Do the ThumbDV™ and PiDV™ Sound Better Than the DV Dongle?

A number of customers have reported anecdotally that the ThumbDV™ and PiDV™ (formerly DV3000) have good audio, but is that just perception or is there some truth to it? I spoke with Rich Kovars, Applications Engineer at DVSI, who talked about the ThumbDV™/PiDV™ AMBE-3000 chip vs the Dongle’s1 AMBE-2020.

From the DVSI Website:

“DVSI’s AMBE-2020™ and AMBE-3000™ Vocoder chips, are both DSTAR compatible. iCOM originally introduced the DSTAR system based on the AMBE-2020™ Vocoder chip that utilizes DVSI’s AMBE+ technology. Since that time, DVSI has developed and produced the AMBE-3000™ Vocoder chip that implements DVSI’s latest generation AMBE+2 technology and is fully interoperable with the the AMBE-2020™ vocoder chip used for DSTAR. The enhancements of AMBE+2™ technology in the AMBE-3000™ vocoder chip can provide superior voice quality in some circumstances. The highest level of voice quality can be achieved when the AMBE-3000™ Vocoder chip (or equivalent software2) is incorporated into the equipment used on both ends of the radio link.”

So the answer is a definite maybe.

1 The DV Dongle is manufactured by Internet Labs.
2 Current ICOM D-STAR products use a software vocoder that incorporates the 3000 advancements.

5 Responses to Do the ThumbDV™ and PiDV™ Sound Better Than the DV Dongle?

  1. Michael Gray says:

    I assume you’ve asked, but it would be interesting if DVSI could provide sample audio so we could hear the improvements. Even if it’s subtle, it let’s us understand a bit more deeply, choose the right ICs in our designs, and understand interoperability.

  2. Improvements in AMBE+2 can be one issue. But i think more important is the timing of the CODEC packages that are send to the AMBE. The timing of the AMBE2020 is more critical then the AMBE3000. AMBE2020 is a CLK data type of bus while AMBE3000 has a UART. Exact timing gives less bit loss and will be sound better due to the fact that the AMBE has less to correct.

    • Michael Gray says:

      Could you point me to some documentation on that? I wasn’t aware the AMBE encodedecode process was asynchronous (not disputing it, just hadn’t heard/realized that). That said, they’d have to be doing a particularly poor job of asynchronous sample rate conversion to for it be audible (or even detectable). Studio grade audio gear commonly does ASRC, where that tradeoff can result in overall performance gains (where ASRC distortion is lower than whatever is gained by moving to an async model).

  3. Rob Fitzgerald says:

    I am using the USB Dongle on a Windows 8.1 tablet and it sounds amazing. I am comparing it to my DVAP connected to my Icom ID-31A. I also use a very nice KOSS headset with the USB dongle so that may be helping. It really does sound great….