New MSB Technology PRO USB review part one

One of the real luxuries of my job is the ability to explore the new existing product before the product launch. This is no different to other industries. The automotive branch is among the first that comes to mind. I've been closely connected to digital audio from 80's and technically inclined to anything that contributes to the shifting up the audio performance and this prolonged journey is getting more and more interesting and intriguing.

Daniel and Jonathan as well as the complete MSB Technology team seems to never rest. A lot is happening under the radar at their headquarters and the latest product brings something very interesting to their product portfolio.

The all new MSB Technology Pro USB is a USB to ProISL adapter, that allows you to play music from a computer or server via USB into any of the latest MSB Technology DACs (Discrete, Premier, Reference, and Select) through the isolated, clock synced ProISL interface. Pro USB computer setup and operation is the same as other MSB USB inputs.


- 768kHz PCM Playback
- 8x DSD support*
- Full MQA decoding*
- 100% Electrical isolation between the DAC and server/computer
- Uses the audio clock from the DAC
- Supports ProISL cable lengths up to 1km without any loss
- Requires ProISL Input module in the DAC
- Will only work with current DACs (Discrete, Premier, Reference, and Select)
- *8x DSD and MQA support require firmware updates in the DAC


The Pro USB is one part of a multi-part low noise USB solution. It converts the USB signal from your computer into MSB’s proven proprietary Pro ISL format. The full connection requires the following:

- USB media device
- Current generation MSB DAC
- Pro ISL Input Module
- Pro ISL cable
- Pro USB


Installing and using the Pro USB is no brainer. What you need is USB media device that connect to the current generation MSB DAC through the Pro ISL cable going into Pro ISL Input Module in the DAC.

Basically a Pro USB a low noise USB module that converts the USB signal from computer, music server or music network player into the MSB’s proven proprietary Pro ISL format.

"The benefits of this system are mainly be for isolation of noisy computer solutions.  Using any length (3ft to 50ft+) Pro ISL Cable, the computer/server can be removed from the audio system. This removes the need for network cables in the system setup."


Before emails starts to purr in with the subject title: "There is no difference" with cables and protocols do take a deep breath and focus your energy anywhere else. 

The sole modus operandi of yours truly is the exploration and discovery of the products (technologies) that can push the performance up on the ladder of state of the art realms. It took quite some time and efforts to bring my reference system up to the level where any new product introduction would be of instant recognition. 

I've connected the MSB Technology Pro USB to three of my computers and the Lumin T2 under the review. Lurking into my listening notes highlighted one repeated remark. Organic flow! Now, there are tons of other attributes one would associate with the any digital product or accessory like speed, transparency etc. The word organic is surely not on the top of the expected list. Yet... The proof is in the pudding...


Here is a small portion of insights music references that easily revealed what MSB Technology Pro USB brings to the performance...

Contemporary Chamber Ensemble, Arthur Weisberg - Spectrum: New American Music might be a bit Avantgarde, but it's a reference track capable revealing so much with it's utterly dense nature.

An opening track Quartet, for tenor saxophone, trumpet, percussion & piano, C. 122: Lento is in my "stress" folder and on my subconscious's "hard drive", that was overwritten with this probably hounders times if not more:). The very first change I've noticed was the above mention organic (less fatigue) music rendition. It's never exactly easy to translate the impressions to the paper (yes, even from listening notes :-) ). Saying it out loud that differences are happening on the minuscule, probably quantum level will surely blew few mind roof tops off. Then again, I'm not here to please, but report right :).

The organic impact can deciphered throughout many parts and parcels including decays, delays, acoustical anchor points, uncluttered harmonic fusion, timbral correctness etc.

With MSB Technology Pro USB in action Spectrum: New American Music sounded more three dimensional, projecting the more dramatic sonic scenic impact. The key point attribute to the sheer sense of drama is believability of portraying much more viable aural illusion. And this is exactly what Pro USB delivered. Not a small feat by any means, especially for the digital playback.

Those of you who were ever involved with sound design or synthesisers surely know about ADSR (attack, decay, sustain release). In sound and music, an envelope determine how a sound transforms over time. Envelopes can also relate to sonic gradients like such as pitch, amplitude etc. Any string instrument in orchestra when struck and prolonged by finger press manifest an instant sonic imprint that eventually fade out to the complete silence in due time. This is where my further listening notes pointed at. The more viable and vivid decay and delay times in space. This projected greater real world density, that was evident also with increased number of acoustic anchor points, that's crucial in recreation of the aural atmosphere and sense of space.

If we're considering that also the timbre is closely connected with an envelope, then any upgrades in signal transfer affect  how the sound varies over time. This might be one of the key points connected with the initial organic impact described above. Our human listening mechanism is highly perceptive about tinniest spectral changes and especially with the instruments's timber this plays a key role in a more believable projection of the real world instruments.

This was further confirmed with Sanford Sylvan, Boston Modern Orchestra Project, Gil Rose, Sanford Sylvan / Boston Modern Orchestra Project / Gil Rose - Charles Fussell: Wilde. An enormous dynamic music's motion with wide palette of sonic complexity and density. Pro USB has delivered increased image clarity, more coherency. This again can easily be connected to addressing of the phase and spatial information. The increased level of details gave some more verisimilitude, that was easily noticeable. Not exactly the subtle, but evolutional step up!


Only in recent years our niche industry and audience started to take more seriously the dealings with the digital signal transmission and what affects it. We've been trying to amend all sorts of analog noises, RFI and other sources of signal disturbances for decades. The state of the art digital audio transmission is finally picking up and MSB Technology Pro USB is without the doubt an exemplary product of push forward mentality.

As I've described its hard to pin-point the exact reason for Pro USB positive shift in performance, but there is no going back once the ears and mind are "updated" with what the Pro USB adds to performance.

If you own one of the latest MSB Technology DACs it's more than worthy to try out Pro USB. In my reference system, the difference was really beyond subtle.

I'll write up in the part two and add more music references. Stay tuned.

Matej Isak


Stand Alone Pro USB converter

This option is for users who already have a Pro ISL input module.


- 1 Pro USB Module
- MSRP $990.00

Pro USB Starter Pack

This option is for users who do not have a Pro ISL input module.


- 1 Pro USB Module
- 1 Pro ISL Input (Discrete, Premier, Reference, or Select DAC compatible)
- 1 Pro ISL cable (3ft standard length)
- MSRP $1980.00


Pro USB Specs

USB Connection Format: Type B Powered USB
Power Consumption: 400mA Constant Draw
Supported Formats:
- 768kHz PCM Playback
- 8x DSD support
- Full MQA decoding

Pro ISL Fiber Cable:

- Cable Type: Customized LC Duplex Single Mode Fiber Patch Cable
- Connectors: LC UPC
- Cable length: Greater than 1 km


MSB Technology Corp
625 Main St.
Watsonville CA, 95076

Sales contact:

National Sales Manager, Vince Galbo.
Phone: (716) 688-3527
European Sales Manager, Frank Vermeylen.
Phone: +32 472 42 5775
Factory Contact (for vendors):
Phone: (831) 662-2800

Email: Form