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Gear / Technical Help => Battery Boxes, Preamps, Mixers, ADCs, and Processors => Topic started by: BJ on November 02, 2005, 12:00:39 AM

Title: AD-20 mod to 24bit?
Post by: BJ on November 02, 2005, 12:00:39 AM
can the ad-20 be modded to do 24 bit conversion? I have been looking at other options for pre's, but would like to stay at 24bit, but dont want to fork out a grand for a a/d.   these seem to be had in the affordable price range...if someone could swap out the guts for 24 bit, it seems this would be ideal unit.  small, runs of batts (I am guessing - no idid not search!)  >:D >:D 

thanx guys...just looking around for other  options

b
Title: Re: AD-20 mod to 24bit?
Post by: MattD on November 02, 2005, 12:22:04 AM
Can you find the pinout for the AKM5351 chip used in there?
Title: Re: AD-20 mod to 24bit?
Post by: JasonSobel on November 02, 2005, 06:03:30 AM
the Core Sound Mic2496 is basically the same size as the AD-20, and that outputs 24 bit.  might be easier to buy that instead of trying to figure out a mod.  just a thought...
Title: Re: AD-20 mod to 24bit?
Post by: pfife on November 02, 2005, 08:21:53 AM
You could use the A/D in whatever recorder you are thinking about using for 24bit... the R-1's A/Ds sound spectacular to my ears.  I've heard one recording using the MT's A/Ds, and it sounded really good too.

Title: Re: AD-20 mod to 24bit?
Post by: scb on November 04, 2005, 09:16:46 AM
it already otputs 20 bit right? so recording the normal ad20's output to a 24 bit recorder would get more bits than sending to a dat/jb3
Title: Re: AD-20 mod to 24bit?
Post by: lstelie on November 10, 2005, 01:50:40 PM
it already otputs 20 bit right? so recording the normal ad20's output to a 24 bit recorder would get more bits than sending to a dat/jb3

Good question I'm interested.
How would a AD-20 -> MicroTrack give ? Good association ? bad one ?
TIA
Title: Re: AD-20 mod to 24bit?
Post by: spoogles on January 18, 2006, 12:37:35 PM
tested my d mic 20 into the microtracker @ 24/48. everything sounded fine. seems to fill the last 4 bits with null data. so yes this seems to be better than a 16/48
Title: Re: AD-20 mod to 24bit?
Post by: ghellquist on January 25, 2006, 06:22:21 PM
Rarely will you find any real-world AD converter with more than 20 bits of true resolution. Although does not advertize it, you can guess it from their published S/N ratio. And, well, not all of them are too careful when measuring things.

20 really good bits would give you an S/N of about 120dB. Several of the "so-called" 24 bit boxes spec at below 100dB S/N which to me suggest that their true resolution is about 16 bits (16 true bits is about 96dB S/N). The Edirol R1 I tried measuring on came in at about 15 bits (it might have been a faulty individual though) so the last 9 bits were simply meaningless noise.

In conclusion, if you have a quality 20bit converter you are about as good as typical converters get today. I would see no reason to upgrade that as probably the S/N is governed by the analog circuits rather than the AD.

Gunnar