DAC modding

ajinkya · #11 24th September 2008, 07:43 PM

Having read the thread, I'm curious what the Cambridge Audio DACMagic does then and why people would be buying it at all:
Cambridge Audio DacMagic Upsampling Digital to Analogue Converter Released

pnredkar · #12 25th September 2008, 09:06 AM

Hi Ajinkya,

The reason why you would use an external DAC:
(1) For the same input specs, the quality of the output (and hence the DAC) differs. External DACs typically have the better quality DAC chipsets.

(2) There is science behind upsampling. The intermediate (time-wise) values are interpolated intelligently, so that the control over the output waveform is greater. How much you actually like the sound of upsampling is entirely up to your personal choice.

(3) No moving parts, better isolation of components, etc.

The ways in which you would use the external DAC:
(a) Digital music stored on portable players, USB drives or PCs would benefit largely from such external DACs.

(b) CD transports (the cheaper versions, atleast) may have errors while reproducing the bits due the spin of the CD. If you can make a bit perfect copy of the CD using some software like EAC on your PC/USB drive, you may eliminate some of these transport errors. You now need only a DAC to complete your high-quality "CD player".

These are some of the points off the top of my head. There may be others.

Regards,
Prasad Redkar.

ajinkya · #13 25th September 2008, 09:39 AM

Prasad,

Thanks very much for the information. Yes, what you say makes sense. However, the upsampling part is still 'black magic' to me because all we are doing is substituting some curve (spline or other curve "du jour") in between the sampling instants. So information is being 'created', not recreated. Which makes me wary of the final sound. But as you rightly mention, that is upto individual taste. The same idea is used in HDTV upconversion as well and my eyes don't seem to be unhappy watching those, so why should my ears reject audio upsampling?

As an aside, anyone have an idea on what the price in rupees of the CA DacMagic would be?

pnredkar · #14 25th September 2008, 09:50 AM

Quote:

Originally Posted by ajinkya

The same idea is used in HDTV upconversion as well and my eyes don't seem to be unhappy watching those, so why should my ears reject audio upsampling?

Good comparison!

Quote:

Originally Posted by ajinkya

As an aside, anyone have an idea on what the price in rupees of the CA DacMagic would be?

The price in UK is 200GBP, in US it is $399. Looking at the prices of other CA products, I would expect it to be around Rs. 18000/-.

Regards,
Prasad Redkar.

neo · #15 25th September 2008, 05:16 PM

Quote:

Originally Posted by odyssey

Prasad
Actually, I believe the answer is not so simple. Definitely if the information is there then its best to pass it all, so in terms of bits, if the pre-recorded information has only 16 bits, what would padding extra bits do? Oversampling is a different story and there are two camps - Zanden, DCS, audio note some which believe that oversampling is better and some believe that NOS (non-OS) is best. I personally like them both for different kinds of music (I have a CDP where I can select this). In terms of modding, perhaps you referred to the bit resolution only, but if you take other mods that can be made - output caps, op-amps, quality of components such as resistors, etc there can be a huge difference in the sound quality of the DAC so much so that it can be mistaken for a completely different DAC at a different price. Even tube rolling for example can be thought of as such a mod for an output stage...
Recently I got an NOS DAC built to my specification with no op-amps and filters using black gate caps ($200 just for the caps), the sound is phenomenal and am sure it can go head to head with CDPs costing Rs 1 L.

cheers

Hey! can pl share more info your DAC. Details?Spec?Availiblity?Cost?etc

odyssey · #16 25th September 2008, 05:29 PM

Its for personal use (at least so far) quite a few people have asked me already, so I am thinking of carrying it

Will share more details later.

cheers

kaushik · #17 29th September 2008, 10:45 AM

Need help regarding DAC mobbing .

I have a pioneer Dv 300S DVD player.I feed 2 Towers fitted with amps [RCA -RCA analogue connection] .

yes it is good for video .. but the audio output is not satisfactory.I witness very poor mid and high end with this .[ although 24 bit DAC is specified...usual case in low cost players] .

I cant go for HiQ CDP because of cost .
Can any one suggest a DAC mobbing technique , that can be applied for
[ want to spend ... max 150$... ].

I have seen some kits for Audio CDP construction.... costing 500$+..for full player .But in my case changing DAC board will be enough i think.

venkatcr · #18 29th September 2008, 01:55 PM

Quote:

Originally Posted by kaushik

Need help regarding DAC mobbing .

I have a pioneer Dv 300S DVD player.I feed 2 Towers fitted with amps [RCA -RCA analogue connection] .

yes it is good for video .. but the audio output is not satisfactory.I witness very poor mid and high end with this .[ although 24 bit DAC is specified...usual case in low cost players] .

I cant go for HiQ CDP because of cost .
Can any one suggest a DAC mobbing technique , that can be applied for
[ want to spend ... max 150$... ].

I have seen some kits for Audio CDP construction.... costing 500$+..for full player .But in my case changing DAC board will be enough i think.

I am not sure I understood you well. You want to change the DAC in your DVD Player? This is not something you can do at home. In most DVD Players, the DAC will be a chip that is integrated into the motherboard. You have to know the motherboard circuitry very well to bypass the circuitry and build your own DAC circuit. In the US, this is done by dedicated electronics experts who attempt with a few units, then get their design right. Also this is not done on all - only on some dedicated units the experts feel are worthwhile.

The better option will be to buy an external DAC system and route your output through that. At your price, the closest high quality DAC I can think of is the Beresford. This will cost you some 7,500 Rs.

BTW, the modification of any circuitry including a DAC is called Modding, not Mobbing.

Cheers

kaushik · #19 29th September 2008, 03:18 PM

thanx venkat,

i intended to add one more board internally tap the internal DAC inputs.... seems may not be feasible option.. as per your pointers ,

actually i have seen low jitter clock boards being sold, to add to existing CD Player for better sound ,because of that i thought extra DAC board also may be available !

i wl go the ext-DAC way, but doubt weather the cheap transport output[possibly!] limit external DAC utlity...

oh yes modding is correct word...

thanks a lott for the detailed reply ...!!!