Hi there

We have been experimenting with outboard DACS for our events, and I am keen to give the Buffalo DAC a go. Basically, we have a high end analog PA system (Opus Audio from UK) and we have had some fantastic results using pro audio interfaces. However i think we can do better - the concept is that instead of using the cheap DAC on each of the CDJs, i want to take the SPDIF output and covert that separately, run it through our nice analog mixer then into the high power analog amps - no digital in the power amp side - and its amazing how it can sound.

Now we have tested a couple of pro audio DACs (Apogee, RME) but the issue I had was when the DAC SPDIF was synchronised off one cd player, the other one sounded terrible (jitter). Otherwise i had to buy 2 separate units.

So, I am keen to build my own - I have always been fascinated by the reviews on this ESS chip and the buffalo, especially for that price.

What I need is simply to convert two separate coax SPDIF inputs to 4 channels of audio simultaneously. Primary design consideration is sound quality, as you can really hear it when amplified to 15,000 watts of pure analog audio.

I just need some guidance on the best design for this using the buffalo DAC.

Questions:
- Do i need two completely separate buffalo boards?, as both inputs clock differently? Or will the SPDIF receivers sort it out when converting to I2c? Or is two separate DAC boards the best design for this for the best sound? (in the one chassis)
- Can the power supplies be shared between the two DACS?
- I see a lot about the two line stages - i prefer non op-amp based, so is the legato the way to go?
- Do i need a scope and tone generator to put this together? I don't think so but need advice

In a practical sense for this application, i would like to have the unit in the rack away from the DJ booth where the mixer and CD players are (up to 5m away), so would it be good to use the teleporter to send the two SPDIF digital signals back to the rack, and then balanced analog back to the mixer?

One final though, i like to hear stuff before I buy, but from looking at the quality of the power supplies and the multi boarded approach and modularity, it looks like it would sound better than these pro dacs i have tried - RME and Apogee. Can anyone comment on sound compared to these mid level pro brands? (that use switched mode PSUs and op amps)

Thanks for your help its much appreciated and I look forward to responses so I can get this stuff ordered

Cheers

Dave

Thanks for the quick reply Leon

I will test out the two output stages as recommended to select the best one for my application.

So, if its racked say 5m away from where the inputs and outputs will be, is it best to use long SPDIF cables or the teleporter for that type of distance?

Reading up about the ESS how it is great at sorting out the jitter.. look forward to hearing it...

Cheers

--Dave

I recommend AES/EBU over that kind of distance, but I assume that is what your pro-gear is using (XLR connector). You can use the single S/PDIF level converter module (on Buffalo-8 page) to convert AES/EBU for either Buffalo module.

You should be just fine to use the SPDIF signal. 5m is not that long a run for spdif. :) Even 10m should be ok in most circumstances.

For your application I would suggest using the IVY-III.

As for stock, well we try to keep them around, but its hard to tell when they will sell out.

Hi, just a few more questions, thanks in advance

Basically, my requirement is to have balanced output at the location of the DAC for one 2 channel configuration (digital mixer/single converter/DAC into RIG), and in the 4 channel configuration (CDJS/2 converters/Dacs into analogue mixer) I need SE output at the mixer location (up to 5-10m away)

Would it then make sense to implement the 4 channel BAL/SE converter separately (4 x Ventus) in a separate box by the mixer, and connect 4 x balanced from the DAC all the way to the BAL/SE converter, and then short run from there to the mixer?

I know more expensive but it means no long SE runs, which is the drawback for such a big converter racked a distance away. This way everything is discrete, balanced, and i don't have long SE runs.

Also, i see a lot about power supplies for the IV stages, 1,2 or 3 needed. In my configuration of dual stereo DACS i should just need:

1 x LCDBPS with 1 x 9v transformer (to power the DACS)
2 x Placied HD Bipolar Supplies with 2 x 15v transformers (to power the 2 x Legatos)

Is this correct?

And if I want to use SE on the Legatos do I need another supply?
What supply would I need for 4 x Ventus's? (note NOT powering headphones just RCAs into the mixer.) With 9v Transformer?

Thanks again,