USB Class Compliance: For Discussion of Issues & Bugs

dcarmich1 wrote:I've been interested in an MPC One for a long time and tested in a store with my MOTU 624, and the same pop/click issue happened. Can you explain what "hw_params" are?

Give up now and dont ever count on any MOTU device working on it in the near future. If you're lucky, in a few years someone might port a driver over to the regular Linux kernel (my old 828MK2 works beautifully in Linux but its Firewire and 20 years old) and then you might be able to use it. Until then MOTU is not happening on an MPC as its only class compliant where MacOS is concerned and nothing else.

Monotremata wrote:

dcarmich1 wrote:I've been interested in an MPC One for a long time and tested in a store with my MOTU 624, and the same pop/click issue happened. Can you explain what "hw_params" are?

Give up now and dont ever count on any MOTU device working on it in the near future. If you're lucky, in a few years someone might port a driver over to the regular Linux kernel (my old 828MK2 works beautifully in Linux but its Firewire and 20 years old) and then you might be able to use it. Until then MOTU is not happening on an MPC as its only class compliant where MacOS is concerned and nothing else.

What device brand/model would you recommend for use with the MPC?

dcarmich1 wrote:

zangetsu01 wrote:No improvement on external audio interface support. Still getting pops and clicks on my Iconnectivity Audio4C. Guess it's too hard to add a few drop down menu's in the audio device settings menu to let us choose the buffer size. I've checked the default buffer size in the hw_params in the MPC that's given to the Audio4C. It's 256 and it needs to be reduced..!!

I've been interested in an MPC One for a long time and tested in a store with my MOTU 624, and the same pop/click issue happened. Can you explain what "hw_params" are?

I’m running custom firmware on my X. So I’m able to ssh into my MPC and see the internal folder structure. After some digging I’ve found the settings of my external audio interface inside that file.

I think I’m going to get the RME Fireface UFX II today. (The price is steep I know)

Once I’ve tested it properly I’ll let you know.

Does using an external audio interface disable the MPC's internal cv/gate outputs?

I need to make sure it doesn't before buying an interface because I need the cv/gate outputs more than extra ins/outs.

Thanks to anyone who knows!

Couple of data points that may or may not be useful:
- Using my RME UCXII with MPC Live II, I get pops and clicks monitoring audio that get a lot more frequent after everything's been powered-up for 20-30 min or longer (i.e. circuits are nice and warm).
- Using S/PDIF from my Virus to clock the RME (instead of internal) almost eliminates the pops & clicks. I still get the odd very faint click which is annoying.

Moskwa96 wrote:Behringer UFX1204 works very good with MPC Live2. All 12 channels streams clearly , no problem to record 8 simoultanious tracks in standalone. No cracks or pops. And all of this with one usb cable. Amazing.

Very good upgrade raising MPC to next level. Now there is no competitor in standalone music producion over the world. Thanks to all people from AKAI , great job.

About the functionality of the Behringer UFX1204:

Contrary to this statement, I must unfortunately bring the opposite to your attention.

No matter whether to the MPC via the 12 input channels or out of the MPC via the 4 output channels - crackles and fizz all over the place. Was tested with firmware MPC v2.11.

To the creator of this post: Could you please test again?

During the test different USB cables and different audio cables were used to exclude this source of error.

I also downloaded the USB Driver V6.13 from the Behringer website and tried to adjust the buffer size via the Behringer UFX1204 USB Control Panel - no matter with which setting - no success.

I'm a bit annoyed that people without technical knowledge of the matter just claim "it works" but hey what do I expect from the internet.

I'm posting this to prevent others like me from making the mistake of getting this mixer thinking it would be hassle free. It is not.

Polynominal wrote:
I'm a bit annoyed that people without technical knowledge of the matter just claim "it works" but hey what do I expect from the internet.

I'm posting this to prevent others like me from making the mistake of getting this mixer thinking it would be hassle free. It is not.

What more 'technical knowledge' do you want? Akai didn't give us shit to do with the interfaces. You plug one in, it either works or it doesn't. This isn't the MacOS or Windows that give you a control panel to mess with the device's driver. It's either plug and play or it isn't plain and simple. There's no 'digging in' to the MPC to figure out why it doesn't work unless you're on Akai's development team. Using the driver on Windows to set the buffer only applies to WINDOWS. It doesn't have the ability to also magically tell the driver on the MPC to do the same.

Here's some 'technical knowledge'.. Im able to play out 10+ tracks with a Behringer UMC1820 on my OG Live perfectly every time. Records my projects into Cubase just fine. Not much more 'technical details' you can get aside from that. It either works or it doesn't and there isn't anything anyone can really do about it otherwise.

It all has to with the buffer size Akai is locking the audio interface to. One hacker on Facebook has been able to play around with the buffer sizes.

This is what he had to say about his findings:

Some Good and Some not so Good news!

The Bad:
1: The Buffer values are hard-coded (burned) inside the Program.
192 samples for Internal and 128 Samples for all external Interfaces.

2: 192 is the Max buffer that will work. Any higher and it will crash due to Memory errors (I might revisit it later in future but for now I am tired of looking at Arm machine/assembly code ).
3: To make 192 buffer work the MPC executable will need to be binary patched.
4: Some audio interfaces that can use 192 sample buffer, might be able to handle audio better, but not all can (as we found out with certain behringer products).

Monotremata wrote:

Polynominal wrote:
I'm a bit annoyed that people without technical knowledge of the matter just claim "it works" but hey what do I expect from the internet.

I'm posting this to prevent others like me from making the mistake of getting this mixer thinking it would be hassle free. It is not.

What more 'technical knowledge' do you want? Akai didn't give us shit to do with the interfaces. You plug one in, it either works or it doesn't. This isn't the MacOS or Windows that give you a control panel to mess with the device's driver. It's either plug and play or it isn't plain and simple. There's no 'digging in' to the MPC to figure out why it doesn't work unless you're on Akai's development team. Using the driver on Windows to set the buffer only applies to WINDOWS. It doesn't have the ability to also magically tell the driver on the MPC to do the same.

Here's some 'technical knowledge'.. Im able to play out 10+ tracks with a Behringer UMC1820 on my OG Live perfectly every time. Records my projects into Cubase just fine. Not much more 'technical details' you can get aside from that. It either works or it doesn't and there isn't anything anyone can really do about it otherwise.

Guess it all depends on knowledge of the matter which is obviously still lacking in this answer. Nevermind the try though. My post was about the UFX1204, not the UMC1820.

Polynominal wrote:
Guess it all depends on knowledge of the matter which is obviously still lacking in this answer. Nevermind the try though. My post was about the UFX1204, not the UMC1820.

Well, you missed the point. There is no 'technical knowledge'. It is what it is, Akai hasn't given anyone any details beyond what people have found digging through scripts and code. Your shit either works or it doesn't and there isn't much anyone can do otherwise about it. Even the UMC1820, working great here since the day they let us use USB audio interfaces, others ran into trouble just like with the RME stuff. It's all hit or miss and no one knows anything about why it works for some and not for others when this is all supposedly the same hardware and software inside.

Audient Id44mk2 works like a charm, replaced the umc1820. No clicks or pops in dac outputs or adat.

I don't want a big mixer but I want all 32 inputs, so...

Does anyone know if linking 2 Midas DN4816-i's together, then connect them to an DN4816U & sending its USB to the Akai MPC/Force will work without pops & clicks?
& yes I know its only line-level ins.

If it doesn't work I may get 2 Roland UA-1610 Studio-Captures since @Jtpack said it works with their MPC & that the fact you can link 2 giving you 32ins & 20outs plus some digital in\out & other cool features.

B-Wise wrote:If it doesn't work I may get 2 Roland UA-1610 Studio-Captures since @Jtpack said it works with their MPC & that the fact you can link 2 giving you 32ins & 20outs plus some digital in\out & other cool features.

I ask @Jtpack if the Studio-Capture still works & was told no;

Jtpack wrote:Hello B-Wise, unfortunately I have experienced a few audio dropouts while recording with the Studio Capture. I haven't been able to determine exactly what causes them, as it could go days without any issues and then suddenly start doing it during a session. I don't recall having any issues with the Studio Capture when only playing back audio.
To answer your question, would I still recommend the Studio Capture for use with the MPC? I don't think so. It almost works, or it works most of the time, but not all the time.
A couple of notes:

- when glitches occurred while recording, rebooting the MPC usually made them go away for a while.
- Since the last time I used the Studio Capture with my MPC Live II, I've updated the MPC a couple of times. Perhaps the experience will be different now.
- Some settings of the Studio Capture's internal mixer and buffers can't be adjusted from the Studio Capture user interface, and you have to connect it to a PC or Mac to change them.

I also asked to see if updating the MPC would help...no reply as of yet.
Even if it does work, in order to link 2 Roland Studio Captures to have 32-ins/20-outs both need to be connected to the Force/MPC & I don't know if that would work

I might buy 2 new locally & if it works take it back & order them used online.

Monotremata wrote:Even the UMC1820, working great here since the day they let us use USB audio interfaces, others ran into trouble just like with the RME stuff.

I have used the UMC1820 with Windows, Linux (Fedora) and the MPC One. I works with all systems, but...

If I understand it correctly what happens is that the UMC1820 seems to remember sample rate, bit depth and buffer size. If I change the values on Windows or Linux eg to 96kHz sampling rate the MPC One will not even detect the device.

One must set all values within ranges that the MPC One understands. For me only 42kHz with 16bit worked. I am not sure sure about the buffer size,

What would be an ideal buffer size (when the MPC One had no limitations)?

Masi

PS: Once the MPC One didn't want to detect the UMC1820, so I started up Windows. Panic! Even Windows complained about issues with the USB device. I tried to fool around with the control panel and turned the audio interface off and on again. After some while it worked again magically.

TASCAM MODEL 24
I tried it yesterday with my MPC Key 61 and it was awesome. I could select all the Tascam's 'PC' input channels as outputs on the Key 61, meaning you could have all the advantages of an external analogue mixer, coupled with all the INSERT EFX on the Key 61. I could create a new SONG on the TASCAM and have it output MTC to the KEY 61, which then triggered the Key 61 sequencer playback, by selecting 'SYNC' at the top of the 'MAIN' page.
I could record up to 22 tracks from the Key 61 to the TASCAM. I could also use the pre-amps on the TASCAM by inserting a mic and selecting 'LINE' on whichever channel the mic was plugged into. I could create an 'AUDIO' track on the Key 61 and choose the input to it to be whichever channel I had on the Tascam. I could then select an unused channel on the TASCAM and choose 'PC' as the input. Whatever this unused channel number was, I could select the output of the audio track to the same. By doing this the mic went from the pre of the TASCAM, through the Key 61 and returned to the TASCAM, from where I could record it to the TASCAM's SD multitrack recorder.I could treat the mic with EFX etc. These two pieces of equipment have replaced ALL my non-computer music making equipment and are going to be amazing. No clicks, pops or other issues working in 44.1 and 16bit.