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Yes, finally, after xxx promises, the Digistore is now open and you can download the 5.1 upgrade. Visa/MC ONLY!

P4B533-E Review

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Greg Malcangi Tue, 03/13/2001 - 01:52

Hi audiokid,

I downloaded and installed 5.1 last week.

Strange thing:
I've got a 9600/350 (OS8.6) because of the slots, I need all six. As I work in surround most of the time I really needed the 5.1 upgrade so I started researching new G4s and expansion chassis. I then gave Digi UK a call and asked their advice. They told me that they were running 5.1 on OS 8.6 and were surprised to hear that on the website Digi only supports 5.1 on OS 9.0 or above! I thought I'd give it a go and installed 5.1 on my 9600. It loaded and seems to run just fine. I've been using it for a week now and it seems just as stable as 5.0.1. Speed also seems fine so I'm going to save my money for the time being and stick with my 9600 and OS 8.6.

The stereo and surround mixer plugs do gobble up more DSP. I would say it uses about one chip more than previously. However, with the ability to make resources inactive and with better DSP management I'm finding that overall I'm not using much more DSP on say a 40 channel mix than I was previously.

The extra 32-buses are certainly useful, as is the MIDI event window. But the winner for me is the I/O Setup. Being able to group and output to the channels I want is a great help, as is the ability to assign more than one output per channel. I can now create a stereo mix from a surround mix automatically, and it works great.

Another tip for PT users:
Are you using an 888? There has been a lot of talk over the years on the DUC about the sound quality of the 888s. I've got 2 888/24s and a 1622 and had been seriously considering selling one of the 888s and getting an AD8000. I then saw a thread on the DUC about clocking and decided to get a Rosendahl Nanosyncs ... Wow! The difference is amazing, even the director of the film I'm working on could tell the difference! I can honestly say it's the best UK£750 (US$1000) I've ever spent on the studio.

Greg

Greg Malcangi Tue, 03/13/2001 - 17:35

Hi audiokid,

>

To be honest, my system seems to be running great and I'm a little scared of screwing it up with an OS upgrade. I'll probably miss out OS 9 and go straight to OS X when I upgrade to a G4 later in the year.

>

A little. I Couldn't see much of a difference except of course the event window which certainly helps. The event window has everything you would expect, including a filter so you can just see the type of events you are interested in.

>

Not knowing how much you know, I'll start from the beginning: :)

Every piece of digital equipment uses a vibrating crystal to create a clock to measure the duration of a sample, 44,100 48,000 or whatever. Inaccuracies in the clock causes jitter. Furthermore, if you factor in delays caused by daisy chaining you are looking at even more jitter.

Now, the A/D conversion in the 888s is pretty good. However, what lets the 888 down over say an Apogee AD8000 is first, the internal clocks in the 888s are crap and secondly, the analog circuitry in the 888s isn't as good as in the AD8000.

The Rosendahl Nanosyncs is a very accurate clock source. It has six word clock outputs on the back, 3 of which are configurable for x256 (superclock) which is what the digi 888s/1622s need to be fed. I then use two of the remaining three word clock outs to feed my time-coded DAT maching and my DA98. The Nanosyncs also has 4 video sync outputs, I feed one of these into my MOTU MTP/AV. Not only have I effectivly replaced the crappy clocks in my 888s and 1622 but all my digital kit now has it's own feed from a single and very accurate clock.

I'd have thought that the reduction in jitter that I've accomplished would result in a relatively minor improvement. I was expecting to hear a slight difference. Wrong! The difference is major, much cleaner and richer.

My 888s now sound much closer to the sort of quality I've experienced with an AD8000. Still not quite as good, but close.

Would I be happy to run a PT rig without a Nanosyncs? ... I'd rather chew my own leg off! :D

Greg

Greg Malcangi Wed, 03/14/2001 - 05:41

Hi audiokid,

>

It depends. The MTP/AV doesn't directly have anything to do with your audio datastream, unless you are slaving your A/D converter/s to the word clock out of the MTP/AV.

I'm not sure you've got it. Let me give you an example, let's say you have a MTP/AV, two 888's and a DAT machine for mastering. There are two ways to set this up:

First scenario; take the word clock out of the first 888 and into the second 888 (daisychain). When mastering to the DAT a word clock signal (from the first 888) is automatically embedded in the datastream when transfering digitally from one of the 888s to the DAT machine. In other words you are starting off with a jittery clock and then daisychaining this clock to the second unit and the DAT machine, welcome to Jitterville! In this scenario the MTP/AV is just a MIDI interface and a time-code generator/reader. Connecting a Nanosyncs just to the MTP/AV in this scenario isn't going to affect the quality of your audio in anyway.

The second senario is to use the MTP/AV as the master clock and feed the word clock out from the MTP/AV to the first 888, then daisychaining as in the first scenario. This scenario is marginally better than the first because the internal clock of the MTP/AV is marginally more stable. Adding a Nanosyncs in this scenario just to the MTP/AV will improve the audio slightly by replacing the internal clock of the MTP/AV with the Nanosyncs clock.

Ideal scenario: Use the Nanosyncs as the direct master clock for all your equipment. Each piece of kit gets it's own output from the Nanosyncs. This reduces the jitter caused by a less stable clock and totally elimiates the jitter caused by daisychaining. As a nice added bonus you will find that you get SMPTE lock at least twice as fast between PT and say your DAT machine. Of course, this scenario will only work if your digital equipment has a word clock (or video sync) input. All professional gear does but it is often dispensed with on more budget gear.

Thus the improvement you will notice with the Nanosyncs depends on the amount of jitter currently in your system. ie., the quality of the internal clock in your current clock source, plus the amount of daisychaining. For example, if you have an AD8000 the internal clock is quite good. The Nanosyncs will still improve the overall sound but it won't be as big an improvement as you will notice with say an 888.

BTW, the effects of jitter vary according to the amount. Mild jitter causes a slight narrowing of the stereo image, poorer frequency response and slight distortion. Severe jitter can cause clicks and pops and severe distortion. In my case I probably had mild to moderate jitter but nothing I noticed until I added the Nanosyncs.

Check out the info at:
http://www.rosendahl-studiotechnik.de/nanosyncs.html

Be sure to read the PDF manual at the bottom of the page. There's quite a lot in there specifically for Digidesign users.

If you decide to get a Nanosyncs you must get cable with the correct (75ohm) impedance, otherwise you add more jitter than you eliminate: 75ohm Coax cable with BNC connectors. It should be quite cheap and easy to find.

>

Rosendahl is based in Germany. The price in the UK is UK£750 which at the current exchange rates is about USD1,000. However, I don't know exactly the price US dealers offer. Probably a little higher due to shipping costs and import duties. HHB distribute the Nanosyncs both in the UK and the US.

This whole concept of clocking seems quite complex, probably due to my explanation, but once you've got your head around it, it's actually quite simple. Regardless of whether users realise it, clocking is an area that affects everyone using digital audio and as you expand your equipment list it's understanding and correct implementation becomes critical.

Greg