MSB Technology M500 Mono Amplifiers review part one

As a great introduction and preface to the MSB Technology M500 Mono Amplifiers review, I asked the CEO and designer Jonathan Gullman of MSB Technology a few questions about their technical tour de force flagship solid-state monoblock power amplifiers. There are also some exclusive photos that give an insight into the production of the M500, kindly provided by MSB Product Designer Daniel Gullman.

- How did the idea for the MSB amplifiers come about? 

We’ve been making amplifiers for years. We originally started making them  because the market lacked an amplifier refined enough to show off  the full potential of our own DACs. So, after years of development, the M500/S500 amplifier was born. 

- How  do they compare technically and sonically to the previous amps?

The M500/S500 amplifiers are an all new design.. We started with fresh design parameters and a new set of requirements. Our goal was to build an amplifier that had the dynamic range and performance necessary for what the Select DAC can do. Our new M500’s amplifiers have a blacker background, more controlled bass, and overall, a lot more detail and dynamics while sounding natural. With the new amplifiers, there’s no fatigue when listing--even at very high levels. The first time we heard the M500 amplifiers we felt like we were  listening to the Select DAC for the first time... 

- What’s   the biggest difference between this model and the previous iteration? 

The biggest difference technically is the input stage. With a matched impedance mode that scales to the needs of our  DACs, you get a huge leap in performance. By having a matched impedance input, we get maximum signal transfer from the DAC, allowing us to remove the first part of the input stage. All in all,  the most limiting part of an amplifier--in regards to dynamic range and performance--are eliminated.

- What’s the Select/Reference DAC direct driving compatibility? 

The M500/S500 amplifiers have three input gain modes. 75Ω (To be used with the Premier, Reference, and Select DAC), 300Ω (To be used with the Discrete DAC), and 1.2kΩ. The M500/S500 can be used with any external preamp, assuming the preamp has the power necessary to drive the rugged input stage. From our research, almost every preamp on the market will easily drive one of these three input impedances.

- Are they heavily biased towards Class A?

The S500/M500 amplifiers are heavily biased towards class A in the output stage. The input stage is a full class A design. 

- What are the noise/measurements/technical specs highlights?

The wonderful  thing about the M500/S500 is the amplifier has exceptionally high power while maintaining very low noise. You get the power of a high power amplifier while keeping the low noise of a much smaller amplifier. With the high power and low noise, you can play the music loud while keeping the detail and dynamics of the original recording. You don’t lose the micro details by driving the speaker hard.

The amplifier is a fully differential balanced design. The amplifier has no global or local negative feedback. Every part selection is picked for extra long life. For more information about our technical specs, visit our website or see below at technical specifications...

- Why the horizontal design?

It’s the most thermally efficient shape while being the most accepted form factor in listening rooms. . Doubling the height of a heatsink doesn’t add much cooling capacity as increasing the depth or length. What emerged was a product that’s as efficient as it is beautiful to look at. 

- Tell us some insights about the new chassis design.

This amplifier was truly an all out design. We targeted  the results and performance we wanted, then specced the size, transformer, and heatsink area that would get us there... With all new architecture and a clean slate, we were able to implement everything we’ve learned previously  to push the boundaries of what’s possible.

- What’s the level of technology compared to the Select DAC?

We use modern bi-polar transistors. The technology is entirely  different; the amplifier is a pure analog design while  the Select DAC is mostly a digital design.

- What’s  the biggest advancement compared to  what’s currently out there?

The single biggest advancement is the new input stage design. This design is what gives the amplifiers the low noise and incredible dynamic range of the amplifier. It’s a totally unique design that hasn’t been used in the industry before.

- Who  do you see as potential customers or who already have them?

Our current primary customers are owners of our DACs looking for another performance leap with their system.

-  How was the amp gain chosen?

We had one goal: for our DACs to drive the amplifier to its limits. The different gain settings are for a system matching. You can adjust the gain of the amplifier to match your speakers and room. There’s no reason to have more gain in the amplifier than is necessary. This way, the full output of the DAC/Preamp can be sent directly to the amplifier. There’s no point in turning the volume down by an extra 12dB on the DAC/Preamp if you’re going to  turn it up again with too much gain.

- What are the proprietary materials and approaches?

One of our unique approaches is the modular design. This modular design improves reliability and allows each stage to be tested independently before final assembly. The internal modular concept allows for the possibility of future upgrades. Thermal management is tightly controlled with the use of large heatpipes to maintain a low thermal gradient on the devices.

- What’s the purity of signal flow?

When the M500/S500 is used with our current DACs, there’s only one gain stage in the entire signal path. This is the cleanest signal path possible. By only having one gain stage, you’re not amplifying the distortion and noise repeatedly. . By keeping the signal path short and eliminating the extra gain stages, we’re eliminating the added noise and distortion that would be there if we had many gain stages.

-  What’s special about your transformers?

The M500/S500 amplifiers have two low noise transformers with extra shielding. One of the transformers is for our unique input stage and the second transformer is for the output stage. In addition to two transformers, our power supply filtering capacitors give over 1,000,000uF of capacitance.

- To what degree are your products built in the USA?

We pride ourselves with in-house design, manufacturing, and assembly. It’s at the core of who we are. Starting in our CNC machine shop, we create more than 20 chassis components for each amplifier. Hand populated circuit boards with custom cabling creates a tested and tuned work of art.

-What’s unique about your heatsinks? 

The 500 series amplifier is designed and lovingly crafted in our factory based in California. Each of the heatsinks start out as a 51lb aluminum block before sixty percent is removed over eight hours of machining, resulting in 17.5 lbs of refined aluminum. This high efficiency design provides a surface area of over 10,000 sq in per amplifier. What’s more–the fin thickness is slightly varied to help reduce resonances and ringing in the heatsinks, while multiple high power heat pipes distribute heat evenly for optimal thermal and electrical performance.

Please elaborate on the design of the “golden” cage we see on your products.

Building the 500 series amplifiers with a core enclosure greatly improved their reliability and performance. Upon completion, the cores are rigorously tested and stocked for orders, ensuring the highest quality product is ready at a moment’s notice. With this segmentation, your system is optimized for performance and resilience.

- trigger in system…

The 12V trigger system allows for the M500/S500 to be connected with the DAC and transport in the system, making it easy  for the entire system to be turned on/off with a single button. If the M500’s are used, when one amp is put into standby, the other will follow and automatically go into standby. 

There’s  also an adjustable power-up delay;  if both amplifiers are on the same circuit, the inrush current will be controlled, preventing a mains breaker from tripping. More info can be found here:


The MSB Technology Corporation M500 monoblock amplifiers have already been awarded "Best of 2019" by Mono & Stereo, but this is only a start. 

As can be seen from the above questionnaire, the M500 monoblocks were developed from scratch with a clear objective: To deliver amplifiers that are not only worthy of the MSB Select DAC, but a top-class amplifier to be a potent partner for the whole range of MSB Technology DACs.

As a result of careful research and development, the S500 and S202 stereo amplifiers have recently been introduced with the same technological level. 

The M500 amplifiers from MSB Technology are far more than just worthy successors of the previous generation of electronics. These amplifiers set new standards with impeccable design and acoustic characteristics and performance at the highest level. 

Stay tuned for part two, in which I will focus on particular sonic qualities and virtues of these state of the art technical over achievements.•

Matej Isak


- (Pair) MSRP $118,500.00


Continuous Power Output (8Ω) less than 1% distortion
500 W
Continuous Power Output (4Ω) less than 1% distortion
1000 W
Frequency Response (20 to 20kHz)
Signal to Noise (20 to 22kHz)
more than 136dB (more than 140dBA)
Equivalent Input Noise (22kHz BW)
Low Gain (75Ω source impedance)
Medium Gain (75Ω source impedance)
High Gain (75Ω source impedance)
Input Impedance (User Selectable)
75Ω / 300Ω / 1.2kΩ
Output Impedance (20 to 20kHz)


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