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Old 20th April 2018
  #6
Gear Maniac
 

Hey guys,

The interest and kind words are really lovely! Thanks so much!

So we have to finalise the costings and changes to the 500R8/500ADAT with the next prototype run before we announce anything. We hate to let people down by prematurely announcing stuff... But I promise I'll give you guys a full update in May if that's ok?

Some really good questions from cheu78, here are answers:


Quote:
Originally Posted by cheu78 View Post
Dear Sean,
1. What is the definitive feature list of the R8?
Every feature detailed and shown on our website at the moment is on the 500R8, except 1 thing - S/PDIF. We took this off as not a single person we asked thought it was useful. Everything else is additions. I can allude to what these are - additional routing options and things to make CAST more useful... More to come next month if that's ok... Again, we just want to verify everything before promising things to you guys!

Quote:
Originally Posted by cheu78 View Post
Dear Sean,
2. It's an external power supply you're using, how it's regulated? any specs? how much pwr could provide per rail?
Hugely important question as during our development we've found there are a lot of pretty bad power supplies in 500 series racks... Even the big names (who will remain nameless). We found that certain racks have VERY noisy power rails which impacts the performance of any modules in the slots. Not acceptable for us...

So our power supply... First of all, it's external. Where it should be. A massive power supply in a relatively small box full of sensitive electronics is far from ideal. You can overcome this with loads of shielding, etc, but even then you will get noise coupling into the audio path. With an external supply, this simply doesn't happen. Our PSU is 24V switch mode power supply. Switch modes can have switching noise but we went with a high quality supply and we have further linear regulation on the DC inlet of the 500R8/500ADAT and linear regulation on each slot of the 500 series chassis to make sure power noise and intermodulation distortion doesn't find itself on the audio rails. This is a step that not many 500 series chassis makers do, which is surprising. Then again, it's probably because it isn't cheap!

Each slot has 250mA of power on the 500R8/500ADAT. But there's also headroom if it's drawing that much current... Some chassis say a similar number but you can hear the added noise and distortion when it's close its published limit. This won't happen with a 500R8/500ADAT.

Quote:
Originally Posted by cheu78 View Post
Dear Sean,
3. which converters are you using? instead of signal-to-noise would be great to see the dynamic range specs (although this doesn't tell all the story of course). Power supply, clock and analog stages have a tremendous impact on the sound of converters. Is the clock a new one? If these 3 important parts are well made, there are good chances you have a good sounding unit.
Preach breddrin!

We totally agree. For the ADCs we're using the new AKM5578s - a new octal part from AKM. Our implementation of the 5578 results in 121dB Signal-to-noise ration and - 112dB THD+N.

The DACs we use are the CS43198 which are 130dB signal-to-noise ratio (a-weighted... about 127dB unweighted) and -115dB THD+N. The interesting thing with a THD number so low is the limit then becomes the analogue circuit (you'd need 0.0003% THD to match the DAC performance) which we might match - we'll see when we get the next prototype and hook it up to our APx555.

As for our clock, we're using an extremely high performance clock that results in 0.5 picoseconds of jitter. I would tell you the part but it's part of our secret sauce

Quote:
Originally Posted by cheu78 View Post
4. Who makes (code) your usb drivers?
This is another one of those trade secrets... What I can say is it's the same USB driver company who does loads of other high-performance USB interfaces. The company who does this may be based in Switzerland like you

Quote:
Originally Posted by cheu78 View Post
5. Is there a master fader/pot, can be rerouted to slot 7 and 8 or should be patched with cables into the channel inputs/inserts?
So on the back of the unit you have "Mix Output" which is the summed analogue signal. You could bring this back into another slot. But this shouldn't be needed as the analogue summed mix has its own dedicated USB channels that you can bring back into your DAW. This is why we have 2 more USB outputs than we have inputs - the 2 extra outputs is the master mix that goes back into your DAW so you can record the analogue summed mix - think a Dangerous 2BUS but with a high quality ADC and USB interface built in.

Quote:
Originally Posted by cheu78 View Post
6. do you have real pics? or gut pics of your stuff?
We could shoot some pictures but nothing looks particularly pretty at this point. It's a lot of PCBs with loads of wires and bits hanging off with all the mods we've been doing. We'll be ordering "production prototypes" of 500R8/500ADAT soon which will be the proper things with the right metalwork, silkscreen, etc... whereas anything I can take a picture now will look like Frankenstein mad engineering!

Thanks for all the great questions cheu78. If you have any others I'd be happy to answer if I can.

Last edited by Karpmentalise; 20th April 2018 at 01:00 PM.. Reason: spelling ::bleugh::