[ardour-users] Analog Input level Monitoring for delta1010LT ?

[Jason Jones]

> Now, to monitor some live inputs, head down to any of the HW In 
> channels, and unmute/up level on an In channel that you have an input 
> on (mic, guitar, etc).  Make sure to up the level at the analog 
> pre-amp as well, making sure to account for the numbering difference 
> (H/W In 3 is controlled by ADC2, etc).  At this point I sometimes run 
> 2 instances of envy24control (yup you can do that) so I can watch the 
> level meter while adjusting the proper ADC.  Once that is adjusted, 
> unmute and raise level on the monitr mixer tab and the audio will be 
> sent to the Digital Mixer and you should hear it.  That's that...
>
> The IPGA0-7 adjustments on the analog page is an additional gain boost 
> for line inputs.  If you turn up an ADC all the way on a given 
> channel, and the signal is still not hot enough, this amplifies it 
> internally, thus adding distortion.  In my opinion, anytime you use 
> these you are band-aiding a problem somehwere else.
>
Doug, I can't thank you enough.  It would have taken me quite a bit to 
figure that one out on my own - and... it saved our bacon for today's 
recording session.  Thanks.

Now.... Some bad news..  I followed your advice, and everything with the 
line-in levels made sense, and worked like a charm, but....  as far as 
the xruns go - I'm still crying.... :-(

Instead of getting an xrun per song now, I'm only getting one per 
every-other-song - but obviously, this is still unacceptable.  I changed 
my periods to 2048, and my recording rate to 44.1K - (I tried setting it 
to 4096, but when I tried to start jack, it told me alsa wouldn't allow 
a period with that setting...  Is that normal?)  I had a latency of over 
a second - but, like you guys said, it didn't affect the recording at 
all...  Didn't even notice it.  I also enjoyed recording with the 
digital mixer on, so I could hear what was being recorded...  Very nice..

The only thing I can think of to get rid of the xruns is to start 
removing hardware (like my wireless NIC... maybe my second video card, 
although that one would hurt.  I use the full screen of both screens... 
:-(  )...  Maybe start removing processes which are running...  I've 
removed all the ones I know I don't need, but there are some in my 
"rc-update show" screen that I don't know what they do.  I wish I had a 
list of my processes, but I don't have my computer here with me.  I'll 
get that list later.  Maybe you could give me a list of processes 
running on your system, Doug?  That'd help me out quite a bit.

Also - maybe there's something in my kernel that I've got set that 
shouldn't be set, or vice versa?  Are there any red flags out there for 
kernels that I should be aware of?  I've heard the controversy over the 
pre-emptible kernel... Should that be on?

I'm getting closer...  just not quite close enough.

Maybe if I understood exactly what an "xrun" is, I'd have better luck 
trying to figure out why my system insists on giving em' to me?

Anyway...  I'm far from throwing my hands up..  There are still too many 
things I don't know.  Too many options to explore...  Too many headaches 
yet to receive.. :)

Thanks again

--Jason