[Linuxsampler-devel] Sustian pedal in CVS, Via C3

[<be...@ga...>]

Hi, yesterday I committed sustain pedal support in CVS 
(notes simply add up so you can max out polyphony if you keep hitting
the same key with the sustain pedal pressed).
If you max out the polyphony a crash is almost certain (due some
missing checks in the LS code, probably Christian's fault :-) ).

Now on the console you see a voice and stream counter that is updated in
real time. 

Below responding to Robert's C3 questions: 

Scrive Robert Jonsson <rob...@da...>:

> 
> The use case is actually very specific in our case. To build a sound module
> to 
> connect to the brain of a digital drumkit. 
> MiniBox+LS+Drumkit_from_hell is the most likely combination at the moment.
> >

That would be cool.
For mini-itx hardware I suggest you to use the cases from Cubid:
in particular the Cubid 2699R
http://linitx.com/shop/product_info.php/cPath/8/products_id/155
83 EUR+ VAT
The fastest VIA C3 Mainboard you can get is the 1GHz Nehemiah
use this and not the slower ones because even the 1GHz is slow, so a 600-800MHz
box will probably be too slow to achieve decent polyphony

http://linitx.com/shop/product_info.php/cPath/12/products_id/207
137 EUR + VAT

With these two things all you need is a
DDR266+ DIMM RAM Module (the mainboard has only one RAM slot so chose
the right size, I would say go with the 512MB to allow loading large samples
since RAM is not that expensive these days). (512MB about 100 EUR)

and a standard IDE HD. (I'd suggest a Maxtor :-) )

The cool thing of the Cubid case is that it has room for 1 PCI expansion
card this means you can use a different audio card if the internal VIA audio
sucks too much (it does indeed :-) ).
I'd suggest you a cheap C-Media PCI card with dual stereo out and builtin
MPU MIDI port (so for your MIDI-in you just need a cable, no USB MIDI in needed).
Or alternatively use a card 24bit card like those from Terratec, about
100 EUR AFAIK *
for example according to the alsa soundcards page
http://www.alsa-project.org/alsa-doc/

the Terratec Aureon 7.1 Space
supports:
 
Aureon 7.1 Space The ultimate quality in sound

    * 8 (7.1) separate Speaker Outputs
    * Uncompromising 24 Bit / 96 kHz Playback and Recording
    * Digital In/Out, Optical 24 Bit / 96 kHz
    * A3D, EAX 1.0 and EAX 2.0 Support

http://productsen.terratec.net/modules.php?op=modload&name=News&file=article&sid=149&mode=thread&order=0&thold=0

based on the  Envy24HT

Not sure if this card works well but I have M-Audio Delta cards based on the
envy24 and the alsa support is excellent. (low latency works well).

> 
> >
> > > Though we where wondering how RT capable the platform was. If it's
> > > a mini-itx board you are using I guess that it works :)
> >
> > There's no particular reason to suspect problems with the
> > architecture, and I've seen reports of VIA Eden working well with
> > RTAI...
> Great.

No need for RT Linux etc. I have a VIA C3 CPU (although in a different
kind of mainboard, not soldered on the board) and the latency with a 
cmedia PCI (with the right lowlatency kernel) is as low as 3msec.
(It's where I currently test LS :-) ).

> 
> > > What about the built-in soundcard, know anything about it?
> >
> > It's an AC'97 chip with 18 bit full duplex I/O, but I can't seem to
> > find any detailed specs. Anyway, the actual quality depends a great
> > deal on the analog cirquitry on the board, 
> 
> Yes, I think the sound quality would be good enough at the moment. I was more
> 
> thinking in the lines of RT capabilities. I've heard discouraging stories of
> 
> badly functioning ac97 cards/drivers with ALSA.

Put in a PCI soundcard as described above and forget about bad VIA audio
problems (and solve the MIDI in problem too).


> 
> The problem with the mini-box solution is that there is no possibility of 
> connecting any other soundcard, it won't fit in the box ;)

See my solution :-)

> 
> USB is a possibility, but I'd rather not go there... MIDI would have to be 
> handled that way (I'm hoping the latency for that isn't too bad) it would not
> 
> be good for lateny or reliability to connect audio there also...

Better avoid USB if you want good note-on MIDI response.
See above :-)

> 
> > unless you use the digital 
> > I/O and external converters.
> Yes, that's true, a way out if the analog-outs suck. :)

BTW: I already ordered stuff from linitx.com: fast delivery, good prices,
good selection for VIA embedded stuff (for example they sell
cheap compact flash to IDE adapters so you can put in a CF card
and boot off that card like it were an IDE disk).

At the ISP I work for we ordered a few (Nehemiah C3 + Cubid 2699R cases)
because we are building some special network appliances for internal Hotel TVs.

I think your LS drumkit expander would be quite a nice case study 
to show the general audience that LS can actually be used in a professional
and live enviroment (of course when it will be stable and somewhat finished,
not this developer version).

Robert, as you have seen the above prices are not high compared to traditional
hardware. (mainboards, CPUs).
Yes the case is a bit
 more expensive than a traditional case but it's the price you pay for
reduced size, fanless power supply unit, the C3 is a bit slow but I think
it is more than enough for your purpose.

cheers,
Benno
http://www.linuxsampler.org




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