Presonus Inspire 1394

mellowd · Post by **mellowd** » Wed Feb 07, 2007 3:05 pm

Anyone know if Ms. Pinky will play nice with the Inspire? Can I set it up as an aggregate device in OS X? Because I would like to get something with phono inputs and instrument inputs. Thanks.

Post by **dlpinkstah** » Thu Feb 08, 2007 4:40 pm

Looks very cool. Haven't tried it myself. But I generally like FireWire devices, especially on OSX. Give it a shot and let us know

mellowd · Post by **mellowd** » Fri Feb 09, 2007 2:07 am

Presonus tech support said that I could use it with the aggregate device editor in OS X. Even said that I can have two Inspires and aggregate them, because OS X is sweet like that. They also seemed to be familiar with Ms. Pinky, so I have my fingers crossed. But I doubt my Windows compatriots will find similar luck.

Dumped the U46DJ and bought one; one turntable is all I need. I hope it arrives tomorrow. In which case, I'll report back when it arrives.

mellowd · Post by **mellowd** » Sat Feb 10, 2007 6:09 am

Well, it works. It was a little tricky, but I managed to figure it out without screwing up too badly. Just don't edit Audio Midi Setup while running BinkyToy, for instance. Or changing the Audio I/O in BinkyToy to something other than an aggregate device.

Open up the Inspire 1394 Control Panel, turn on the phono input, and set an appropriate input level. I dialed it in halfway.

Set up the Audio Device in the Audio Midi utility as you would probably do anyways (44.1 kHz, levels set to 0 dB or whatever for both input and output). Set up the aggregate device as you normally would.

If you just did that, you would probably hear the control signal sound pumping through your monitors. The trick now, is to open up the Inspire 1394 Control Panel and mute all the channels (1-4). Now you can't monitor any signal at all in the Inspire 1394 Control Panel for channels 1-4. But you can still see the main mix output. I guess the mute is pre-mix, but it does not mute the input. Kind of weird considering that any mixer would mute the channel but still monitor the sound. It is also important to mute channels 1 and 2 even if you aren't using them. I've read reports that the jacks will pick up noise.

Sound quality is not so distorted as the U46DJ to the point of ear fatigue. Error is between .1-.3, which is good. Latency is good as well, using 128 samples at the moment.

Overall, I'm pleased. There is a weird "firewire whine" that becomes more pronounced when the Inspire 1394 Control Panel is open. I think I've read that it's related to ATI cards. Don't know why, but the same thing happens on my Lunix DAW (another computer) when running Gnome with the real-time kernel. The whine doesn't seem to be injected to my signal, though. Maybe a clock of some sort?

Now if only I could understand why there is no difference between "relative" and "absolute" mode in BinkyToy and gen3 vinyl. A needle drop anywhere will move the playhead. And Side A must be played at 33 RPM, while Side B must be played at 45 RPM. Hope this helps.

mellowd · Post by **mellowd** » Mon Feb 12, 2007 12:56 am

I just realized that you don't even need to create an aggregate device for the Inspire to interface with Ms. Pinky. Just select Inspire 1394 from the drop-down menu. But you always do have the option of creating an aggregate device if you so desire.

mellowd · Post by **mellowd** » Tue Feb 13, 2007 3:01 pm

I'm going to have to downgrade the Inspire from good to mediocre. There is a nasty hum on the phono input that is only activated when you use the phono input and set the gain at medium levels. It's not there if you use line-level. There must be something really wrong with the RIAA circuit. So you might have to buy a phono preamp anyways if you aren't using a M447. That way, you can set the phono gain a bit lower.

The hum doesn't even show up on my mixer if I plug the turntable direct. So I'm pretty sure it is the box. Any suggestions?

Post by **dlpinkstah** » Tue Feb 13, 2007 9:24 pm

The hum you're experiencing when using the phono inputs is probably just a grounding problem. Where do you have your turntable's groundwire connected to?

mellowd · Post by **mellowd** » Thu Feb 15, 2007 3:49 am

I connected the ground wire to my mixer. I connected the ground to chassis screw of the Inspire. I connected the ground to the outer sleeve of the phono input (lasso around the rca input). Nothing seemed to make a difference.

With nothing plugged in, and phono switched on, I don't get any noise. As it should be.
With RCA in, no ground, phono on, I get hum. As expected.
RCA in, ground, phono on, I still get hum. No visible decrease on the meters, either.

Running off of firewire bus power, by the way. Not using the AC transformer helped a bit.

Am I just hitting the SNR of most phono preamps? I'm not sure how to tell on the software mixer.

mellowd · Post by **mellowd** » Thu Feb 15, 2007 3:20 pm

It's a combination of a few noise sources.

HUM: use firewire bus power, not the supplied ac adapter; if someone can tell me the DC equivalent to 16 V AC, 1000 mA, I would appreciate it

Firewire WHINE: download the Apple CHUD tools, and turn off processor cycling (nap mode) in system preferences; a google search returned this

http://en.440forums.com/forums/index.ph ... opic=17480

MOTORBOAT: close the software mixer, and the noise will stop

Doing all these things will result in a much cleaner performance.

mellowd · Post by **mellowd** » Tue Feb 20, 2007 2:22 am

If you're interested, don't buy the stock Inspire. Get the Inspire GT Limited Edition (Guitar Center exclusive) I've been informed by Presonus that the GT (easy to tell) and the new Inspires (hard to tell) fixes a lot of the noise issues.

I have the GT, and it is so much quieter. It also looks much nicer.

BinkyToy error metric seems to be a bit better as well.

Dan · Post by **Dan** » Wed Feb 21, 2007 12:29 pm

Thanks for the in-depth coverage of the Inspire!

Presonus Inspire 1394

Great Success!

doh

phono hum

Make sure everything's grounded properly

I think I've figured it out

GT limited edition