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. 
Another small audiophile company on the brink of extinction! Good luck if you try to sell the Exogal gear!
I am sympathetic but they need to step forward and let people know what is happening. Being evasive and hoping the problems will go away is not helpful. They are saying they have a European distributer which indicates that possibly the remote module is out. Otherwise you would have to be crazy to buy the brand. 
I still really enjoy my Exogal Comet and have no plans to change, but, I agree with other users frustration of no longer having the iOS or Android app. I recently discussed this with Exogal and they sent me a prototype version of their RF remote and RF receiver called the Pulsar and it is a functionally adequate solution to their challenges of maintaining and distributing an app in the Apple and Google App Stores, but, it not as convenient and elegant as the original app-based approach. It seems like a complicated technical solution for what I believe is a simple business problem. The last thing I wanted was yet another remote.
I have to say that for this outlay of money  we should have something better than functionally adequate, to use your characterization. Also, I was part of the same trial and I did not feel the remote replacement worked very well. This product is, was, application based as the designers openly stated in their own advertising and as they were themselves quoted in reviews. No application means pretty close to unusable product.
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I have a number of Wadia DACs and based on the great sound qualities i have recently acquired the Exogal Comet. The unit is a Plus version with enhanced linear power supply but doesn’t come with a remote.

I didn’t thought it was an issue initially because there are IOS and Android apps to support phone control of the Exogal Comet functionality.

Unfortunately the IOS version is no longer available from Apple Store and the Android version doesn’t really work as it can’t find the unit after installation.

This becomes a challenge because i plan to use multiple DACs in an active 3-way digital crossover setup. And being able to adjust the volume is essential.

Luckily I noticed that there is a 5v TTL serial communication port on the Comet.

I wrote to the CEO of Exogal requesting for the serial communication specifications and Jeff was very kind to sent me this information.


I managed to write a C# communication program in .NET to map all the functionalities of the remote control to the equivalent commands via the serial interface. I managed to gain full control of the Comet DAC.

I have tested this and is working just fine.

So for those of you out there experiencing difficulties in communicating with the Comet, i highly recommend getting a FTDI  5v TTL serial to USB cable from Aliexpress and give this approach a try.


This is the cable recommended by Exogal for serial interface :


AU $11.13 10%OFF | USB to TTL Serial Adapter Converter Cable FTDI Chip 5V TTL UART 6ft to 3.5mm Audio Jack Plug Stereo Cable TTL-232R-5v-AJ


To provide a nice user interface, I obtained an image of the remote control, upscaled this image using AI imaging based on Fractal geometry for enhanced details. This allows me to capture the image for each control button so that i can map these to the C# GUI buttons to program a touch screen GUI interface to work as a remote control for the Exogal Comet 🤩👍


With this small enhancement to restore the UI, the Exogal Comet is once again a very nice choice for those of you looking for a ultra high resolution DAC with a very analog sound. The Calculus design really works magic even compared to the Wadia DigiMaster... it is definitely a step ahead. 😬👍


Thats purdy cool stuff.   I have 2 Wadia 321's 

Do the 321's use the Digimaster software?  Can you go a little more into detail about the Calculus? I might be interested in seeking out the Comet on the used market given what you have done.





Wadia 321 is an excellent DAC. With twin 321, are you running 2-way active digital crossover set up? 

Unfortunately, the 321 doesn't feature DigiMaster. 

You might be aware that Jeff Haagenstad and his team when they left Wadia and form Exogal, they decided to build what they have always wanted in a DAC, but were limited by the hardware processing power, at the time when the DigiMaster were developed at Wadia.  This is the Comet, essentially the next logical evolution from the DigiMaster, but leveraging the much improved huge processing power of the latest hardware technology. 

I shall do one step better than providing you with more details on the 'Calculus' approach.   

Here's an excellent white paper that details the Calculus approach towards deriving the upsampled data that dramatically improves the resolution power of the Exogal DAC. 

White paper :

Link 1:

Link 2:

User Discussion :

The brilliant aspect with Wadia's DigiMaster and now the Exogal's Calculus approach is that these techniques are based on analog functions that have the potentials to provide infinite resolution. Just like fractal geometry, the closer you look, the more details can be revealed. It is only limited by the hardware's processing power. 

From a practical application perspective, i would rather have a meaningful 24-bit 192khz PCM decoding, with tons of high resolution details that are cohesive in nature than some super high upsampled PCM that is meaningless, in terms of providing more resolution details, but was necessary to enable the use of digital filter, with a gentler rolloff slope, which imparts less digital artefacts.  You can read up on the white paper from PSAudio Directstream DAC and Chord Hugo M-Scaler. They are technically excellent, but if you read closely on the approach, there isn't much intelligence in deriving more detail and cohesion from the quantised data. 

I started with my audio hobby in the 1980's, when digital CD technology just started. We were lucky to have good exposure to high quality analog sound sources as well from great turntable setup to Nakamichi tape decks. And despite the hissing background and static clicks from these sources, there is definitely a sense of musicality they project, that is missing from the early digital sources. 

That is until i had the great pleasure of auditioning the Wadia DAC. First the Wadia 2000, then subsequently the majestic Wadia 7+9. Then later the Wadia 27ix. 

To me, the Wadia DAC's ability to convey a dynamic, yet musical sound has always been a major attraction aspect. The bass is phenomenonal. And the highs, has a very analog sounding quality with high resolving power. It's very believable.

The Wadia 121 is the last iteration that Wadia managed to squeeze all the combination of Wadia technologies into single DAC unit, including DigiMaster, before the company has changed ownership of Fine Sounds. 

Thereafter the newer DAC's are based on ESS Sabre, but no longer features DigiMaster, but still benefit from Wadia's proprietary analogue output stage innovations and technology. These are the Wadia 122, 321 and 322.
The great sound from these DAC has less dependency on the ESS Sabre DAC chip they use, but more so on the Wadia proprietary analog stage that follows. 
Don't get me wrong, these DACs still sounds amazingly good. 
If you set up the 122 in a manner to extract the very last detail from the 122, you would be more than impressed by how good it sounds. In this regards, the Wadia 122, IMO is the best sounding DAC in its price range. The 321 and 322 builds upon the 122 platform, with a much enhanced power supply that fortifies its earth shattering bass department with the visceral power to command total control. This makes a very notable improvement in a larger setup. This is the typical Wadia DAC forte, yet the highs are much better than the classic Wadia DAC's with more resolution and extension. 
Compared to the 122, the 322 sounds is more luxurious, it has an elevated sense of detail and embellishment. The sound stage is wider and dynamic content is more assertive and lifelike. It is very close to being an ideal DAC. 
The bass department is as perfect as i can ever hope for. 
The only small aspect i wished for, is an improvement in the ultra high frequency resolution. Without the DigiMaster, its hands are tied. Here, this is where the Exogal Comet shines. 

I have learnt in the past two decade that by resolving the high frequency properly, together with restoring the missing harmonics in the ultra high frequency range, this not only adds musicality but restores realism. When this happens, you can start to forget about the equipment and focus on the joy from music. 

It may sound like an easy goal. But finding a DAC that provides the most analog sounding property is no easy task. Wadia and Exogal are the two great examples, dCS is another. And the other challenge is to find an amp circuit that has ultra high bandwidth that can resolve all these details in high accuracy and coherence. This is where the Goldmund Job4 1Mhz bandwidth comes into play. There are a few different implementations of the Goldmund Job4 in various disguises, obviously the Goldmund, but there are Stellavox, Job Amp and even Nuforce STA200. If you combine these two elements(Wadia/Exogal Comet + Goldmund Job4) suddenly you will start to experience true musical 'magic'! 

Throw in a crossover approach that focuses on preserving the absolute signal integrity by operating in the digital domain, suddenly everything just clicks, and you have a system that would provide everything you can possibly hope for, as this system would finally be free from all the typical distortion and limitations that are responsible for holding back most other setup, as they continue to battle the various challenges in the analog signal path. 

I run twin Wadia 322 DAC in my main set up and now introducing the Exogal Comet. 

For Wadia 322 runs the high frequency and the other for low frequency, in a fully active digital crossover setup, utilising a DEQX HDP-3 operating in digital domain with the optional digital IO card. All my front end is managed by a Goldmund SR8 Digital Universal Preamp, which process all signals in 24-bit 96kHz PCM. 

My main transport is a Esoteric X01 Limited. 

Streaming is from a iFi Zen Stream. 

Both DEQX and Goldmund SR8 are limited to 24bit 96khz. 

Since the system needs support for the Pioneer TAD PT-R9 Beryllium Ultra high frequency reproduction in the 120kHz region, which augments the JBL Project K2, i need to upsample the PCM to 24bit 192khz to meet the Nyquist frequency requirements and get the sound reproduction close to the 96khz. 

To ensure clock accuracy, the upsampling to 192khz is performed by the brilliant Lake People RS05, equipped with a Femto clock oscillator. The sonic improvement from 24-bit 96khz to 192khz is very notable. You only have to listen to a good track for 10 seconds and most people would noticed the improvement. 

I deploy 7x Wyreforsound Remedy reclockers in all digital paths as well, to ensure the clock is reclocked to Femto grade accuracy. 

I love the sounding of the 322. It is very similar to the 321, with the added support for DSD. 

I helped my friend set up a very similar 2-way fully active digital crossover setup, that is based on twin Wadia 122 (since 121 are extremely hard to source). The active digital crossover is done by Nanodigi instead, with 7x Wyreforsound Remedy Femto reclocker deployed in each stage of the digital transmission, driving a pair of JBL 708i, with Goldmund JOB4 based high frequency amps and low frequency monoblocks based on Icepower 500w. His system sounds jaw-droppingly good. Although we started small and overall very budget friendly, the end result was mind blowing and certainly puts many systems costs over 10x more in shame. It's definitely still has much potentials to explore as we upgrade the ultra high frequency to incorporate a pair of Pioneer TAD PT-R7iii. 

The closest pure DAC from Wadia you can currently get that utilises DigiMaster is the Wadia 121. But it is extremely hard to source in good condition. 

I managed to source 3x of these Wadia 121 in my other setup and they do sound very nice. You can read up on various 121 reviews. 

In my second setup i run 3x Wadia 121 DAC's in a 3-way Active digital crossover setup, driving a JBL M2 setup augmented with Pioneer PT-R7iii. Crossover is based on Nanodigi. 


Now, by having a solution to harness the greatness of the Exogal Comet, i believe we have open up a great opportunity window for many audiophiles that would like to try the Comet, but concerned about the lack of technical support on the phone app. 


Let me know if you need any further information to develop the serial port communication solution. 

I have included some screen captures on the solution that i have quickly put together. You can get C# sample programs in serial communications and augment that easily to suit the Exogal Comet. 

In the version i am using, i captured an image of the Exogal Comet remote control, run it through AI image processing and applied fractal geometry to upscale, enabling me to obtain good resolution to get images on each button to compile a nice graphical user interface that resembles the actual remote control itself. 

The biggest advantage with this solution over the wireless is, i have incorporated display to show the state of each function, including the current state of the volume, on/off, input, output and mute. In addition, left click would increment the volume by 1 step, and right click will rapidly increase this by 50.

So from 0 to 200, you only need 4x right click on the volume button. 😬👍

Exogal Comet Remote control App via serial interface



Wadia 321 is an excellent DAC. With twin 321, are you running 2-way active digital crossover set up?

No, but it sounds interesting and would love to try it if there is not to much investment. How do you build the crossover?


interestingly there is a Wadia 121 on ebay for $500

There are 2 mainstream methods of implementing digital active crossover. 

The most comprehensive method is the DEQX. This is also the most popular method. 

It offers automatic software driven calibration for both the speaker and listening environment. And will time align the drivers as well. Very sophisticated. And supports very steep - 300db/oct crossover, depending on the filter chosen.  But has a higher acquisition cost.

The second method is via MiniDSP nanodigi 2x8.

Not many people know about this method, but this nanodigi is highly capable and would also sound incredibly if setup correctly. 

You would also need the plugin software to work :

Unfortunately miniDSP officially stopped making nanodigi last year. But you can still source these easily from other suppliers at a reasonable cost. 

Supports up to 24bit 96khz PCM and up to - 48dB/oct crossover.

The most attractive aspect is the very friendly entry cost. 

It's less than 10% cost compare to DEQX.

It does not offer automatic calibration, time alignment of drivers nor room correction. All setup are done manually via the pkugin software. But if you know what you are doing, it is a straightforward way of setting up active digital crossover quickly in 15 minutes.

@damianhl incredible stuff! I too agree that the Exogal Comet Plus has perhaps the most natural timbre of any DAC I’ve owned. The mids are simply beautifully depicted.

I spent some time not long ago probing the Bluetooth chip output in my Comet, trying to understand the pulses it sends to create a directly wired replacement. My one gripe with the DAC is its UI - the remote and the android app I run on an old phone have proven to be unreliable and quite slow. 

I’ve considered replacing or piggybacking off of the Bluetooth receiver with an Arduino or RasPi, either to have directly wired physical controls or to create a web interface for the DAC. Any documentation or help would be greatly appreciated. Thank you for helping keep this DAC alive!

- Mike

If those among you who like the Comet are out on the West Coast why not send one to Amir at Audio Science Review for testing? That would be a real contribution to this subject. It would be extremely enlightening to put this unit to the test and determine if it is objectively makes the grade. 

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Hi Mike,

I managed to obtain the Exogal Custom Install Instruction Manual from Jeff Haagenstad, the CEO of Exogal. He was very kind and helpful. Hope this information would be helpful to you.

I have uploaded this doco to share with others, who are interested in developing their own touchscreen GUI interface to communicate with the Comet unit.

The serial communication is very reliable and it is possible to query the serial interface and achieve auto COM port selection and connection if you look for PID 0403 and VID 6001 or FTDI as the manufacturer of the USBC serial inferface (i have the latter as the secondary method to perform auto com port lookup) . I got this working reliably.

If you perform a high resolution scan on the Exogal Comet remote and map the button images to command buttons nicely, it is possible to provide a very realistic remote control for the Comet unit. Actually in actual use it much nicer IMO, because you can program single finger click for slow volume increments and double finger clicks as fast volume increments (I have the latter set to 50 by default. So in 4 clicks i can easily go from 0 to 200). It works really well on touch pad interface. Have these increments customisable as user selections and store these settings in a JSON file. I am elated with the results 😊👍 and actually prefer this over the real remote, as it shows the current volume, current state of On/Standby, Input, Output and Mute status... the real remote doesn’t 😅

Here is the link: Exogal Custom Install Instruction Manual P

This is the text URL in case the embedded version doesn't work:



Since the demise of the Exogal remote control app I just use the supplied remote control that works fine. The only downside is that I have to use a flashlight in order to  see the display on the front of the Comet Plus.

Hi Mike, 

Bluetooth interface would be difficult, even if you have a replacement unit, you need to have the key to pair up with the Comet unit via a complicated procedure. 


Much easier to achieve a more reliable outcome via the serial port interface. 

If you want more fancy wireless access, you can easily convert the C# classes into an API and establish a client server app, providing a web interface front end. 😊👍


Keep us posted. 




Buy an RME and enjoy fantastic performance and simplicity of operation —you don’t even need a flashlight and magnifying glass to read the display. 

Hi @damianhl

Thank you! I agree, Jeff has been a wonderful help. I should’ve checked here earlier because I too wrote an app that interfaces over serial with Comet! I wrote mine in Python since it’s what I’m familiar with and easy to port to any modern OS.

It’s a simple button based GUI app that currently allows you to select which COM port, power on/off, choose input/output, mute/half mute /unmute, increase/decrease volume or enter a specific volume value.

I’m currently working on adding a rotary encoder and an IR receiver to a RasPi Pico to handle desktop volume adjustment and living room IR remote use. In the future, I would like to run it all off a full RasPi to add streaming capabilities. There are a lot of hidden functions on comet that I’m excited to see implemented, but right now this is where I am.

I am so thankful to Jeff, Bob, and to you for helping keep this DAC alive and well. Maybe we should start a new thread, but I’m happy I at least landed here. Thanks!


Would appreciate any and all help implementing this solutions for someone who has zero tech skills. I love my comet but the remote issue is becoming a problem for me.

@markhh2 hi!

The easiest option is via PC. All you’d need is a USB to serial (5v TTL/UART 3.5mm. $10-30) and the app I’ve been working on. There are a few kinks I need to work out but I should be able to reach out when alls said and done. It looks like this for now:



Update: 3/19/2023


IR remote code is COMPLETE! There are some oddities:

1. The 'Mute' functionality isn't controllable over serial, only Bluetooth. There's a note about it 😔 While you can't mute from the IR remote (could set Vol = 0 I guess), you can unmute! 😀

2. The NEC protocol (common for 'universal' IR remotes) specifies 'repeat' functions in a silly manner - if a button is held, regardless of the button, the 'repeat' command sent is identical 🤨 I have not ironed out logic to allow holding Vol +/- yet for this reason  



Just about any IR remote can be coded in. A friend found some awesome OEM aluminum remotes, went ahead and ordered a few to test Happy with the progress so far! I don't have a lot of time to devote to it, but I am excited to have it done haha.


Update: 3/23/23

Finished the desktop app! 😀 It's more or less feature complete depending on the DAC firmware version (some don't have 'Mute' control available: to unmute, simply press one of the volume buttons).

The app is written in python and made stand-alone with 'pyinstaller'. No need to install anything, simply unzip the folder and open the 'CometCampground.exe' (I thought the name was fun). It should automatically choose the right COM port: If not, it can be clicked to show a list. To use it, you'll need this cable (non-affiliate link):

I take no responsibility for anything at all: not for damages, the apocalypse, your DAC and life spontaneously combusting to smithereens, etc. You use it at your own risk :) With that out of the way, the goods - Dropbox link to the app:

For any adventurous souls; there is a Comet over on USAudiomart for like $1,250. Even has a remote.



Didn't hold it's resale value very well did it?

I would venture to say that much gear takes resale hit when the company defuncts.  They can be a good deal but its a gamble of course.  I have a wadia 321, purchased before The Mcintosh group shelved it all but I got a great deal on it brand new as they were spinning down the brand. It has provided years of trouble free service. 

Exogal gear still holds better resale and musical value than your gear takes rtorchia 😂go back to simping Amir and listening with SINAD instead of your ears.

Myself and others I know like what the Exogal team made because of the way it sounds - they made something special. Why else choose to own a piece of audio equipment? 😉

I am doing what I can to help others continue to enjoy that gear in new and (hopefully) helpful ways. It's a learning experience for me for sure 🙂 I keep updating progress here and in other threads in the hope that it reaches everyone looking for such a solution. I've mentioned this before: IR remote and desktop control are features I've been searching for long enough to finally try to do it myself. Huge thanks again to Jeff and Bob, as well as Jan and the rest of the Exogal team, for helping me get these projects started and for making this special piece of kit ☺

Update: 3/24/2023

Since native mute functionality isn't accessible over serial for every firmware revision, I wrote custom logic/code to add mute capability to the IR remote! I'll add it to the desktop app as well 😊

Update: 3/28/2023

Updated the app to fix a stupid mistake on my part - I didn't include the app icon in the distributable! Also made it one simple executable file.

Comet Campground (desktop remote) v1.1:

Important update - that version of the app is borked: I didn't include the app icon in the distributable! After I did so, it triggered Windows Defender. Oof. So instead I kept it one simple executable file and signed it with a Windows Security certificate so it shouldn't trigger your antivirus. First run takes a second but after that it's quick.

Comet Campground (desktop remote) v1.2:

You shouldn't need to install any dependencies unless MS Visual C++ is out of date:

Let me know if you (or anyone for that matter) run into any issues!
Update: 4/6/2023
Waiting on more case parts. Order got pushed back a month  In the meantime, Mac app is ready to test! Mac OS is... not my favorite haha.
Once I get GitHub sorted and the codebases the same, I plan to open source the program. Hopefully soon  

Long time no post. Apologies, life finds a way. I'm hoping to finalize the hardware design in the coming months. If that does not in fact happen and you, the reader, feel so inclined - please feel free to PM me 😊

Looking at a comet and ion on eBay at the moment at 1400gbp and very tempted as I owned them a few years ago. Only issue I have is that my ion gave up the ghost but I managed to get it fixed by returning it to exogal just before they went bust… I playing with fire purchasing or worth the risk?

Just for the record, I would not pay more than USD 1200 for a mint Comet with box and all the et ceteras. Most people bought these when they were offered by Underwood at under USD 2,000 some years ago, so ignore the high list price. 

I have no idea why you would want to buy a unit with which you have already had a negative experience. Also, DACs have really improved in both technology and price over the years so you would be buying something rather dated and extremely awkward to use. The single thing to recommend about the Comet is the aluminum case.

I strongly recommend the RME ADI-2 which you can get new for under the used price of this unit. Another fine option is the Topping DX 7 pro plus. Both of these have fine headphone amps built in; the Topping goes for well under USD 1,000. Read some of the reviews on Audio Science Review. Last but not least, both these units and their relatives actually have screens that you can read without a magnifying glass!  


Thanks for your work. Does this application work on Windows/Android? How to connect computer to Comet? Is it possible to program some universal remote, just in case the original dies?

@michrt : What good quality universal compatible remote would you recommend for the Exogal Comet? I too use a Comet DAC and am concerned about the flimsy remote that comes with it. Jeff

I believe that very late on Exogal made a superior remote that cost around $100  because the original one was bad. You should probably try to get one of those. I took part in a program to use the prototypes for these so they sent all participants a free remote. Truth be told, it was an improvement but not that great. Even a good company like RME supplies an awful remote. 

@ciszyn11 This application doesn't work in Android, however the official APK is out there. Works on older Android handsets, before Android 9. The one I wrote is primarily for Windows. @yoby It's not possible to program a universal remote without some interface to the DAC, since it only has hardware for a specific set of calls over BT.

What @rtorchia is referring to is probably the Pulsar. I have one, it's a BT repeater that works with any IR remote and interfaces with Comet. It does work very well, but is tricky to find. The physical remote it came with looks the same as the proprietary BT remote, but at least with the Pulsar add-on you can use most any NEC IR remote. My hardware solution seeks to do something similar with more features. I need to start working on it again. Life happens lol but hopefully some have been helped so far