hi guys, i hope someone can help me.

I have the issue with dual mono configuration. Here are some facts, i will start with configuration:

I have two buffalos III in dual mono, with two power supplies. The DACs are feeding single legato, with two power supplies, no jumpers 1-4 are installed. The headphone/single ended stage is not powerd on. All the thing is controlled from arduino (modified hifiduino).
All feeding two mono ncore power amps (balanced out)
Looks like this:



Now, here is my problem:

Both buffalos are working as mono, all internal dacs are set to in-phase. All tested and working fine, 4 even dacs connected together and 4 odd dacs connected together work fine on each buffalo!

- The problem appears when i want to put all even and odd dacs of each buffalo together, here what happens:
-- if i put 2 even dacs and 2 odd dacs together, it works but only on 6 bit quantitizer, the sound is distorted on diffrent quantitizer settings, but still works.
---if i put 3 odd and 3 even dacs together, the sound is there, but it is distorted an all configurations of quantitizer plus there is a constant noise in the background.
----now, when i sum all 8 dacs there is no sound at all! No mather what settings, there is no joy!

I have the same issue on both buffalos (right and left). even dacs ok, odd dacs ok, phases ok, right left mono ok, but all 8 dacs give just no sound...nothing, quiet!

Hope you can help me guys, im getting crazy.

Best regards

Edited by user Thursday, February 5, 2015 1:14:10 PM(UTC)  | Reason: Not specified

Hi LeonvB,

Thanks for the answear.

I have not followed the description on the page 71, as i am using external controller. In my buffalo all 8 dac (even and odd) are in phase, then they go straight into the I/V stage. What i have noticed by the way, no matter how i connect it to I/V it still works fine (but only 4 even or 4 odd dacs summed)

It makes me think there must be setting i miss, but from my tests it seems all works fine and is set properly to dual mono, what i cannot proove are singnal phases!?

Here is the register of sabre which is set in hifiduino to 10011101 (0x9D), then first bit is set to proper channel.

Register 17 (0x11) (MC5)
|1| | | | | | | | Mono Right (if set for MONO)
|0| | | | | | | | Mono Left (if set for MONO) (D)
| |1| | | | | | | OSF (Oversample filter) Bypass
| |0| | | | | | | Use OSF (D)
| | |1| | | | | | Relock Jitter Reduction
| | |0| | | | | | Normal Operation Jitter Reduction (D)
| | | |1| | | | | SPDIF: Auto deemph ON (D)
| | | |0| | | | | SPDIF: Auto deemph OFF
| | | | |1| | | | SPDIF Auto (Only if no I2S on pins) (D)
| | | | |0| | | | SPDIF Manual (Manually select SPDIF input format)
| | | | | |1| | | FIR: 28 coefficients (D)
| | | | | |0| | | FIR: 27 coefficients
| | | | | | |1| | DPLL: Phase invert
| | | | | | |0| | DPLL: Phase NO invert (D)
| | | | | | | |1| All MONO (Then select Mono L or R)
| | | | | | | |0| Eight channel (D)

---

plus there are regs for setting the phase

---

writeSabreReg(0x0D,0x00); // DAC in-phase
writeSabreReg(0x13,0x00); // DACB anti-phase

Basically, hifiduino users reported no problems, but dont know why it doesnt work by me.

thanks again for the answear

Are you using your own controller? Or the on board controller? What I mean is - are you trying to use both at the same time?

Edited by user Friday, February 6, 2015 2:08:49 PM(UTC)  | Reason: Not specified

Hi Russ,

thank you for your posts.

I am using just one controller, no on board controllers are installed. I have anyway followed the integration guide and put the jumper on r7 on one buffalo, plus I put the addr jumper on one buffalo. Its all working just fine, i can change the settings, volume, inputs, etc.

As far as i can proove, also mono is set on both boards up, and all dacs of each buffalo are set to left and right channel respectively.

for input i am using smart input configuration from hifiduino:

https://hifiduino.wordpr...reo-input-configuration/

I would like to connect the buffalos to legato as on the picture i attached, i.e. straight into the legato board, without any crossings (+ dac to + legato and - to -).
That is why i use configuration aff all dacs in-phase.

are the balanced inputs on legato mirrored? I mean, left channel + 0 - and right chanel - 0 + respectively?

best regards

Tomasz

No I think it won't work for mono configuration. In fact the best situation for mono is I2S input. In which case simply wire D2,D3,D4,D5 together (or use the jumpers on the b3 which connect those nets). In any case if you do run PCM/SPDIF you should always disable SPDIF auto-detection while playing PCM.

Edited by user Friday, February 6, 2015 7:54:50 PM(UTC)  | Reason: Not specified

If you *only* plan on doing SPDIF that is ok too, just don't add the jumpers. :)

Start basic - get it working - then perfect your input scheme if you like.

Edited by user Friday, February 6, 2015 7:57:35 PM(UTC)  | Reason: Not specified

Russ, what is the default configuration of reg 14 (input mapping), are all open?
If I were to use sidecar, how shall I set the inputs to use I2S and SPDIF?

https://hifiduino.wordpr...ode-and-buffalo-iii-dac/

My advice is still to start simple. :) Get it working with PCM then try SPDIF.