FLAC to CD player internal DAC

[Dyolf]

Hi
I simply love the sound from my Cambridge CD3, and wondered if it was possible to somehow connect the digital output from my computer to the internal dac (4 x tda1541)
I do not have the schematic, but after reading a lot on the net about this player, it seems to be a relativly simple design.
Any chance that it could be done simply by finding the correct number and placement of the legs, and then solder an input cable?
any thoughts and maybe diagrams will be highly appreiciated.

Steen

 

[rfbrw]

It is possible but it will take a lot more than a connector and a bit of wire especially if you want the CD side to remain operational.

 

[T Leung]

Not just AB switch to go FLAC / PCM from cd ?

 

[Pano]

Probably not, tho it's a cool idea.

The Cambridge dac is most likely fed with an IIS (I2S) bus. It's more than 1 wire.
You could buy a USB to I2S adapter from someone like miniDSP and patch it in.
But the problem of switching still remains.
I²S - Wikipedia, the free encyclopedia

Dyolf, did you ever do anything with this?

 

[analog_sa]

But the problem of switching still remains.

Nothing that a relay or two cannot solve. More elegant solutions are no doubt available but this worked for me for a couple of years and i could hear no degradation.

 

[Pano]

OK, cool. You didn't have any bandwidth or noise problems with the relays?

 

[analog_sa]

44kHz does not need that much bandwidth. The only limiting factor a relay can present is interelectrode capacitance which to me appears to be on par with the pcb tracks. Didn't really measure the pulse's fronts but couldn't hear any degradation with or without the relays.

 

[wwenze]

If you can't measure the digital-in to the DAC, how about measuring the analogue-out from the DAC to see any degradation in numbers?

 

[analog_sa]

Why would i even suspect a "degradation in numbers"? The very worst i can expect is a slight rounding of the slopes due to the added capacitance. As the I2S is fed into an ASRC in this particular DAC, it seems to make no difference. A relay is just not all that different from a longer PCB track.

 

[rfbrw]

No ASRC in the op's cdp. Makes things a little more complex.

 

[Pano]

Probably a moot point for the OT. This thread is over a year old. Doesn't look like he came back to visit it.

FWIW, the DCX2496 has its digital signal pass thru a relay. I don't know what harm it does to it, never measured it.

 

[rfbrw]

Most likely none. If a relay is good enough for serial digital video, it'll probably do for digital audio.

 

[qusp]

well video is mostly buffered, there will be some effect, but probably negligible, many MUXes use relays and i've never had any issues with relays and spdif or even i2s. can always add a line driver after the relay if you are concerned