Dual Mono D-A Converter
User Guide

Conformity

EMC / EMI
This equipment has been tested and found to comply with the limits for a Class B digital device, pursuant to part 15 of the FCC rules. These limits are designed to provide reasonable protection against harmful interference in residential installations.
Canadian Customers
This Class B digital apparatus complies with Canadian ICES-003. Cet appareil numerous de la classe B est conforme a la norme NMB-003 du Canada.

Certificate Of Conformity
Bricasti Design, 123 Fells Ave., Medford MA, USA, hereby declares on its own responsibility the following products:
M1 –Dual Channel A/D Converter
-that is covered by this certificate and marked with the CE-label conforms to the following standards:
EN 60065 Safety requirements for mains operated electronic and related apparatus for household and general use
EN 55103-1 Product family standard for audio, video, audiovisual and entertainment lighting control apparatus for professional use. Part 1: Emission.
EN 55103-2 Product family standard for audio, video, audiovisual and entertainment lighting control apparatus for professional use. Part 2: Immunity.
With reference to the regulations in the following directives: 73/23/EEC, 89/336/EEC
January 2020
Brian S Zolner
President

Introduction

This is a preliminary edition of the M1 user guide covering theory of design and setup and use. In the future you can always find the latest version available at our web site www.bricasti.com.
Congratulations on the purchase of your new M1 Dual Mono Digital to Analog Converter. We at Bricasti Design have set out to design the world’s best digital processors and to offer the finest products made for the professional and consumer audio markets.

Product Overview

The M1digtal to analog converter is a dual mono design; there are 2 completely isolated channels, a left and right, each with its own dedicated linear power supply, D/A converter, DDS clocking, and analog circuitry. This design insures that analog cross talk is virtually non existent, that the necessary power requirements for each channel are well met and isolated from each other and the digital processing is isolated, having its own power supply. With our twin DAC design, the dynamic range for each channel is  optimized by using
the stereo ADI 1955 D/A converter in a mono configuration, plus clocking is for each channel done directly at each DAC with a technique called DDS (direct digital  synthesis) which takes clock induced jitter to immeasurable levels.

Build Quality
The M1 is robustly constructed of milled and CNC machined aluminum sections. There is no typical bent metal chassis and top cover found on most products. All sections of the construction, the front and rear panels, the sides and even the bottom and top plates start out as solid blocks of aluminum which are precision machined to shape, with exact tolerances for a perfect fit. These parts are then anodized and the text and markings are laser etched for a clean and enduring look.
The Sound
The intention of the M1 is to provide a state of the art, Digital to Analog converter, utilizing the best designs and materials that can be found today. The D/A converter is a very critical part of the digital audio chain, after all you have to convert it to analog to hear it, and we feel this should be a true as possible in its reconstruction of the original signal. The sound of the M1 is intended to be transparent and revealing, and fully dynamic. This in part is made possible by the lowering the jitter to extremely low levels, providing a pure digital signal chain with sample rate converters, superior digital filter design, coupled to a fast transparent analog signal path with a discreet analog output section and plenty of good clean linear power for optimum analog performance.
Many hours of listening were done to tune the M1 to an exacting sound, with all types of music, and with extensive testing done in the studio and in the home. We hope you find the M1 to be pleasing and enjoyable to hear and use in the home, or as a precision tool for high level reference monitoring for the professional.

Unpacking and Inspection

After unpacking the M1 save all packing materials in the event you ever need to ship the unit. Thoroughly inspect the M1 and packing materials for any signs of damage in shipment. Report any damage to the carrier at once.
Precautions
The Bricasti Design M1 is a rugged device with extensive electrical protection. However, reasonable precautions applicable to any piece of audio equipment should be observed.

• Always use the correct AC line voltage as set by the manufacturer. Refer to the power requirements section of the manual and adhere to any power indications on the rear or bottom of the chassis . Using the incorrect AC line voltage can cause damage to your M1, so please check this carefully before applying power.
• Do not install the M1 in an unventilated rack or directly above any heat-producing equipment like power amps, tube preamps etc. Maximum ambient operating temperature is 40 C. Exceeding the maximum ambient temperature may cause the M1 to enter thermal shutdown and stop processing sound as a safety precaution, and may cause damage to the internal processors and components.
• Care should be taken when connecting the M1 to a computer via the USB. The M1s USB subsection receives its power from the computer and it is advisable that you power the computer off before changing USB cables to prevent possible damage from inrush current from the computers 5V supply to the M1s USB section.
• To prevent fire or shock hazard, do not expose the M1 to rain or moisture.

Notices
In the interest of continued product development, Bricasti Design reserves the right to make improvements to this manual and the product it describes at any time and without notice.
Copyright 2011
Bricasti Design LTD
123 Fells Ave
Medford MA 01255 USA
bricasti.com
All Rights Reserved
This publication is protected by copyright and all rights are reserved.

Important Safety Instructions

Notice!

• Read these instructions.
• Keep these instructions.
• Heed all warnings.
• Follow these instructions.
• Do not use this apparatus near water.
• Clean only with dry cloth.
• Do not block ventilation openings; install in accordance with manufacturer’s instructions.
• Do not install near any heat sources such as radiators, heat registers, stoves, or other apparatus (including amplifiers, pre amps) that produce heat.
• Do not defeat the safety purpose of the polarized or grounded type plug. A polarized plug has two blades with one wider than the other. A grounding type plug has two blades and a third grounding prong. The wide blade and prong are for your safety. If the provided plug does not fit in your outlet, consult an electrician for replacement of the obsolete outlet.
• Protect power cord from being walked on or pinched.
• Use only attachments/accessories specified by the manufacturer.
• Unplug this apparatus during lightning storms or when unused for long periods of time.
• Refer all servicing to qualified service personnel. Service is required when the apparatus has been damaged in any way, such as by being dropped, exposed to rain, liquid being spilled on it, or otherwise does not operate normally.

Service

•  There are no user serviceable parts inside.
• All service must be performed by qualified personnel.

Warning!

• To reduce the risk of fire or electrical shock do not expose this equipment to dripping or splashing water and ensure that no objects such as vases are placed on the equipment.
• This apparatus must be earthed.
• This equipment requires the correct AC line voltage as set by the manufacture and is not auto sensing or scaling.
• Use a three-wire grounding-type line cord like the one supplied with this product.
• Be aware that different operating voltages require the use of different types of line cords and attachment plugs.
• Check the voltage in your area and use the correct type. See table below:

unswitched outlet plugs

• This equipment should be installed near the socket outlet and disconnection of the device should be easily accessible.
• To completely disconnect from AC mains, disconnect the power supply cord from the AC receptacle.
• Do not install in a confined space.
• Do not open the unit -risk of electrical shock inside.

Caution

• You are cautioned that any change or modification not expressly approved inthis manual could void your authority operate this equipment.

Design Overview

There are 4 basic sections to the M1, the digital input section, and the left and right analog sections, and the front panel:
Digital Input Section:
This is located in the center of the unit, provides 5 transformer isolated digital inputs, are selectable from the front panel, and has its own linear power supply. This means that the digital processing section is isolated from the analog sections, providing excellent low noise performance and eliminates digital noise from entering the analog chain via the power supplies and ground plane. This section features an Analog Devices Sharc DSP that is used to run the front panel and general operations of the M1, to control and synchronize the DDS clocking on each channel, and to provide a selection of our own over sampled antialiasing filters.

Analog Output Sections, Left and Right:
These are identical and are laid out as mirror images of each other to fit with the over all symmetrical industrial design of the M1. Both are independently powered by their  own linear power supply insuring clean double regulated low ripple power and isolation from any digital switching noise from the digital supply.

Each section has its own Analog Devices 1955 DAC, coupled with a dedicated DDS clocking circuit located millimeters away from the DAC, assuring extremely low jitter and  minimal trace length for the clock signal. As both boards have their own clock, precise clock synchronization of the left and right boards is handled by the Sharc DSP on the main digital processing board.

The next stage, at the analog out of the converter for the gain and filter sections there is a fully differential analog design with fast high slew rate analog operational amps. This is followed by 2 transistor designed output buffer sections, balanced and unbalanced, each separately buffered and isolated. The balanced output level as shipped is set with a fixed resistor at +13.5 dbm. For custom level matching, an internal the jumper on the board can be moved to engage a precision adjustable potentiometer. This adjustment is set from the rear panel screw near the XLR connector. When the potentiometer feature is engaged the level is adjustable from +8 to +23 dbm and can be referenced to a fraction of a db to match any setup. This level is set as a default +10 dbm at the factory so when the jumper is engaged this will be the new level. Please contact us for detailed instructions on how to change and set these levels. The unbalanced is set to normal hi fi levels of 2V RMS (+8dbm) by precision resistor values on the board.
Typical circuit boards in most products are made from FR4 fiber glass. But, the M1s analog boards are made from a ceramic substrate used in RF applications. This material  has excellent very high frequency impedance characteristics, and was chosen for use in the M1 to yield an open and clear sound and to allow its very high slew rate audio circuit design to perform at optimal levels.

Trigger In/Out:
On the rear panel the M1 has a stereo connector (Tip/Ring/Sleeve) for triggering the M1 into standby mode from an external device like a preamp and for optional external remote control with the M1 remote. NOTE the tip is connected is return ground, the Ring is the input + voltage. The M1 will go into standby when it has a positive 5V or 12V DC voltage at the ring. The function of the trigger jack at the rear panel is set in the status menu. NOTE! If the function of the trigger is set to CtlTRIG, and there is no oltage present at the trigger in, the M1 will go into standby mode. If this occurs make a long press on the standby button to invert the phase of the trigger signal.

Front Panel Overview
The front panel has a large, simple, easy to read display, an encoder for adjusting and selecting settings, 6 keys that are labeled for their use, and a power stand-by switch that will set the M1 in to low power mode and mute the outputs.

Rear Panel Overview
Looking at the rear you will find on the left and right side the analog output sections, each with its own balanced and unbalanced outputs, and level adjustment set screw. In the center input section are the 5 digital audio inputs, AES, SPDIF 1 and 2, Toslink, and USB. There is a small jack below the circuit breaker and this is for a trigger input to remotely place the M1 in standby from a pre amp or other system controller. The main power on/off switch and AC fuse are at the rear, note that the front panel and the trigger in are used to set the M1 to stand by. Full power on off is done from the rear panel.

Setup and Operation

AC power and the M1
The AC power is connected at the rear of the unit; the filtered AC inlet also has the main power on-off switch. This filtered inlet helps provide clean AC power to the M1’s power supplies and as well will prevent any digital noise from the M1s digital processing section from going back out the AC inlet to contaminate the mains. Take note that because the M1 utilizes linear power supplies care should be taken to use only the power range indicated on the unit, other wise damage can occur to the power supplies and other circuits in the M1. Please note and adhere to any voltage indications on the outer box, rear panel or chassis all of which will indicate how the M1 is set at manufacture.

Note that the main AC power switch is at the rear and the front panel switch is a low power consumption stand by switch. For complete power on of you must cut power with the rear panel switch or from an external AC power on off switch that may be used to power other devices in your setup.

Quick Connecting the M1 and power up
When you first power up the M1 it will come up in AES input, you can then using the adjust knob select the desired input.
Operating the M1
There are 6 front panel keys, input, filter, status, level, display and enter

• Input select
  When the M1 first powers on, it will default to the STATUS page display on the front panel. This will show what input is selected and the sample rate. Pressing the INPUT key will take you to input select mode. If you turn the knob you will scroll though all inputs and auto select each one with an audible click of the mute relays.

Inputs are:

• 1 AES: Selects the XLR connector

• 2 SPDIF: Selects the RCA connector

• 3 EIAJ: Selects the Toslink connector

• 4 USB: Selects the USB connector .

• 5 SPDIF 2: Selects the BNC connector

•  # 6 LAN: ( optional )

Status
The status display key has 8 levels in the menu. On first press or on power up it will display input type selected and the running sample rate. For PCM this will range from 44.1k to 384K and DSD will simply display DSD for DSD 64fs or DSD 2 for 128fs.
Temp Monitor: Displays the internal temperature at the digital processing board, there are no adjustments as this is just a monitor of internal temps.
Version: Displays the software version.
Clock Sync: This sets the function of the M1 DDS clock to a fine a very accurate tracking to a wider more forgiving one of the incoming master clock.
Trigger function: This sets the function of the trigger in jack at the rear of the M1. This is not for remote on off functions. Care must be taken when changing these parameters.
CtlREMOT: Sets the function of the trigger in for remote control from and external source, in this mode M1’s IR remote will not function in this mode.
CtlTRIGI: Sets the function of M1s as a trigger IN to be triggered and out of standby from another device like a pre amp; the M1s remote will function in this mode.
CtlTRIGO: Sets the M1 to send a trigger OUT voltage to another device to trigger it on or in and out of standby; the M1s front panel IR remote will function in this mode.
If the function of the trigger is set to CtlTRIG, and there is no external voltage present , the M1 will go into standby mode. If this occurs make a long press on the standby button to invert the phase of the trigger signal or a + voltage must be applied to the trigger in SLEEVE at the rear panel. A long press on the standby will invert how the M1 reacts to a trigger signal; goes into or out of standby
Phase: The M1 is absolute phase meaning that it does not invert the phase. With this adjustment you can invert the phase of the signal as some recordings may benefit by this change or correction. Normal setting is NON inverted.
Remote ON/OFF: Disables the IR for the M1 remote.

• Display
  This allows you to set the display intensity in 3 levels and set it to a sleep or off mode. Press DISPAY anduse the knob to select the brightness of the display, press ENTER to set it. Selecting OFF will shut the display off after a 20 sec time out, leaving one LED dimly lit. Pressing any front panel key will wake up the display so you can make adjustments to the M1, and then after a short period of no use, it will go to off mode again.

• Filter
  Pressing FILTER will take you to the filters select mode. Here you can select 9 different types of linear phase digital over sampling filters, labeled Linear 0-8 and 6 minimum phase filters labeled Minimum 0-5 Press FILTER, turn the knob to change, press ENTER to select. These are loaded immediately with very little delay, so the change is very fast, allowing for quick comparisons of their effect on the sound.

• Level
  The M1 USB includes a digital level control. For many applications this feature will allow the M1 to be used directly to the power amp, eliminating the need for an analog line pre amp, providing perfect level adjustment control for the outputs of the M1. It is a digital adjustment so it will affect both the balanced and unbalanced outputs exactly the same and insures perfect channel balance at all gain settings. Operation is simple: press Level and it will display the level in db, normally this will be set a 0db.  urn the knob and you can cut the level in one db steps. Pressing the Level key a second time will set the output to MUTE, pressing again will un-mute. Upon power up, if the M1 was left in any level state other than 0db, it will power back at the last setting. If you do not use the level adjustment and leave the setting a 0db, the unit will power on to the Status page.

• Enter
  This sets or selects values in the other menus.

Input Renaming: Any input can be renamed from a preset list of names. Press a long press on the desired input to change and the display will flash and show “default” use the adjust knob to scroll through a list of names, to choose one, for example “CD”, press the input key again and it will set the new name. To revert to the normal name, just repeat and reselect “default”.

USB Features
On the rear panel you will find the USB 2 type interface and it is based on the latest generation of asynchronous design and supports PCM sample rates up to 384k/24 bit and DSD 256 native. For superior noise performance the interface is electrically isolated from the host computer, eliminating any grounding or power induced noise issues that could be transmitted to the M1 from the computer. No driver is needed for Macs or Linux but for PC use a driver is necessary and the latest version for windows can be acquired from our web site in downloads section.
Note that it is advisable that you power your computer off when changing USB cables or you risk possible damage to the M1s USB subsection. Do not hot plug the USB with the M1.
Optional Network Interface Feature
When configured with the optional network streamer, on the rear panel you will find the RJ 45 Ethernet connector. This connector is for using the M1 as a DNLA and Roon compatible network player. When The M1 is connected to a network router it will appear as a player in the media player and server that it’s connected to as a device to “play
to” from the server. This server can be a PC, Mac or even an android type UNpN or DNLA network player installed on your pad or phone. The M1 player is also known as a “renderer” or “streamer”. To set this up your server application must have network sharing functions enabled and there is no need to down sample and should be set to  play native sample rates. The M1’s player supports sample rates up to 384k PCM and DSD128 as DoP.

DSD playback and the M1
The M1 supports both Native and DoP formats for DSD playback. Most common method files can be transmitted is via DoP format and as such can be read with any input, but in most common is the USB as there are few disk players that play out DSD as DoP via the AES or SPDIF from the SACD layer. DoP, or DSD over PCM, is the DSD data embedded in a 176.4k 16 bit PCM data stream with the extra 8 bits out of the 24 bits used for identifying that it is DSD not PCM. This is true DSD and not PCM conversion. When using a computer audio setup, the media player will send out the DSD as DoP, the M1 will see that as 176.4k pcm for DSD 64fs or 352.8k for DSD 128fs, read the data header and see that it is actually DSD and unpack the data in our digital signal processor as the original DSD data, and send it out to the DAC for conversion to analog.
To use it all you need is DFF or DSF files, set the media player to play the files as DoP, and the M1 will play them. When DSD is received for playback the status and filter displays will read DSD, and when it next plays a PCM file it will revert to your last used PCM or DSD filter and display will update accordingly. Playback is seamless as any other PCM sample rate change.
The current version supports both DSD 64, DSD 128 and DSD 256. DSD 64 is the SACD standard and 99% of all content is released an mastered at this rate. There is some content appearing that is DSD 128 or 2x the rate but for the most part you will find DSD 64 as the standard. We also implemented the ability to have DSD post noise filtering. An artifact of DSD processing is the buildup of ultrasonic noise and with DSD 64, this noise starts at 24khz and rises to peak level at 50k and beyond. Ideally this should be removed in the digital domain before any analog stages, and we offer a few options.
Filter 0: This filter has no post filter and allows any ultrasonic noise to pass thru. There is a belief that the noise would be filtered by other things in the chain, and is in effect benign, so we created this option to let the user decide.
Filter 1: This filter starts at 32k pass band and ends at 64k stop band, so there is less attenuation of the noise, a gentler one, so a compromise filter that might allow some noise to pass.
Filter 2: This filter starts at 28k pass band and ends for full attenuation or stop band at 48k, so good attenuation of noise takes place. Technically this is a very good filter for bandwidth and noise removal. A great source for DSD downloads is: www.channelclassics.com

Specs and Performance

Audio Performance
The typical audio performance spec of the M1 is outstanding; Total Harmonic Distortion is an impressi0.0006% at all frequencies.

Digital Oversampling Filters
There are 9 Linear Phase filters and 6 Minimum Phase Filters that can be selected for use in the M1 and they are selected via the filter menu on the front panel. These are labeled Linear 0-8 and Minimum 0-5 in the user interface. Since the M1 converters use over sampling techniques, these filters are calculated at a very high rate for very high
precision filter construction.
Note: The the M1 uses delta sigma 8 x oversampling conversion so it is not recommended to “up-sample” the digital audio that is being sent to the M1. Defeat all up-sampling features in your media player or CD transport. Up- sampling the data before the M1 will yield poor results and always use the original source audio bit and sample rates, so for example if the source is 44.1k then sends this data unprocessed to the M1and let the M1 reconstruct the data correctly.

You will find despite the close numbers of the specs, that they all have very unique and different sound characteristics, and you may find one more suitable for different kinds of music than others as well. Here is a brief description of them. Note that since both types have the identical characteristics that there is one table of characteristics for both filer types

Filter Descriptions

For filters 0-5 this chart is accurate for both Linear Phase and Minimum Phase filters.. The 6 Minimum phase filters have the same characteristics as the linear phase filters of the same number, allowing easy comparison between filter types. As an example, Linear 2 has the same basic frequency response characteristics as Minimum 2 but they are based on a different filter construction techniques and yield different results. Filter types 6-8 are only available as linear phase. For simplicity and as a general guide to their characteristics, the list below lists filter # but in the M1 menu they are called out as Minimum and Linear.

• Filter 0 – 20kHz bandwidth, Stop-band at Nyquist frequency with low ripple and high attenuation
• Filter 1 – Low delay filter with full attenuation at Nyquist Frequency
• Filter 2 –Same as # 1 with a gentler slope and the passband at 19.5kHz
• Filter 3 – Same as # 1 with a gentler slope and the passband at 19kHz
• Filter 4 – Same as # 1 with a gentler slope and the passband at 18.5kHz
• Filter 5 – Same as # 1 with a gentler slope and the passband at 18kHz
• Filter 6 – A halfband type filter with 6dB attenuation at Nyquist frequency
• Filter 7 – Similar to 0 with a slightly gentler slope filter at 19k
• Filter 8 – Steepest slope, highest bandwidth, with low ripple and high attenuation

Filter Tables
Table of filter characteristics at 48khz.

Table of filter characteristics at 44.1khz

Technical Specifications

Connectors:| XLR:  AES/EBU 24 bit Single Wire
BNC:   SPDIF
RCA:  SPDIF
USB: USB 2
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Sample Rates AES, SPDIF:| 44.1 kHz, 48 kHz, 88.2 kHz, 96 kHz, 176.4 kHz, 192khz DSD 64, 128 DoP
Sample Rates USB:| 44.1 kHz, 48 kHz, 88.2 kHz, 96 kHz, 176.4 kHz, 192khz
352.8kHz, 384kHz, DSD 64fs- 256fs Native or as DoP
Jitter:| 8 psec @ 48k / 6psec @ 96k

Balanced Analog Outputs

Unbalanced Analog Outputs

General Specifications

EMC|
---|---
Complies with:| EN 55103-1 and EN 55103-2 FCC part 15, Class B
RoHS|
Complies with:| EU RoHS Directive 2002/95/EC
Safety|
Certified to:| IEC 60065, EN 55103-2
Environment
Operating Temperature:| 32 F to 105 F (0 C to 40 C)
Storage Temperature:| -22 f to 167 F (-30 C to 70 C
General|
Finish:| Anodized Aluminum
Dimensions:| 17” x 12“ x 2.5”
Weight:| 12 lbs
Shipping Weight:| 15 lbs
Shipping Dimensions:| 22”x 17”x 7”
Mains Voltage:| 100, 120, 220, 240 VAC, 50 Hz – 60 Hz
Trigger In:| TRS connector for 5-12V external trigger at the ring.
Power consumption:| 28 Watts (6W standby
Warranty parts and labor:| 2 years

Copyright 09/2022- Bricasti Design Ltd.-123
Fells Ave,- Medford MA 01255 USA

Documents / Resources

| Bricasti M1 Dual Mono D-A Converter [pdf] User Guide
M1 Dual Mono D-A Converter, M1, Dual Mono D-A Converter, Mono D-A Converter, D-A Converter, Converter
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References

• Bricasti Design
• Bricasti Design
• Bricasti Design
• Channel Classics | Outhere Music
• Channel Classics | Outhere Music

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