Your amp manager for Positive Grid® Bias

Get the best out your Positive Grid® Plugins & Apps: start owning your amps !

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Ampl4 is not associated or affiliated in any way with Positive Grid®


$19.99 on the Mac App Store

Main Features


Import Bias® amps from compatible PositiveGrid® Apps (Bias® Amp mobile/desktop, Bias® FX mobile/desktop, JamUp®...)

Manage your amps

Tired of the vague amps namings ? Rename your amps using their real names, add descriptions and working notes, find duplicates in your collection and more ! (see specifications)

Manage your collections

Drag Amps from one collection to another. Create collections by style, brand, years, etc.


Pick a collection and export it back in few clicks

Ampl4™ powered Positive Grid® amp flows

$19.99 on the Mac App Store

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App Store reviews

Worth the buy!!! ⭐️⭐️⭐️⭐️⭐️ by Monox480 - USA

This app is awesome for Bias users. It’s very easy to use and customer service is outstanding.
Definitly give it a shot because you won’t be disappointed!!

If you like BIAS, you’ll love this! ⭐️⭐️⭐️⭐️⭐️ by UnsungHeroGuitars - UK

Great little add-on this. Nicely executed and a very useful tool for managing and renaming your amps. Of course, BIAS itself is a digitial recreation of a bunch of classic amps - being able to edit them and add pictures of the real amps certainly helps to enhance the overall vibe and whilst you’re obviously not suddenly sat there with a real Dumble, JCM800 or Deluxe, it does help to bring them a little closer.

Increíble!!! ⭐️⭐️⭐️⭐️⭐️ par javiover - Spain

Es una aplicación que merece mucho la pena!! se la recomiendo a todos los usuarios de BIAS!!! Es una forma de tener toda tu colección de amplificadores perfectamente ordenada. Puedes hacer varias colecciones diferentes y copiar y pegar amplis de unas a otras. Además lo de las imágenes de los amplis reales está brutal…pero aunque no tuviera eso, sólo por la forma en que te permite organizar tus colecciones tanto en el mac como en el iPad ya merecería la pena!!! le doy 5 estrellas! dinero bien invertido!!

Aufgeräumte AMPs ⭐️⭐️⭐️⭐️ von Schindipunk - Germany

Die App sortiert meine Bias Amps wunderbar. Gibt ihnen Orginalnamen und Beschreibungen
Durch die Originalbilder die man einfügen kann wirkt Bias nochmal schöner ../..
Super App für Leute die mit Bias arbeiten.

Aufgeräumte AMPs ⭐️⭐️⭐️⭐️⭐️ von SnaJ80 - Germany

Bin zufällig auf diese App gestoßen und sie ist genau das, wonach ich insgeheim länger gesucht habe. Ich erstelle/verändere Amps sowohl auf dem Mac als auch auf dem iPad und über die Cloud ist es oft lästig, Amps zu „synchronisieren“. ../.. Es können beliebig viele Kollektionen gespeichert werden, die man nach Bedarf kombinieren oder auch einzeln in BIAS einspielen kann. So kann ich mir z.B. für ein Live-Set genau nur die Amps aufs iPad speichern, die ich benötige - so gibt es in der Hektik kein Vertun.

Excellent ! ⭐️⭐️⭐️⭐️ par DrNicks79 - France

Ampl4 vient gommer un des defauts de Bias Amp en redonnant aux amplis leur vrais noms et vrais visages. Très pratique et simple à utiliser. ../..
Bravo ! Le petit + : une équipe au taquet très sympa qui répond à vos questions sans délai.

ユーザーにはおすすめ ! ⭐️⭐️⭐️⭐️ - byKurokun - Japan

BIAS AMP DesktopやBIAS FX Desktopのアンプの名前や画像を編集できます。



  • Import Bias Amps from Positive Grid® Applications (see list bellow)

  • Backup your existing amps

  • Edit Amps metadata (Brand, Name, Year), add description and relevant notes

  • Customize Amps pictures (Appearance in Positive Grid® apps varies)

  • Manage collections:

    • Break down your amp list into manageable collections that you can easily export to Apps on need. Remove amps, drag amps from one collection to another
    • Sort your Amps by brand, category, version, etc.

  • Identify duplicates in your collection (based on Amps internals, not names)

  • Export collection to a Positive Grid mobile App or Plugin (Exporting Amps to iOS applications requires iTunes) - See Supported Apps bellow -

  • Automatic lookup of defaults amps to get you started (update amps descriptions from Ampl4 database - beta)


  • Mac OSX 10.7 and later
  • one compatible Positive Grid App or plugin.

Supported Positive Grid Applications:


  • Desktop:
    • Bias Amp
    • Bias FX
  • Mobile:
    • Bias Amp iPad/iPhone
    • Bias FX
    • JamUp Standard/Pro


  • Desktop:
    • Bias Amp
    • NEW– ** Bias FX as **Bias FX presets Bank
    • Bias FX through Bias Amp Desktop integration
  • Mobile:
    • Bias Amp
    • Bias FX, JamUp Standard/Pro using iTunes Document Sharing

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These trademarks of other manufacturers are used solely to identify the products of those manufacturers.

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