SPDIF vs Analog outs


  • The suggestion was to use the Kemper's out output to the monitors while recording with SPDIF. Monitors that only take a single source for their input.



    I think the suggestion was to run both the spdif and eg. master out into the sound card - then record the spdif, but turn off the spdif monitoring in whatever mix control software comes with the soudncard, while real-time monitoring the master output of the kemper. I.e., the sound card sends only the master out + the playback of the DAW to the monitors.


    From what I can see in the screenshot, this is perfectly possible in the OPs "mix control" software.

  • How are you meant to even use the Kemper's own monitor outputs when using or recording with a DAW anyway?


    Pure monitor mixer? That's one way to guarantee that what you hear as you record isn't what goes down on tape...


    I'm no professional, but not sure I get your point. If I'm recording through spdif directly, meaning digitally, it would be alway up to the DAC (and other equipment) how it would sound when played back. How does it help to use crappier audio interface for monitoring? Anyway, I think I'm looking from guitar player's angle not from studio engineer's... and as a player, I want myself sound as good a possible during performance and check afterwards how it turned out.

  • I think the suggestion was to run both the spdif and eg. master out into the sound card - then record the spdif, but turn off the spdif monitoring in whatever mix control software comes with the soudncard, while real-time monitoring the master output of the kemper. I.e., the sound card sends only the master out + the playback of the DAW to the monitors.


    From what I can see in the screenshot, this is perfectly possible in the OPs "mix control" software.


    Possible, but you're still going through the soundcards DAC there (as well as the ADC and the Kempers DAC before that), so it's just drifting the sound away from what's recorded, better to monitor the SPDIF on the soundcard. As you mentioned he also says the playback is fine, so it still would make no sense to do this.


    From what I could gather though it soudned like hte suggestion was to plug the output form the Kemper directly into the monitors. Not the same thing at all.

  • I'm no professional, but not sure I get your point. If I'm recording through spdif directly, meaning digitally, it would be alway up to the DAC (and other equipment) how it would sound when played back. How does it help to use crappier audio interface for monitoring? Anyway, I think I'm looking from guitar player's angle not from studio engineer's... and as a player, I want myself sound as good a possible during performance and check afterwards how it turned out.


    How are you proposing to monitor the output mix (everything other than the guitar) of the track while recording your Kemper? Also how are you going to hear how it sounds in the mix while recording or setting up tracking?

  • 1. Just to rectify a small mistake: The Kemper output (and input) jacks are NOT TRS, they are just TS. Not a big deal but wanted to mention it.


    ... taken from the technical specifications:


    Analog Inputs

    Front Input: 1/4 inch TS unbalanced, dynamic range >108dB, impedance 1 MegOhm
    Alternative Input: 1/4 inch TRS balanced with ground lift, dynamic range =105dB
    Return: XLR balanced, 1/4 inch TRS balanced with ground lift, dynamic range =105dB


    Analog Outputs


    Master L and R Outputs: XLR balanced, 1/4 inch TS unbalanced with ground lift, max output level: XLR +22dBu, TS +16dBu
    Monitor Output: 1/4 inch TS unbalanced with ground lift, max output level: +16dBu
    Direct Output/Send: 1/4 inch TS unbalanced with ground lift, max output level: +16dBu

  • I am assuming you mean the interface's digital to analogue converter, going to the monitors.


    Those would still be used for playing back the recording, which, as the OP said, sounds fine. So I don't think that's the problem.

    thats exactly the problem , u take the pure digital signal from the kemper and convert it via ur interface, u should let kempers converter do the job it is superior, never heard anything like it...and then use the analog out from kemper( if u own a studio with equipment worth thousents ignore all the above :thumbsup: )

  • recording NOOB here, but:


    if I record through spdif and monitor through a "far superior" analog output I would think that I am not monitoring what I am recording - or is that oversimplifying on my side?

  • recording NOOB here, but:


    if I record through spdif and monitor through a "far superior" analog output I would think that I am not monitoring what I am recording - or is that oversimplifying on my side?


    Why would you think that? SPDIF and analog outputs should be indistinguishable.
    It's not that you're playing different rigs through different outputs.

  • Why would you think that? SPDIF and analog outputs should be indistinguishable.
    It's not that you're playing different rigs through different outputs.



    Agree. The conversion SHOULD not make a difference.


    But the levels can be set differently, which may impact how you hear the sound, yadda yadda yadda... :-)


    I think you can also EQ the main output under "master".


    So, in conclusion: provided you haven't messed with any of this, it should be the same :-)

  • Wow, this thread totally confused me.


    Agreed, the SPDIF and analog outs should sound the same.


    If they don't, as the OP complains about in a monitoring situation, I suggested monitoring the analog signal while recording SPDIF.


    To do this, you need to set the appropriate mode in your DAW, whcih would be tape monitoring (on or off? I can't remember) What this effectively does is unless you select the monitoring button on an individual track channel, you won't hear anything.


    So set one channel to analog 1-2, set other to SPDIF. Click monitor on analog, click record on SPDIF. And you should be good.


    When playing back, this would actually work well, since selecting input monitoring on a track would normally mean you can't hear anything. So in this case, you would play back the SPDIF track without having to keep d*cking around with that monitoring button.

  • SPDIF vs Analog....



    Im going to give a short very basic overview of the signal flow of the Kemper and some ideal monitoring situations for beginners.
    This will be very basic, and there will be points to make arguments for and against some points. It is ideally for beginners, so if you want an "in depth discussion" / argument about anything I say, go to gearslutz or something :P



    ------------------------------------------------------------------------------------------------------------------------------

    In theory at least, SPDIF should be the superior sound, as it is passing the audio through 1 less conversion process.
    (in laymans terms):
    SPDIF: Guitar -> digital conversion within Kemper -> output as digital via SPDIF into soundcard -> soundcard sends digital signal to DAW for mixing (the incoming signal is already digital, so no conversion needed before sending the signal to the DAW)


    Analog: Guitar -> digital conversion within Kemper -> conversion to analog at Kemper output stage -> soundcard converts the incoming analog signal to digital -> soundcard sends digital signal to DAW for mixing




    Generally speaking, whenever a signal gets converted to or from analog, you lose a tiny bit of quality. In other words, the less conversion processes you have in your signal chain, the better.
    Now, the thing is, the human ear cannot really hear the tiny audio loss from the sound conversion process of analog to digital (or vice versa) in most situations.

    The only place you MIGHT hear a difference is in a really well sonically-designed room with high-end speakers and in a perfect listening environment, which very few users have....and even then, any noticed difference could be subjective in a psycho-acoustically sense (read: all in the users head!).


    So generally speaking, digital vs analog should not be noticeable. Any difference is 99% likely down to human error, ie, a setting accidentally left on, or a plugin one thought was disabled...








    ------------------------------------------------------------------------------------------------------------------------------
    Now onto monitoring:

    When you load up your Kemper and connect via your DAW, with a lot of soundcards there is a front-end monitoring panel, that is almost DAW like in itself! It can get a bit confusing, but think of it as a latency-free monitoring tool for now. Then you have your DAW, and finally you have your soundcard again before it is sent to headphones / speakers.


    So it looks like this:
    Audio into soundcard via SPDIF from Kemper -> "Latency-Free Monitoring" (LFM) Software -> Soundcard -> heaphones / speakers
    ................................................................................L-> DAW (Logic, ProTools, Cusbase, etc) -> soundcard -> heaphones (HP) / speakers


    So the signal here is sent to BOTH the LFM and DAW software respectively AT THE SAME TIME. (the "L->" is a mis-aligned break-out arrow)


    (What I mean by "Latency-Free Monitoring" software (LFM) is for example, RME Totalmix for RME hardware, UAD Console for UAD Appollo, Maestro 2 for Apogee, Mbox for Mboxes, MREditor for MR816X/CSX, QUAD Control Panel for Roland Quad Capture, etc etc...)


    Now, the signal passing through your LFM and DAW software do not hit the soundcard at the same time. Often, the DAW is slower due to audio buffers etc that the DAW populates first, amongst other things. If you put plugins on your track in your DAW, this further slows down the signal getting to your soundcard due to the extra processing of the plugins. For now, lets presume that we are not mixing and have no plugins on the DAW track.... it is just setup so we can record our takes (as it ideally should be, though perhaps bar a level monitoring plugin or something).


    Due to the time difference of the audio getting to the soundcard via the LFM and DAW routes, the combined signal output to your HP will sound different than the sound coming straight out of the HP jack on your Kemper, for example. The 2 signals combine at the soundcard at different points in the original wave form that was first sent from the Kemper to the soundcard, and cause "phasing" to occur (aka "comb filtering" to some)
    For more info on phasing, this explains it quite nicely:

    http://www.soundonsound.com/so…articles/qanda-0613-3.htm



    Note that if you record in your DAW anyways, and then listen back to the recorded audio that passed through your DAW, you will not actually hear the phasing sound that you heard through your HP while you were recording. The DAW has no knowledge of the LFM audio stream, so only the DAW audio stream was actually recorded. The phasing wont actually be printed within your DAW and you wont lose that awesome solo you just played! :thumbup:



    So what can we do about it? How do we stop it?
    Simple...

    Simply go into your LFM software OR your DAW and mute the audio stream being heard. This will stop that audio stream being sent to the soundcard (and out to your HP / speakers) and what you hear in your cans should be what you get out of the Kemper.


    Which one is best? Well, there are Pro's and Con's for both.
    Personally when I record guitars, I usually mute the LFM as I dont monitor with latency-free effects, that a lot of LFM software allow. Since Im tracking guitars, I usually already have the drums and bass tracks in my DAW to play along with, so for me it makes it the best option.

    When I record vocals, I do the opposite...I mute the DAW stream and monitor via the LFM as I like to add some reverb to my headphone mix. This does not mute any other tracks from the DAW...all you do is, in your DAW setup a new track, arm it, and mute the output of that track within the DAW. Presto, you can heard your LFM headphone mix with your monitoring reverb, AND the instrument tracks from your DAW at the same time while recording!
    :thumbup:
    Just dont forget to unmute it when you're mixing .... (you'd be surprised...you really would! :) )


    ------------------------------------------------------------------------------------------------------------------------------


    I HTH some folks with basic signal flow and setting up the ideal monitor mix for you.




    to the OP, have a look at the "Space" section of the headphones. Ive noticed that if this is on, it can be imprinted into the SPDIF output going into your daw. Possibly also your analog too, but I connect via SPDIF and not analog so Im not sure about that. Either way, try turning it off. :)
    HTH

  • I just got a new interface, well new to me. An RME Fireface 400, with SPDIF ins and outputs. I had the same issue the OP is complaining about. The SPDIF sounded horrible. The analog outputs sounded great. What I did notice is that the RME preference panel showed that the sample rate at 48 and it seems the Kemper is sending 44.1 out. I switched the clock source of the Fireface to SPDIF and the problem instantly went away, but now my system runs at 44.1 khz... which is less than optimal for me so I'm not sure if I'll use it. I like the extra hz as it helps when using software that uses audio rate modulation.

  • I just got a new interface, well new to me. An RME Fireface 400, with SPDIF ins and outputs. I had the same issue the OP is complaining about. The SPDIF sounded horrible. The analog outputs sounded great. What I did notice is that the RME preference panel showed that the sample rate at 48 and it seems the Kemper is sending 44.1 out. I switched the clock source of the Fireface to SPDIF and the problem instantly went away, but now my system runs at 44.1 khz... which is less than optimal for me so I'm not sure if I'll use it. I like the extra hz as it helps when using software that uses audio rate modulation.


    The 44.1 samplerate is problem for me too. I'm recording mostly at 48 and sometimes at 96 khz. Is there any solution on this?

  • Hey hows it going


    I'm currently trying to just hook my kemper to my UAD apollo twin solo interface to my DAW on my mac.
    I know analog TRS or SPIDF are my options, however when it comes to SPIDF my interface has an optical out for the cables


    I want to know what SPIDF cables are needed and if I need some type of converter or other material needed.
    please any help would go far.

  • Hey hows it going


    I'm currently trying to just hook my kemper to my UAD apollo twin solo interface to my DAW on my mac.
    I know analog TRS or SPIDF are my options, however when it comes to SPIDF my interface has an optical out for the cables


    I want to know what SPIDF cables are needed and if I need some type of converter or other material needed.
    please any help would go far.

    You may need something like this https://www.walmart.com/ip/Mon…-Audio-Converter/43458576


    BTW welcome to the community @nunog89.