Buffalo III - flexibility without compromise.

[Russ White]

This thing get messier and messier as time passes

How so? There is nothing really tricky. The ES9018 simply cannot have PCM/DSD and SPDIF data present at the same time. You have to switch out the PCM/DSD before you attempt to lock on to SPDIF or you will be asking for trouble.

That is what sidecar does. It switches out PCM/DSD and switches in SPDIF.

 

[LeonvB]

This thing get messier and messier as time passes

That just isn't true. The design is perfectly simple and elegant. As an engineer I like it, this is how the BII propably should have been. Let's face it, if you want I2S and S/PDIF input, you'll wind up with something closely resembling the Input module + Sidecar. On the BII the on-board S/PDIF switch and comparator mess things up, that's why they're now off-board. Of course Russ & Brian have added a few small things like LEDs to show the current input selection, etc. but the basic design of the BIII + modules is very simple.

 

[Russ White]

On the BII the on-board S/PDIF switch and comparator mess things up, that's why they're now off-board.

Hmm, I would not exactly put it that way. The Buf II solution was geared toward simplicity of use for the most common cases instead of for total configurability.

Buf II made configuration simple, but extension difficult. It simply was a module with a different set of design goals.

 

[regiregi22]

That just isn't true. The design is perfectly simple and elegant. As an engineer I like it, this is how the BII propably should have been. Let's face it, if you want I2S and S/PDIF input, you'll wind up with something closely resembling the Input module + Sidecar. On the BII the on-board S/PDIF switch and comparator mess things up, that's why they're now off-board. Of course Russ & Brian have added a few small things like LEDs to show the current input selection, etc. but the basic design of the BIII + modules is very simple.

It's not the design, but me understanding it. No need to though, as I plan to build mine in a long time.

I cannot see neither why is this bunch of extra boards doing what a rotary switch cannot do alone. Take one with as many poles as you need, just use one input on the Buffalo, and you're done. Want to switch between I2S and SPDIF? Put a secondary switch after it so to route the output of the first switch to either the I2S or the SPDIF inputs.

Nothing to complain about this great design, just letting fly my thoughts.

Best regards,
Regi

 

[Takaji]

You have to switch out the PCM/DSD before you attempt to lock on to SPDIF or you will be asking for trouble.

That is what sidecar does. It switches out PCM/DSD and switches in SPDIF.

Where can I find more information on the physical connections I'll need to make in order to switch between 8-channel I2S and S/PDIF? The incoming 8-channel I2S signal would consist of wires BCK, LRCK, GND, D1+2, D3+4, D5+6, D7+8, correct? What would the S/PDIF connections require?

Perhaps I need to wait for the BIII user manual to figure it out.

 

[BrianDonegan]

It's not the design, but me understanding it. No need to though, as I plan to build mine in a long time.

I cannot see neither why is this bunch of extra boards doing what a rotary switch cannot do alone. Take one with as many poles as you need, just use one input on the Buffalo, and you're done. Want to switch between I2S and SPDIF? Put a secondary switch after it so to route the output of the first switch to either the I2S or the SPDIF inputs.

Nothing to complain about this great design, just letting fly my thoughts.

Best regards,
Regi

The actual S/PDIF switching is done by the ES9018's internal MUX. The rotary switch is just setting the bits, telling it what source to use. You could switch S/PDIF sources with a switch as well, but...

The S/PDIF input module board is just a 4-channel level shifter, from consumer (0.5Vp-p) to TTL (5V). You can't do that bit with a switch .

The Sidecar is a very simple board, just to make the switching cleaner. Nothing special there.

 

[StasioPe]

Yes it can, but it is not usually optimal for several reasons.

Thank You

 

[glt]

(This is what I gather from reading the datasheet) In theory you do not need sidecar. The Sabre chip has 8 input lines. The last 3 are assigned (and multiplexed) to spdif. The first 5 lines can handle both spdif and PCM (I2S). If the firmware allows selecting between I2S and SPDIF (say spdif 8), then when selecting spdif, the I2S pins are ignored and when selecting I2S, the spdif pin is ignored.

The manual for BIII is not yet available, so I don't know what is the facility (dip switch combination) to do this kind of switching.

I did the experiment for switching i2s <-> spdif a while back with a 1 pole 2-throw switch and s/w switching in BII This is what I found:

It works as I expected. Both I2S and SPDIF signals are live at all times. However you must follow a switching sequence in order to avoid noise:

Case 1: switching to spdif (i2s is now playing): s/w switch first and then h/w switch
Case 2: switching to i2s (spdif is playing): h/w switch first and then s/w switch

For case 1 if you switch the h/w switch first, you will get noise, because the DAC doesn't know you switched to spdif and with the other input lines have data, the DAC thinks the data is I2S
For case 2 if you switch the s/w switch first, then the DAC thinks all data lines are spdif when they are not.

Thus, even thought the solution works, it is not optimal as one cannot follow this sequencing every time. However, if one does everything in s/w (that is, using a relay), then one can automate the sequence.

BII shares data input pin 1 (SPDIF with I2S) -thus a relay is needed to switch the input for that single pin.

In BIII, all input pins are available. Based on this experiment, I suspected BIII would support switching (without getting confused) if one does not share the input pins for I2S with the input pins for SPDIF. (But needs to be tested)

 

[Russ White]

Even better use the solution that has been tested.

 

[drone]

Resonanz for Buf III?

Hi,

before getting confused to much:

Is there an audio reason to Change from Buf II to Buf III if I only listen to stereo? For Input Selektion i have a Mux-board with output set to i2s (should I use spdif) all sources are spdif or toslink. For the cd Player I am in the Process of building a cd2pro, for which i understand i have also to use spdif (would i2s with metronome be better choice? And if so Gould i use a relay to Switch bereden Mux-i2s and Metronome-i2s?)

Thank you for Clearing this up for me.

Branko

 

[BrianDonegan]

Is there an audio reason to Change from Buf II to Buf III if I only listen to stereo?

No

 

[pmchoong]

The reason then is have more flexibility. B111 is easier to configured to have 2-8 channels, is this correct?

 

[BrianDonegan]

The reason then is have more flexibility. B111 is easier to configured to have 2-8 channels, is this correct?

Partly. 1-8 channels of output, 1-8 channels of input, built in volume control (instead of needing Volumite), more configuration options in the onboard firmware and switches, easier remote control of those options via the IO header. Of course external I2C control is still possible as well.

 

[regiregi22]

The actual S/PDIF switching is done by the ES9018's internal MUX. The rotary switch is just setting the bits, telling it what source to use. You could switch S/PDIF sources with a switch as well, but...

The S/PDIF input module board is just a 4-channel level shifter, from consumer (0.5Vp-p) to TTL (5V). You can't do that bit with a switch .

The Sidecar is a very simple board, just to make the switching cleaner. Nothing special there.

But with Buffalo II you could directly conect the consumer spdif input to the DAC board, isn't it possible with Buffalo III?

 

[LeonvB]

May we know which switches/configuration options were chosen?

 

[LeonvB]

But with Buffalo II you could directly conect the consumer spdif input to the DAC board, isn't it possible with Buffalo III?

There is no comparator on the BIII, so TTL level S/PDIF only. You could use a toslink module, an old mux, or the new S/PDIF input module.

 

[regiregi22]

There is no comparator on the BIII, so TTL level S/PDIF only. You could use a toslink module, an old mux, or the new S/PDIF input module.

That what the point I was missing, thanks!

 

[BrianDonegan]

There will be a single S/PDIF module sometime soon. Basically a single channel of the 4-Input module (trafo, comparator, etc).

 

[cersepn]

There will be a single S/PDIF module sometime soon. Basically a single channel of the 4-Input module (trafo, comparator, etc).

Any reason why the single module wasn't offered at the same time as the 4-input module? Correct me if i'm wrong, wouldn't it be easier and cheaper to manufacture?

If i knew there would be a single module, i would have probably waited out for that, instead of paying more for the multi-input (which i don't need)

 

[LeonvB]

Available time is likely the reason. Plus the 4:1 module is a good replacement for those in need of a Mux (which incidently also is undergoing a full overhaul) for their Buffalo. And I think the 4:1 is relatively cheaper than a single input version (as in the price per port is lower).