Denon 2900 - no digital out?

[davee70]

I don't seem to be getting any signal from the digital out connection on my Denon 2900. I got the unit last year mainly for the SACD/DVD-Audio capability and have been quite satisfied with it. I have found that the 2900 is also a very respectable CD player and I am now using it to listen to all my CDs. Unfortunately, a few of them are in dire need of a bit of EQ which I had been doing with a Behringer DEQ 2496 all digital equalizer (thus avoiding the time and spatial smearing of analog circuitry). However, when I connected the unit to the Denon, lo and behold I found I had no signal coming from the optical digital output... none, nada. (I know this because the DEQ 2496 has a level meter which I can use to detect the presence of an input digital signal.) Up until now I had only been using the analog outputs on the Denon.

At first I thought maybe it was something in the setup menu that was causing the problem but I checked the audio menu and both the Digital Out and LPCM settings are set to their default settings, which means I should be getting a 44.1 kHz, 16 bit signal from the optical output. Is there something else on the Denon I could have overlooked that could be the causing the trouble? Could dust have gotten in the outlet and be causing a loss of signal transmission? Is there a way to clean the optical outlet without damaging it to eliminate that as a potential cause? Has anyone else had have any experience with this kind of problem?

 

[MDS]

At first I thought maybe it was something in the setup menu that was causing the problem but I checked the audio menu and both the Digital Out and LPCM settings are set to their default settings

What are the default settings?

I'm not familiar with that player but the options are pretty much the same on all players.

Digital Out should be set to Bitstream if you want to play DD/DTS thru the optical out. For CD only it would work if it were set to PCM.

The LPCM setting must be set to PCM - not OFF, NONE, or whatever that player labels it. If it is not set to PCM, the player will convert the PCM to analog. Considering you were using analog connections before and everything worked, I'm betting that's where the problem lies.

 

[davee70]

Thanks for the reply MDS.

The Denon DVD-2900 manual states that bitstream signals (DD/DTS) are converted to PCM when the Digital Out is set to PCM and PCM signals with bit rates higher than 44.1/48 kHz 16 bit are converted to 2-channel 44.1/48 kHz 16 bit when LPCM is set to ON. For CDs, which are obviously already 44.1 kHz 16 bit PCM, the implication seems to be that it should make no difference and that does indeed appear to be the case because I am getting no signal from the optical out no matter what the setting, when Digital Out is set to NORMAL (the default) or PCM and the LPCM to OFF (the default) or ON.

I seem to recall being annoyed when I first got the DVD-2900 that the dust cover was missing from the optical out and I inserted one I wasn't using at the time, which is why I asked about cleaning it. Should I attempt to suck it out with my Mach 2.7 Windtunnel vacuum? or is there a more subtle approach I should try? How likely is it that dust alone could cause a complete loss of signal? Surely someone has had a problem like mine.

 

[j_garcia]

It is extremely unlikely that dust has completely stopped light transmission. Simplest way to "clean" would likely be a can of compressed air, but I don't think that will solve your problem. Now when you say missing "door", not all devices have covers on the optical out, many come with little caps that just sit in there to cover it, and looking at the spec sheet it appears that the 2900 is one that is like that.

 

[MDS]

What about the optical cable itself - did you remove the little plastic or rubber cap on the tip of the cable? I know it sounds silly but the cables don't come with instructions and many people have forgotten to remove that dust cover.

 

[davee70]

Thanks j_garcia. A can of compressed air! Why didn't I think of that?

By missing the dust cover I mean there was no cap over it and no plug inserted into it. However, as you say, it seems unlikely that is the real problem.

I did think to remove the dust cover from the digital cable - though I still appreciate the thought, MDS.

If dust is not the problem though, then what is? Am I looking at a repair job in the shop? Maybe I should trot down to Radio Shack and get that can of compressed air just to be sure.

As I said before, I really like the Denon. It's much better sounding through the analog outs than my 15-year old Onkyo CD player - more detail and sharper focus. I suspect that's due as much to the transport as the DAC's, and I'd really like to try using the Denon with the DEQ 2496 and keep things in the digital domain, for those CD's that really need it.

 

[j_garcia]

DEQ takes only optical? How about a coaxial to optical converter?

 

[davee70]

The DEQ 2496 also has XLR digital connectors (which I have actually used to connect up to my PC and, on occasion, "record" my re-equalized re-creations. Not for the faint of heart mind you.)

Anyway, I just tried connecting the coaxial digital out on the Denon to the XLR digital in on the Behringer using the same RCA to XLR adapter I used to connect to the sound card on my PC.

Still nothing.

Hmm... seems portentous.

 

[j_garcia]

XLR digital?

 

[davee70]

Yep, XLR. It's pro-audio.

Isn't there a line "everybody must go pro" set to a well known Dylan tune?

 

[davee70]

Holy smokes! It just dawned on me.

The Pure Direct Mode on the front panel was ON. That's how I had it set for listening and then forgot all about it. The Pure Direct was on Mode 1 and Mode 1 was programmed so the Digital Output was turned OFF.

Flaming idiot! I can't believe it.

j_garcia, I guess I owe you.

 

[j_garcia]

That was going to be my very next question actually, because I have done that a few times too....just the other day in fact, because I just hooked this guy up after almost a month due to moving.

 

[davee70]

I know what you mean. I'm good at falling into my own traps.

 

[jmrife]

When I have problems with functionality of my equipment, the first thing I suspect is User Error.

I am usually right!