From the download to your PCM81.

1. Check your setup

You need a physical PCM81, a MIDI interface that passes SysEx in both directions, and the audio connections you normally use with the hardware. PCM81 Control edits the hardware; the PCM81 produces the sound. Plug-in audio passes through unchanged.

The developer has tested PCM81 Control 0.4.0 as AU in Logic and VST3 in Ableton Live.

2. Install the download

1. Download Full from your purchase confirmation or email, or download Free from the product page. Double-click the ZIP in Finder to extract it.
2. Quit your DAW and any running copies of PCM81 Control before copying the bundles.
3. Copy the formats you want to the folders below. In Finder, choose Go → Go to Folder and enter a folder path. Create the folder if it does not exist. The ~ means your home folder.

Full standalone · PCM81 Control.app

~/Applications/PCM81 Control.app

Free standalone · PCM81 Control Free.app

~/Applications/PCM81 Control Free.app

AU · PCM81 Control.component

~/Library/Audio/Plug-Ins/Components/PCM81 Control.component

VST3 · PCM81 Control.vst3

~/Library/Audio/Plug-Ins/VST3/PCM81 Control.vst3

Open the standalone app from its installed folder. For a plug-in, reopen your DAW and let its plug-in scan finish. Use AU in Logic or VST3 in Ableton Live. If it does not appear, check the folder and use your DAW's plug-in rescan controls, then restart the host.

Version 0.4.0 is ad-hoc signed and is not notarized. macOS may require your approval the first time you open it. See Apple's guidance for opening downloaded apps. If a plug-in scan still fails, send support the exact warning.

3. Connect MIDI and audio

1. Connect your MIDI interface's OUT → PCM81 IN, and the PCM81 OUT → interface IN.
2. Keep the hardware's audio connected through your mixer or audio interface. MIDI carries settings; your existing audio routing carries the sound.
3. In PCM81 Control's MIDI controls, select the ports connected to the PCM81. Both directions must pass SysEx, so allow SysEx through any MIDI filters in your setup.
4. Connect and read the hardware's current patch before editing. Keep a backup of patches you want to preserve before using a permanent hardware Store action.
5. Make a small parameter change and use Undo to return to the previous setting. Ordinary edits affect the temporary edit buffer; use Store only when you intend to save a hardware register.

If MIDI does not respond, check the two cable directions, port selections and SysEx filtering first. Try the standalone app with other MIDI applications closed to narrow down the connection.

4. Activate Full

Free needs no code; skip this step if you installed Free. AU and VST3 are included with Full only.

1. While online, quit all PCM81 Control instances and DAW hosts, then open one copy of the standalone app.
2. Click License at the bottom right. Enter the activation code from your purchase and click Activate.
3. Once the panel shows Licensed, quit and reopen the app to check that activation is saved. You can then reopen your DAW.

Full is a one-time USD 75 purchase, with activation on two computers. It is not a subscription. Activation issues a licence valid offline for 90 days; the app refreshes it automatically when online. The expiry date is shown in the License panel, and Refresh lets you check it manually.

To move an activation, use Deactivate this computer in the License panel while online. Quit the app and DAW hosts after deactivating, then activate on the other computer.

5. Get updates

For Free, get the current standalone ZIP from the Free download on the product page.

Lifetime updates are included with your purchase. When a newer version is available, the app's Update button opens the shop. Use the download link from your original purchase email or confirmation page to get the current Full ZIP. Download access requires a valid purchase that has not been fully refunded.

Quit the app and DAW hosts, then replace the installed bundles with the new versions. Reopen your host and rescan if needed. Keep the purchase email and activation code private so you can find them again.

6. Get help

Email info@cass.app or send a message for setup, licensing, billing or refund questions.

To request a refund, email info@cass.app within seven days of purchase. Read the refund, updates and privacy information for the purchase policies.

Include the PCM81 Control version, macOS version, DAW version and plug-in format, MIDI interface, and a short description of what happened. An exact error message helps. Leave activation codes, private purchase links and card details out of the message.