Kemper and audio interface connection question

  • Hello everyone


    Long time lurker first time poster here.
    I am a proud owner of a Kemper head for the last year and a half but being abroad most of the time I've rarely ever had the chance to use it and only through headphones.
    Coming back to the UK for good soon though I thought I'd ask a couple of question concerning my rig and how to set it up.
    I will be using the Kemper for practice/home use and recording with a pair of HS8 monitors and a focusrite 18i20 to an iMac.
    After doing some reading on these forums I see that connecting with the focusrite via spdif is the way to go esp for reamping so I intend to do that.
    So on with the questions:
    1. Given that the focusrite has its own power supply am I correct in assuming I should be able to get sound from the kemper through the monitors even if my computer is not turned on?


    2. Would I need another connection other than the spdif one for that to happen?As in have the spdif cables for use with the computer and recording and for solo use of the kemper connect to the focusrite via xlr or 1/4 inputs?Or just connecting via spdif would be enough to cover both functions?


    3. Would it make any difference to the quality of the sound if I connect the focusrite to the monitors via trs cable or trs to xlr as the focusrite outputs are 1/4 trs.


    Thanks in advance and my apologies if my questions are a bit silly,I'm only getting started with all this technology malarky, was strictly a tube person until I got my Kemper. ;)

  • Your Yammy HS8 are powered monitors so no worries about sound their. The 18i20 can only output line level which would not work if your monitors weren't powered. I go out of the KPA both ways to my 18i20, S/PDIF and the Master out L/R. That will leave you with plenty of options for routing in Mix Control.


    Welcome!!

  • Thanks for the reply Zapman,are you going out of the Master out using a splitter cable or something like that to the focusrite input?
    And what advantage would it have if I were to do that compared to just using the spdif?
    Thanks!

  • Master out of KPA has left/right outs, no splitter needed. My monitor out goes directly to my DXR12. S/PDIF out of KPA, I find I don't use that much really, not sure but the volume level of S/PDIF out always seem to be kinda low even when jacked up in the KPA. Might be normal, maybe a hotter signal to the 18i20 with the analog out of the Master. Anyway, doubt you could hear the difference between analog and digital signal anyway. Cables are cheap, try it both ways and compare it. Good luck and enjoy!!

  • If you bought your interface recently, it will be the 18i20 generation 2 model and I’m not so familiar with the control software for that ... the older gen 1 models use Scarlett MixControl software on PC/MAC for setting up the interface. Using the software, you can configure the inputs & outputs how you need them - in your case, it would be fairly simple, just send the inputs that your Kemper connects to, to the outputs for the monitors. You can tweak the sound levels here as well.


    The Kemper SPDIF Out uses a sample rate of 44.1 and it must be the Master for the digital sync, so you need to configure the Focusrite to use 44.1 and the sync source set to “SPDIF” or “external”. Once you’ve made and tested your settings in the control software, you have an option to save the configuration to the hardware - this then allows the interface to operate standalone with that setup.


    The SPDIF cable from Kemper to interface can carry the stereo signal, or you can configure the Kemper to send 2 mono signals eg the processed and unprocessed (wet/dry) signals. The SPDIF Out from interface to your computer can then carry those 2 channels for recording.


    You should be aware that when the Focusrite is configured to get its sync source from the Kemper for SPDIF, it will NOT process any audio (even analog) unless that sync source is present. So if you’re using the interface for other devices as well (mics, keys, line level audio or as a general mixer), you won’t get any audio out unless the Kemper is powered up! This may be a gen 1 model limitation, certainly it is for me. In the end, I chose to use the Kemper Master Outputs via 1/4 inch cables into my 18i8 so I could use the latter as a mixer; I rarely have the computer hooked up to it so not easy to change the sync source.


    If your interface is close to the Kemper and the cable can be short, using TRS would probably sound similar to XLR, the latter is better for longer cable runs due to the balanced connection (the Kemper TRS Master outputs are not balanced) - if you’re buying cables, you may as well get XLR at the Kemper end if the price is similar. Most people say SPDIF is better because you’re not going through multiple analog/digital conversions - the sound stays in the digital realm until it goes through the interface outputs. I personally didn’t notice much if any difference between TRS and SPDIF, but I’m only using cheapish 5” monitors right now. You may see more of a difference...


    BTW, not silly questions at all! I hope you get it working well.
    -Durwin

  • Gen 1 18i20 and I wondered why sometimes I lose audio. You just turned the light on @Durwin99 , thanks for that. S/PDIF and Analog Master Outs connected, but I did notice in losing audio (turning off KPA and still wanting audio from my computer) if you turn the 18i20 off/on the sound then works without the KPA and S/PDIF in the chain. I might just do away with the S/PDIF connection also, I don't really need it.

  • Hey Durwin99,


    Thanks for the input,I was aware of the 44.1 sample rate and the fact that the kemper needs to be master but I had no idea about Kemper needing to be powered up in order to use other devices.
    My Focusrite is 2ng generation so I will test it and let you guys know how things work.
    The problem being that I am still abroad and it ll take a few weeks before that happens.I am just so eager to go and play with my Kemper that I've preordered everything and I thought I'd make the thread here just to be battle ready when I get home :D
    I will follow Zapmans advice, initially I will connect the kemper in every possible way to the focusrite and I'll see what works best for me.


    Once again thanks everyone for being so helpful, makes me feel very welcome!

  • Just another angle to suggest which you could consider as I have a pretty similar set up (focusrite 6i6 using the s/pdif in and out, Yammy HS-8 and iMac). I described my set up in detail in this post: Set up


    Since the time of that post I have also in addition started using the KPA direct out and Monitor out, each going into channel 3 and 4 resp. on the focusrite, this in addition to using the s/pdif connections as well. Now I use s/pdif for full stereo signal, full KPA stack wet signal (record in 2 separate tracks in Logic), and KPA direct out for dry signal and KPA monitor out for KPA stack only (no fx), also each recorded to seperate tracks in Logic. So total of 4 tracks at a time. Allows for a lot of flexibility when mixing after tracking since you have full wet in stereo if you are happy with it, or totally dry if you want to reamp, or stack only with no fx if you want to add your fx via your DAW instead or even reamp that track instead with KPA fx instead.


    Lots of fun, yes? :)

  • Indeed nottoohigh,I am beginning to realise that the options are endless.
    When I started the thread I was wrongly assuming that you somehow have to chose one type of connection for your kemper and stick to it and with all you guys' posts I realise that as long as you have cables and inputs in your interface theres loads of solutions.
    It's like expecting a linear computer game from the 90's and being landed in an open world sandbox game of today,I kinda feel like Alice in Wonderland :D

  • I’m glad I could help a little. I know the feeling Vanbaal, before I got my Kemper (only recently) I was drawing routing diagrams on sheets of paper, trying to work out the “perfect” way of connecting everything up (Kemper through interface, Digitech Trio+ looper, the odd pedal & music tracks in from iPad and/or iPhone). Thankfully I didn’t buy all the proper cables until after I had it physically connected up, using instead old cables I had sitting in drawers - because I still got caught out by various things like dealing with Mono outputs from the looper, working around tone suck issues also with the looper, low volume from iPhone and this SPDIF Master thing on the interface. Once I settled on a “good” setup with the cables I had (which were either cheap or far too long) I replaced the ones I needed with better quality of the right length. So, in your situation (when you finally get to connect it all up!) play around with the setup with what you have, and leave off buying additional stuff until you know you need it!

  • I had to learn a few things at first like going into my interface with an XLR (I figured balanced was a better line) meant going through the Interface Preamp == Tone Suck.


    So I needed to go LINE in. But the problem with LINE in was the DAC conversion was noticeable compared to the SPDIF.
    I figure if you can really hear the difference. So was it the KPA DAC or the Apollo's ADC or the combination?


    Since the SPDIF sounded like what I was hearing in headphones AND the KPA had to do a DAC for that, it must have been the Apollo, is my guess.


    Bottom line, SPDIF was the bomb so I stuck with it. Apollo has an optical IN that is not RCA so I had to get a conversion box. AND I found out that for some weird reason, this same routing worked for the Clarett but NOT the ID22?!?


    In any case, it has me thinking a lot more about ADC/DAC and what a really good unit would be, and what cost would be worth it. Not for the KPA, but for a tracking chain.

  • Indeed nottoohigh,I am beginning to realise that the options are endless.
    When I started the thread I was wrongly assuming that you somehow have to chose one type of connection for your kemper and stick to it and with all you guys' posts I realise that as long as you have cables and inputs in your interface theres loads of solutions.
    It's like expecting a linear computer game from the 90's and being landed in an open world sandbox game of today,I kinda feel like Alice in Wonderland :D

    Yes, KPA is very flexible as far as outputs for performing, monitoring and recording goes.

  • Hey db9091 thanks for your reply,


    What you are saying, that Spdif sounds best is what I had been reading myself before opening the thread.
    I guess I will be able to test it for myself and draw my own conclusions soon enough, it is just good to know that there is a variety of options and all you need is some cables.


    Durwin99 as far as the cables are concerned yeah,I've got a bunch of cables lying around and that should do the job to begin with,I have already splashed out a lot on the kemper lately without even being able to play it and good quality cables don't come very cheap.
    I will definitely have to buy the coaxial cables for the spdif but looking at amazon you can get those pretty cheap and if their quality is an issue in the long run I can replace them with something better later.

  • If you’re buying spdif coax cables, you need to have a good look at the connector end of the cable and where it connects to the Kemper ... the spdif sockets on the Kemper are recessed (well, certainly on mine) and NONE of my current cables would fit in the Kemper because they were too “chunky” to go into the hole around the sockets. In the end I used an old video RCA coax cable just to test it out. I never got around to buying a decent spdif cable because I went back to analog instead. I was going to get this one, it looks like it has the right connector to fit, but I stress, I haven’t tried it yet. Less than £9 for 1m...
    https://www.amazon.co.uk/dp/B0…colid=2CQ1M3D20L7YN&psc=1

  • The price is certainly right for this cable Durwin99,much cheaper than the options I was looking at maplin.
    I have read a couple of threads where people have problems making their coax cables fit properly so I will probably grab the toaster and go to my local maplin when I get to the UK just to make sure that whatever i get will fit(assuming marlin is still open by the time I get there as I read they collapsed :rolleyes: )

  • concur with @Durwin99 that there is very limited space around the spdif sockets on the KPA. For my cables, shown below, luckily you can unscrew the external sleeve which otherwise bulks it up too much to fit into the socket. With sleeve removed, it fits no problem. So do look out for that.