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Major EXOGAL Comet/Ion problems

Five years ago I bought an Exogal Comet to use as a DAC with my Rogue Medusa amplifier. It proved itself an excellent unit in all respects and I was positively impressed with the company's support and helpfulness. A year ago I bought the matching Exogal Ion amplifier (at considerable expense) to go with the Comet and was delighted. (The Medusa was wonderful but I wanted something with a smaller footprint). 

Reviewers have invariably criticized the Comet's diminutive window for being extremely difficult to read and the cheapness of the remote control. Noting these deficiencies, the TAS reviewer Vade Forrester (June 24, 2015) wrote, "I learned the Comet is really intended to be operated remotely from an iPhone or iTouch." My experience was that the window and remote were exercises in frustration, but that the Apple application I downloaded from the Exogal site for my iPad was ideal; I had total control over the unit and the app was a delight to use--very Space Age. For the record, I liked the Comet so much I unloaded my Rogue RP 1 and used it as a preamp. 

All was well until I got a new iPad and couldn't download the application. When I called Exogal I received a somewhat garbled account that Apple was no longer permitting them to use the application. Ditto with Android. After a while they announced a remote control module was being developed and in the pipeline. They sent me an experimental prototype that in my opinion wasn't much of an improvement over the original. On the few occasions I can reach them they say it will be ready in a week but weeks have passed. This is tantamount to having a fancy TV where it is a major struggle to perform a simple action like change the channels! 

Exogal is singularly uncommunicative about this problem. Their website is scarcely used and they seem to have moved over to Facebook. The strangest thing is that on the website they list under "Products" a series of four Vortex streamers, described in detail, that apparently were never manufactured! They don't answer their emails. They say their site has been hacked and various other things. In a rare new posting on their website and Facebook they claim the they have just opened a distributorship in Europe. This raises the question how are the European purchasers going to operate their units? None of this inspires consumer confidence.  

My point here is that when someone spends 7k and above on supposedly elite components they deserve responses and explanations. It is Exogal's responsibility to ascertain that these units are operable as designed. I have to question the business sense of relying on an outside entity like Apple that is notorious for being proprietary. It is totally unbusinesslike not to make a public explanation of these issues with a timetable to correct them. Customers should not have to go foraging around Audigon forums to learn what is, or isn't, happening. 

Now the window on the Comet periodically goes blank (it was never even illuminated). Having 7k worth of Exogal equipment that is extremely difficult to operate, I went and bought a Wyred 4 Sound integrated and a Black Ice DAC so I can actually listen to something without a struggle. The Exogal stuff is in a box waiting for who knows what. I am beginning to think that Exogal is indeed out of this galaxy, but for all the wrong reasons. This is very surprising because a couple of years ago they were exemplary in all respects. I would like to hear from other frustrated owners to see what solutions they have devised. 
rtorchia
rdixey
4 posts
 

OMG- that is crazy! So the red light on the front does nothing? All is explained!!
There was I thinking it was a line of sight remote!!

Since you cannot readily replicate bluetooth signals, I finally understand why replacing the phone app is such a priority. I will look closely to see how your project is progressing!!

In the meantime I will have to treat the existing remote with kid gloves. If I break it, the exogal is useless as far as I can see. 

 

michrt's avatar
michrt
29 posts
 

Part 1: I am putting together a mini encyclopedia of things I’ve learned testing, troubleshooting, and fixing the Exogal Comet DAC over the past few years. Below you will find a very condensed list of some fixes for the common issues I’ve come across. I hope it helps those of us still clinging to this DAC  It is worth noting that all links posted in this post are from my DropBox, containing files directly from Exogal (unless otherwise stated). Any harm, accidents, damages, etc. are entirely your own fault With that out of the way - onward!

 

​USB: Exogal said the Comet supports up to 24bit 384khz over USB. I have only gotten it to properly clock 384khz outside of Windows. Comet also doesn’t always play nicely with the default Windows drivers or the universal XMOS drivers. The official driver works well though (up to 24bit 192khz) in both WASAPI and ASIO.

 

Official Manuals and Firmware: Official Exogal Comet User Manual - https://www.dropbox.com/scl/fi/wyot2mz0ea743d8x24sbi/CometUserManual.pdf?rlkey=5sebvybfy6gpp7h40fkrs0kcl&st=smdz6ogx&dl=0

 

Firmware/FPGA Upgrades/Downgrades: Firmware upgrades carry risk! You CAN brick your DAC! READ THE OFFICIAL INSTRUCTIONS PLEASE. Disclaimer that anything negative that happens is entirely your own fault

 

You will need an FTDI USB to 3.5mm Serial Cable to perform firmware changes. This is the Windows FTDI Serial Cable Driver from Exogal (a newer version might be available elsewhere) – https://www.dropbox.com/scl/fi/byhi3209xmcrsj5t5pqjg/Comet-Firmware-Update-FTDI-Cable-Driver.exe?rlkey=8vxxa9o2ylcammtupuq4v8m7y&st=wl97etjl&dl=0

 

The Exogal Pulsar was an optional add-on device that came later, allowing you to use IR remotes with Comet (the stock remote is NOT IR, but is Bluetooth. More on this and workarounds in Part 2). It is difficult to sync up the first time but it remembers the last Comet it connected to.

 

Pulsar Pairing/Sync/User Manual (NOTE - This manual is entirely wrong): https://www.dropbox.com/scl/fi/2h7w6w3gklm0qmexsr2fr/EXOGAL_Pulsar_IR.pdf?rlkey=77sln9u08byqfofp3w4359jbr&st=70pclit2&dl=0

 

Instead, to reset Pulsar pairing: 

  1. Unplug Pulsar. Wait 30sec.
  2. Hold Pair button down. While holding, plug in Pulsar
  3. Keep holding the Pair button until blue, red, and green lights are on. Unplug Pulsar. Wait 30sec.

To pair Pulsar with Comet (after reset):

  1. Hold Pair button and plug in Pulsar. Release after blue and red lights are on
  2. Wait for it to pair and press Power button on IR remote

I haven't seen this information combined elsewhere, but I'll be adding it to the respective threads on diyAudio and SBAF. I will put together a Part 2 that will hopefully answer your questions about remotes/DAC control 

qbitstate's avatar
qbitstate
11 posts
 

@michrt Sent you a PM.  Could you please upload your latest Windows + MAC versions of the desktop app?  your old link to the win one doesn't work anymore.

 

thanks!!

 

 

qbitstate's avatar
qbitstate
11 posts
 

if anyone has the desktop app for controlling the Comet DAC could they PM me please?

michrt's avatar
michrt
29 posts
 

For anyone finding this place via Google search:

I have been asked about control schemes for the Comet, because the default UI is… quite not good. The remotes that came with most Exogal Comet units are proprietary and render the DAC useless without one. Unless there was a way around this issue 😉

I have spent considerable time deep diving, deconstructing, and putting together each of the solutions and conclusions below. A very special thank you to Bob and Jeff, formerly Exogal.

First: The retail Exogal Comet DAC does NOT have built-in IR hardware. It was DESIGNED to (that is a story for another day), but it is absent. The Exogal Comet has 5x means of control - only 3x were properly internally documented. The official means are:

  • The stock Bluetooth Remote
  • Exogal Pulsar
  • Exogal Comet Phone App

The unofficial control avenues are:

  • Serial Control over Bluetooth LE.
  • Serial Control via the 3.5mm TRS serial port.

Options 4 and 5 might be the most useful to us, but I will go into detail about each. Feel free to skip to the scheme most interesting to you 😊

 

1. Stock Bluetooth Remote

This is the standard remote that came in keychain and “half-size” variants. If your remote has a red-tinted LED on the front, then this is the remote you have. Inside you’ll find a variant of the same Bluetooth module as Comet. Each remote pairs automatically with the first un-paired Comet it sees. Comet can only be paired with 1x Bluetooth control at a time (either the standard remote, the Exogal Ion, or the iOS/Android app).

It cannot be overstated just how abysmally slow it is to register button presses and send commands, while also having terrible range. It’s just bad.

The BT remote can be replicated with a modern chipset and hardware, but not as an off-the-shelf turn-key solution. The protocol and commands are non-standard in a shoddy, half-baked way that won’t solve the UI/control problem.

 

2. Exogal Pulsar

This is an add-on device that allows you to use actual IR remotes with Comet (reminder that the retail Exogal Comet DAC does NOT have built-in IR hardware). It is powered by micro-USB, and can run off the USB port on the back of Comet. The Pulsar puck listens for IR remote codes and communicates with Comet over an upgraded Bluetooth module (ESP32). It came with a “half-sized” Exogal remote that looks identical to the standard Bluetooth remote, only this one is IR and has a clear IR blaster and is actually IR.

Pulsar fixes the remote control issues by being way faster and far more reliable! I cannot overstate just how much better, faster, and stronger Comet feels to use when you have the Pulsar.

Pulsar could be worth replicating for some as you just need an ESP32 and a universal IR remote, but the simplest and most reliable control method is the next one.

 

3. Exogal Comet Phone App

In technology terms, this app is old and relies on defunct libraries. Released for Android and iOS, Android APKs exist do exist (targeting Android 5.1.1) but I could not find the Apple .ipa. The app rarely functioned correctly even in its prime and refuses to function when side-loaded on modern devices. Even on an old Android phone, it functions maybe 15% of the time (tested on my Nexus 4 in the year 2023 running android 5.1.1 and 6). When the app works, it is miraculously even slower and less reliable than the stock Bluetooth remote. It is a special ring of UI hell (fun fact: the app’s space wallpaper is internally named “joy.jpeg”).

There is a silver lining to all this negativity is the next section 😊

 

4. Serial Control over Bluetooth LE

The phone app is supposed to communicate serial commands over BT. I have successfully documented most of what the app sends, which is reliably repeatable via a serial console over Bluetooth LE.

Using a BT serial terminal (such as the Android Serial Bluetooth app), you can control Comet over Bluetooth! Important commands are as follows (Simple Name – SERIALCOMMAND):

  • Power Toggle - BTNS:42
  • Mute Toggle - BTNS:08
  • Increase Vol - BTNS:30
  • Decrease Vol - BTNS:31
  • Input Toggle - BTNS:10
  • Output Toggle - BTNS:20

The commands are very descriptive and easy to understand without any code comments, great job app dev :) I chuckled for a good bit after uncovering these. To make things easy, here is a link to the profile I whipped up for the Android Serial Bluetooth app that adds the commands as buttons in the bottom row: https://www.dropbox.com/scl/fi/ygmcmm4m6jqzcrq7ugw7a/Exogal_Comet_BT_Config.txt?rlkey=ymu2kycl5850qkp6otxpeggrl&st=fbnpei91&dl=0

A serial terminal isn’t pretty to most folks, but it is free for many folks and better than the app or no remote at all!

 

5. Serial Control via the 3.5mm TRS serial port

There are 2x 3.5mm TRS jacks on the rear of Comet: The silver panel-mount jack is for the trigger out. The unmarked black PCB mounted 3.5mm TRS jack is a serial port. This port facilitates firmware upgrades, but it is also the fastest and most reliable way to control the DAC – including hidden functionality!

To use the serial port to control the DAC:

Windows FTDI Serial Cable Driver (from Exogal, might be a newer version available) - https://www.dropbox.com/scl/fi/byhi3209xmcrsj5t5pqjg/Comet-Firmware-Update-FTDI-Cable-Driver.exe?rlkey=8vxxa9o2ylcammtupuq4v8m7y&st=bxl0xya3&dl=0

5v TTL/UART USB to 3.5mm serial cable (this link is provided as an example of what I bought. No affiliation and it’s likely dead by now but you get the idea) -  https://www.amazon.com/dp/B07J3XS7DQ?psc=1&ref=ppx_yo2ov_dt_b_product_details –

You can use your favorite OS serial terminal app. ComTest is the app the Exogal team used in-house - https://www.microridge.com/comtestserial/

The steps:

You'll get a “COM error” at first. All good. Click the "Serial Port" button on the bottom right of the app and select the serial port belonging to your USB cable (will likely be between 1-4). All other parameters are set up via the downloaded profile. Hit "OK", and the shortcuts are the labeled buttons in the bottom row!

This should work on most everyone’s machines (unlike the desktop app I shared previously and have not worked on in some time).

 

Final Commentary

I love the Exogal Comet DAC and have put this shortened guide together to the best of my ability to hopefully inform and help those of us that love this DAC 😊 I have been slowly developing a hardware interface with a physical volume wheel and IR receiving capability (Jan 2026 - code and hardware are done!). I just need to finalize the design and put documentation together before I can share it.

I did not share all of the commands I found in my research and testing – there are far too many, some of them actively harmful to the DAC functionality (for example, the filter option selections break the FPGA. Ask me how I know), but I hope I have provided the necessary pieces. I apologize for how long it has taken me to write this but know it was not forgotten on me. Thank you for your patience 😊

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