Werner,
> There is no (cheap) Soundchip in the radio. The USB Audio Codec is
> directly created out of the IF-DSP of the transceiver. There are no
> inaccuracies of the cheap soundchip quartz and there is no cascading
> of DSP's, that is a significant difference in quality.
The block diagram tells a completely different story. It shows the
USB sound chip IC3202 is a PCM2901 with AAFO and UMOD. PCM2901 is
from the same family of USB CODECs used in many of the amateur
"soundcard interfaces" - e.g., RigExpert, Navigator, Signalink USB,
etc. The connections - AAFO and UMOD - are AUDIO. AAFO is ANALOG
demodulator audio (the output of D/A IC1692 following the DSP) and
UMOD is an AUDIO input to the transmit DSP modulator (IC1661).
The performance of "USB Audio CODEC" in the 7200 is (and can be)
no different than that of any other well designed PCM2901 circuit
driven by the "demodulator" output on the ACC jack in any of the
other Icom transceivers.
> This is an interesting approach in my opinion and has two major
> advantages. Better quality of the signal for soundcard modes
> independent from external soundcards, no additional cables and
> devices for mobile use.
The only "advantage" is the lack of a separate box. The design
is no different than the IC-7000 and a product like the microHAM
USB Interface III. However, IC-7200 lacks support for FSK, pFSK
(fldigi), audio keyed CW, a computer CW interface and audio pots
to allow optimizing drive levels to take full advantage of the
PCM2901 dynamic range (the PCM2901 has *NO* input gain control).
73,
... Joe, W4TV
On 8/17/2010 2:21 AM, Dr. Werner Furlan wrote:
> hi Joe,
>
> I am a bit late for a reply, but anyway.
> The way the codec is implemented is (as far I understand it) different and
> more straitforward. There is no "soundcard" in the radio, but the data
> stream is directly derived from the IF-DSP.
> My friend Gert, OE3ZK described it as follows:
>
> Es wird kein eigener (billig) SoundChip eingesetzt. Die USB Audio CODEC
> Aufbereitung erfolgt direkt aus der ZF-DSP der Transceiver. Abgesehen von
> den Quarzungenauigkeiten der billig Sound-Chips wird DSP nicht
> kaskadiert, das ist der wesentliche Qualitätsunterschied.
>
> I translate:
> There is no (cheap) Soundchip in the radio. The USB Audio Codec is
> directly created out of the IF-DSP of the transceiver. There are no
> inaccuracies of the cheap soundchip quartz and there is no cascading of
> DSP's, that is a significant difference in quality.
>
> I have a block diagram of the IC-7200 on my website, you can see it here:
> http://oe9fwv.shacknet.nu/oe9fwv/bilder/IC-7200%20USB.jpg
>
> This is an interesting approach in my opinion and has two major
> advantages. Better quality of the signal for soundcard modes independent
> from external soundcards, no additional cables and devices for mobile use.
> A radio and the computer.
> Thats all. Remote control included.
>
> 73! de Werner OE9FWV
>
>
> Joe Subich, W4TV-4 [via Elecraft] schrieb am 13 Jul 2010 um 9:17:
>
>>
>>
>>> I don't trust the quality of an external soundcard of this price.
>>> It might be sufficient for PSK31 but probably not for Winmor. The
>>> Signalink USB is good, but not for 20 bucks.
>>
>> The USB Audio CODEC integrated circuit in the IC-7000 or IC-7600 has
>> the same specifications as the USB Audio CODEC in Signalink or a $15
>> USB headset adapter. There is no benefit to putting audio to digital
>> conversion in the radio and bringing the audio out using a driver
>> dependent protocol.
>>
>> An integrated "USB audio CODEC" is nothing more than a gimmick that
>> provides no performance benefit while limiting user flexibility/choice,
>> increasing cost and decreasing reliability.
>>
>> If one were going to provide digital output, it would be far better
>> to stream the raw in I/Q data from the DSP's ADC via firewire rather
>> than push it through two additional A/D and D/A steps and reduce it
>> to a single channel of audio.
>>
>> 73,
>>
>> ... Joe, W4TV
>>
>>
>> On 7/10/2010 3:48 PM, oe9fwv wrote:
>>
>>>
>>> I don't trust the quality of an external soundcard of this price. It
>> might be
>>> sufficient for PSK31 but probably not for Winmor. The Signalink USB is
>> good,
>>> but not for 20 bucks.
>>> I have not heard of a problem with the DSP in the IC-7200 or 7600.
>>>> From what I have heard this is not a real soundcard but the IF passband
>>> after the DSP is sent to the audio codec via USB.
>>> It would make it very easy using the K3 for digital soundcard modes
>> without
>>> another external device.
>>>
>>> 73! de Werner OE9FWV
>
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