ODP: diy GM synth

[Roman Sowa]

> -----Oryginalna wiadomość-----
> Od:	Mikko Helin [SMTP:MHELIN at tne01.ntc.nokia.com]
> 
> So you think (at least Roman) that this could be a feasible
> project idea?
	[Roman Sowa]  
	considering 'wide' response for it I think it's going to die

> I think the converters may be any brand, anything we could find
> easily, if the quality is good (>90 dB THD). A $2 DAC is not
> expensive if there are enough people buying the 50 pieces
> ($100), which is enough just for 25 synths.
	[Roman Sowa]  
	$2 DAC? it's for free then!

>  The SAM9773
> chip is 31.60 USD /piece in France, 
	[Roman Sowa]  
	AD1858 is $7.80 +VAT here in bigger volume
	($9.10 for singles)

>  If it's impossible to find a
> DAC all could get, we could just put the I2S headers
> there for interface to separate DAC board (which
> could also be a s/p dif transmitter).
	[Roman Sowa]  
	I don't think it's a good idea. Most of discrete
	circuitry goes with DAC, so everybody should
	make DAC PCB by themselves which is more
	complex than synth chip PCB - why bother then...
	OTOH it's TQFP80...

>  Then the hard part
> seems to be the soldering of the  TQFP package.
> The pins are nom. 0.65 mm apart from each other.
> Any ideas for solve this problem?
	[Roman Sowa]  
	Few years back I was looking for automated assembly
	facilities. I found one company which does that
	but they told me that for 10 pieces it is more economically
	justified to hire someone to solder it manually.
	I've solder many little devices in my life, but 0.65mm 80 leads
	is like a nightmare.
	I recall someone on the list has good experience
	with 0.5mm ICs though...

> They (Dream) also have evaluation kit for 9773 for
> $125. It fits into standard waveblaster connector.
> Maybe there wil soon be commercial card based
> on this chip with lower price.
> 
> 
> -Mikko
> 
>