Diamond DAC IV <i>plus</i>

Diamond DAC IV plus

Diamond DAC plus
“ All I can say is that Harry Connick Jr.‘s ‘A Nightingale Sang in Barclay Square‘ was absolutely transfixing through this system -- and perhaps the best digital reproduction of music I have heard. It was clearly on the same level as the previous champ, the benchmark four-box dCS Paganini stack.”
Paul Bolin - The Audio Beat, Feb 2012
“For the first time in 30 years I can listen to Jacques BREL which was impossible since CDs replaced my LPs. Thank you for this.”
Stefan - Diamond DAC IV owner, France
“The MSB stack gave me the best digital sound I've ever heard in my system. I know it's a cliche, but I was digging out music from all corners of my collection, just to hear it 'real' before the MSBs had to go back. The best recordings were a sheer pleasure to listen to. I spent many long nights going from track to track, feeling closer to the truth of each recording than I had previously imagined possible.”
Jon Iverson, Stereophile, Sept 2012
“In most ways, MSB Technology's Diamond Platinum DAC IV offers the best measured performance in the digital domain that I have encountered.”
John Atkinson, Stereophile, Sept 2012


The Diamond DAC IV plus is the reference DAC in the world today. It is flexible, upgradable, with customized features and color, and offers the most life-like sound possible. It was designed in a way that it can be used as the last component in your system before the amplifiers.  With the added convenience of having multiple digital inputs and one or more Analog inputs you can easily eliminate your preamp. You may connect your turntable through the analog input and all your digital sources directly to the DAC IV plus.   The Analog Output is volume controlled (if the optional Volume Control is installed).  

History of the DAC

The Diamond DAC IV plus is the result of wild abandon in the engineering budget. MSB had several good years of sales and we decided to invest the proceeds in finding out just how precise a DAC could be made, and whether it would be noticeable or if other system limitations would mask the improvements. The project was surprisingly successful and the outcome most gratifying. By 2007 we had a concept that was theoretically going to exceed the accuracy of our outstanding Signature DACs. In mid 2008 our first rough prototype indeed provided clear sonic improvements over the very high precision Signature DAC. In 2009 the final design was finished and the results were outstanding. Not only has the DAC still been the limiting factor, but it has been a significant limiting factor. (For more information on How DACs Work!   see this simple but accurate explanation.)

Now the Diamond DAC IV plus is not just a better DAC, it is a whole new DAC. It includes new DSP code, a new clock and new DAC modules as well as additional shielding, as the already low noise design required additional shielding as the DAC precision increased.

Let's compare the Diamond DAC to the industry standard Signature DAC.

  • 2 More Bits of Resolution -- You might think one more bit of resolution is just a little thing, but it actually doubles the size of the DAC. Our standard Platinum DAC has two 24 bit sign-magnitude DACs per channel resulting in 25 bits of resolution. The signature DAC has two 25 bit four-quadrant DACs per channel resulting in 26 bits of resolution and improved accuracy. The Diamond DAC contains four 26 bit DACs per channel for a true 27 bit resolution with greatly improved accuracy.
  • New Data Format -- The Diamond DAC has a new internal data format which results in a lower digital noise feedthrough.
  • Hand Shielding -- So here is the story with shielding. As electrical noise is minimized magnetic and temperature effects begin to dominate. The Diamond performance has reached a place where the remaining noise is magnetic in nature. Stray magnetic fields are unpredictable. Fortunately an amazing nickel alloy exists with which shunts magnetic fields about a hundred times more effectively than steel. The Diamond DAC modules themselves are made of this material, and shields are installed in the power supply, over the critical clocks, and around the volume controls. Then we set the unit up to our measurement system and begin the process of optimization. Each unit is a little different, so we work out what shields should be put where to get the best possible result. Remember that this material shunts magnetic fields so more is not always better. Just the right size shield must be put in just the right place. The result is stunning, with noise reductions of 10 or 15 dB!
  • Great Resistor Accuracy -- A precision resistor is defined as a 1% resistor, meaning its actual value falls within 1% of the nominal value. In our Diamond DAC modules, we have precise resistors made especially for us by a high-tech aerospace supplier, that are orders of magnitude more accurate. This DAC will never be mass produced and will never be affordable, but for those who want and can afford the best, MSB has set a new benchmark of performance. And on top of all that, these resistors are completely microphonic resistant (They are not sensitive to vibration).
  • Half the Output Impedance The Diamond DAC has an output impedance of 250 ohms, half that of the Signature DAC. Half the impedance means twice the output current and twice the noise immunity.
  • Greater Reliability and Temperature Insensitivity -- The Diamond DAC Motherboard, volume controls and DAC modules are coated with a low dielectric conformal coating that makes them impervious to surface contamination, moisture effects, ionic contamination and reduces sensitivity to vibration. The advanced heat pipe thermal management keeps the DAC modules at the same temperature.
  • Clock Optimization -- The Diamond DAC IV plus has the on-board clock eliminated, making full use of the new differential clocking methods employed in the Femto 140 and Galaxy Femtosecond Clocks. These clocks are optimized for use with the Diamond. As a result, no other MSB DAC modules will work in the Diamond DAC and the Diamond DAC modules cannot be used in older MSB DACs. This method results in lower jitter and higher sample rate capability.

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Diamond DAC IV plus Specifications

All 384 kHz, 64x and 128x DSD on all inputs, .DFS, .DFF and .DXF files played native
Coaxial (RCA and BNC), Toslink, Balanced AES/EBU, MSB PRO I2S (32 bit) and Balanced Analog input (<600 ohms)

RCA Outputs:
3.6V RMS (10V pp)

Balanced Outputs:
7.5V RMS (20V pp)
Output Impedance:
50 ohms at 0 dB

Volume Control:
1 dB Stepped Attenuator with 1/2 or 1/4 db steps selectable
(+9 to -69 dB)

Sampling Frequency:
1.5 MHz up to 3 MHz
64x and 128x DSD

Digital Filter:
Digital Filter Suite by MSB Technology

Slew Rate:
>1000 V/Microsecond

Settling Time:
<90 Nanoseconds

Control Features:
Aluminum Multi Remote
Display Dim Mode
Phase Invert
384 kHz Upsampling
Volume Control
Maximum Volume
Input Selection
Filter Selection Bit-Perfect Test

Upgrade Options:
Diamond Volume Control
USB2 192k input
USB2 384k input
Additional S/PDIF inputs
Pro I2S or MSB Network Input Option
Galaxy Femtosecond Clock Upgrade
iLink II Upgrade

Power Base:
Power Base Manual

About the Sound

The Diamond DAC IV plus takes your listening experience to a new high.   The lower noise and distortion allow the dynamics to come to life with more room for the music.   The top end is much more open and the bass response is more musical and more resolving.  It may be hard for owners of the Signature DACs to believe that their DAC IV can get much better, but it can.  All we can say is listening is believing.

About the Diamond 384 kHz Upsampler

The upsampling technology applied in this product is based on years of development, experimentation and speculation. It goes beyond what should matter and has really only been enabled by the continuously improving DSP technology. It offers offers several advancements:  

  • It upsamples 44.1, 88.2 and 176.4 to 352.8 kHz at a resolution of 32 bits
  • It upsamples 48, 96 and 192 to 384 kHz at a resolution of 32 bits
  • It enables the S/PDIF inputs (coaxial and balanced) to accept inputs from the standard of 192k to 384 kHz

About the Digital Filter

The Diamond DAC IV plus uses a specialized version of our own Custom 32x Digital Filter. It is built to our specifications and standards, and is designed to get the most out of the Diamond DAC modules.   

The performance of this new Digital Filter is one step above the Signature filter described by one dealer as follows:

When my client described an “uncluttered” sound, I think he is describing another commonality that people notice and talk about. They say “the music is coming from dark back grounds” or, “there is silence between the notes” . It is my contention that common digital harness (in the vocal range and above up into the harmonics), results in the human perception that there is a “continuum” or “smear” across the music that is not natural. When the digital harshness is not there, then there appears to be more discrete notes and silence between them. It is also described as organic and natural, etc. I think it crosses a threshold that makes the presentation believable and the music then gives up the emotion that the musician was trying to convey. You start to notice things like the natural sound from another room. Some other indicators in this category are: Am I thinking about the equipment or am I pulled in by the music? Am I listening to a song here and there on a disc or am I listening to more cuts, maybe whole CDs? Am I listening way too long when I should be doing other things? 
The Diamond DAC IV plus comes with a family of digital filters for you to evaluate and best match to your system. Updates to this suite of filters will be available as time goes on.   

The Digital Filter is a 32x oversampling, single stage filter with 32-bit input resolution, 80-bit computation, and 36-bit coefficients. 

About the Clock / Jitter Control 

Jitter control devices (and inputs on most DACs) normally clean up or phase lock loop the input signal from which the DAC clock is derived in an attempt to lessen the jitter of the DAC clock. The Diamond DAC IV plus does no such clean up. We actually pay no attention to the clock on the input signal.  All DAC clocks are generated by the Femto 140 clock. This extremely low jitter - less than 140 femtosecond clock sets a new industry standard. Since the input clock is no longer related to the clock of the DAC, an intelligent half-second buffer is used to maintain data synchronization. 

The Femto 140 clock is mounted in a clock socket and it can be replaced with the amazingly low jitter Galaxy Femtosecond Clock. This clock is the lowest jitter clock in the world, with less than 77 femtoseconds of jitter. This clock can be easily installed and any time. No setup is required.

Keeping the Source in Sync 

We have demonstrated very clearly that a major sonic improvement can be experienced if the source device can be clocked off the DAC clock. Our PRO I2S interface keeps our transports in sync, by sending the super low jitter clock generated in the DAC out to the transport. Some servers also support this PRO I2S interface and run in sync. Other servers provide a clock input, and the MSB Clock Adapter can be plugged into either the PRO I2S output or the older MSB network output. The BNC output is a LVDS level 512x master clock output that can be used to keep the server in sync. This is a great upgrade and has already been approved by Aurender.

About DSD playback

The DAC IV plus is able to accept DSD in all of its digital inputs, not just the USB input like most DACs. You can play .DXD, .DFF and .DFS files and can play 64x DSD and 128x DSD. Please note, you must have a 192 kHz USB input rate for 64x DSD and a 384 kHz USB input rate for 128x DSD. (You have been wondering why MSB has been shipping 384 kHz inputs for years now!) The extreme speed and resolution of our DACs provide a DSD experience unlike any in this world. You must hear it to believe it.

About the Diamond Attenuator 

Our Preamp philosophy is based on the belief that from the moment analog audio is created, every transition that is made degrades the quality. This is why we have used a passive attenuator and a single op-amp within the Diamond DAC IV plus, to achieve the simplest, shortest possible signal path with the least possible degradation of the true music.  The Volume is controlled in 1 dB steps from +9 to -69 dB.  Half or quarter db steps can be selected as a menu option.  The Volume Control is completely bypassed when at 0 dB.  It is individually shielded to provide the lowest noise floor possible, at least 5 dB lower than the Signature Volume Module.

About the Diamond Power Base 

The Diamond DAC IV plus is equipped with an outboard power supply. It has twice the power rating of the Standard Power Base. This remarkable power supply has a total of 6 separate toroidal transformers! See Power Base Comparisons

The Power Base includes a positive and negative analog supply and a digital supply to run all the digital processors. But it also contains an entirely separate extra clean digital supply to run the sensitive digital clocking circuits on the DAC modules themselves. Each of these Diamond supplies is tightly regulated, filtered and shielded in the box, so no noise is introduced into the DAC chassis. Each transformer is hand shielded and extra capacitance has been added to provide a little extra punch.

The analog supplies are quite remarkable in the Diamond Supply. Rather than the high-quality rectifiers used in our other supplies, the Diamond uses super fast Silicon Carbide Schottky Diodes. These vacuum tube like devices turn on and off instantly with zero reverse recovery current.

This Power Base can also power a transport. A 12 V DC supply is included. These supplies are completely independent and their combination do not degrade performance.

An optional front panel control can also be provided. This option adds a power switch to the front panel and remote control.


This is the Diamond Power Base. See Performance Chart