How to connect external synths?

Hi guys. I have Cubase Pro 10.5, Maschine Mk3 and Komplete 12 running on a Windows 10 PC.

All is working just fine - but I recently purchased 4 hardware synths that I am struggling to connect properly. At the moment these synths are connected to my PC via USB. Their mono audio outs go into my hardware mixer, and the stereo outs from here go into Maschine, which is acting as my audio interface.

I have used the “add external instrument” feature and Cubase - it can see each hardware synth and I can record midi into an Instrument track for each device. However, I get nothing when I try recording audio from my external synths. I suspect this may be because the “add external instrument” feature is expecting to see an individual midi connection and an individual audio connection for each device. As my 4 synths are routed through my mixer and then sent to the stereo inputs on Maschine all Cubase can see is these stereo inputs. Is there a way around this?

I am new to external hardware, but from what I have read I wonder if I would be better off just getting an audio interface such as a Behringer U-Phoria UMC1820 which will allow me to connect all my external synths and have Cubase see them as individual audio connections. Should the stereo out of my Maschine also be connected to inputs on the UMC1820, thus making my mixer unnecessary? The UMC1820 is affordable and big enough for future expansion, but are there any alternative interfaces I should consider?


Yes, the Device Port of the External Instrument has to be exclusive in Cubase. Therefore you cannot use it for multiple Synths.

In fact your Synths are not connected with cubase, but your mixer is.

Yes… and Yes!!!

Thanks guys - it looks like an audio interface with a minimum of 4 inputs is definitely the way to go then, though more inputs would allow for future expansion. I was thinking about the Behringer UMC1820 - or would I be better spending more than double the cost of the Behringer on something like a Focusrite Scarlett 18i20? I have no experience with audio interfaces so I am not sure what features might be important and whether it is worth the extra expense…?

My son works with the behringer and it is not bad! The key question here is what your setup looks like - for example what speakers you use for monitoring, etc.

me - and many others - have best experiences with RME audio interfaces. The drivers for those are excellent, lowest latency, great sounding.
Other users are very happy with some of the Steinberg interfaces - which seem to be excellent but I can see many users (most likely the ones that are not willing to study a manual ;o) ) asking a lot about “how to” with these pieces.

Thanks Elien. I have 4 external synths, Maschine Mk3 (and Komplete 12 plus loads of additional VSTs) so I am going to need 6 inputs minimum, though a few spares would be good for future proofing. I monitor via a pair of KRK Rokit 5 speakers.

The RME audio interfaces look great - but they are expensive. I am looking to spend around £400 max. Steinberg interfaces with sufficient inputs are also getting a bit pricey. There aren’t many in my price range with enough inputs, but the Behringer UMC1820 and the Focusrite Scarlett 18i20 stand out. I am new to audio interfaces, and though I enjoy a decent manual, something easy to use and of decent quality are priorities. Do you think I would be better reconsidering the budget?

Well, I am assuming you are not using your studio to make a living from it, so budget restricitions are more than ok!
The results of your productions will depend on so many factors that the gear-question should not be overrated.

by the way: If you dont need to record all your synths at the same time (!) then your setup will also work. You just would have to adjust your workflow and set up the external synths as “favorites”. You then would have to recall the correct favorite to be used for a certain track. I do understand that this is cumbersome. JUst wanted to give you that hint.

Finally if you are not sure about what to buy, you could order the interface online, try it and return it if you are not pleased.

Hope to help, Ernst

PS.: If reconsidering your budget really is an option, I personally would again and again stretch out for an RME Interface. They are not cheap, but hardware and software are absolutely top-quality.


Myself, I would even go for 2nd hand high quality device (what RME definitely is) over the new low quality device. RME drivers are awesome and they are working for many many years very stable. Even really old devices are still supported and using the latest drivers, fully compatible and working.

Hi Guys
I have looked at RME audio interfaces and the prices make me want to cry. Even second hand ones currently on ebay are going for way more than I can spend. I am sure they are fantastic but I just can’t justify that kind of money for what is just a small non-professional home studio.

Thanks Elien for pointing out that there is a way to get audio into Cubase with the gear I have. I was sort of aware of that, but (as you can tell) I am new to audio routing so I am really after something I can set up once and have it really easily usable from that point on. I did wonder about a Steinberg UR816C because I thought it might integrate well with Cubase - but looking at the forum there appear to be lots of people struggling with set up for that device (or is that just because they have not read the manual as you suggested Elias?). I also wondered whether I could plug synths into the two Hi-Z inputs on the front panel? I want something that can expand with me in the future, but this unit is not for me if the front panel inputs are only good for mics or guitars. Could I plug synths in here if the pad button is engaged and gain kept down, or is that a no-no?

I have looked at the finances and I can stretch to about £500 at a pinch. What would you do in my position?

The Steinberg ones are pretty decent and allow for good integration in Cubase IF you are willing to read the manual as others have mentioned.
I’ll recommend to connect synths to a line level input and not the Hi-Z inputs as these are for Guitar/Bass with passive pickups. By using the Hi-Z inputs for synths you will get impedance missmatch, how much that is audible is another topic though.

Hi, how do you record in audio using the “external instrument” function. At the moment I use a midi track and a separate audio track. Every time I’ve looked at the external instrument option, I don’t see a way to record the audio into the session, just midi. FYI I can hear the audio, but the only way I’ve figured out to record it, is to use a second track which seems to defeat the purpose of the “external instrument” track.

Hi jcbfoos,

the point is as follows: External Instruments are basically a way to include a soundproducing hardware device (synth, etc.) into cubase in the SAME way as VSTi (virtual instruments) are included. This means that the the audio outputs are part of the vsti-channels which do not have a record button! (not to be confused with midi and instrument channels, which BOTH record MIDI data - instrument channels output audio, but cannot record it).
in order to record audio you can either render the tracks or (in cubase pro) use the output of these channels as a source for additional audio tracks (that you have to create!). Only audio tracks have the record function for audio.

So: The point is - what we are missing is a direct option to RECORD vsti-tracks (a record button on these tracks). But this would interfere with the concept of instrument tracks which are taking midi as input and produce audio as output (and thus record midi).

what you are - rightly - observig is not special for “external instrument” tracks, but a general thing for instrument tracks and vsti-channels - they produce audio but have not record button (pls. note again: if they had that button it would interfere with the concept of instrument tracks).

HTH, Ernst

Render in place…

Okay - that’s what I was afraid of. I totally get it for VSTi’s. It wouldn’t make sense to have a record option on those tracks. But IMO “external instruments” are kinda useless without this if you are using external hardware synths. My reasoning is that external hardware synths are sometimes really difficult or impossible to recall, so I always print the audio to be safe.

Oh well, the two track solution (midi and audio) works well enough. Thanks!

@khs I’ll try render in place, thanks!

Personally I would love to have record buttons on all types of audio tracks including vsti-channels (and thus also those belonging to external instruments). This would make the artificial “rendering” steps unnecessary. Track versions ans lanes would accomplish re-recording the same track again and again in a way that is consistent with all other “normal” audio tracks.
I think most of us have become so familiar with “render i.p.” that we dont question the approach any more…

Just out of curiosity, why? The only time I’ve ever needed to render a VSTi is when there is a glitch or error during a tempo change. Otherwise I never render them out, the sound is just included in the final mix.

Curious to hear your workflow.

Midi tracks and instrument tracks are NOT audio tracks. They already have a record button for recording midi.

HTH, Ernst

Render in place…

So I can confirm that Render in Place works with external instruments. For me this is a game changer, thanks for the tip!