Mbox 2 / Pro tools LE 8.04 - Distortion when arming audio track

[stained]

Hi chaps,

I've been at this for a total of 60 hours so far and am stumped although your forum has been an excellent help with troubleshooting/system optimisation so far.

I was a Logic Audio user for years but have recently (last week) moved to Pro tools to make working with my friend easier. Anyway, what is happening is this:

I have my guitar DI on input 1 of the mbox 2 and a mono audio track (no effects) in position within pro tools. I can hear my guitar clearly through the mbox but.... As soon as I arm that track (just arm, not actually record) and hit the guitar to set the input level the signal distorts horribly and the result is a mixture of overdrive mixed with a wierd 'modulated' sound which drops in and out. The track input meter shows a normal level. It is possible to record this distorted signal and play it back (it plays back distorted obviously).

The demo session 'Filtered Dream' plays back perfectly and I can load and play the pro tools instruments so if I can just find out what is causing this distortion problem when arming an audio track I'll be ready to get back to creativity as opposed to endless hours of installing, uninstalling win xp and pro tools.

I would be very grateful for any assistance with this.

Here's what Sandra says about my system:

SiSoftware Sandra

System
Modell : BIOSTAR Group H55 HD

Processor: Intel(R) Core(TM) i5 CPU 760 @ 2.80GHz
Speed : 3GHz
Cores per processor: 4 unit(s)
Threads per core : 1 unit(s)
Type : Quad-Core
Integrated datacache: 2x 32kB, Synchronous, Write-Thru, 8-way, 64 Byte line size, 2 geteilte Threads
L2 Onboard Cache : 2x 256kB, ECC, Synchronous, ATC, 8-way, 64 Byte line size, 2 two Threads sharing
L3 On-board Cache : 8MB, ECC, Synchronous, ATC, 16-way, Exclusive, 64 Byte line size, 4 threads sharing

System
Mainboard : BIOSTAR Group H55 HD
System BIOS : AMI 080015 06/15/2010
Bus(es) : ISA X-Bus PCI PCIe IMB USB i2c/SMBus
MP support : no
MP APIC : yes
total memory : 3GB DIMM DDR3

Chipset
Model : Biostar Microtech Clarksfield/Lynnfield DMI
Front Side Bus speed : 2x 2.41GHz (4.82GHz)

Chipset
Modell : Intel QuickPath Architecture Generic Non-Core Registers
Front Side Bus speed : 2x 2.41GHz (4.82GHz)
total memory : 4GB DIMM DDR3
memory bus speed : 2x 670MHz (1.34GHz)

memory module(s)
memory module : Nanya M2Y2G64CB8HC5N-CG 2GB DIMM DDR3 PC3-10700U DDR3-1334 (9-9-9-25 4-34-10-5)
memory module : Nanya M2Y2G64CB8HC5N-CG 2GB DIMM DDR3 PC3-10700U DDR3-1334 (9-9-9-25 4-34-10-5)

Grafics
Grafic card: NVIDIA GeForce 210 (24 SP 1.4GHz, 512MB DDR2, PCIe 2.00 x16)

Grafics processor
Adapter : NVIDIA GeForce 210 (16SP 2C 1.4GHz, 511.7MB)
Adapter : NVIDIA GeForce 210 (16SP 2C 1.4GHz, 511.7MB)

drives:
ST3500418AS (500.1GB, SATA300, 3.5", 7200rpm, NCQ, 16MB Cache) : 466GB (C:)
ATAPI iHAS124 Y (SATA150, DVD+-RW, CD-RW, 2MB Cache) : 8GB (D:)


hard drive (C:) : 466GB (NTFS) @ ST3500418AS (500.1GB, SATA300, 3.5", 7200rpm, NCQ, 16MB Cache)
Pro Tools LE (D:) : 8GB (CDFS) @ ATAPI iHAS124 Y (SATA150, DVD+-RW, CD-RW, 2MB Cache)

Peripherals
LPC Hub Controller 1 : Biostar Microtech P55/PM55/3400 LPC Interface Controller
LPC Legacy Controller 1 : T2 87-21h
Audio Gerät : Biostar Microtech P55/PM55/3400 High Definition Audio
Audio Gerät : 29559 0BE3h
Audio Codec : nVidia 000Bh
Audio Codec : nVidia 000Bh
Audio Codec : nVidia 000Bh
Serial Port(s) : 1
Parallel-Port(s) : 1
drive controller : Biostar Microtech P55/PM55/3400 4 port SATA IDE Controller
drive controller : Biostar Microtech P55/PM55/3400 2 port SATA IDE Controller
drive controller : VIA PATA IDE Host Controller
USB Controller 1 : Biostar Microtech P55/PM55/3400 USB2 Enhanced Host Controller
USB Controller 2 : Biostar Microtech P55/PM55/3400 USB2 Enhanced Host Controller
System SMBus Controller 1 : Intel 801xx/63xx SMBus

printers
printer : Microsoft XPS Document Writer (600x600, Farbwiedergabe)

network services
Network adapter: Realtek PCIe GBE Family Controller #2 - Paketplaner-Miniport
Network adapter : AVM FRITZ!WLAN USB Stick v1.1 - Paketplaner-Miniport (Ethernet, 48Mbps)

power state: on

Microsoft Windows XP Home 5.01.2600 (Service Pack 2)
Platform Compliance : x86

[albee1952]

You probably should update XP to SP3. You definitely should trash prefs as that solves odd behavior a lot of the time. I also see no audio drive and you MUST record to a separate physical hard drive if you hope to have any performance past 4-6 tracks. You could try creating a new session and importing session data from the bad session(do a few tracks at a time and test as maybe it a corrupt audio file). For info on trashing prefs, look here:
General Troubleshooting - Pro Tools LE on Windows
or find the skunkworks trasher utility as that works great. BTW, the audio drive needs to meet certain requirements such as, NO USB drives, 7200rpm minimum and firewire drives must use a Oxford 9xx chipset.

[stained]

Hi and thanks for your time. I actually went from sp3 back down to sp2 in the hope that.... well, you can guess the rest. No change. May as well put sp3 back on though.

Yes, I understand that I'll need a second drive and it's on its way at the moment but what I don't understand is how simply arming an audio track can cause this problem. It's not even the same every time I do it. Sometimes I can arm the track and there is nil reaction to me hitting the guitar. Sometimes there is a lag before the distortion comes in. Sometimes there is instant distortion. Sometimes a constant digital 'note will sound which then competes with the distortion'. Arming the track whilst not even touching the guitar can result in that digital 'note'. Arming and disarming the track quickly can cause that 'note' to change pitch. It's the closest I've got to a tune in Pro Tools since I installed it :)

Just a quick edit: as this all seems very illogical (like it can't have anything to do with the pro tools software) I closed down PT and opened up windows sound recorder to see if I could duplicate the problem. Windows is showing the mbox as the default unit for playback, record and midi so if I get a distorted recording in sound recorder that would take the PT software and any of its settings out of the 'who's the culprit here' equation. Well, recording a guitar through the mbox and into sound recorder also results in the same distortion so I'm thinking that I have some kind of audio driver incompatibility here? Or a defective Mbox 2?

[sw rec]

Sounds like there's a good likelihood that you're sending the OUTPut back to the INPUT somehow, which will create digital feedback whenever you arm the record track.

[stained]

As a Pro Tools noob I'm more than happy to concede that I might be doing something like that :) How would it be possible though? My 'session' consists of just one mono audio track set to input 1/output stereo and my guitar is plugged into DI input 1 on the Mbox. I can hear the guitar nice and clean through the Mbox headphone socket at that stage but as soon as I hit the arm button it all goes astray. As I say, this problem is also apparent even without Pro tools loaded.

[stained]

I've continued testing different configurations and nothing has changed. Whichever USB port I use the result is the same. I've again gone through the Win XP optimisation guide and a second SATA drive is in place. The mbox is definitely the only active audio interface on my computer. I can import audio files into PT and they play back flawlessly - MIDI is also working perfectly as are plugins and instruments. No problems at all apart from the fact that I continue to get at best 5% distorted guitar and 95% digital noise and at worst nothing at all whenever I arm a track.

One thing I did notice was that the Mbox is listed under 'hardware' as a USB controller. It is shown as 'Digidesign Mbox 2 Firmware Updater'. Is that correct?

Edit: I had a look at how the pc has connected the Mbox. Anything odd here?

Advanced PCI to USB Universal controller => Roothub USB Port 1 => Standard USB Hub => Port 1 => Mbox 2

[stained]

The last part of that post should read Port 1: Mbox 2 (well, the listing doesn't say 'Mbox 2' but I can see from the description that it is the mbox)

Can anyone possibly help me further with this arming problem?

[albee1952]

Did you trash prefs and reboot?

[stained]

Hi,

Yes, I was doing that whenever I attached the mbox to a different port but unfortunately trashing prefs has no effect on this particular problem. I'm still getting either a mixture of digital noise and guitar or just the digital 'note' whenever I arm a track.

[stained]

Still no luck but I've continued trying various things. I've noticed that if I create a stereo audio track for the guitar (guitar connected to input 1 DI on mbox) and then arm it that I get a clearer signal in the left stereo channel (but still broken) and pure digital distortion in the right channel. Odd. If I then create a mono audio track in the same session and arm it the guitar reverts to 5% guitar 95% digital distortion on that track. Sometimes nothing at all.

Another thing I noticed was this:

I can -
create an instrument track and load instrument plugin
create audio track
select audio track
hit keys on midi keyboard - instrument sounds.

If I load up three instrument tracks it is always the instrument on the first instrument track which sounds.

Is this useful information which might help to solve my problem?

Edit: just as background info it might be worth mentioning that if I revert to PT 7, 7.3.1 or 8.0 the problem is slightly different. I get a constant ticking sound like a clock which starts as soon as PT opens. When I create a mono audio track and arm it that noise is still there but is joined by loud irregular pops. If I loaded any audio it would play back distorted. The PT demo song will not play on my system until I load PT version 8.0.4