusercontent.com/FutureSharks/preamp-two/master/images/logo-adafruit_blinka_angles-left.svg?sanitize=true\" width=\"60\"\u003e\u003c/a\u003e      \u003ca href=\"https://www.oshwa.org/\"\u003e\u003cimg src=\"https://raw.githubusercontent.com/FutureSharks/preamp-two/master/images/logo-oshw-outline.svg?sanitize=true\" width=\"60\"\u003e\u003c/a\u003e      \u003ca href=\"http://kicad.org/\"\u003e\u003cimg src=\"https://raw.githubusercontent.com/FutureSharks/preamp-two/master/images/logo-kicad.png\" width=\"60\"\u003e\u003c/a\u003e\n","project_url":"https://awesome.ecosyste.ms/api/v1/projects/github.com%2Ffuturesharks%2Fpreamp-two","html_url":"https://awesome.ecosyste.ms/projects/github.com%2Ffuturesharks%2Fpreamp-two","lists_url":"https://awesome.ecosyste.ms/api/v1/projects/github.com%2Ffuturesharks%2Fpreamp-two/lists"}