Toasted DAC

[dsavitsk]

I have an old CAL audio sigma which I used primarily in a second system in my office decoding a signal from a usb soundcard. I have had problems with it off and on not locking in a signal very well. With this DAC, when it does lock the signal, it makes a click, and when it is unable to make a lock, it clicks a lot very very fast (probably a few hundred times per second, but I am not really sure). The solution has always been to turn it off and back on -- sometimes taking a few tries.

Something about this sound has always seemed like trouble. Anyway, I have been building a PC for use in my stereo, and I put in a Chaintech card to use its toslink out. It did work with the CAL, but on occasion would fail to lock and make the horrible noise.

Anyhow, my good DAC is in for repairs right now, so the CAL has been in the main system. I turned on the computer, and when it came on and the DAC tried to lock its signal, it failed. I was across the room, so it took me a few seconds to get to the CAL and shut it off. By the time I did, the CAL had stopped the rapid clicking, and started making a pathetic wimper of a click. It seems that something has gone horribly wrong, and the CAL is no more.

Now, this is a sad tale and all, but it brings up what is the important question. Is it possible that this was caused by the Chaintech, or is it purely the CAL's fault. In other words, should I be nervous about connecting this soundcard to my Cary DAC which cost 10x more. Fwiw, the Chaintech only puts out toslink, so there should be no problem with surges, so this is purely a digital issue.

Thanks for any insight.

And as a side issue, can a dolby multichannel digital signal damage a two channel DAC?

(Oh, and anyone who wants to talk about the Mullard tube in the CAL (purchased less than a year ago) should pm me.)

-d

 

[jefemeister]

Since the CAL was clicking when using it with 2 different cards, I think that the CAL was on its last leg. I wouldn't worry about trying out the Cary. Maybe just don't leave it on when you're not around for the first couple days.

A multichannel digital signal will not hurt your DAC. It's just putting out a signal within specified voltage/current for a given digital input. I might be worried about your speakers though. I've accidentialy played 5.1 data through my DAC, and the resulting sound was loud, clicky, and very worrisome in general.

 

[dsavitsk]

Great, thanks. You were just the person I was hoping would answer this question.

The Cary does't click like the CAL, but it does show what the connection frequency is, so it is at least easy to diagnose problems.
I think the dolby signal was my bigger concern as that noise is really awful.

-d

 

[dsavitsk]

Sort of an update ... I opened up the CAL. It turns out that it uses a cd8412 as a receiver, and that it is socketed. I popped it out, popped in a cs8414 I had around for another project, and all is well.

-d

 

[jefemeister]

good to hear.

 

[Mr.Radar]

Some PCM-only DACs will reject DTS and Dolby Digital signals, but that depends on the receiver chip.

 

[dsavitsk]

Quote:

Originally Posted by Mr.Radar Some PCM-only DACs will reject DTS and Dolby Digital signals, but that depends on the receiver chip.

This definitely is true, but that wasn't the isue here. It really was just unable to make a lock with a jittery signal. If I used a soundcard directly, it would just click trying to connect. If I ran thre soundcard through a jitter reducer, it would work much better. With the replacement chip, it doesn't seem to have a problem at all.

b/t/w/, the cd8414 is a surface mount chip. I mounted it on an aries adapter.