Hi guys, I'm really hoping you can help here.

I bought my buffalo a month ago and have finally completed the build:
PSU+ buffalo/tridents/legato fed direct via I2s from Rasberry Pi (no sidecar or anything). However I'm not getting a squeak.

Mute LED is on but the lock LED remains resolutely dead.

I therefore need to run some tests to check where the fault is, but all items appear to be working fine.

1) Can you advise how to check a buffalo fully? Superficially it appears to be from the following measurements:

a) VD voltage to buffalo is 5.29V.

b) Tridents are measuring:
VDD XO 1.16v
DVCC 3.28v
VDD 3.27v
AVCC dual: 2 x 3.47v
AVCC is a little high, but you say you run them a little high in your documentation and according to the ESS datasheet this is only 0.05v outside the 3.3v +/- 5% recommended tolerances.

c) dip 5 on header block SW2 is set to 'off' to disable spdif autodetect. All other dips are on, both blocks.

d) Data inputs (D2-D5) are jumpered with JPCM1-3 and measure continuity, also 0v on a DMM when powered up.

e) Outputs are all jumpered for stereo J1-12, and measure no resistance between output vias on either side,

f) Internal volume control is off, measures 3.3v on PB4.

g) Voltages at the output to I/V header pins on the Buffalo board (O4 and O3) are measuring approx 10mv/ 0 /10mv both sides.
The ESS datasheet indicates diff voltage offset should be AVCC/2 which would be getting about 1.74V / 0 / 1.74V.
However, I assume this is fine if attached to a legato as the I/V input should bring the output voltage of the dac to GND?

2) The Legato
a) trimmed perfectly to within 0.1mv each side on initial set up without Buffalo mounted.
b) Legato VD voltages are around the 2 x +/- 12.5v with the b/se feeding off 1 channel's psu via jumpers. c) Outputs when connected to the buffalo, SE, are 01.mv and -2.9mv

This looks fine to me, unless you can think of any other points to check?


3) RPi running Volumio 1.4 and I've tried all the I2s drivers, principally the hifiberry one. Audio out via the headphone socket is functional and fine with 12s drivers deactivated.

Do you know any tests to check I2s signal out of a rpi is likely ok using a DMM? I don't have a scope though.

My only noted comment is Volumio seems to be pretty buggy with 12s drivers activated, though it runs fine through phones when I2s deactivated. Has anyone else had this experience?


I'm really hoping you can help me get this working, but I'm scratching my head as to what the problem might be?

Many thanks for your help.
Best regards

Cedric

Ahem... what an id**t. A schoolboy's error and couldn't see the wood for the trees.
Took 2 seconds to fix, happily nothing fried, and all sorted, thank you very much indeed Brian!

Sound quality wise, first impressions are not bad, not bad at all. Certainly already in the same league as my heavily modded Naim CD player; look forward to seeing how it settles down.

Also identified the USB hub as the root of my Rpi problems, and music not cutting in and out every 20 seconds anymore.

Congratulations on a great product.

best regards
Cedric