Review of TRN Black Pearl: Portable USB DAC & Headphone Amp with 10-band PEQ

[staticV3]

@jkim i have a question. sorry i dont know how to read these graphs. all i understand is the max power output of trn black pearl is around 100mw per channel, almost no difference in unbalanced and balanced?

With high impedance headphones, the Black Pearl can play about 50% louder using Balanced output.

The lower the headphone impedance gets, the smaller this advantage gets.

At 32Ω, Balanced output can play just 30% louder and at 16Ω and below, there is no longer any difference in maximum output.

 

[pavv3l]

Hi, I recently bought the TRN Black Pearl. Is it normal that when I plug in my iems(Fiio FH3) hear crackling / clicking sounds? I also have the JCALLY M20 Max and I don’t have this issue there.

 

[Lesmodio]

Hello! If you'd allow me to know, wanted to ask how you perform measurements like your TRN Blackpearl Review.

I wanted to do the same thing but for YouTube as barely anyone, if any, does anything similar. It's mostly subjective he says, she says bs statements on YouTube's end where any objective measurements are lacking.

I don't mean to offend or anything if I came off that way and I respect your response if this is something you don't want to share.

Thank you!

 

[staticV3]

Hello! If you'd allow me to know, wanted to ask how you perform measurements like your TRN Blackpearl Review.

I wanted to do the same thing but for YouTube as barely anyone, if any, does anything similar. It's mostly subjective he says, she says bs statements on YouTube's end where any objective measurements are lacking.

I don't mean to offend or anything if I came off that way and I respect your response if this is something you don't want to share.

Thank you!

Hi @Lesmodio! Welcome to ASR.

The measurement setup is listed at the beginning of the review:

Measurement Setup

• AD converter: E1DA Cosmos ADCiso Grade A in Mono Mode, and Cosmos Scaler as a buffer.
• Software: Room EQ Wizard (v5.40 beta 85 and 95).

The basic steps are:
-You plug the DUT and ADC into a computer via USB
-connect the DUT's output to the ADC's input
-launch the measurement software (REW, RMAA, ARTA, Multitone, ...) and configure I/O
-start the signal generator within the measurement software and record the DUT's output.

Depending on what metric you're trying to measure, you would also connect a dummy load between DUT and ADC.

 

[KDRN]

re-reverse-engineered the black pearl's driver to windows written in python, gotten most of it working. theres no PEQ yet though. i may or may not include it. idk, gonatake a while for me to figure out

source: https://github.com/cheesyserg/pyBlackPearl

edit: Big ui Improvements and added PEQ

PEQ Page

 

[Deckard01]

Can be added more than 10 bands for PEQ? Thanks

 

[KDRN]

Can be added more than 10 bands for PEQ? Thanks

not really, it would require firmware modification. and even if i could. its most probably a hardware limitation. s

 

[KDRN]

re-reverse-engineered the black pearl's driver to windows written in python, gotten most of it working. theres no PEQ yet though. i may or may not include it. idk, gonatake a while for me to figure out

source: https://github.com/cheesyserg/pyBlackPearl

View attachment 530288

edit: Big ui Improvements and added PEQ
View attachment 530328

PEQ Page
View attachment 530327

All of it's Functions are all reverse engineered

Features:
- hardware Info
- MIC Gain
- Channel Balance
- DAC Settings

• Digital Filters
• Gain
• Amp topology

- factory reset

- PEQ (thank you to potatosalad775)

• Options for Grid and List view

(clickable labels to hide them)
- import your targets, iem/headphones measurements for easy EQ'ing
- interactive PEQ. you can select a point. drag it around (play around with the scroll wheel to change the q factor) all in real time

 

[blanket]

All of it's Functions are all reverse engineered

Features:
- hardware Info
- MIC Gain
- Channel Balance
- DAC Settings

• Digital Filters
• Gain
• Amp topology

- factory reset

View attachment 530518


- PEQ (thank you to potatosalad775)

• Options for Grid and List view

View attachment 530516View attachment 530517
(clickable labels to hide them)
- import your targets, iem/headphones measurements for easy EQ'ing
- interactive PEQ. you can select a point. drag it around (play around with the scroll wheel to change the q factor) all in real time

hello. somehow after using reset device. my headphone FiiO JT7 has much lower volume. windows volume before 8. after reset must be 50

 

[KDRN]

lower volume

yeah it is expected, due to how TTGK/TRN programmed the firmware when changing the PRE-AMP in the PEQ causes the independant volume to reset

the reason when you reset the device in my driver. it "flatten" everything in the DSP, including the pre-amp. and of course due to the way the firmware behaves with the Pre-amp, it turnes it back to 50% volume

you can test it too in the official walkplay driver

edit: i have located the volume registries. i am making a hotfix soon. to address the issue

the way this dac handles volume and pre-amping is very bizarre. might give a report explaining how it works

 

[NEO Dan]

Dumb question: Are the balanced headphone 4.4mm outputs suitable to drive balanced XLR inputs on an integrated amp?

Or should I stick with the standard 3.5mm to RCA/unbalanced type connections?

 

[carlcamper]

I wish they implement a Disable DRE button, as I still hear distortion even with the optimize DRE option…

 

[Bewitched Bolt]

All of it's Functions are all reverse engineered

Features:
- hardware Info
- MIC Gain
- Channel Balance
- DAC Settings

• Digital Filters
• Gain
• Amp topology

- factory reset

View attachment 530518


- PEQ (thank you to potatosalad775)

• Options for Grid and List view

View attachment 530516View attachment 530517
(clickable labels to hide them)
- import your targets, iem/headphones measurements for easy EQ'ing
- interactive PEQ. you can select a point. drag it around (play around with the scroll wheel to change the q factor) all in real time

Hello, I tested the app and it works great on my end. I also put together a slightly cleaner setup with my modified .bat files and attached them in a zip.

For reference, my build comes out at 45.4 MB, while the released TRN_Black_Pearl_Driver.exe is 64.0 MB. Mine seems a bit smaller, but it runs fine.

Most importantly, huge respect and thanks for your incredible reverse engineering work: really impressive stuff.

Thanks again for sharing the project!

 

[KDRN]

Hello, I tested the app and it works great on my end. I also put together a slightly cleaner setup with my modified .bat files and attached them in a zip.

For reference, my build comes out at 45.4 MB, while the released TRN_Black_Pearl_Driver.exe is 64.0 MB. Mine seems a bit smaller, but it runs fine.

Most importantly, huge respect and thanks for your incredible reverse engineering work: really impressive stuff.

Thanks again for sharing the project!

What version of the firmware you have on the black pearl? I'm wondering if this works with versions of the black pearl with 0.6 firmware

 

[Bewitched Bolt]

What version of the firmware you have on the black pearl? I'm wondering if this works with versions of the black pearl with 0.6 firmware

My Black Pearl is on firmware 0.6, and the modified version works correctly with it.

I’m attaching a summary of the Windows DPI / Zenbook multi-monitor rendering issue, along with my current modified app.py. The behavior changes depending on whether the Zenbook internal display is enabled, so this may be related to Qt/PySide6 per-monitor DPI handling rather than layout alone.

With this modified version, the interface now displays fully on my side, without clipped text, cut-off labels, or truncated fields. The main remaining issue seems to be display-dependent rendering behavior related to the Zenbook / external monitor DPI setup, rather than basic layout breakage.

 

[staticV3]

Dumb question: Are the balanced headphone 4.4mm outputs suitable to drive balanced XLR inputs on an integrated amp?

Only if the 4.4mm pin 5 (Sleeve) is connected to USB GND.

You can test that with a basic multimeter.

 

[KDRN]

My Black Pearl is on firmware 0.6, and the modified version works correctly with it.

thank you for the Confirmation, glad to hear it works with 0.6 firmware

With this modified version, the interface now displays fully on my side, without clipped text, cut-off labels, or truncated fields. The main remaining issue seems to be display-dependent rendering behavior related to the Zenbook / external monitor DPI setup, rather than basic layout breakage.

for this, i have addressed it in the latest release. thank you for the feedback and suggestions!

 

[ziggurcat]

thank you for the Confirmation, glad to hear it works with 0.6 firmware



for this, i have addressed it in the latest release. thank you for the feedback and suggestions!

Do you have a version of this that will work on MacOS?

 

[KDRN]

ported the driver to android. it is "functionally complete"

 

[ddmareo]

is there any way to update firmware on windows guys? i don’t have an android phone