Pinging Jim Williams, Rochey or anyone that could help with PCM4222EVM...

Saxophonus · 14th February 2009

Hi Everyone,

It has been mentioned before. What happens if you have more than 1 PCM4222EVM ADC board and you want to make them work together. The fact is these boards are not ready to receive wordclock.

In my case I have 4 PCM4222EVM and a AES16SCR card waiting on my computer for those sweet bytes via 4 AES/EBU...

What would be the most effective way of making this whole deal work, without having to spring for any aditional equipment?

Radioman once suggested this way:

"Yes, and any PLL isn't necessary, you have only to pick the quartz clock output of one board and connect it into all the other boards inputs.

Pin 3 of the 2 quartz blocks (or maybe better pin 4 of U20) of PCM4222EVM connected to the Ext clock of all the other boards, the other boards setted on the external clock and all the other clock switch (SW6, SW3 etc) on the same settings."

Please take no offence Radioman, but is this option credible??? any precautions??

Thanks very much for your help.

Best regards,

Luis

Matt Syson · 14th February 2009

Hi
Yes it should be as a 'proper' TTL or whichever output should drive up to 10 inputs of a similar architecture. Make sure wires are as short as possible and similar length.
May be best with a seperate 'clock' and drive all 4 boards the same, but try as 'slaves' from 1 first.
Matt S

Saxophonus · 16th February 2009

Matt,

Thanks for you reply.

What kind of cable would you suggest to run? It´s mini coaxial with shield grounded a good choice, or just any wire would do?

Thanks!

Luis

Matt Syson · 17th February 2009

Hi
Probably any single thin wire will do. Make it short.
Matt S

Saxophonus · 20th February 2009

Thanks, will do.

Rochey · 6th July 2009

your fastest way to get audio working with this is to simply take the s/pdif out of the converter into the AES/EBU of the AES16 card.

The sample rate converters used on the card should isolate you not only in sample rate, but also in sample phase. (i.e. 44.1kHz on the PCM4222EVM and the AES16)

The noise levels of the AES16 should be lower than that of the PCM4222, so you shouldn't really notice any difference in audio quality.

Cheers

/R

mlange · 14th August 2009

So how did things end-up working Sax? How's the quality of the final product?

magruith · 9th April 2010

hi
have you a final result for clock multiple 4222??
i wouldlike made one with 8 cards....
regards

atap · 13th July 2010

If anyone is interested, I have one of the TI PCM4222EVM converters up for sale.

Just drop me a message

featherstone · 16th January 2012

Reviving old thread. Did anyone end up connecting multiple pcms using one of the onboard clocks as a master? I took mine out of my rack last night to take a look at what needs to be done according To radioman.

mlange · 16th January 2012

Never got a the final solution, here. But I'd give it a go if schematics / details were made available.

A side note, I went as far as I could within TI before I was finally told they couldn't assist with modding an EVM.

featherstone · 18th January 2012

Maybe I'll just get an external clock and only use it when I need more than two channels. I've soldered quite a bit but nothing as small as what needs to be done to send the clock out of the board. Mlange, please post if you ever do get something going.

14th February 2009	#1
Saxophonus Gear interested Joined: Sep 2008 Posts: 7 Thread Starter	Pinging Jim Williams, Rochey or anyone that could help with PCM4222EVM... Hi Everyone, It has been mentioned before. What happens if you have more than 1 PCM4222EVM ADC board and you want to make them work together. The fact is these boards are not ready to receive wordclock. In my case I have 4 PCM4222EVM and a AES16SCR card waiting on my computer for those sweet bytes via 4 AES/EBU... What would be the most effective way of making this whole deal work, without having to spring for any aditional equipment? Radioman once suggested this way: "Yes, and any PLL isn't necessary, you have only to pick the quartz clock output of one board and connect it into all the other boards inputs. Pin 3 of the 2 quartz blocks (or maybe better pin 4 of U20) of PCM4222EVM connected to the Ext clock of all the other boards, the other boards setted on the external clock and all the other clock switch (SW6, SW3 etc) on the same settings." Please take no offence Radioman, but is this option credible??? any precautions?? Thanks very much for your help. Best regards, Luis

14th February 2009	#2
Matt Syson Lives for gear Joined: Sep 2004 Location: UK Posts: 4,822	Hi Yes it should be as a 'proper' TTL or whichever output should drive up to 10 inputs of a similar architecture. Make sure wires are as short as possible and similar length. May be best with a seperate 'clock' and drive all 4 boards the same, but try as 'slaves' from 1 first. Matt S __________________ Matt S www.mseaudio.co.uk

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16th February 2009	#3
Saxophonus Gear interested Joined: Sep 2008 Posts: 7 Thread Starter	Matt, Thanks for you reply. What kind of cable would you suggest to run? It´s mini coaxial with shield grounded a good choice, or just any wire would do? Thanks! Luis

17th February 2009	#4
Matt Syson Lives for gear Joined: Sep 2004 Location: UK Posts: 4,822	Hi Probably any single thin wire will do. Make it short. Matt S

20th February 2009	#5
Saxophonus Gear interested Joined: Sep 2008 Posts: 7 Thread Starter	Thanks, will do.

6th July 2009	#6
Rochey Gear Head Joined: Feb 2003 Posts: 36	your fastest way to get audio working with this is to simply take the s/pdif out of the converter into the AES/EBU of the AES16 card. The sample rate converters used on the card should isolate you not only in sample rate, but also in sample phase. (i.e. 44.1kHz on the PCM4222EVM and the AES16) The noise levels of the AES16 should be lower than that of the PCM4222, so you shouldn't really notice any difference in audio quality. Cheers /R

14th August 2009	#7
mlange Gear addict Joined: May 2006 Location: Brentwood, TN Posts: 441	So how did things end-up working Sax? How's the quality of the final product?

9th April 2010	#8
magruith Gear interested Joined: Feb 2010 Posts: 6	hi have you a final result for clock multiple 4222?? i wouldlike made one with 8 cards.... regards

13th July 2010	#9
atap Gear interested Joined: Aug 2009 Posts: 23	If anyone is interested, I have one of the TI PCM4222EVM converters up for sale. Just drop me a message

16th January 2012	#10
featherstone Gear Head Joined: Mar 2010 Location: minneapolis Posts: 57	Reviving old thread. Did anyone end up connecting multiple pcms using one of the onboard clocks as a master? I took mine out of my rack last night to take a look at what needs to be done according To radioman.

18th January 2012	#12
featherstone Gear Head Joined: Mar 2010 Location: minneapolis Posts: 57	Maybe I'll just get an external clock and only use it when I need more than two channels. I've soldered quite a bit but nothing as small as what needs to be done to send the clock out of the board. Mlange, please post if you ever do get something going.