best choice of DAC - my MB200 or my ARcam AVR280??

[notfes53]

Please can someone educate me on some basics of the MB200, please? I have had my MB200 for a while and have started to rip my whole CD collection to FLAC. These are on a a hard drive in my networked PC.

Should I be outputting analogue to my Arcam AVR280 receiver, or will I get better results outputing the Flac file via the MB200's coaxial digital output to my AVR280, which would then presumable turn it back into analogue using its own Wolfson 24-bit 192kHz DACs?

a) I want to avoid double/unnecessary processing of the signal, and
b) I have the option of feeding the Arcam Receiver with a pure analogue stereo input, by pressing a 'Direct' button. The Direct mode bypasses
automatically all processing and any surround functions. In Direct mode, digital processing is shut down to improve the sound quality by reducing the digital noise within the AVR280 to an absolute minimum.

All help and advice much appreciated!

[adrianr]

Hi there,

I think I may be able to clear up what I think is a misunderstanding of the processes in the two options. Apologies in advance if I underestimate your current knowledge:-)

Both the receiver and the MB200 have a digital-analogue converter (DAC). To quote from the MB100/200 manual:-

"Equipped with 24-bit/192KHz audio DAC from Analog Devices Inc, low noise Op Amps from Burr-Brown® (famous for their clean output and ultra-low distortion characteristics), our own specially developed timing circuitry and FLAC lossless compression support ...

The Audiophile Edition (MB200) adds a low jitter TCXO (temperature compensated crystal oscillator) to dramatically improve spaciousness, clarity, impact, and purity; providing the highest quality audio playback available in anynetwork media player."

Wolfson, Burr Brown and Analogues devices are all well respected manufacturers of circuitry, but have produced many different model numbers over the years. However, there are many more hardware issues affecting sound quality than the DAC and filter alone. Even if you knew which model DAC was in each device, I would say the only way you can decide which is best is to use your own ears. Good sound is very subjective! Perhaps you can enlist a friend to hep you run a blind test between the two (or two friends for double-blind test, look on wikipedia or google for more info).

In very simple terms, a stereo-audio DAC will only convert PCM digital audio (the format of original CD's) into analogue sound. Compressed audio files need to be decoded into that format to be fed to the DAC. Whilst some receivers can decode MP3 or WMA, I do not think there are any that can de-compress FLAC.

So, the result is that you have two options:-

1) Coax or optical digital to Arcam. The MB200 decodes the FLAC into PCM which is sent to Arcam. The ARCAM's DAC converts into analogue.

2) MB200 decodes to PCM and it's internal DAC converts to analogue for amplification by the ARCAM.

Therefore, there is never any duplication of processing; it is simply a choice of which DAC is used to convert the identical PCM data. Any surround effects you add on with the ARCAM will be applied to the PCM data.

Not sure if it is the same for the Arcam, but my Sony receiver needs to be in an 'auto' mode to enable the internal crossover to send the low frequency sound to my sub. Using 'direct', my small satellite speakers cannot handle the low frequency stuff, and nothing goes to the sub, so it sounds crap! If you have full-size front speakers you should be OK with direct. Again, the Arcam may deal with the low frequency stuff differently to my Sony.

I hope I am clear, and I am sure their are experts out there with far more technical knowledge! I've tried to keep my explanation simple...

Adrian

PS, a third option is to buy an external DAC. I do this with a Musical Fidelity X-DACv3, which I think is slightly better than both my MB100 and Sony receiver. However, the difference is slight, and Arcam have always been well rated by What HiFi for having receivers which have a very musical sound. The expense of another DAC may not be worthwhile. If you are interested, have a look at http://www.computeraudiophile.com/ or other sources for current DAC reviews.