64 Khz! "Overclocking" a 'singlespeed' interface ADAT wordclock acrobatics.

[Land Fish]

Hi,

I was wondering if anyone out there has experimented with trying to crank the sample rate as high as it can go on their ADAT AD converter or interface, by means of variable external word-clock?

yes. I am thinking that one may be able to get as high as 64khz, or so, out of a 48khz ADAT box, by manipulating the wordclock.

yeah, I know what I'm supposed to do... use 88.2khz and then use the single speed clock output so that the behringer is getting a clock source in its designed range (44.1) and then I assume that it gets upsampled or converted somehow in the fireface... it works... but I know that the behringer is capable of 48khz or even higher.

or just but a second fireface... i don't have that kind of dough... that is why I put this post in 'low end theory!!!'

see, what is happening when you do that is there is the sample-rate of the project which is say 88.2 khz... you have 2 streams of 8 channels of data coming in one that was sampled natively at 88.2hkz and anther that was sampled at 44.1khz from a unit that is capable of doing higher that gets processed somehow (interpolated at least, i hope) so that it's samplerate becomes 88.2...

can't we meet halfway???

if you still don't quite understand this madness... I'm trying to have both the fireface and behringer running at the same native speed. not both running at different multiples with sample rate conversion. AND without using the variable +/- 4% coarse/fine sliders...

why? to get the highest fidelity, while still having ample CPU headroom. freedom to throw convolution reverbs and fancy modeling plugins and instruments all in real time. 48khz 24bit runs and sounds fine, but 88.2 sounds noticeably better, but starts really limiting things and becomes slightly more unstable.

64khz seems like it would be the perfect balance!

I even have a dual G5 2.0 with 2 gigs of ram, running the best DP5.12. I don't want a stupid TC powercore or UAD-1 or that kind of stuff. I'll just stick to 48 khz instead of spending thousands more... or buying a Mac Pro... same consequence...

BTW, Do plug-ins work okay at 64khz??? maybe the frequency settings are not accurate to their markings, but sounds fine? I'll try it without the expander...

I just got a RME Fireface 800. It has very powerful clock technology. I've already noticed an improvement in the sound of my ADAT expander when slaved to the RME's clock at 48khz. I am satisfied and plan on doing my next few sessions without trying higher than 48khz 24bit for now, because I don't want to ruin sessions... the idea will be on the back burner, and this is more of a theory discussion/debate...

I know that I'm very close if it is possible with this combination. I actually got the behringer ada8000 to "sync'' at 64 khz, without having to activate the clock divider!!! However; there are clicks (too be expected when attempting such a thing... but I wonder...) that you can see happening by the meters jumping in the audio monitor windows and you can hear them when things are quiet.

as soon as you turn off the clock divider, the unit drops out of sync. again to be expected. that is what 'should' happen when interfacing a single speed unit to a double speed unit. But I am hoping to break the sample rate barrier!

(single speed, divides the clock frequency down the the native frequency is 88.2 or higher) on the RME's sync wordclock out. It is only designed to operate at 44.1-48k, but probably can do 32 khz. (yuk)

I also don't want to have to use the variable pitch sliders. I don't want to end up with any weird sample rate conversion pitch issues when it comes time to do master bounces...

[Sensual Ears]

what the ****.

[tnjazz]

Walters, is that you?

[Land Fish]

Who is Walters?

The reason that I posted this in Low End Theory, is that no one here seems to actually have any theories. Any one with money just wouldn't even think about this stuff. They would just sell their soul to digidesign for $20,000... and use 96k or higher, like it's no big deal.

Personally, I would get a Daking console and a modified Ampex MM-1200... and f* dealing with computers...

trust fund? Lottery? Grant money? Major Label ties?
where do you people get your money? certainly not be recording local bands!

I've always wondered why 64 khz never caught on as an industry standard... It's just 32khz satellite b-cast x2. It's the missing link between 48k and 88.2k... I've always wanted to try 53k or 78k or any random sample rate I want. why not???

somewhere in there is the threshold at which cranking the sample rate up starts to not really matter in how it sounds to most people. So why not be able to use several more plugins in realtime? that goes for high end DSP systems like Protools HD as well, not just native 'hacks' like me. hahah.

I know people are going to question my ideas... I'm a free thinker. I try new things... I know people are thinking 'why would you even waste your time with such a wierd thing? just use 48k'

I'm looking for input from other 'ENGINEERS' remember back in the early days... when Bill Putnam wore a LAB COAT!

[evilgrill]

a very cool idea! i have no clock with that sample-rate though so i can't try it.

[Land Fish]

Originally Posted by evilgrill

a very cool idea! i have no clock with that sample-rate though so i can't try it.

thanks!

Think of the potential benefits! at least 33% more CPU headroom (less crashing, more plugins etc...than 96khz) many gigs less of potentially wasted hard drive space! lower latency, more virtual instrument instances, higher track counts. why not?

64k (or so) is right in the sweet spot! the frequency response would go up to 32khz without harsh/phasey anti-aliasing filters that are associated with 48k and under. It's the ideal semi-pro or hell even pro standard!

I haven't really looked into it much since I thought of the idea and made that post on a whim, but it seems like the new Drawmer wordclock units won't do it, and Apogee Digital doesn't really specify either... It looks like RME and MAYBE Lucid (SSG192) may be the only units that mention 64k right now. What other companies make studio master clocks? I haven't really been very motivated or inspired to spend that kind of cash on such a trivial thing since I still don't have an automobile!

However! I am positive that you could do a full session if you have multiple RME Fireface units and run Digital Performer 5!!! Both support 64k!

I still haven't tried messing with plugins at 64k... but it's really just a random idea that could turn out to be a really cool thing if it gets attention and support from the right people!!!

[Joe Porto]

Cubase supports 64k (or maybe 60k, can't remember). I tried using it with an RME multiface, and the RME did support 64k, but the big ben doesn't, and I am using a couple of AD/DA-16xs, so I cannot really slave everything from the RME clock. I'm back to 88.2

I agree, that 60-64k would be a great compromise. I may mess with it some more and see what I can come up with.

[Land Fish]

update. tried it again. syncs but are a few clicks. sessions run fine, but can't use my Waves plugins so it is kind of worthless... the DP plugins work though and the masterworks EQ is my new favorite eq. I was stuck on the Renaissance EQ since before 9/11.

it is so close!

how about the Alesis AI-3 or the Lucid converters? Mytek? c'mon Mytek! I know you can!!!

I know a second rme would for sure, but what about low end adat boxes?

some product somewhere must not have what limits the top end of the variable clock... or whatever... I don't know quite that much about converters, but I did once build my own from a Crystal-Semi Evaluation board...

[daverich]

I've been a long time advocate of 64khz.

That said I doubt overclocking would work - but if you manage it let me know

Kind regards

Dave Rich

[Jamzone]

Stupid Uad or Powercore??

Well, beware or you could end up with something that actually sounds good.

I can tell you that the majority of what you call "pro users" still are in 44.1/48khz. Look elsewhere for improvement.

Best,

Jamzone