Swapping converter chips / daughter board

[Tashi]

Okay so I’ve had an idea that might be lunacy.

I’ve just bought an A&H GSR24 console with a 32ch converter/FireWire module card. DIYer that I am I inspected the board and noticed all the I/V stages and buffers are TL072, which I feel like swapping out at some point. The converter chips are TI 1404 (4ch) & Cirrus 5368 (8ch), not terrible but room for improvement.

So my thought was why not upgrade both? Could I make a daughter board with new DAC/ADC on them and simply patch them in? Reroute the clock, logic and I2S and bypass the existing converters? There’s enough room in the enclosure for one to sit right on top but I don’t know if even an inch would be detrimental to clock jitter etc.

Trying to hunt down a schematic of the card but I imagine I’d only do a handful of channels to start with. The new higher spec converters would be the likes of pcm4222/4220 & pcm1794 but they’re all 2ch parts, so I’m not sure how to implement them if the receiver is only expecting a certain number of I2S streams, also if the logic protocols are the same between different converters.

Is this at all doable?

 

[shabtek]

No. Too ambitious.
If you can improve this than you can probably design your own “ green field”.
I mean the refinements at the level you aspire to have as much to to with layout as chip swaps
But it is over my head

 

[JohnRoberts]

I only was involved in one high performance codec layout/design and the PCB design was a PIA. Even with 4 layer technology, maintaining good analog and digital signal integrity was not trivial. I can't imagine putting one in a socket... but maybe somebody smarter than me could.

JR

 

[Tashi]

Maybe I’ll just work on upgrading the analogue side then..