HD Radio Tuner Modifications

[Netdewt]

An externally hosted image should be here but it was not working when we last tested it.

Really, the only two units available are the Sangean HDT-1/1X and the Sony XDR-F1HD. The 1X has a digital out. I have seen some modifications stuff on the net.

radioxtuners.com Sony modifications
Sony tests and modifications
more Sony stuff

modified Sangean - $800

Have you guys tried these? Any modders out there? I'm especially interested in getting a digital out from the Sony? Ideas on how to hack it?

 

[Netdewt]

One answer I got via email:

Have you or do you know of anyone who has been able to get the digital
signal from the tuner, so that it can be sent to a decent DAC? Or is it not
good enough to be worth trying?

A digitized version of the audio of not available at the module level. There are pins inside the module on the chip for the purpose, but I don't know whether they are driven.

The DAC uses a huge oversampling factor to shape the quantization noise and push it outside the audible bandwidth. Why would you want to undo that?

Am I asking a stupid question?

 

[darkphader]

I am also looking to get digital (Optical or Coax) out of this tuner as my new gear does not have analog inputs. An external converter would mean three separate conversions (the internal DA, the outboard AD, then the processor DA) which would not be to the benefit of the audio quality.

Here's a link to the service manual:
Service Manual
The schematic shows an I2S_OUT line not connected to anything but I don't know exactly what that is and if it can be used to this purpose.

Have you had any success?

Anyone have an idea if this can be accomplished?

Thank you,

Chris

 

[tiefbassuebertr]

I am looking for modification advices for DVB-S, DVB-T and DAB+ tuners.
Who can give me here some advices?

 

[len_scanlan]

I am looking for modification advices for DVB-S, DVB-T and DAB+ tuners.
Who can give me here some advices?

Hi tiefbassuebertr,

The biggest problem I see with digital radio today is the move to lower and lower bitrates (worse audio quality). The broadcasters pay for a certain amount of radio bandwidth, and it is up to them how many radio stations they squeeze into that bandwidth. More stations = more $$$ advertising :-(

Just like an MP3 player, you get poor audio quality at low bitrates. Below 192Kbps its worse than FM radio quality... Some stations are on 128K or only 96K (AM radio!).

The codec used in DAB+ is more efficient than the original DAB, so there can be some improvement in audio quality **at the same bitrate**, however the broadcasters see this as an opportunity for more radio stations, not better audio!

So I don't see any point in trying to modify a digital radio when the source material is already compromised to such an extent!

Now, who makes the receivers?

Frontier Silicon provide the chipset or module for a large percentage of DAB+ radios in Europe.
Something like this:
Frontier Silicon | Digital audio products | Venice 7 Low-power, low-cost DAB/DAB+/DMB-A/FM tuner module

If its a car radio, then probably NXP.
SAF3561HV :: NXP Semiconductors

(I used to work for a car radio manufacturer, so I have some knowledge of the vendors)

A DAB receiver usually consists of an RF front-end IC ('RF to bits'), followed by a digital baseband IC which decodes and processes the bitstream, and outputs audio (analogue usually) or I2S digital (if you're lucky).

You might be able to find a digital audio output that you can send to an external DAC, but other than that there is not much you can modify.


Thanks,

Len.

 

[tiefbassuebertr]

Hi tiefbassuebertr,

The biggest problem I see with digital radio today is the move to lower and lower bitrates (worse audio quality). The broadcasters pay for a certain amount of radio bandwidth, and it is up to them how many radio stations they squeeze into that bandwidth. More stations = more $$$ advertising :-(

Just like an MP3 player, you get poor audio quality at low bitrates. Below 192Kbps its worse than FM radio quality... Some stations are on 128K or only 96K (AM radio!).

The codec used in DAB+ is more efficient than the original DAB, so there can be some improvement in audio quality **at the same bitrate**, however the broadcasters see this as an opportunity for more radio stations, not better audio!

So I don't see any point in trying to modify a digital radio when the source material is already compromised to such an extent!

Now, who makes the receivers?

Frontier Silicon provide the chipset or module for a large percentage of DAB+ radios in Europe.
Something like this:
Frontier Silicon | Digital audio products | Venice 7 Low-power, low-cost DAB/DAB+/DMB-A/FM tuner module

If its a car radio, then probably NXP.
SAF3561HV :: NXP Semiconductors

(I used to work for a car radio manufacturer, so I have some knowledge of the vendors)

A DAB receiver usually consists of an RF front-end IC ('RF to bits'), followed by a digital baseband IC which decodes and processes the bitstream, and outputs audio (analogue usually) or I2S digital (if you're lucky).

You might be able to find a digital audio output that you can send to an external DAC, but other than that there is not much you can modify.


Thanks,

Len.

most user's think, the reason for the unsatisfy reproduction are the bit-rates. But I have heard burned MP-3 music material (384Kb/sec, 192kb/sec and 96kb/sec, acoustical jazz, classic) in a listening test against PCM (i. e. from CD Player).
The sonic quality in MP-3 is clearly associated with losses regarded the resolution, but sound quality is very good, even at 96 KHz.

The main reason for the unsatisfy sound reproduction from broadcast stations must result from an other source. I think, the source are Audio devices like this: Optimod-FM 8500; go to
ftp://ftp.orban.com/Audio_Quality/Maintaining_Audio_Quality_in_the_Broadcast_Facility_2008.pdf
ftp://ftp.orban.com/8500/8500FM/Documentation/8500_3.0.2_Operating_Manual.pdf

Two schemas from DVB-S receivers:
??????.?????
??????.?????

 

[lcsaszar]

I am also looking to get digital (Optical or Coax) out of this tuner as my new gear does not have analog inputs. An external converter would mean three separate conversions (the internal DA, the outboard AD, then the processor DA) which would not be to the benefit of the audio quality.

Here's a link to the service manual:
Service Manual
The schematic shows an I2S_OUT line not connected to anything but I don't know exactly what that is and if it can be used to this purpose.

Have you had any success?

Anyone have an idea if this can be accomplished?

Thank you,

Chris

I had a look at the Sony XDR-F1HD circuit diagram, and I would like to know what is the function of the IDM module TUX-HD01. I have read in some test that the analog FM part of the tuner is also excellent.

 

[DF96]

most user's think, the reason for the unsatisfy reproduction are the bit-rates. But I have heard burned MP-3 music material (384Kb/sec, 192kb/sec and 96kb/sec, acoustical jazz, classic) in a listening test against PCM (i. e. from CD Player).
The sonic quality in MP-3 is clearly associated with losses regarded the resolution, but sound quality is very good, even at 96 KHz.

Most users are right. DAB uses MP2 coding, which at high bit rates can be better than MP3 but at the low bit rates used for DAB MP2 fails. MP3 would be better. AAC, as used for DAB+, is better still but few broadcasters seem to be interested in sound quality.