Symphony I/O: User Guides

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 Power Behavior Modification

Can Symphony I/O be set to power on automatically when power to the studio is turned on?



There is a jumper on the Main board internally that can be moved to set the Symphony I/O to turn on automatically when it senses current. The instructions are in the users guide found here:

Symphony I/O User’s Guide

Choose “Symphony I/O Hardware”, then “Auto Power” to find the article.

Updating Symphony I/O firmware

This article applies to the Original Symphony I/O only, not the MkII.

Note: The updater program is only compatible with OS X 10.6.8 – 10.10. This means you need a Mac running one of these operating systems in order to update your Symphony I/O’s firmware. Once the firmware update is complete, you can plug the Symphony I/O into a newer version of macOS and it will fully function. It is only the updater that needs the older OS.

If you do not have access to such a Mac through a friend, local business, or library and you are in the US or Canada, contact Apogee Support to arrange for the unit to be shipped to Apogee for the update. You are only responsible for getting it to Apogee however you choose, and Apogee will update the unit and ship it back to you for free via standard Ground shipping services. (If you are not in the US or Canada, contact the Apogee Distributor for your region. Be aware additional charges for service may apply if purchased in a different region.)

Before you begin the update process, trash ANY older Symphony installer packages you may have on your computer (desktop, downloads folder, etc.) Old installers can mistakenly trigger ‘firmware mismatch’ warnings.

  1. Download the latest Symphony installer package from our website:
    • Fill out the registration form. For Product, select “Symphony I/O”.
    • For Operating System, select the version on which you will run the fully updated Symphony I/O.
  2. Once you have the DMG file downloaded, open it and inside are many files.
  3. Locate the file “Symphony System” and run it. Follow the prompts to a restart of your computer.
  4. When the computer is back up, open the same DMG file but this time located the “Symphony Software Installer.pkg” and run it. Follow the prompts to another restart of your computer.
    • If on macOS 10.13 High Sierra or newer, make sure you allow the Apogee extension to run or it will not be recognized properly: Read More
  5. Plug in the Symphony I/O via USB to your Mac.
    • If your Mac has USB 3.0, you should first try it with a USB hub (an Apple keyboard with USB ports is the best hub to use if you have one) to do the firmware update… the firmware update will not work on most USB 3.0 ports, so a hub will bring it down to USB 2.0. Note- USB Audio should work fine on USB 3.0 ports.
  6. Power up the Symphony I/O.
  7. Locate the file for “SymphonyIO Firmware” and open it.
    • If the firmware needs an update, copy this newest to a USB memory stick and transfer to a Mac running OS X between 10.6.8-10.10, and connect the Symphony I/O via USB to that Mac to perform the update.
  8. Note any settings you may have made for your Symphony I/O in the Maestro software, as these settings can get reset after an update.
  9. Open the “SymphonyIO Firmware” and update the firmware. Make sure the firmware successfully updates before proceeding to the next step.
    • If the firmware updater gets stuck or doesn’t work, quit the firmware updater app, power off the Symphony I/O, power the Symphony I/O back on and try the update again.
    • You may need to try different USB ports.
    • If the updater says it ‘failed’, click ‘try again’ and run the update again.
    • If you have multiple Symphony I/Os, make sure to update EACH of them by selecting each unit in the drop-down menu of the firmware updater (Symphony I/O 1, Symphony I/O 2, etc.)
    • Once the update finishes, quit the updater and then relaunch it to confirm that the firmware is up to date for each unit.

Once you’ve confirmed that your Symphony I/O’s firmware is up to date, ensure it is in the correct Audio Interface Mode (AIM):

  • Push in and hold down the right-side front-panel encoder knob until you get to the audio mode menu.
  • Let off the knob and then turn it to scroll through the different modes.
  • One the desired mode is selected, push in on the knob again to restart the unit in that mode.
  • Here is a video demonstrating how to change interface modes: Video

If you’re using Symphony I/O with Symphony64 PCIe or Symphony64 Thunderbridge:

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.  Wait until the unit/units sync and stop clicking before launching Maestro. This can take a couple minutes if you’re using 2 Symphony I/Os.



Updating Symphony I/O Software and Firmware

Updating Symphony I/O

Maestro includes an update notification feature that is enabled simply by connecting your Mac to the Internet. Maestro will ping Apogee servers to determine the latest versions of Symphony I/O firmware and software, and notify you if updates are available. If updates are available, the dialog shown below appears.

Click on the link provided in the dialog and download the Symphony I/O firmware and/or software updates.

Before updating:

  1. It’s recommended to note critical Maestro settings such as Trim levels before performing an update.
  2. Unplug headphones and power off speakers connected to Symphony I/O.

To update firmware and software:

Click here for instructions on updating the Symphony I/O firmware and software.



Symphony I/O: Installing I/O Modules

Installing I/O Modules

In most cases, Symphony I/O ships with the first I/O Module installed. For the infrequent case where no I/O Modules are installed, this section describes both how to install the first I/O Module as well as a second I/O Module.

Symphony I/O Module Installation Video

Symphony I/O Screws

Be careful to keep track of these screws and use them only for their intended purposes

Stand off – This secures the Modules to the chassis when using 2 Modules

  • 4-40 1.5” length, ¼” Hex M-F STANDOFFS Aluminum
Module/Rear Screw – Use these round head screws to secure Modules to the chassis and to secure the rear of the cover to the chassis

  • 4-40 ¼ PHIL PAN EXT Black
Rack Ear Screw – Use these undercut screws to attach the Rack Ears

Case Bottom Screw – Use these undercut screws to attach case on bottom of unit and to secure the center support

  • 4-40 ¼ PHIL flat-head blk


When installing a Mic Pre I/O module, first install an 8×8 or 16 Input I/O Module in the lower slot, then install the Mic Pre I/O Module as described starting with Step 12.

1. Discharge Residual Electricity- IMPORTANT! Even when Symphony I/O is powered off but connected to the AC wall socket, voltages remain active throughout the system. Manipulating circuit boards under these conditions may result in permanent damage.

a. Turn Symphony I/O off, but leave the AC cable connected

b. Ground yourself by touching the front panel of Symphony I/O to discharge static electricity

c. Unplug the AC cable from Symphony I/O

d. Wait for at least 2 minutes to let the power discharge from the circuitry

2. Use a Phillips screwdriver to remove the 11 screws holding the cover on.

3. To remove the cover, slide it straight back until the underside clips prevent further movement. Then grasp the cover’s side panels and gently bow the cover until the bottom lip is free.

4. Remove the 2 screws holding the center support in place, and lift out the support.

5. Remove both I/O Module blanking panels and set the screws aside for later use.

6. Remove the 9 screws indicated below, and set them aside for later use.

7. Place the first I/O Module into the chassis by inserting the I/O Module rear panel into the Symphony I/O Card 1 opening, then gently dropping the front of the I/O Module into place. Line up the I/O Module’s mounting holes with the 9 nuts on the bottom of the chassis.

8. Secure the I/O Module by installing the 9 screws removed in Step 6. If you’re installing a second I/O Module, install 9 stand-offs in the place of the 9 screws.

9. Secure the I/O Module rear panel to the chassis rear panel using the two screws from Step 4.

10. If you are only installing a single Module, replace the second slot’s blanking panel.

11. Connect the provided ribbon cable between J1 on the Main board and J1 on the I/O Module. Be sure to align the key on each ribbon cable connector to the key slot on each receptacle.

12. When installing a Mic Pre I/O Module, first remove the Input Bridging Jumper from the lower I/O Module, and connect the Mic Pre IO Module’s 50-pin ribbon cable to the now-empty socket.

13. To install a second Module, insert the I/O Module rear panel into the Symphony I/O Card 2 opening, then gently dropping the front of the I/O Module into place. Line up the second I/O Module’s mounting holes with the tops of the 9 stand-offs, and install 9 module screws.

14. If you are installing a Mic Pre I/O Module, connect the Mic Pre IO Module’s 50-pin ribbon cable to the Mic Pre IO Module

15. Connect the provided ribbon cable between J2 on the Main board and J1 on the second I/O Module. Make sure that the lower Module ribbon cable is nested into the upper Module ribbon cable as shown below.

Do not tuck the Primary I/O ribbon cable underneath the second Module or it could become frayed.

16. Reconnect the center support bar.

17. Reversing the steps to remove the cover, slide it back into place and secure with the 11 screws removed in Step 2. Use 6 undercut screws to secure the cover bottom and 5 round head screws to secure the cover’s rear tab.

Rack Mounting Symphony I/O

Rack mounting Symphony I/O

Rack ears are included in the Accessories box for mounting Symphony I/O in a standard 19” equipment rack.

1. Orient one rack ear to line up the ear’s three holes with three holes found on the side of the chassis immediately behind the front panel extrusion.

2. Insert 3 screws (included) and finger tighten.

3. Connect the second rack ear to the other side of the chassis.

4. On each side, line up the top and bottom of the rack ear with the top and bottom of the front panel extrusion and tighten the screws with a Phillips screwdriver. Don’t overtighten the screws.

5. Remove the screw-on feet by turning them counter-clockwise by hand or with a Philips screwdriver.





Symphony I/O: Understanding Latency

Understanding Latency

What is latency?
When recording with most computer-based digital audio applications, a delay between the input and output of the recording system often disturbs the timing of the musicians who are performing. This delay, known as latency, means that the musician hears the notes he produces a few milliseconds after having produced them. As anyone who has spoken on a phone call with echo knows, relatively short delays can confuse the timing of any conversation, spoken or musical.


To illustrate the effect of latency, let’s think about the typical signal path of a vocal overdub session. A vocalist sings into a microphone, which is routed through a hardware interface to the audio software application for recording. In the software application, the vocalist’s live signal is mixed with the playback of previously recorded tracks, and routed back through the hardware interface to the vocalist’s headphones. Because of the audio application’s latency, the vocalist hears his performance delayed by several milliseconds in his headphones.

How does Maestro resolve latency?

By routing the hardware input directly to the hardware output and mixing in playback, it’s possible to create a headphone listening signal with a much shorter delay.
First, the signal being recorded (in this case, a vocal mic) is split in the hardware interface and routed to both the software applicaton for recording and directly back to the hardware outputs without going through the latency-inducing software; this creates a low latency path from mic to headphones. Next, a stereo mix of playback tracks is routed to the low latency mixer and combined with the hardware input(s). This allows the performer to hear both himself without a confusing delay plus the playback needed for overdubbing.
Note that the software application’s mixer is used to set a stereo mix of playback tracks while the low latency mixer is used to set the balance between the stereo playback mix and the hardware inputs.


Do I need the Maestro Mixer?

The Maestro mixer serves to provide a low latency listening mix while recording. Therefore if you’re using Symphony I/O to listen to iTunes or audio from another program, there’s no need to use the mixer.
It’s also possible that the latency of your particular recording system is low enough to be unnoticeable by you or other performers, especially when connecting Symphony I/O via the Symphony 64 Thunderbridge or PCIe card. If you’ve set your audio software’s input/output buffers according to the guidelines below and latency doesn’t bother you or other performers, there’s no need to use the Maestro mixer.



How do I set my software’s I/O Buffer?

The I/O Buffer setting found in most audio software is one of the most crucial, but often ignored, settings in a Mac-based recording system.
When choosing a buffer setting, a compromise between the latency through the application and the amount of computer processor power accessible to the application must be made.


A lower Buffer setting results in lower latency but less available processing power. If the application can’t access enough processor power, processor overruns may occur, resulting in audible clicks and pops or error messages that interrupt playback and recording.


A higher Buffer setting, on the other hand, results in greater amount of accessible processor power (i.e. less chance of overruns) but increases the latency. Determining the best setting requires some trial-and-error in order to find the best compromise.
Keep in mind that as tracks and plug-ins are added to a software session, processor requirements increase. Thus, the buffer setting that works during the early stages of a session might result in processor overruns during later stages.
The best strategy is to set the buffer to a lower setting during recording and accept certain limitations on plug-in usage, and then raise the buffer during mixing to utilize the computer’s full processor power when latency isn’t an issue.
With the processing power of today’s Macs, you may find that adjustment of the Buffer isn’t necessary, and you can leave it at a setting for low latency and still access a sufficient amount of processing power when adding tracks and plug-ins. If you do encounter clicks, pops or software errors, don’t hesitate to experiment with the Buffer setting.


Step by Step instructions to record with the low latency mixer

1. Configure your software application for use with an external low latency mixer. For example , in Logic Pro uncheck the Software Monitoring box (Logic Pro > Preferences > Audio) so that when a track is in record, audio output is muted from Logic. Thus, only audio through the low latency mixer is heard.


1. Set the software application’s mixer output to Out 1-2.

2. In the Maestro Output Routing tab window, assign Mixer 1 to hardware output Line 1/2, Mixer 2 to hardware output Line 3/4.



3. In the Output tab window, assign Headphone 1 to Line 1-2, Headphone 2 to Line 3-4


4. In the Mixer tab window, set the Software Return drop down menu to 1-2 and set both the Software Return and Mixer Master faders to 0.

5. In your software application, play back the session. You should hear playback in headphones connected to Symphony I/O’s HP 1 and HP 2 outputs. Next, create a suitable mix of playback tracks. In this example, both Mixer 1 and 2 are in use, but under many circumstances only one mixer is necessary.

6. Connect the signal to be recorded to Symphony I/O’s Line In 1 – the signal level will appear in the Mixers’ Line 1 meter.

7. Raise the Line 1 fader to create a monitor mix of the input and playback signals.

8. Record!



Symphony I/O: Setting Levels

Setting Levels


How do I set a recording level?

Once your microphone or instrument is connected, your audio software is configured and youʼve created a new recording track, just how do you set the input gain for a proper recording level in your audio software? Thereʼs no simple answer, but with a few guidelines and a bit of experience, you can master setting a proper level.
Ideally, the input gain should be set so that when the input signal is at its loudest, the level in audio software (or in Maestro) is just below maximum without lighting the Over indicator. In reality, itʼs unlikely that youʼll be able to guess just the right gain setting to accomplish this – when your gain is too low, the signal never gets close to maximum and when your gain is too high, a digital Over may occur.


Now, with a 24-bit system (such as Symphony I/O), the noise floor is so low that thereʼs no real penalty for undershooting the gain setting and recording at a lower level. There IS a penalty for overshooting the gain setting – a digital Over that results in significantly increased distortion. Thus, itʼs better to work with a recording level thatʼs a bit too low than a level thatʼs a bit too high.


Just how much to undershoot the gain setting is determined by the nature of the sound being recorded. As a general rule, instruments such as bass and organ have a more consistent level than percussive instruments, such as a tambourine, and may be recorded at a higher level. Also, the performerʼs skill and playing style can dictate more or less caution when setting levels. As you gain experience, youʼll be able to more accurately set a good recording level while avoiding digital overs.


How do I set the input level of my powered speakers?

Most powered speakers offer an input volume control, often labelled as input sensitivity. Rather than describe an overly complicated method for setting this control, the easiest way to determine the right setting is to note where you generally set Symphony I/Oʼs output level. If you find yourself rarely turning the output past a very low output level (say, -35 dB), decrease the input sensitivity on the speaker. If, on the other hand, you find yourself setting Symphony I/Oʼs level for full output and the speakers arenʼt loud enough, increase the input sensitivity. Ideally, Symphony I/O’s Speaker output should be at 0 dB (i.e no attenuation) when you’re listening at your absolute maximum desired volume.



Symphony I/O: Working with Front Panel and Maestro Level Meters

Working with Front Panel and Maestro Level Meters

Meter Characteristics

Level meters on Symphony I/O’s front panel and throughout Maestro display audio levels in the range of 0 to -48 dB full scale (fs).
An Over indicator at the top of each meter lights when three or more consecutive full scale samples have occurred. Though three consecutive full scale samples is most likely inaudible, the Over indicator serves as an “early warning” that the level should be reduced.


Peak and Over Hold

The amount of time that Peak and over indicators are held may be selected with the Peak Hold and Over Hold drop down menus, found in Maestro’s System Setup tab window.


Both Peak and Over Hold may be set to the following times:

  • Off – Peaks and Overs are indicated but not held.
  • 2 seconds – Peaks and Overs are held for 2 seconds, then cleared.
  • Infinite – Peaks and Overs are held infinitely (or, more accurately, a really long time) until cleared by the user by pressing Clear Meters in Maestro or clicking the front panel lefthand encoder.

Clear the Front Panel and Software Level Meters by clicking the Front Panel Left Hand Encoder or the Maestro Toolbar Clear Meters button. The message “Meters Cleared” will appear on the front panel OLED Display.


Front Panel Meters

Symphony I/O includes 2 banks of 8 level meters on the front panel. Select the audio signals to be displayed on each bank using the Meters buttons in the Device Settings tab window.



Symphony I/O: Using Soft Limit

Using Soft Limit

Soft Limit is Apogeeʼs proprietary analog process for taming transients before A/D conversion. By gently rounding transients in a transparent manner, itʼs possible to maximize level BEFORE the A/D conversion stage.

Soft Limit Settings

Soft Limit may be engaged on each analog input in Maestroʼs Input tab window. The following settings are available:

  • -2 dBfs – Soft Limit begins to attenuate transient peaks at a level of -2 dBfs. This is the most transparent Soft Limit setting.
  • -4 dBfs – Soft Limit begins to attenuate transient peaks at a level of -4 dBfs. This is the threshold of previous implementations of Soft Limit.
  • Soft Saturate – a lower threshold, plus asymmetrical clipping in a manner similar to tube circuits.
  • Soft Crush – The most extreme setting, where audible distortion and dirty mojo are required. Take that, drums!


Soft Limit on the 16×16 Analog IO Module:

On the 16×16 Analog IO Module’s inputs, soft limit functionality is restricted to On and Off. The On setting corresponds to the -4 dBfs setting on other IO Modules.


When to use Soft Limit

Soft Limit is an analog process that instantaneously rounds transient peaks; for all intents and purposes attack and release times may be considered instantaneous. As with any peak reduction device working at such fast time constants, Soft Limit is most effective with signals whose peak information is much greater than its average (or RMS) information, such as drums, percussion and plucked instruments. Soft Limit may not be the appropriate choice for limiting signals whose crest factor (peak to RMS ratio) is low, such as bass or organ.


The two more radical settings, Soft Saturate and Soft Crush, are intended to be used as creative effects rather than subtle control of digital overs. Throw caution to the wind, set Soft Limit to Soft Crush, Input Analog Level to Variable, and push up the slider until your signal is warm and crunchy!