How do I control volume of an intstrument connected to SPDIF

retired&wired · Post by **retired&wired** » Sun Feb 12, 2012 9:14 pm

Wanting to add another instrument input to the Presonus FP10, I decided to go optical OUT from my Kronos thru an M-Audio c02 optical-to-coax converter into the S/P DIF IN on the back of the FP10. Then I read in the Kronos manual that the Kronos' volume knob does not control the volume output from the Kronos' S/P DIF optical OUT. There is no gain knob associated with the S/P DIF IN connection on the FP10, so how will I control the volume output from the Kronos via this connection?

I understand the use of the FP10 control program. I'll need to run that and set the sync source to S/P DIF.

I'm running Live 8 on a Mac, if that makes any difference.

Thanks in advance for any info you can provide.

Mutter · Post by **Mutter** » Sun Feb 12, 2012 11:43 pm

this type of output is to my understanding not normally volume controled at the source as if it was a degradition of sound quality would occur do to limited bit depth. I used to run keyboards spdif to a motu 896mk2 but gave up as it was to problematic for me i now run all anologue to a presonus studieo live mixer and i am much happier. Jerry

Lou · Post by **Lou** » Sun Feb 12, 2012 11:54 pm

The only volume adjustment you will have is the Value slider.
I suggest as Mutter above, is to use lives channel strip for you source.
Also, using spdif in this way can be a pain in the butt because every time you change a program or combi the volume of Kronos jumps to the saved Master setting.
Bringing down Lives channel strip, you have control of this.

retired&wired · Post by **retired&wired** » Mon Feb 13, 2012 3:03 am

Lou wrote:The only volume adjustment you will have is the Value slider.
I suggest as Mutter above, is to use lives channel strip for you source.
Also, using spdif in this way can be a pain in the butt because every time you change a program or combi the volume of Kronos jumps to the saved Master setting.
Bringing down Lives channel strip, you have control of this.

Lou, pardon my ignorance, but what is 'Live's channel strip"?

and what is "Bringing it down" mean?

Thanks

Lou · Post by **Lou** » Mon Feb 13, 2012 6:13 am

Sorry, "Lives channel strip" (What I meant to say is the actual fader assigned to the track that Kronos is in) "Channel Strip"

If you are recording midi and then to audio, which is what I do, I adjust the monitoring volume from "Kronos channel strip in Live" it's only midi, your not recording audio just yet so volume doesn't matter until you record to an audio track or "Freeze it" then you simply raise or lower your Channel Fader for an appropriate level and record your audio track from it.

Hope that was clear and helps a bit..

AdDeRoo · Post by **AdDeRoo** » Mon Feb 13, 2012 9:26 am

I have experimented yesterday with having a Korg PA2X output through SPDIF to the Kronos input (using a Lindy converter from RCA Coaxial to Toslink). Works fine, except that the resulting volume on the Kronos is quite low. Can't change that on the PA2X, and on the Kronos the input volume is already set to 127, so you can only reduce it.

andreidelait · Post by **andreidelait** » Mon Feb 13, 2012 11:59 am

I have also a small problem with the optical out of the Kronos. When I record it in Cubase for instance via optical out the volume is low.

retired&wired · Post by **retired&wired** » Mon Feb 13, 2012 12:46 pm

Lou wrote:Sorry, "Lives channel strip" (What I meant to say is the actual fader assigned to the track that Kronos is in) "Channel Strip"

If you are recording midi and then to audio, which is what I do, I adjust the monitoring volume from "Kronos channel strip in Live" it's only midi, your not recording audio just yet so volume doesn't matter until you record to an audio track or "Freeze it" then you simply raise or lower your Channel Fader for an appropriate level and record your audio track from it.

Hope that was clear and helps a bit..

But in this case I am not recording MIDI. From what I understand, the optical out on the Kronos is digital audio, not MIDI. Wouldn't you think Korg or Presonus could shed light on this?

SeedyLee · Post by **SeedyLee** » Mon Feb 13, 2012 1:17 pm

The FP10 does not provide hardware digital mixing capabilities, which is why you need to use software, such as Abelton Live, to provide the same functionality. In this case, it has nothing to do with MIDI specificially.

Essentially, the SP/DIF data is routed to Live, where you can use the mixer/channel strip to adjust the relative volume before outputting back to the FP10 for playback through speakers or headphones. In this case, Live is simply being used as a digital mixer, using the FP10 for audio IO and nothing more.

It's also not uncommon practice to not be able to adjust the gain/volume on SP/DIF outputs.

Since I'm not a Live nor an FP10 user, I can't be of much more help than that

retired&wired · Post by **retired&wired** » Mon Feb 13, 2012 2:01 pm

SeedyLee wrote:The FP10 does not provide hardware digital mixing capabilities, which is why you need to use software, such as Abelton Live, to provide the same functionality. In this case, it has nothing to do with MIDI specificially.

Essentially, the SP/DIF data is routed to Live, where you can use the mixer/channel strip to adjust the relative volume before outputting back to the FP10 for playback through speakers or headphones. In this case, Live is simply being used as a digital mixer, using the FP10 for audio IO and nothing more.

It's also not uncommon practice to not be able to adjust the gain/volume on SP/DIF outputs.

Since I'm not a Live nor an FP10 user, I can't be of much more help than that

That does help. I don't have the co2 converter yet to test this, but the audio tab in Live's preferences shows the FP10's channels 1/2, 3/4, 5/6, 7/8, and 9/10. 1/2 is the line level connection I made on the back of the FP10, which overrides the front panel 1/2 mic/instrument jacks. 3/4, 5/6 and 7/8 represent the remaining front panel connections -- so I have to assume the 9/10 entry is the S/PDIF input on the rear panel.

retired&wired · Post by **retired&wired** » Thu Feb 16, 2012 6:35 pm

so I have to assume the 9/10 entry is the S/PDIF input on the rear panel.

Presonus and Ableton confirmed this to be true.

Dniss · Post by **Dniss** » Fri Feb 17, 2012 3:52 am

Isn't SPDIF just digital data?

I could be wrong but isn't the notion of volume irrelevant when you're talking digital?

retired&wired · Post by **retired&wired** » Sun Feb 19, 2012 6:17 pm

Dniss wrote:Isn't SPDIF just digital data?

I could be wrong but isn't the notion of volume irrelevant when you're talking digital?

It is relevant if you want to hear what you're playing.

retired&wired · Post by **retired&wired** » Thu Mar 01, 2012 3:16 am

retired&wired wrote:
Dniss wrote:Isn't SPDIF just digital data?

I could be wrong but isn't the notion of volume irrelevant when you're talking digital?
It is relevant if you want to hear what you're playing.

FYI, the CO2 arrived and after connecting it to the FP10, this is the procedure I use to make it work:

In OS X's Audio/Midi Setup utility, on the Audio Devices screen, select the FP10 and change the Clock Source to Device. Close the utility.

Then run the FP10 control program and change Sync Source to SPDIF. Leave that control program running.

Then run Live and assign the synth to inputs 9 and 10.

No snap crackle or pop. And the volume is indeed controlled via Live's fader.

Thanks everybody for all your input.