[sdiy] dsPICs with DACs: linearizing the 12 bit ADCs, external RAM?

[Robin Whittle]

Hi Eric and Antti,

I wondered about downsampling the reverb - it sounds promising and a
lot less trouble than using external RAM.

I have soldered a TSOP device - and would be quite happy to use SMD
devices in adaptor boards for one-off projects and the like.
However, for small to moderate scale production, I would like to
avoid SMD if possible.  I am thinking partly of the long-term
serviceability of the machine, assuming a few DIP chips are kept as
spares.  I am also thinking of hand-building a few boards and then
getting a batch of 10 to 50 assembled somewhere.  If it has even one
largish SMD device on it, the whole thing might as well be SMD and
then there is a major set-up cost for automated assembly, purchasing
large quantities of parts and boards etc.

An SMD device in an adaptor board, plugged into an IC socket might
be OK, since it can be treated like a component.  Making a mess of
desoldering that does not upset the main circuit board.  However, I
think this is only worthwhile for smallish devices, such as ADCs or
DACs - not for 100 pin dsPICs etc.

It is probably overly ambitious to expect usable audio from a 12 bit
ADC, but it one day I will try it out, since it would be so cute to
have ADC, DAC and DSP on a single 28 pin *DIP* package which only
costs a few dollars.

  - Robin