[sdiy] Stereo Audio CODEC ICs

[Jay Schwichtenberg]

I did some research into this about 6 years ago. Several things to keep in
mind about using real audio codecs.

A number of the converters whether they be discrete (separate ADC/DAC) or
codecs is that they want to be clocked at a constant rate at certain
frequencies. Some will not work varying the clock rate like you do with a
BBD. Has to do with some of the digital filters and that they sort of use
the clocking to do the conversion. They have internal integrators in these
things that rely on a very accurate clock. Multi-bit converters seem to
sound better to me than single bit. They are not as critical of clocking
either.

The layout of these on a PCB is extremely critical. Read all the app notes
and data sheets on these things. It might be a problem using SMD adapters
with these chips.

I've also found some the app notes and data sheets had the wrong values in
their filters on the DACs. Can't remember if it was Cirrus or AKM I know it
was one of the ones I used so those would be my choices. Might want to do
the math and make sure they are right before you build something.

Also AKM makes converters. I looked at there disti and sales rep list on
their web site. Didn't look good to buy just a few of them.

Jay S.

-----Original Message-----
From: owner-synth-diy at dropmix.xs4all.nl
[mailto:owner-synth-diy at dropmix.xs4all.nl]On Behalf Of Seb Francis
Sent: Saturday, January 28, 2006 4:03 AM
To: Simon Brouwer
Cc: Synth DIY
Subject: Re: [sdiy] Stereo Audio CODEC ICs


Simon Brouwer wrote:

> At 04:00 28-1-2006, Seb Francis wrote:
>
>> For anyone who's following this digital delay thread and is
>> interested in some nice quality audio CODEC ICs, here are the ones
>> I've shortlisted so far:
>>
>> www.cirrus.com
>> CS4272 (24-Bit, 192 kHz, 114 dB Stereo CODEC with differential I/O
>> and internal oscillator) SSOP-28
>>
>> www.wolfsonmicro.com
>> WM8778 (24-bit, 192kHz Stereo Codec) SSOP-28
>> WM8590 (24-bit, 192kHz Stereo Codec with differential I/O) SSOP-28
>>
>> www.ti.com
>> PCM3010 (24-bit, 96kHz ADC, 192kHz DAC Stereo Codec) SSOP-24
>> TLC320AD77 (24-bit, 96kHz Stereo Codec) SSOP-28
>>
>> These are all 2 in, 2 out.  I was hoping to get something with 4 in,
>> 4 out, but this doesn't exist (you tend to get much more outs), and
>> in any case I'm not brave enough to go any deeper into SMD than SO or
>> SSOP packages at the moment!
>
>
> Where could these be ordered by individuals, in small quantities?
> Farnell doesn't seem to stock any comparable audio CODECs.
>
>

Farnell stocks:
CS4272 (p/n 1023371) at £5.07+VAT
PCM3010 (p/n 8434794) at £4.74+VAT

Profusion (www.profusion.co.uk) stock:
WM8778 at £5.64+VAT
WM8590 at £3.49+VAT

Seb