External wordclock (Stupid question!)

[Pip]

I remember reading  a discussion about this some time ago. It was Apogee vs Lavry. 

I think it was at a mastering forum, maybe it´s still online.

What I kept  after the reading  is that more than 96Khz is useless marketing bullsh*t. Also external clocks for better sound .As many have said it has to do with the difficult design of a great PLL. It is much easier to have a great sound from an internal clock than slaving to an external one.

I remember one quote saying that if your converter sounds better slaving to your external clock then your converter have serious design flaws.
Great reading and a funny heavy weights fight

I don't  think that is true (not that it was said but that its relevant) I don't think one has to do with the other. Sampling rate and the clock that runs it are interrelated but that is all. The subject of the sampling rate is greatly debated and does IMO have tons to do with the sound as does word size. Look at what is happening in the delivery market place. We are back to SACD and DSD levels as delivery options.

As you say that is if your clock is good. Some equipment skimps on clock attributes and an outside clock will make a difference. Also the level of and depth of integration must be considered. How many different devices from different manufactures are cascading into each other. How is it done AES/EBU, SPDIF, TOSLINK, SCSI, USB 1, 2, or 3, Firewire A or B and of course Thunderbolt?

I point out that Mr. Lavry has never put a Firewire equipped product on the market. As I understand it it is because it does not do what it is touted to do. He does offer a USB option though.

To add a talking point Cranesongs David Hill has an interesting bit of science on his company website. Turns out we might actually prefer jitter like we prefer different harmonics distorting.

http://www.cranesong.com/jitter_1.html

Once again IMO it does matter depending on what you are doing and to what level.

 

[JohnRoberts]

Maybe you can sell a plug-in that adds jitter... :

JR

 

[Andy Peters]

I point out that Mr. Lavry has never put a Firewire equipped product on the market. As I understand it it is because it does not do what it is touted to do. He does offer a USB option though.

One might argue that since he's a "small guy," he wouldn't get the necessary support from TC for their DICE Firewire audio interface chip. And since he's a "small guy," rolling his own FireWire interface is simply not an option. (I remember looking at a FireWire device interface chip from TI. TI was quite clear about how they were going to support the chip: "You have to prove that you'll sell thousands of units per month or you can't even have the full data sheet.") Oh, and drivers. But -- nobody can argue that FireWire doesn't do what it's touted to do, because how many thousands of recording guys rely on it daily?

USB is another story. It's a LOT easier for the small guy to implement than FireWire ever was. For the longest time, the simple solution for USB Audio was the TI TAS1020B chip. TI support was kinda meh but they gave you all of the source code for their eval board, and it worked as advertised. The most expensive part of the development process was that you had to buy the Keil 8051 compiler.

Now, to support > 48 kHz sample frequencies, you need USB 2.0 and USB Audio Class 2, which that chip doesn't support. But XMOS has a pretty neat family of devices and drop-in designs which just work. While it might take some time to wrap your head around the XMOS processors, they give you all of the tools for free and they want to sell chips so their support doesn't suck.

Also, almost every ARM processor (Cortex-M3 and better) has a variant that comes with a USB device interface and an I2S port to talk to the converters, so it's a simple matter* of writing firmware.

-- a

* that's a joke.