Traxis DBS 4500 and AC-3 Audio

[jjpicou]

I decided to try out a Traxis DBS-4500 receiver and for the most part am happy with the results so far, however I decided to test the S/PDIF outputs.
The unit has both an optical and Coaxial outputs.
I connected the coaxial output to my JVC System and it didn't work at all, No audio. I then tried the optical and still nothing.I checked several stations that use AC-3 stream and no luck.
Attaching my Pansat 2500A to the loopthru of the DBS 4500, and then using the S/PDIF Coaxial output of the Pansat the audio is decoded just fine.
I appears the Traxis is not passing AC-3 at this point.
Does anyone else in this group have a Traxis DBS4500 and able to get AC-3
audio ?
Thanks

Opps, It looks like I posted this in the wrong fourm, as it would be best suited in the general discussion instead of the PC fourm

 

[Mr Tony]

I didnt think the 4500 did pass AC-3

It sounds like my KUsat 2600....has a optical output but doesnt pass AC-3

 

[jjpicou]

Iceberg:
It sure seems that way
however when looking at the features list in the owners manual it states it has S/PDIF Coaxal and optical AC-3 Output.
Also the Traxis web site states...
Basic Features

* MPEG-2 Digital & Fully DVB Compliant
*256 color OSD Friendly User Menu
*60 Satellites
*4,000 Channels
*Software Upgradeable through RS232
*Multi-Satellite Search
*Favorite Sorting
*Multi-Language OSD
*DiSEqC 1.0 & 1.2 compatible

Extra Features

* Digital Audio Bit-stream output
* USALS satellite position
* Timer Set-Up
* 16:9 / 4:3 Automatic setting
* Auto PID / Manual PID
* 0/12V switching
* Fiber Optical Connector
I am trying to confirm with DMSI and Traxis but haven't heard back yet

Jerry..

 

[Mr Tony]

Fiber Optical may not be AC-3

I know because my KUSat says Optical Audio Output (SPDIF) which I thought meant AC-3

 

[lilyarbie]

same thing really.....

Fiber Optic is the same as the digital coax output. The only difference is your sending the Dolby Digital 2.1/5.1 or DTS signal via light instead of electrical impluse down a copper wire. With the fiber optic cable, there is very little if any chance of interference whatsoever (an extremely small percentage) because of this (no electrical interference due to the transmission of light instead of electricity).

 

[Tron]

Basic Features

* MPEG-2 Digital & Fully DVB Compliant
*256 color OSD Friendly User Menu
*60 Satellites
*4,000 Channels
*Software Upgradeable through RS232
*Multi-Satellite Search
*Favorite Sorting
*Multi-Language OSD
*DiSEqC 1.0 & 1.2 compatible

Extra Features

* Digital Audio Bit-stream output
* USALS satellite position
* Timer Set-Up
* 16:9 / 4:3 Automatic setting
* Auto PID / Manual PID
* 0/12V switching
* Fiber Optical Connector

"Digital Audio Bit-stream output" doesn't necessarily mean AC-3 (Dolby Digital). This probably passes PCM uncompressed digital audio only...

 

[jjpicou]

"Digital Audio Bit-stream output" doesn't necessarily mean AC-3 (Dolby Digital). This probably passes PCM uncompressed digital audio only...

Tron you are correct, as the S/PDIF ports do pass audio (PCM) but no dolby, as I have tried several AC-3 Channels,and no audio is present.
I guess I must be confused, As I thought AC-3 was dolby. both the DMSI ( http://www.dmsiusa.com/dbs4500.htm )website and the units Manual state is passes AC-3 but mine obviously doesn't.
I wonder if the new Traxis software update will solve the AC-3 problem?

 

[jjpicou]

Update. I did get a reply from a DMSI technician, and was told the Traxis 4500/5500 does pass AC-3 Audio , but you need an external amplifier to make it work ?? :
I use a JVC audio/Video controller,100 Watts per channel, to decode AC-3 (works with My Pansat 2500A) but not with the Traxis. I don't exactly know what they mean by needing an additional amplifier.
I'm getting even more confused now..

 

[Tron]

AC-3 is Dolby Digital, these are two names for the same thing. The term 'AC-3' is often found on older consumer equipment or professional equipment to refer to Dolby Digital.

I'm thinking you might be getting PCM digital audio (standard uncompressed digital audio, not AC-3 Dolby Digital) off of the Pansat. Are you getting the Pansat 2500's digital output to work with AC-3 channels such as ImaginAsian on G-10R or PBS on 87w?

Not just any amp or receiver with a digital input will do. You will need an amplifier that specifically decodes Dolby Digital, and you will need to use a Dolby Digital input (either coaxial or optical) on that amplifier (the DVD input should work well for this, but DON'T use the CD input as a CD player only outputs PCM).

 

[jjpicou]

Are you getting the Pansat 2500's digital output to work with AC-3 channels such as ImaginAsian on G-10R or PBS on 87w?

Yes, AC-3 channels, ImaginAsian, The Tube ( On G3C) and PBS Work with the Pansat. The JVC decoder auto senses the audio format and switches to Dolby audio.
When using the Traxis the above channels are silent.

Jerry

 

[Tron]

Hmmm... that makes me wonder if the receiver truly passes AC-3. If it works with the Pansat, there's no reason why it shouldn't work with the Traxis if it really passes AC-3.

 

[Mr Tony]

on the Traxis, can you see the PID's if you hit info?

The audio PID should be the same as what shows on the Pansat

 

[jjpicou]

on the Traxis, can you see the PID's if you hit info?

The audio PID should be the same as what shows on the Pansat

Yes, I see the PID's on the Traxis Screen and the Audio PID is not the same as shown on the Pansat.
I did a manual search on the Traxis, entering the same PID's as on the Pansat
and still a no-go with the audio, So it appears at this point,to me, contrary to what the manual states and what I've been told, The Traxis does not Pass AC-3 and as Tron suggested, just passes uncompressed audio.

Jerry

 

[Mr Tony]

If the audio PID isnt the same, then it probably doesnt pass AC3

 

[saidias]

does the Traxis DBS4500 do blind scan?

 

[PSB]

No!

 

[saidias]

then what makes it so great??? any better then Pansat 2700

 

[Mr Tony]

Its a nice little unit...works great for someone who wants just one satellite or maybe motor to a couple satellites.

Blind scan is nice but not a necessity. I had a Friday Fun Poll a while back and the question was "if you could have a reciever and it could have blind scan OR a motor, which one would you pick"?

I think everyone who voted said motor