[Newk Yuler]

Steve,

Do you know if there is another TDA1543 based DAC in production similar to the Valab NOS but with an Off Ramp compatible I2S input?

Alternatively, how hard/expensive would it be to mod the Valab for an Off Ramp compatible I2S input?

BTW, in case you didn't know, the latest production revision of the Valab now runs both USB and SPDIF into reclocking circuits and no way to avoid it.  I'd think that would be a new deterrent to using a new Valab DAC with an Off Ramp.

Thanks.

Rand

[audioengr]

Steve,

Do you know if there is another TDA1543 based DAC in production similar to the Valab NOS but with an Off Ramp compatible I2S input?

Nothing I'm aware of.

Alternatively, how hard/expensive would it be to mod the Valab for an Off Ramp compatible I2S input?

It can easily be done.  I dont have time for this though.  Maybe Rick Cullen?

BTW, in case you didn't know, the latest production revision of the Valab now runs both USB and SPDIF into reclocking circuits and no way to avoid it.  I'd think that would be a new deterrent to using a new Valab DAC with an Off Ramp.

That's too bad.  I had heard that the latest version was compromised somehow.  The Off-Ramp 3 will probably still improve things, but you may hear the jitter of the reclocker crystal now.

Steve N.

[Newk Yuler]

I've been catching up on the Head Fi Valab forums today.  I haven't looked in a while.  Apparently Gigalab made the 2nd clock an addition to their Moon DAC then strongly flaunted it on eBay against the competition, forcing TeraDak and Valab to update.  That's what I gather, anyway.

I emailed Kevin about including an I2S input.  I mentioned a need to bypass the clocks when a superior signal is available.  His reply simply states "Ok, I understand your requirement! I will seriously consider developing one version with i2s input. It is not a hard work."  A dedicated version would be sweet but I imagine it will be added to a normal production revision of the DAC.

The new clock in the Valab is a small TeraDak board strapped to the top of the DAC section.  I got the impression that the second clock reclocked the signal from all the inputs (a second reclock on the USB).  Kevin mentions in a current eBay auction page Q/A "one for usb reciever master clock, another for I2S reclock".  Taken literally that means the I2S is reclocked before the DACs, but is it possible to reclock the I2S and run a pure input to the I2S before the DACs?

Link provided for you to get a quick look at the TeraDak second clock upgrade images:

http://cid-1eb7027489224a7d.skydrive.live.com/browse.aspx/Reclock%20installation

I'm glad I have the March 09 revision without the second clock for use with the Off Ramp.  Thanks for the Cullen Circuits suggestion.

- Rand

[audioengr]

I've been catching up on the Head Fi Valab forums today.  I haven't looked in a while.  Apparently Gigalab made the 2nd clock an addition to their Moon DAC then strongly flaunted it on eBay against the competition, forcing TeraDak and Valab to update.  That's what I gather, anyway.

I emailed Kevin about including an I2S input.  I mentioned a need to bypass the clocks when a superior signal is available.  His reply simply states "Ok, I understand your requirement! I will seriously consider developing one version with i2s input. It is not a hard work."  A dedicated version would be sweet but I imagine it will be added to a normal production revision of the DAC.

The new clock in the Valab is a small TeraDak board strapped to the top of the DAC section.  I got the impression that the second clock reclocked the signal from all the inputs (a second reclock on the USB).  Kevin mentions in a current eBay auction page Q/A "one for usb reciever master clock, another for I2S reclock".  Taken literally that means the I2S is reclocked before the DACs, but is it possible to reclock the I2S and run a pure input to the I2S before the DACs?

I dont see how. Maybe if he was reclocking with MCLK from the I2S bus, but this I2S bus only has SDATA, LRCLK and BCLK, no MCLK.

Link provided for you to get a quick look at the TeraDak second clock upgrade images:

http://cid-1eb7027489224a7d.skydrive.live.com/browse.aspx/Reclock%20installation

I'm glad I have the March 09 revision without the second clock for use with the Off Ramp.  Thanks for the Cullen Circuits suggestion.

- Rand

This TeraDAK thing is poorly implemented IMO.  One shared ground with power and three signals, and they are not even close together???  It would flunk logic 101.

If the designer can add an I2S input with three resistors to ground, 120 ohms each, then this would be useful.  The best thing would be an RJ-45 with the correct pinout to get direct connection with my I2S outputs.

Steve N.

[Newk Yuler]

To let you know what Kevin wrote me in supplement to the I2S input.

Dear Sir:

This reclock circuit will not harmful to original i2s signal, it will be even better, it can work just like a i2s bus buffer. In many dac with i2s input, they also need a i2s booster circuit to keep i2s signal.

How does that sound?

- Rand

[donunus]

Any more impressions with this dac?