SPDIF clicks and pops
 

Hi

I have a Cambridge DVD79, and a Denon DVD-1920 playing DVD, using digital out coax into DDDAC SPDIF board (CS8414). Schematics on www.dddac.de. I get loud clicks/pops every 5sec-1min on both DVD players on DVD playback; sounds like a static discharge, big transients. Voices sounds a bit distorted, "metallic" like. Not so often clicks on CD playback. DVD and CD media are new with no scratches. Tried to change FILT values on CS8414 (R=1K and C=0.1uF) to C=0.47uF), no significant change. Tried digital pulse transformer on dig in, no change.

Unfortunately, I don't have a scope, only Fluke 189 DMM.

Oh boy am I frustrated. Any tips out there?

Tom, Norway :-(

With your set-up connected and working (playing music) measure resistance between DVD player case and DDAC case. If it is NOT 0 (zero) ohms - connect a 0.1uF capacitor between DDAC SPDIF input RCA ground pin and case.

Good luck!

Extreme_Boky

Are you using the oscillator on the dddac board?

Yes, I am using the Tent clock as adviced...
So this mean that I have 2 master clocks competing, one in DVD player and one in SPDIF board? Is it normal to construct it this way? Hmmm. Perhaps disable Tent clock and change mode on CS8414? I.e. lift M0 pin from V+ and connet to GND?

Tom

If the clock derived from SPDIF drifts from the Tentclock then expect the occassional pop and click. In DVD mode if the audio is anything other than 44k, unlikely I would have thought, then crash, bang, wallop, it all hits the fan. Try running the dac using the MCLK from the CS8414.
BTW, I would not have thought truncating the DVD audio and possibly the CD audio by 8 bits would do much for the sound.

The reclocking with the Tent clock is meant for playing CD. If you use DVD the output might be 48 or 96 kHz sample rate. This can cause irregular effects like that.

Have you tried a straight forwars CD player or sound card with real 44.1 kHz 16 bit output ?

Indeed, if you want to to tweak the spdif receiver to work with DVD you should change the CS8414 set up to mode 2 by cutting the little wire connections for FS and BCK (this will cut of the Tent Clock) and put pin 23 to ground. Not just like that as you will short the Vd-rail, but by lifting the leg from the chip and connect to ground

doede

Thanks, I will do this in the weekend. This should do the trick.

Tom :)

Sucesss!
 

Did lift the M0 pin and connected it to GND, circumvented the Tent clock, and voila, no more pops when playing DVD...

Cheers,
Tom :)

Re: Sucesss!
 

good stuff :)

If you want, you can send back the circumvented clock for refund ....


best regards,
doede