Let's Get Technical with the Mackie DLZ Creator

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Mackie DLZ Creator

Technical Description, Comments and Repair Attempts.

Part 1: Back Story

I've wanted a compact digital mixer to replace my Samson L1200 analog mixer. At a minimum, the mixer should have 4 proper mic channels, as well as at least a couple stereo line level inputs. I also wanted it to have compression on the mic channels, which my L1200 lacks.

My primary intended use is live mixing for PA/DJ, but using a small mixer for Video production is a secondary consideration.



Part 2: Disassembly and Technical Description

Disassembling the Mackie DLZ is fairly straight forward. Most of the internals are accessed by removing the screen section.

Remove 3 torx screws from the bottom rear half. With the unit flipped back over right side up, remove 3 screws from the top edge of the rear of the unit.

Macke_Linuxslate_01.jpg (52.39 KiB) Viewed 296 times

Lift the rear of the panel with the display, the 5 encoders, and 3 buttons up slightly, and then pull it out from under the mixer panel. CAUTION: Lift it slowly and carefully only enough to access the connector where the display cable goes under the shielded main circuit board.

Here's a trick to access the main boards with minimal disassembly:

Remove the top center 2 screws of the connector panel.
Remove 7 torx screws around the metal shield/cover.

The perforated shield can now be carefully maneuvered to access the PC boards without further removals. Be careful of the Bluetooth antenna cable on the right side.

CAUTION: The display ribbon cable is very fragile. Disassembly is not recommended unless you have experience working with similar circuitry.

Carefully open (lift) the black display connector lock (black stripe) on the display connector. The display ribbon cable will basically fall out of the connector. The top can now be lifted further, and the ribbon cable from the mixer board to the top section can be disconnected. Unless there is a specific problem with the mixer board, this is all that is needed to access most of the unit.


Part 2: Technical Description

The Mackie DLZ Creator Main Circuitry consists of 2 Main Boards. I fully understand that this is a digital mixer, so this may not be accurate, but I will refer to the Green PC board on the left as the "Analog Board", and the Blue PC board on the Right as the "Digital Board".

inside.jpg (243.35 KiB) Viewed 286 times

While plastic on the outside, the internal components seem to be as good as we would expect from Pro Audio company Mackie. The Analog and Digital circuitry is fully enclosed in a metal shield (Shields Removed in the Above picture ). Ventilation is good, with air inlets along the bottom, and outlet holes near the top on both sides and the rear. This, along with the perforated shield should give good convective cooling. If it were me, I would have used slightly thicker pads to raise the unit off the table a bit more, but cooling should be adequate under most conditions. The Processor, and another main chip that we will discuss later, also have heat transfer pads thermally connecting them to the cover of a shield inside the main perforated shield for heat dissipation.

The main processor of the Mackie DLZ Creator is an Allwinner a40i-H. As per this Data Sheet, the Allwinner a40i-H is a Quad-core ARM Cortex-A7 Industrial Control Processor. It has Tonnes of IO built on to the main chip, which is one reason Mackie can produce a device with these features for under $1000.

I have seen some debate online as to what Operating System the Mackie DLZ Creator runs -- with some pointing to the Windows-like circle of dots that appears as it boots. The above linked Data Sheet states: Supports Linux3.10, Android 7.1 "and the above system". [Quotes added] however, I don't see any reference to any other OS or Software company in the data sheet. While the "above system" certainly could be referencing some version of Embedded Windows (The OS formerly known as Windows CE), it is also very possible that Mackie (LOUD Technologies) simply coded their own circle of dots startup indicator.

I would also figure that it would be quite difficult to develop a device like this on an OS that is not supported by the CPU vendor.

Based on the "Look and Feel" of the OS, the appearance of the boot sequence, and the complexity of the software, I am assuming that it is running some sort of Proprietary OS build on a Linux kernel.

UPDATE: I am now quite sure that the Mackie DLZ Creator runs Linux. After quite a bit of searching, I was able to find an old 1.0.2 version of the firmware on a Mackie site in another language. Once I unzipped the downloaded package, I got a Firmware installation PDF, and a Release notes PDF, along with an "evolveupdate-v1.0.2-b49.upd" file. This file has the icon of a zip file, and opens in Archive Manager. Inside the archive are 4 .deb packages.

I tried the same thing with firmware v1.2.0-b1731 (current). Depending on which Mackie website I went to, I got either a .zip file containing only evolveupdate-DLZ-Creator-XS-v1.2.0-b1731.upd, or simply the .upd file directly. The Linux file command identifies the .upd file as containing only:

Code: Select all

ELF 32-bit LSB executable, ARM, EABI5 version 1 (SYSV), dynamically linked, interpreter /lib/ld-linux-armhf.so.3, for GNU/Linux 5.10.49, stripped

Conclusions:

• Pretty definitive that even current versions of the Firmware are based on Linux 5.10.49.
• The Available firmwares do not contain the full OS, only the files that are to be replaced.
• Extracting the full firmware from a working device would be necessary for certain repairs.

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Part 2: Disassembly and Technical Description (Continued)

Here's an annotated picture of the "Digital" or CPU board:

CPU Board Annotated.jpg (132.83 KiB) Viewed 294 times

Photo:linuxslate.com


Additional Notes:

• Note that the 3.5mm Phone plug and USB-C connector are not shown. The USB-C connector is soldered directly to the Analog (Green) board (Visible in the previous post.) The 3.5mm phone jack is attached to the connector panel, and connects to the Analog board via a short cable and a 3 pin JST connector.
• I have not tested it, but I am wondering if a serial console is available through the "DEBUG" connector.
• Note the additional USB (USB 0 and USB 2) connections. I am wondering if one of these is a USB peripheral connection -- like for connecting to the board with ADB, assuming there's an Android OS hiding under there someplace, or perhaps another place to find a serial console? Could additional USB drives (or perhaps internal storage) be connected?
• The button facing the rear panel is accessible from outside via a small hole, but it is not marked "RESET" or anything else, and it is not documented in the manual. Pressing it during operation, or during Boot does not seem to do anything.
• Note also the UBOOT button. With this button, and the above ports, unbricking one of these may be pretty straight forward. I'll also note that this board seems to be very close to some Allwinner A40 development boards. Did the Mackie DLZ Creator start off as someone's Raspberry PI project?
• All Pins of the major connectors are labeled on the other side of the board.
• Power is "Hard switched" by the switch on the back panel before it gets to the Power JST connector. When it's ON, it's ON, and when it is OFF, there is no power anyplace. No sleep or standby modes. This makes sense for a Classic Pro Audio product, but is unusual today for something with a processor, LCD display and a touch screen. Whatever OS this is, it must be tolerant of a hard shutdown.

OK, so now the discussion about that other large chip.

It a GOWIN FPGA (Field Programmable Gate Array). In other words, it's basically an ASIC (Application Specific Integrated Circuit) without the cost of having a custom ASIC developed. Seeing that sales of this unit will be in the Thousands or 10's of Thousands, and not millions or many millions like a PC or mobile phone, it just would not be cost effective for Mackie to have a custom ASIC developed and produced. Of course we have no idea what is burned (or masked) onto that FPGA.

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A little more about the "What OS?" discussion

Another reason why someone in a forum may have thought the Mackie DLZ Creator runs some form of Windows:

The "Media" tab is, in essence, a very simple and limited File Manager. (More on this in a later post). Interestingly, it shows the 2 accessible storage devices as shown below:

screenshot01.png (55.48 KiB) Viewed 83 times

I am assuming that the use of the colon backslash is supposed to be comforting or familiar to the Podcasters and "Influencers" that this device is marketed to. Of course given that most Podcasters and Influencers are probably familiar with internet URL's, and given that may other professional audio and video software at least partially exposes a Linux/Unix filesystem, I'm a little surprised they did this.

Furthermore, as seen in the following screenshot of the "Pads" tab, the path to a given Sample File is displayed as a full Linux Path:

screenshot02.png (83.24 KiB) Viewed 83 times

The path of a Sample I copied from the "Poor Mans GO DJ" is shown even more obviously as a standard Linux Mount Point: /tmp/mnt/mmcblk0p1/Spealer_Test.wav

Why they went to the effort to appear "Windows-ish" in one tab an not the other is something I can't quite fathom. Since the "Media" tab doesn't really allow exploration of the filesystem, copying, etc., why bother showing the path at all? usb:\ is less intimidating than "/tmp/mnt/mmcblk0p1/Spealer_Test.wav" or "/tmp/sda1/Filename.wav" or Simply "USB - Filename.wav"?


Photos from Mackie DLZ Creator Owners Manual. All photo credit in this post to Mackie/LOUD Audio.

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Review/Comments:

In lieu of a more formal review, I will just post some comments here. This will be updated as I learn and use this device:

Good:

• The Mackie DLZ Creator brings fantastic features to a "Prosumer" grade device. The DLZ Creator is a great way to learn Audio Engineering, and highly functional for it's intended use, as well as others.
• Other uses can include Live PA/DJ use, or it can be used as a Multi-track recording deck. It can interface with DAW software running on a computer, but it actually is a simple DAW in and of itself.
• The inputs are flexible and backed with good quality audio components.
• Despite the plastic case, and limited connection options, the internal components and circuit quality are of professional grade.
• The plastic case may not be ideal for road use, but first, that is not the intended use of this product, and second, if it is used for live gigs, it is very light and easy to pick up.
• Most capable Equalizer I have seen on a sub $1000 device (or $10,000 for that matter). It's still only 3 bands (plus a low cut), but each of the 3 bands has a tunable center frequency, and adjustable Q -- All shown on an intuitive graphical display. The low cut is also tunable, and visualized on the display.
• The Reverb, Delay, Telephone, and Voice FX settings resemble "Plugins" on more advanced (expensive) audio equipment. This provides a good introduction to modern mixing consoles for an aspiring Audio Engineer.
• Another feature is the 4 headphone outputs, each of which can have separately programmable level mixes. This essentially allows the Mackie DLZ creator to be used as an audio router, or 4 destination telephone switchboard. This may be able to be further expanded to additional units all connected to a NDI LAN.

Could be Better:

• While inputs 1 - 4 support many connection types and input levels, - More professional mixers in this price range or number of channels would probably have additional sets of input connections for some channels -- for example, adding RCA connectors to the Channel 5/6 and 7/8 inputs. In addition to the 1/4 inch TRS connectors (What us "old folks" call Phone Plugs), Balanced XLR Main Output connectors would also be found on most, if not all mixers in this price range.
• The Mackie DLZ Creator does not have motorized linear pots. This limits the device in 2 ways: First, It does not allow remote control, and second, it significantly degrades the "Snapshot" function, since the individual channel levels are not saved. "Snapshots" will save all of the other settings of each channel, but since it does not preserve the levels, it can't be used to actually save a given program (hence the avoidance of the term "Program". Of course neither of these really limit the device for use as a Podcast mixer/recorder.
• Long Boot Time -- If someone trips over a cable, or the power company does a "bump", there's going to be a lot of down time. Amps and analog equipment will come back up almost immediately, but it's going to seem like an eternity before the Mackie DLZ comes back up again.
• Use of an un-grounded "brick" power supply. Again, if used as intended in a "Podcasting Studio", this probably is not much of an issue, but if we look at the device as an $800 live audio mixer, I would expect a standard IEC power cord, and internal power supply. Note that the 18V power should be fully isolated from the AC Line inside the power brick. This means that if the DLZ creator is not grounded through some device that it is connected to (e.g. a power amp that does have a 3 wire power cord, or the USB connector of a desktop PC), then the entire setup -- including any connected mic's -- will also be floating. Note also that there is no grounding screw on the Mackie DLZ.
• The large "feet" are a good feature of this device. It is very stable on a flat table, However slightly taller "feet" would afford better cooling. With a convection-cooled device, ample airflow into the bottom vents is essential.

Suggested Features for Future Firmware Updates:

• Fix the file path formatting issues mentioned in Post #3 of this thread.
• Include some sort of spectrum analyzer -- possibly on the EQ and De-esser page of each channel, or on a separate tab, with the ability to select any channel (Including Main) as what is displayed. This tab could also have VU meters and level indications. It should have hold and envelope functions. How can you set the De-esser if you don't know at what frequency the Ess'ing is happening? I realize that this may require quite a bit of processor power, but the Allwinner a40i-H does have a fairly capable GPU.
• Support USB and/or Bluetooth Keyboards. There are lots of cool compact keyboards available, and they make it much easier to enter Channel Names/Sample Names/etc.