Re: [Jack-Devel] RME Digi9636 and jack usage (long)

On Fri, Jan 13, 2012 at 12:37 PM,  <[hidden]> wrote:

> I just bought an RME 9636 card and have some questions about using jack with it. I am fully aware that this card is not state of the art anymore and quite outdated, but it will surely be more than sufficient for me for quite a while and it was a bargain.

Its a perfectly excellent device, and is just as state of the art as
anything you could buy today unless you really need a matrix mixer
(most people don't). This is one of the benefits of a "modular"
approach to equipment - although there are A/D-D/A units today that
were not available when the 9636 was first released, both the old and
the new ones all work with the 9636. there is absolutely nothing
substandard in the 9636 at all.

> 1. Hardware monitoring.
>
> With windows there are two possibilities utilizing HW monitoring. You can use the RME driver to directly instruct the card or you can use the ASIO  driver (Haven't actually tried it, as I neither do have any windows nor the required hardware, as stated above, but so I've read in the manual)
>
> I suspect, when starting jack with --hwmon it equals the direct way, while when using qjackctl and redirect the input to an output this would be the ASIO way. Just for my understanding.
>
> Now for my question: when using --hwmon with the Hammerfall Light, how or where can I specify which output to be used for monitoring?

JACK h/w monitoring is basically a waste of time unless you happy to
be one of the lucky few who can really benefit from 1:1 monitoring
(i.e. channel 1 input is monitored on channel 1 output). The actual
operation is done by configuring the RME card, at the request of a
given JACK client. But for most people its not flexible enough. Useful
for simple recording setups, perhaps. Not much more.

> 2. Bitrate
>
> All connected clients need to have the same sample rate, but what about the bitrate? Let’s say I do have 24Bit/48kHz on my first eight ADAT inputs, but I will monitor all on SPDIF Out (be it by --hwmon or via qjackctl), but this SPDIF DA converter only is 16Bit/48kHz capable, would this work, without any intermediate software? Just jack(ctl) and the card?

i'm not 100% certain about this, but there is really only 1 sample
rate on the entire card, and the S/PDIF output will run at the same
rate as the rest of the channels. its vaguely possible that the S/PDIF
outs can sync separately and the h/w may do some kind of rate
conversion but i don't recall this as a feature of the original
hammerfall series.

> 3. Alternate functions
>
> Seeing the screenshots from the windows RME control panel, there are some functions like f.e. setting emphasis bit or spdif/out to non audio.
>
> Those settings (and maybe more) are not present when calling alsamixer. What would be the appropriate way to access these settings with linux? This is

you want hdspconf.

the settings can all be adjusted from the command line with amixer,
which provides full access to every parameter in any ALSA supported
device. but hdspconf is the GUI app that makes this simpler for hdsp
users.

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