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Are you computer audiophile? If so, Fidelizer will help you enjoy the music on computer even more.

Portable Products

Portable Products


I started my audiophile journey around the time they founded iRiver company as a headphile first. Since then, I’ve been on this headphile road long enough to see the rise and fall of iRiver before being rebranded to Astell & Kern which is most popular digital audio player today.

During this journey, I’ve indulged myself with many interesting projects such as optimizing ROM giving something market can’t offer. As you may already be familiar with Fidelizer, optimizing ROM can give unique improvement with great musicality.

But that’s not all. I also modify many portable products from building cables, modifying DAP’s hardware too or even tuned earphone’s crossover. As a result, I gained many invaluable experience from fun experiements with headphile friends in Thailand.

Now I think it’s good time to introduce these projects to worldwide scale with professional modding and services from maker of Fidelizer who get his Nimitra product featured in Stereophile’s cover and claimed many great awards and reviews worldwide in just one year.


Fidelizer Purist ROM


Fidelizer - Purist ROM


I received requests from Fidelizer users from time to time about making Fidelizer for Linux platform. You may not believe it but I’ve been working on Fidelizer for Linux project for over 3 years. Now it reaches maturity to be released for supported devices worldwide.

As for why I never mentioned this before, I have a proper conclusion from my long years of research. When I compared computer transport to Esoteric transport, it was only Windows platform that could provide satisfying performance as you can hear from Nimitra product.

Also, each device in Linux needs specific optimizations such as supported governors and schedulers, root access, and specific tweaks with different hardware. It’d be hard to create multi-purpose utility. But for Android DAP, it’s possible with Purist ROM for supported devices.



-Play Store and Apollo – Fidelity Edition added (If applicable)
-Build configuration tweaks for better video and storage performance and improve battery life
-Bundled audio effects removed but keep main engine (For Poweramp that rely on audio effects)
-Some specific tweaks maybe added for important improvements


Supported devices (installation instructions will be provided inside):

iBasso DX50/80/90
iBasso DX200 (PerfectDynamics applied)
Fiio X5iii (PerfectDynamics applied)
Fiio X7
Fiio X7ii (PerfectDynamics applied)

Since 1st October 2017, Fidelizer ROMs has PerfectDynamics Sound Optimizations applied as a major update. Please contact Fidelizer if you’re Enhanced or Advanced ROM users and haven’t received yours yet.


I modified both device and Amp module (which has soft mute circuit bypassed for better sound than not to)

I can say that this one can go up all the way in the same level as SP1000cu/ss only that the house sound is not the same character.

SP1000 both …



The reason I created Purist ROM is fix issues and improve performance in stock ROM helping users to appreciate the product better. Receiving message like Purist ROM saving someone from selling his device is meaningful enough for me to keep doing this for free.

Just like Fidelizer, if Purist ROM works great for you, you can upgrade to Enhanced / Advanced Purist ROM with personal download link after purchase. I will continue to maintain these projects with most recent version from manufacturers.


  • Fidelizer - Enhanced ROM

    Only US $49.95


    Enhanced ROM is affordable services with additional enhancements.

    You’ll receive the following improvements:

    1. All features from Purist ROM included
    2. Kernel optimizations for audio I/O and remove non-audio services
    3. ฺFull Build configuration optimized for better sound quality
    4. Non-audio components de-bloated for dedicated audio platform
    5. ROM cooking support for troubleshooting services

  • Fidelizer - Advanced ROM

    Only US $99.95


    Advanced ROM is uncompromised services with finest enhancements.

    You’ll receive the following improvements:

    1. All features from Purist ROM included
    2. Applied low-level system/kernel optimizations for best sound quality
    3. Audio driver configuration optimized for neutral sound reproduction
    4. Optimized system libraries improving system performance
    5. ROM’s priority between Purist / Compatibility / Battery Saving


Why does ROM cooking services cost this much?

I think it’s understandable for some people to think $49.95 and $99.95 USD being costly for cooking ROM. Here’s the reason why.

1. I need to cook ROM with actual device in supported list. I even bought some for research purposes.
2. It took a lot of time and effort to research and improve ROM optimizations to its fullest potentials, sometimes even weeks or months.
3. For each customer, I need to repack up to 1GB system image, prepare the ROM and upload with his name.
4. When new version comes out, sometimes it took up to whole week for preparing update, fixing bugs and refining ROM.
5. Giving direct download link has risks for ROM being leaked. One customer can leak to hundreds and that did happen before.

I also asked manufacturers for their approval to provide after-market ROM cooking services. It took a lot of time and effort with very exhausting works at times to cook the ROM for one person unlike to free version with only safe optimizations for all devices.


Will flashing Purist ROM void warranty?

Flashing Purist ROM won’t void warranty. However, it’s recommended to flash stock ROM back before sending back for services.


Upgrade Purist ROM today

You can purchase Purist ROM upgrade by selecting upgrade options below. Please make sure to select correct device model before purchasing.

Purist ROM Upgrade
Device Model
ROM’s priority (Advanced ROM only)
Special instructions

If your desired device isn’t listed in supported device list, please contact [email protected] for inquiry about new device support.


Fidelizer Mod


Fidelizer Mod


There was a time when I suspended my headphile journey and went back to basic smartphone. It’s given when you don’t find anything worth giving serious attention after you’re familiar with high-fidelity sources from stereo systems.

One day, my friend sent me iBasso DX90 for modification since he didn’t use it anymore. With experience from modifying a few highend digital sources, I found it’s possible to bring reference system performance to portable device. It was a huge success and DX90 has become his favorite DAP since.

I’ve been working on various hardware modification projects. With over 10 years of experience, I have 3 levels of modification as below.


Reference – fixing issues with hardware and upgrade parts with my own design while making it affordable. Mostly upgrading some opamps, fine-tuning capacitors or resistors, or apply some tweaks to fix some sound signature issues.

Signature – Once I get device sounding good with reference sound performance, signature mod will take it to further levels with upgraded parts such as opamps, capacitors or resistors with some higher quality ones improving sound quality further.

Ultimate – This is for passionate audiophiles who looks for cost no objective upgrade. Using finest parts, clock modules upgrade, and intensive tweaks that for ultimate sound quality. It’s not about costly stuff together but the best that works together.


Its gettin awesome as it burn in. I cant explain it technically, but this is the best dx200 mod ive heard. Because in indonesia there are few modder that can mod daps too.
Thanks to you!

Aria Nugraha Isa


With these principles in mind, you can see up to 3 levels of my finished modification projects from the following devices. The cost is for finished product with Fidelizer Mod. You may ask about modification cost and ship your unit to apply Fidelizer Mod too.


iBasso DX200


DX200 - Mod


After DX200 launch event, a few DX90 users with Fidelizer Mod have been waiting for DX200 version too. I thought it would be easy peachy since I already modified DX90 intensively with every possible upgrade I can think of but I was so wrong.

The first issue is AMP1 module is quite small but it drives with 10V capacitors. Some even need 16V ones so what I thought it’d go well didn’t fit. It was a lot of hard work trying to fit the best possible capacitors I could find.

I also worked on a lot of challenging tasks until I did the best I could. Here’s how I concluded DX200 modification project with 3 levels mod.


Reference – Replaced stock 2 x 470uF Aluminum capacitor with a single 1,000uF capacitor improving transparency with full sound dynamics. All outputs also have soft mute circuit by-passed with high quality pure copper wire from output stage directly.

Signature – In this level, I re-designed op-amp implementation with completely different set of 6 opamps. iBasso uses 4 of dual buffer opamps and 2 of output stage opamps. With new set of opamps, DX200 can perform closer to reference digital sources.

Ultimate – This level will have all tantalum capacitors upgraded with more than 20pcs of the highest grade tantalum capacitors that can fit inside. It’s very costly but improvement is very rewarding. Some even asked to modify main DX200 body too after hearing this.

DX200 Ultimate – This is DX200 unit with ultimate modification level as my masterpiece. It comes with ultimate modification soldering over 50 points for whole DX200 unit with Fidelizer Advanced Purist ROM as below.


DX200 - Fidelizer Ultimate Mod


-Fidelizer Advanced Purist ROM
-Over 30 of capacitors upgraded with highest grade of tantalum capacitor
-Clock modules are upgraded high quality ones from Japan for processor and XMOS interface
-Re-designed op-amp implementation in AMP module with completely different set of 6 opamps
-Soft-mute circuit by-pass for purist signal transmission in AMP module
-Power capacitor in AMP module upgraded from 2x470uF to 1,000uF capacitor
-Some tweaks for power supply and internal damping in main unit

DX200 AMP module with Fidelizer Mod
Special instructions

The greatest part about DX200 Fidelizer Mod project is you can purchase modified AMP module to use with stock unit so it won’t void your warranty.

There’ll be signal’s burst when trying to play the first track similar to when you open iBasso DX50 with headphone connected in safe level so don’t worry.


Fiio X5iii


X5iii - Mod


Fiio X5iii is the most bang of the buck DAP I’ve ever seen in history of my headphile journey. Not only it offers all outputs and connections like iBasso DX200 has offered, it also come with the same dual DAC used in AK380 and Android ROM for only $400 USD!

After inspecting its hardware architecture, I found uses very good architecture design such as dual stage amplification for low-pass filter and amplification stage for balanced circuit. And it has 4 upgradeable crystal oscillators for ultimate mod level for crazy improvement!

After working on ultimate Fiio X5iii modification project for a while, I can polish this gem with 3 levels mod as below.

Reference – To compensate many features offered in unbelievable price, X5iii has some weak spots for parts quality. After listening observation, the first priority is to get Advanced ROM installed with upgraded highest grade tantalum capacitors to lift veiled and bland sound signature.

Signature – I didn’t put opamps in X5iii in reference mod because original parts are quite good and capacitors deserve more attention. With completely new set of 4 opamps and some treatments, you’ll get full sound performance capable of driving full size headphones decently.

Ultimate – X5iii has very good implementation of clock recovery. It has dedicated system clock, audio interface clock, and dual audio reference clocks upgraded in total. It will become a fearsome beast that can compete many flagship DAPs out there.

Fiio X5iii with Fidelizer Mod
ROM’s priority
Special instructions

Fiio X5iii is very affordable so it’s a device worthy of giving serious hardware upgrade to make good uses of great features to its fullest.


If you want to send your unit to us for modification, please contact [email protected] so I can arrange some good offers for you. I’ve been modding hundreds of portable products and a few highend ones too so feel free to ask anything about modification project.