Vocals and the Roland MC-101

A lot and probably enough has been written about the amazing features of Roland’s MC-101 groovebox. This box has so much to offer – except for proper input connections. In this article I write about different options on how to use the groovebox in combination with vocals for a live performance.

Essentially I want something like the Roland MV-1 with better “portability” or a Roland SP-404 MKII with multiple tracks and a ZEN-Core sound engine.

The only way the MC-101 accepts input is via its type B USB port that connects to a USB *host* device. This effectively means that you cannot easily get vocals into the device.

Side note for the younger folks among us: This is a connector invented in 1996 and was given a second life in 2001 with the advent of USB 2.0. But it has been deprecated since 2017 (some 5 years before writing this article and a good two years before the MC-101 hit the markets).

So once we manage to connect the MC-101 (probably with the help of a USB-C adapter) to our phone or tablet, we can then start sampling sounds into the MC-101. I leave the option to connect to a computer aside as I am focusing on a very mobile setup here. Instead of just using a looper track with limited recording time we can export that looper track to a WAV file and then assign it to a pad on a drum track, which gives a 16 different (vocal) samples per clip.

So besides the problem that we cannot use input effects (like reverb or chorus) while getting audio into the MC-101, we face the problem that we cannot route audio from one external device to another. Though we can attach a microphone to the phone or tablet while connecting to the groovebox at the same time, it seems that audio routing in Android or iPhone/iPad is not a use case for the masses. There is at least one app for the iPhone/iPad called AUM that claims to support audio routing of different devices. However, in my tests though the devices showed up in the app, I could not get it to work on my iPad. And I could not find a single app that would allow me to do this on Android.

So what are our options now?

Basically I want to achive the following:

  1. Perform live with the MC-101 while being able to have live vocals along with that performance.
  2. Ideally, the vocals should be beefed up with effects like reverb or chorus.
  3. I want to record vocals into the MC-101 (as samples) for later playback during the live performance.
  4. The whole setup must be as light and portable as possible.
  5. Everything must be battery or USB powered.
  6. I want to use as few devices and cables as possible.
  7. I expect an Android phone or tablet as a device that I will have with me anyway.
  8. I do not want to rely on other hardware devices that I do not carry with me.

After the initial findings that out-of-the-box support with Android (or even iPad) did not seem to exist, I looked for alternatives which I found in these devices:

  1. Use a Raspberry Pi 3 B with PieJam (or similar software)
  2. Use a Roland GO:Mixer Pro-X
  3. Use a Boss RC-202
  4. Use a Boss VE-5
  5. Tascam DP-008EX

Raspberry Pi 3 B

In this setup we connect a USB microphone such as the Audio Technica ATR2100x USB to one of the USB ports of the Raspberry. The MC-101 will also be connected to one of the USB ports of the Pi. Routing could be done with PieJam. However, we then needed the Raspberry 7″ TFT touch screen as well. PieJam provides basic acoustic effects like reverb. As an alternative, routing via pavucontrol should be possible (not tested), but then we would lose the audio effects.

Rapsberry Pi 3 B+, https://www.raspberrypi.com/

With this we can directly record into the MC-101. For getting the mix out of the Raspberry we can use a simple USB audio adapter like this one, and use the 3.5mm / 1/8″ TRS output port:

Hama USB-A audio adapter, http://digitec.ch
Hama USB Audio Adapter, http://digitec.ch

As an alternative could be to use one of the boards from HiFiBerry in case we want an RCA output or similar.

It would also be possible to use the stereo out of the MC-101 itself to send the combined audio to speakers. We would then not need the additional USB audio adapter.

The Raspberry itself weighs under 50g and even with the case would be one of lightest options here . Power consumption around 400mA (at 5V) without attached USB devices is relatively high when compared to the other options.

Roland GO:Mixer Pro-X

Originally intended for these happy people of SCHÖNER WOHNEN doing podcast-style jam sessions at the coffee table dancing their name on TikTok, this device may actually have some use.

Jamming with the GO:Mixer Pro-X, http://youtu.be/1wBXT-DdR8Q

It features -amongst others- an XLR input to which we can connect our microphone and a 3.5mm TRS input from which we can get the sound of the MC-101. The mix can then be sent out via its 3.5mm TRS stereo out.

The GO:Mixer Pro-X however does not support vocal effects, so no reverb. Recording into the MC-101 would go via the phone or tablet by recording to a WAV file on the mobile device first, and the playing it into the looper track or directly importing it onto a pad. From there we can use all the effects that the MC-101 offers.

A plus with this device is, we can use the phone to create a recording of the whole performance and have the option of a separate fader (or knob) for adjusting the final mix.

With only 220g this setup is quite light. And the power draw of 170mA is pretty small as well.

To get reverb into the signal chain we could use an effect pedal like the TC Helicon VOICETONE R1. However, with a weight of 420g and additional cables needed, this make the whole setup much clumsier. This “weight problem” is due to the fact that pedal are supposed to be sturdy. I was already wondering, if we could replace the metal parts with plastic made form a 3D printer. But that is another story.

Side note 1 (not tested): the pre-previous version, the GO:Mixer is even lighter and uses less power. It is not manufactured anymore, but it can still be purchases on platforms like eBay. It lacks an XLR input for microphones, but provides a 1/4″ (6.35mm) input instead. If this was a working setup and we skip the “reverb” requirement, so might be the even better option than the Pro-X.

Side note 2 (not tested either): There seem to be other devices like Maker Hart JustCombo that appear to do the same as the GO:Mixer. Exact specs, however, are difficult to find or differ from source to source.

Boss RC-202

The little sister of the RC-505 gives us everything we want – and more, which is the weight. With 950g we get a 2 track mixer that can be powered via an adapter cable from a USB power bank. It has all the effects like reverb and chorus, plus the additional benefit of being a real looper with 99 layers. The rated power consumption of 440mA @ 9V is relatively high, but a regular power bank should get you through the gig.

Boss RC-202, http://boss.info

Inputs and outputs are proper 1/4″ (6.35mm) sockets which have the downside of asking for bigger and such heavier cables as well.

Boss VE-5

Another device that does not seem to be sold anymore. There are however a few used models to buy. Though not tested by me, the specs seem promising. It features an XLR input and a 3.5mm TRS auxiliary input and a 3.5mm phones/line output. And it has effects like reverb.

A current draw 190mA @ 9V is more at the upper end of the compared devices.

Boss VE-5, http://boss.info

Recording into the MC-101 for sampling would be done via the phone as with most of the other options.

Tascam DP-008EX

I saw this device first here where someone with a similar use case described his approach to the problem. This mixer is also a built-in recorder and features all the necessary inputs and outputs and effect. However, it is quite bulky and is at a 610g quite heavy as well. Power consumption is rated at 2.5W and thus in the upper spectrum of our devices.

Tascam DP-008EX, http://www.tascam.eu/

Recording into the MC-101 would be done via the two-step approach via the phone or tablet.


It is surpisingly hard to find a way to use the MC-101 with vocals in a live performance envionment. So the folks at Roland did an impressive job to keep us interested in their other (more expensive and heavier) gear – or stuff from other companies.

So what will I choose for my final setup? Difficult to say. But in my opinion I will either go for the Raspberry or the GO:Mixer (Pro-X) if we skip the reverb requirement. The latter has the advantage of best connectivity and low power. And especially with the GO:Mixer (instead of the GO:Mixer Pro-X) it is comparably as light as the Raspberry.

Or … I skip the MC-101 altogether and look for a single device that “does it all” (and possibly change some of my requirements) …

Hope this was helpful to you. What would you do?

The last microphone I ever buy?

In the last post I wrote about my recent purchase: The Neumann U 67. And it arrived today.

I just unpacked and connected it to my Sound Devices 833. The high-pass low-cut filter on the microphone is enabled and the polar pattern is set to cardiod.
The gain is set to 44dB on the recorder, with limiter and NoiseAssist enabled at -6dB. And this is how it sounds:

Sound Device MixPre-3 II Timecode Issue

In this post I would like to talk about an irritating feature, not to say a flaw, in the Sound Devices MixPre-3 II. You can also listen to the whole post on YouTube.

Let’s take it away.

One of the features of the SoundDevices MixPre-3 is Timecode.

However, as it turns out, there seems to be a major flaw in its implementation, that is only apparent when you change presets or use the File Transfer feature. This essentially makes the timecode unusable as it deviates by seconds within a short period of time, instead of microseconds over a course of 24h.

What do I mean by this?

Timecode on the MixPre-3 is received via the 3.5mm TRS Aux input. So in order to be able to jam from an external source you need to do the following:

  1. Go to Menu, Inputs, Aux In Mode and set it to “Timecode”.
  2. Go to Menu, Timecode, set the TC Mode to “Free Run” and select the “Jam” menu.
  3. Jam the timecode from the external source, by pressing “Jam TC”. Depending on your timecode generator, you need to select either “Aux In 1” or “Aux In 2” as the “Source”.

The timecode in the MixPre-3 should now be jammed from the external source. Note down the value, that is shown in the “Diff” line of the screen.

This all works as expected.

However, as soon as you load another preset or you switch to File Transfer mode, the timecode in the MixPre-3 starts to differ from the external source.

This can easily be verified by either doing on of the following:

Option A: Go to Menu, System, File Transfer, to enter File Transfer Mode; and select Exit to leave it. Do this several times. And then go to Menu, Timecode, Jam and note that the “Diff” value between the external source and the internal timecode generator of the MixPre-3 is now different from the value you noted down earlier.

Option B: Go to Menu, Presets and save the current settings to one of the internal presets by selecting “Save to Int 1, 2, 3 or 4”. Then select the previously saved preset by selecting Menu, Presets, Load Presets and selecting the number of the internal preset you saved earlier. Repeat thus serveral times. Go back to Menu, Timecode, Jam and note that the “Diff” value between the external source and the internal timecode generator of the MixPre-3 is now different from the value that you noted down earlier when you jammed from the external source.

Option C: Go to Menu, Inputs, Aux In Mode and select “Mic” as the source. Then via pressing the “Channel 3 knob” go to Channel 3, Input and select “Off” as the source and then go back to the home screen. Then go back to Channel 3 again and this time select “Mic”. Then go to Menu, Timecode, and select “Aux In 1” or “Aux In 2” as the source, even if the correct source seems to already be selected. After a moment, the screen updates and you should now see that the “Diff” value changed from the value you previously saw when jamming to the external source.

So what does this mean in reality?

First, this means, that you have to re-jam every time you want to transfer a file to your computer via the USB-C cable.

Second, even if you were to re-jam every time you used the File Transfer mode, you could only do this when you would not use Aux input for other purposes at all. This essentially eliminates the use of the TRS input as a microphone input that you would have in a headset such as the Beyerdynamic MMX 300.

Are there workarounds? Of course. But they all come with limitations. That is probably why they are called …

Workaround 1: SoundDevices Support suggested to use a USB stick to transfer files between the MixPre-3 and the computer.

This certainly works, but involves a lot of manual work, as you need to unplug from the MixPre, plug into the computer, transfer files, then unplug from the computer and re-plug into the MixPre again and again.

Workaround 2: Do not use timecode at all.

Really? But this removes the functionality of one of the main features of the device. Instead I could then also directly connect to the computer via a different device altogether.

Workaround 3: Do not use a microphone with a TRS jack. And re-jam every time you transfer a file.

Possible. But a lot of headsets actually happen to have such a jack.

Workaround 4: Use an XLR to TRS adapter if you have to use a microphone with a TRS jack. And re-jam every time you transfer a file.

Also possible. But then you need to carry one more adapter with you. And this changed the form factor of the MixPre-3 considerably.

Workaround 5: Go to Menu, System, USB-C and change the setting to “Power Only”.

When doing this, you cannot use your MixPre-3 when you want to play back sound from your computer. This somehow defeats the workflow to record sound on the MixPre-3 with headphones on, transfer the recording to the computer and edit it and then listen back to it with the same headphones you recorded earlier with.

With most of the workarounds we need to re-jam manually every time we transfer a file. In combination of an “auto jam” mode like on the 8-series recorders this might even be a acceptable workaround.

Sound Devices Support told me, that the out-of-sync behaviour is expected when using File Transfer mode as the device would have to sync to the computer clock. This sounds plausible. But there are two things, that do not seem to fit into the picture.

Regarding the out-of-sync behaviour there has not been any explanation at all.

First, this does not explain the behaviour that the timecode also changes when selecting presets and changing Channel settings.

Second, the Sound Device 8-series does not seem to show the out-of-sync behaviour when using File Transfer mode.

I am a little bit disappointed that depsite the richness of features of the Sound Device MixPre-3 – and the price tag that comes along with it – the device cannot deliver its features at the same time.

Hopefully, Sound Devices addresses this in a future firmware update.

Regarding firmware: the behaviour can be reproduced on a Sound Devices MixPre-3 mark II with firmware version 8.0 with build number 5136. The external timecode generator is a Tentacle Sync E connected via a 3.5mm TRS cable to the mixer. The computer used runs on Windows 11 but has shown this behaviour also with Windows 10.


You cannot use the MixPre-3 reliably with timecode and as a playback device and a TRS microphone at the same time when using the File Transfer mode.

Speech synthesis with the Neumann TLM 67

As a follow to my previous post, here is the first audio from the new Descript Overdub voice recorded via the Neumann TLM 67 along with a comparison to the previous overdub voices I recorded.

Descript speech synthesis 44.1kHz @ 16bit

Here is the uncompressed audio, in case you want to find out if you can hear a difference:

Descript speech synthesis 48kHz @ 24bit

In addition, I recorded a section for Librivox (in german), in case you want to hear more audio:

Wilhelm Busch, Volksmärchen, Die Zwei Brüder, 44.1kHZ @ 16bit 128kbp CBR MP3

A new addition to my microphone locker – Neumann TLM 67

Having to stay in a sound-wise medieval croft for the next couple of months could make me think to invest in proper acoustic room treatment – or: to get a new microphone. And this is what I did. I ordered the Neumann TLM 67.

Neumann TLM 67 ordered from Thomann

Originally, I was up for a Neumann U 67 Reissue. However, price and portability really made me hesitate.

So, when it arrived yesterday, I quickly tested it with a short recording from my kitchen desk (speaking directly against a window).

For the recording, I connected the microphone to my Sound Devices MixPre-3 II. The microphone was set to cardoid and had its internal high-pass filter enabled.

As I did not have a fitting microphone shock mount, I had to hold the microphone in my hand during the recording. So sorry for any unwanted noise.

As a side note: I temporarily mounted the TLM with cable ties to my Rode SMR shock mount. It works remarkebly well, so I will leave it for a while. At least as long, as have something better, such as a Rycote InVision USM.

The mixer was running NoiseAssist at -6dB and also had the high-pass filter enabled (as 120 Hz w/ 18dB/octave). The latter should not have a significant effect to it, as the built-in low-cut filter of the microphone covers a much wider range, as you can see in the diagram below:

Neumann TLM 67 Cardoid graph, taken from https://en-de.neumann.com/tlm-67#technical-data
Neumann TLM 67 Cardoid graph, taken from https://en-de.neumann.com/tlm-67#technical-data

The only change I did in post was to level the Loudness to EBU128 (-23 LUFS).

Below are two samples: the first is a short recording with freely spoken text from Instagram. The latter is the “Planet Earth” Descript sample training script from coda.io (a 30min version on YouTube and a 5min version of the raw 48kHz/24bit WAV file).

Neumann TLM 67: 1min
Neumann TLM 67: “Planet Earth” Descript Training Script 30min
Neumann TLM 67: “Planet Earth” Descript Training Script 5min 48kHz / 24bit

So far I am incredibly enthusiastic about this microphone. The sound (at least for my voice and in that environment) is incredible (and incredibly better than the other microphones I tested here). Finally, a microphone that sounds really well out of the box – even in more unforgiving environments.

As soon as the OverDub voice is ready, I will do some tests and post them so we can compare the difference in speech synthesis based on a high(er) quality microphone.

And maybe, I still go for a Neumann U 67 to see how the difference between the two mics is. We’ll see …

Shure MV7 vs Rode PodMic

So finally, today’s the day.

I bought myself a USB microphone. The Shure MV7. Actually, a dual USB / XLR microphone. I did a quick comparison with the Rode PodMic, which you can listen to in this short video:

Here is the transcript of the video:

So finally, today’s the day.

I bought myself a USB microphone. The Shure MV7. Actually, a dual USB / XLR microphone, but what you are now listening to, is the XLR version of that microphone or the XLR output of this microphone, which is connected to a Sound Devices MixPre-3 mk II.

Gain is set to 67 dB, high-pass filter of 100 Hz applied.

NoiseAssist plugin is enabled at -6 dB, because I’m recording here in my living room with actually no sound treatment at all.

So that the whole thing will not become too dry. I will be comparing it to another mic.

The Rode PodMic, which you’re listening to right now.

Gain is set at 65 dB, high-pass filter is also set at 100 Hz. NoiseAssist is enabled at -6 dB.

And, maybe the main difference:

The Rode PodMic has an integrated pop screen, which is only sort of effective;

and the Shure MV7 has the wind foam on top of it, which of course was installed.

So, what do you think? Any differences in sound? What microphone does sound better to you?

Microphone comparison in an untreated room

In the next couple of months I will be in a sound-wise unfriendly environment where recordings are very likely to suffer. As we will have to produce “live” there will be no time for post processing. But as I still want to achieve some kind of intelligible sound, I conducted some tests for find a more forgiving microphone for that environment.

I used a 1 minute sample text from Voices (according to the website free to use) to compare the different microphones and their sound (with windows and doors were open).

All microphones have been recorded with the Sound Device MixPre-3 II with HighPass filter (at 80Hz) and NoiseAssist enabled (at -6dB). For the ribbon microphones Rode NTR and Beyerdynamic M160 the HighPass filter was set to 120Hz. All samples have been levelled to -23LUFS.

Microphones tested:

  1. Beyerdynamic M160 (ribbon)
  2. Neumann TLM103 (large condenser)
  3. Rode NT-1 (large condenser)
  4. Rode NTR (ribbon)
  5. StamAudio SA-47 (large condenser, tube)
  6. StamAudio SA-47FET (large condenser)
  7. WarmAudio WA-87 (large condenser)

In the video you see the visual representation of the audio samples, for which I used WaveLab Pro 10.

If I had to pick my favourite mic, I would go for the Beyerdynamic M160 (when listening on the headphones). However, when listening to the samples on a TV, I would go for the Rode NT-1 or the TLM103.

What is your favourite mic and why?

Sound Devices 8-series Firmware v8.90 bug leads to disabled Channel Input after Recording

The other day I finally got my new sound Devices A20 Mini and connected it to my Scorpio via A10-RX / SL-2. After a quick test recording I came across a small firmware error (that actually has nothing to do with the A20).

[Update 2020-05-21] Sound Devices confirmed to me that they are aware of this and seem to have no intentions to address this due to its rare occurrence. Something I can understand and live with it. [Update End]

Normally, after PowerOn the 8-series asks you if you wanted to create a new (daily) folder. Something which I normally confirm. In addition, if you leave the recorder running after midnight, upon stopping the next recording, the 8-series asks you again, if you wanted to create a new folder (or keep recording to the same folder). So far, so good.

So now to the error: whenever we record something on the 8-series and select any Channel the actual (physical) input to that channel is greyed out (as it makes no sense to change any of its settings. As soon, as the recording has finished, the input menu becomes active againg available for modification.

However, when the 8-series asks for a new recording folder, after a recording has finished, that input menu stays disabled. After leaving the Channel screen and re-entering it, the input is active as normal.

And this is all to it. Only a minor nuisance. But maybe Sound Devices will fix it in a future firmware update.

See the following video for a reproduction of the error:

Sound Devices 8 series v8.90: Channel input disabled after recording when selecting a new folder

Powering the Sound Devices MixPre-10 II via a MyVolts Hirose DC Adapter and a USB-C PowerBank

The Sound Devices MixPre-10 II unfortunately does not support power via USB, but either gives you power options via the battery sled or its Hirose 4-pin adapter. As normal NiMH batteries last to something like zero and the original AC/DC adapter is a bit bulky, I looked for an alternative, which I found at MyVolts with their Hirose DC adapter.

This adapter provides a 2.1mm x 5.1mm socket, so you can plug in virtually any AC/DC adapter as long as it supplies a voltage between 9 V and 18V (and of course a bit of current). For this to work, you have to set the “Ext Power” option in the “Power” menu to either “Full Range” or “12V Ext DC”.

I tested this with a Blackmagic Design 12V adapter which supplies a current of 1 A. With that I could switch all 8 inputs to 48V Phantom Power and have the NoiseAssist plugin enabled. The power meter on the home screen shows a more than 1/2 empty “green battery” when using “Full Range” and 2/3 full with text displaying “EXT”. So far so good.

USB-C Trigger Board

Taking this setup one step further, I connected a USB-C trigger board, set that fixed to 12V output voltage (check YT for a couple of videos on how to do this) and then connected a power bank with a USB-C port. Now I can use my MixPre-10 II on the go with an ordinary USB-C power bank without having to resort to a SmartBattery along with its costly adapter.

This is it for today. Happy recording.

Sound Devices Scorpio with Hirose 10-pin Output

The Sound Devices Scorpio comes with 2 Hirose 10-pin outputs that – according to the block diagram – can be configured for L, R or bus B1 to B10. Sound Devices sells this cable under the product name XL-10. However, this item is no longer sold. And my supplier in Switzerland told me, he would have nothing left in stock, but: maybe Ambient in Germany could still get hold of some cables. One call later, and I found out that these guys neither had them for order, but they manufactured and distributed an exact clone of that cable under the catchy name of HBS10Y10-35W. Once ordered, and waiting for the shipment completed, I could finally make use of that cable giving me an extra pair of full size XLR outputs on my Scorpio.

Sound Devices XL-10 Ambient HBS10Y10-35W
Sound Devices XL-10 Ambient HBS10Y10-35W

In the package, you actually get two cables:

  1. Hirose 10-pin coiled extension
  2. Hirose 10-pin male to 1x 3.5mm TRS jack and 2x full size XLR male jacks

Here is what the cables look like when packaged:

Sound Devices XL-10 from Audient HBS10Y10-35W
Sound Devices XL-10 from Audient HBS10Y10-35W