Symphony I/O: Troubleshooting

No sound or lower level on Symphony I/O outputs 1/2- how to set outputs 1/2 for Line Level

If the first 2 analog outputs of Symphony I/O are too low in level or are muted, it is important to keep in mind that the first 2 analog outputs on Symphony I/O will default to -20dB and can be muted or dimmed, as many people use Symphony I/O as their monitor controller.

If you do not wish to use Symphony I/O as a monitor controller and want to set analog outputs 1/2 to Line Level like the rest of the analog outputs, follow the steps below.
There are a couple of ways to set them to line level like the rest of the outputs-


Using the front-panel encoders


Turn the left encoder knob until you see the speaker icon on the front-panel

Turn the right encoder knob to bring the output level up to 0dB

Using the Maestro’s output tab

Launch ‘Apogee Maestro 2’ from your Applications folder

Scroll all the way to the right

You will see 3 software encoder knobs- one for the Main Speaker outs and 2 for headphones

You can turn the Speaker output knob up to 0dB or click on the drop-down menu where it says ‘Stereo Out 1/2’ and select ‘Line’. This will set it for 0dB Line Level and disable monitor control so you don’t accidentally mute the main outs or turn them down.

Once you make this setting, it will be remembered until you change it again.

The Symphony I/O firmware update fails or gets stuck

Before attempting to update the Symphony I/O firmware, please follow the instructions in this link:

Updating Symphony I/O Firmware and Software


If the firmware update fails or stalls and never completes, quit the firmware updater app, power-cycle the Symphony I/O, and try the update again, using the following steps:

– Try connecting the Symphony I/O to a different USB hub

– Try connecting the Symphony I/O to an Apple keyboard

– Try connecting the Symphony I/O to a different USB port on your Mac

– Try the firmware update on a different Mac if you have access to one


You may have to try the firmware update several times before it gets through. It is not recommended to try downgrading back to the older firmware versions, as the issue with the update is not with the firmware, but with the updater app itself.


Is Symphony I/O compatible with Mac OS X Yosemite (10.10)?

Yes! Symphony I/O is fully compatible with Mac OS X Yosemite (10.10).  Please be sure to download and install the latest 10.10 compatible software package for Symphony from Apogee’s site.


Click to find the latest Symphony Software Installer

Does Symphony I/O work with versions of Pro Tools HD older than version 9?

Depending on what type of i/o modules your Symphony I/O has and what versions of firmware are loaded on it, it can work with older versions of Pro Tools HD, however we recommend using the latest Symphony I/O firmware along with version 8.1.1 or later of Pro Tools HD since the current Symphony I/O firmware is much more stable than the older versions.

If you need to use the older firmware for the Symphony I/O’s modules to emulate a Digi 192, then please read the information below carefully before requesting the older firmware from our Support department. This firmware is not available on our website.


The following i/o modules can be recognized as either a Digi 192 or an Avid HD I/O and can be used with versions of Pro Tools HD older than version 8.1.1 and all the way up to the current version:

– 8×8 Analog + AES I/O

– 8×8 Analog + Optical I/O

– 8×8 Analog + AES/Optical I/O

– 16 Analog Input + 16 Optical Output

– 16 Optical Input + 16 Optical Output


The following i/o modules can ONLY be recognized as an Avid HD I/O and can NOT be used with any version of Pro Tools HD earlier than version 8.1.1:

– 16×16 Analog In/Out

– 2×6


Symphony I/O doesn’t show up in Maestro and exclamation mark (!) icon stays on

If you’re having an issue getting your Symphony I/O to show up properly in Apogee Maestro and the exclamation mark (!) icon stays on the front-panel, there are a few troubleshooting steps to check, depending on what Audio Interface Mode you’re using.


USB Audio mode

1. Confirm that your firmware and software is up to date and that the versions match. Click here and follow these instructions.

2. Confirm that your Symphony I/O is in ‘USB Audio’ mode by pushing in and holding on the right-side front-panel encoder and scrolling through the different modes until you get to ‘USB Audio’ and then push in on the encoder again to restart the unit in ‘USB Audio’ mode.

3. Confirm that you’re using the Apogee USB cable that was included with the Symphony I/O. Unplug USB cable and then plug back in to a different port and restart your Mac.

4. Power-cycle Symphony I/O.


Symphony mode (Symphony 64 PCIe or Thunderbridge)

1. Confirm that your firmware and software is up to date and that the versions match. Click here and follow these instructions.

2. Confirm that your Symphony I/O is in ‘Symphony’ mode by pushing in and holding on the right-side front-panel encoder and scrolling through the different modes until you get to ‘Symphony’ and then push in on the encoder again to restart the unit in ‘Symphony’ mode.

3. Launch Audio MIDI Setup (Applications> Utilities> Audio MIDI Setup). We recommend using Audio MIDI Setup instead of System Preferences Sound. Make sure that ‘Symphony64′ (PCIe or Thunderbridge) is selected in the left-side column. In the ‘Source’ menu on the right, choose the appropriate port selection depending on how many Symphony I/Os you have. If you have 1 unit, choose ‘Port 1: 32ch’… if you have 2 units, choose ‘Ports 1-2: 64Chs’. Quit Audio MIDI Setup and restart the computer.

4. If you’ve gone through the above steps and the exclamation mark (!) icon still remains on the front-panel, there is a chance that the PC-32 port on either the Symphony I/O and/or the Symphony 64 PCIe/Thunderbridge isn’t making a complete connection and needs to be cleaned with rubbing alcohol. Follow these instructions:

Disconnect the PC-32 cable (‘Symphony’ or ‘Digi-Link’ cable) and apply some rubbing alcohol (isopropyl) to the pins on the inside of the PC-32 cable’s connector end. Make sure to apply the alcohol to the top and bottom of the pins on the connector. Now plug in and unplug the cable to the ‘Main’ port of the Symphony I/O. Do this about 20 times, so the port gets clean. Now repeat this with the Main port on the Symphony 64 PCIe or Thunderbridge. After each port has been cleaned, reconnect the PC-32 cable, power-cycle the Symphony I/O, and restart your Mac.

Symphony I/O: No loop sync option in Maestro

The Loop Sync option in the Apogee Maestro 2 software’s System Setup tab will disappear under certain conditions.


1) Loop Sync is not available when Symphony I/O is in Standalone or USB AIM.

2) When in Symphony AIM, if a legacy converter is connected to the other port on the Symphony64PCI or Thunderbridge card, Loop Sync will disappear.

  • The legacy converters affected are AD-16x, DA-16x, Rosetta-200, and Rosetta-800 with the x-symphony option card installed.

If you need to change this setting, you will need to quit the Maestro software, then change your setup to avoid one of the conditions listed above. Reopen Maestro and the loop sync option will reappear.


Symphony I/O: Hardware Reset (Initialize)

To reset Symphony I/O to its default settings

1. Power off the unit.

2. Press the left hand encoder, and while holding down the left hand encoder, power up the unit.

3. Turn the left hand encoder to select either Reset All or Reset All but Cal.

  • Choose “Reset All but Cal” to reset all settings but the level calibration settings – Analog reference, digital reference and Trim.

  • Choose “Reset All” to reset all settings including level calibration settings.

4. Turn the right hand encoder to Yes.

5. Press either encoder.

6. To proceed without resetting, turn the right hand encoder to No and press either encoder.

Symphony I/O Rack Ear Holes Don’t Line Up Correctly

Sometimes those screws don’t align correctly, but it can be corrected without returning the unit by loosening the chassis so the screw holes can be manipulated into alignment. Here’s how:

  1. Remove all the screws from the back and sides of the Symphony chassis. There are six screws on the bottom, 5 screws on the back, and three on each side where the rack ears would go.
  2. Install the rack ears. You may need to twist the chassis a bit to get the screw holes to align.
  3. Only screw in the rack-ear screws half-way.
  4. Reinstall the other screws, again only screwing them in half-way. This makes it so you can twist the chassis again to insert into other screw holes that may not line-up perfectly.
  5. Once all screws are inserted, you can now tighten them so they are in all the way.

“Bus Error” when using Symphony64 PCI card or Symphony64|ThunderBridge

Bus Error is a message that will appear in the Apogee Maestro 2 window under the System Status section. This is typically a communication issue between the connected device, and the Symphony64 or Symphony64|Thunderbridge.

This can be caused by several things:

  1. A common cause for this is that the port setting in Audio MIDI Setup (Applications>Utilities) is set to Ports 1-2, when only one port is actually being used.

  2. A bad PC32 cable (DigiLink)

  3. If using a Symphony I/O, the AIM setting could be incorrectly set to “USB Audio”, “Standalone”, or “Pro Tools HD”, instead of the “Symphony” setting.

  4. Connecting a single device to Port 2 (17-32), instead of Port 1 (1-32)

If only one device is connected and you are receiving the Bus Error message in the system status window in Maestro, please revert back to the Port 1 (32 channels) setting in Audio MIDI Setup. You may need to reboot your computer for the new setting to take place. Secondly, ensure by pressing and holding the right-hand encoder knob on the front panel of SymphonyIO, you are in fact in “Symphony” mode.


Level jumps when adjusting Symphony I/O’s front-panel output encoder knob

There was a known issue with some Symphony I/Os where the output level could jump by several dB when adjusting the output level with the front-panel output encoder knob.

This issue was resolved with Release 4.8 firmware and software


Click here to download the latest Symphony Release and follow the update instructions to ensure a successful firmware update.