The MX49/MX61 connects to your Mac or PC computer via USB. And while we can't say it will help you with your unnamed "88 keys master keyboard" (because we don't know what it is or how it connects to your computer), the MX has a built-in audio and Midi interface.

This means you can select the MX as your ASIO (Audio Streaming Input/Output) device for delivering MX audio to your DAW. It will also act as an audio interface for all your computer applications... Including any VSTi you choose to use and all computer audio will sound through the main outputs of the MX49/MX61.

The MX does not act as an audio interface for any external devices (other than itself)... Because it does not feature an A/D Input for external devices. But it will serve as the audio interface for all computer generated audio.

Depending on the type of computer you are using, your options for your unnamed "master keyboard" vary. Since you say you want to use its sounds and arpeggios, please consult that products manual got details or if you'd like our help, please provide some details. We can tell you the MX cannot serve as an audio interface for it, however. Midi, yes... audio no.

If you connect the Midi OUT of your external keyboard to the Midi IN of the MX, your computer will see this as "MX port 3"; and any Midi data routed OUT from the computer can be routed back to that device via "MX port 3" through a Midi cable OUT from the MX to the IN of that external device. So the MX will act as a Midi interface for one external device in addition to itself when connected to your computer via USB.

But it only acts as an audio interface for itself via USB.

Hope that helps.

Thx for the reply Bad Mister !!

Sorry for an incomplete post 🙂

The 88 key controller I use at the moment is an StudioLogic SL 990 pro with a single midi out port.
The SL990 has no sound of it's own.
The SL 990 pro is connected by Midi, to an old Yamaha P90 sound module.

The laptop (windows 7) I use is strong enough to run Pianoteq well, but the sound is horrible.
It sounds muffled and distant.

So I was thinking of buying an external USB audio interface with midi interface.
When I was listening to some demo's of the MX49/MX61, I stumbled on a demo with Bert Smorenburg (love his demo's)
Here he explained about the audio interface in the MX.

Since I always liked the sounds of Yamaha, the MX49/MX61 could solve all my needs in one buy 🙂 !!!
(It will replace the old Yamaha P90 sound module.)

Then, when I want to practise, I simply switch on the MX and SL990, and I can play. Using the Sounds and arpeggios from the MX.
If I want to use Pianoteq or any other VST, I can boot the laptop and let the sound run through the MX.

Is this Correct ??

Are there ASIO drivers available for the MX, or do I have to use ASIO4ALL ??

Can I play on my 88 keyboard as if I was playing on the MX ?? So with all trick available ??

when I want to practise, I simply switch on the MX and SL990, and I can play. Using the Sounds and arpeggios from the MX.
If I want to use Pianoteq or any other VST, I can boot the laptop and let the sound run through the MX.

Is this Correct ??

Yes.

Are there ASIO drivers available for the MX, or do I have to use ASIO4ALL ??

Yes there is an ASIO driver for the MX, Please do not use ASIO4ALL.... you want to use the Yamaha Steinberg USB Driver which includes both your MIDI and AUDIO driver in one. It is designed for the MX. Remember the MX is both an AUDIO and MIDI interface. An audio interface for itself and the computer, and a MIDI interface for itself plus one device connected to the 5-pin MIDI jacks.

All Yamaha Drivers can be found at the Official Yamaha Download site: http://download.yamaha.com

@Bad Mister

Thx for the reply 🙂

A good tip about not using Asio4all !! I didn't think of that. 🙂

Do you know, what the audio quality will be from the MX audio interface, using the Yamaha Steinberg USB driver ??
As I said in my earlier post above, the audio quality of my laptop is distant and muffled.

The audio quality is always subject to the weakest link in the chain it must travel. By taking your laptop out of the audio equation (the MX will become the audio interface in place of the off-the-shelf consumer audio device in the typical computer) your audio will be several magnitudes improved... (As in night and day).

That said, you must plug the Left/Right Audio outputs of the MX to a pair of quality Monitor speakers... All computer sound will now be handled by the Yamaha Steinberg USB drive through the MX hardware. If you do not have quality monitor speakers, use quality headphones connected to the MX's Phones jack.

Bad Mister wrote:All computer sound will now be handled by the Yamaha Steinberg USB drive through the MX hardware

Will it still be possible, to use the MX only for the Piano VST, and the rest of the sound through the laptop's own soundcard ??
Or will the Steinberg driver get all sound ??

🙂 sorry for all the questions, but if I found out something is not possible after I bought the MX ...
That would be very unfortunate.

It is your choice, by application. That is, you can choose to use the Yamaha Steinberg driver to run you music software (DAW) and use your computer's own sound card for all your other applications.