Did you adjust the power supply to produce higher current? You need about 450ma for handing the additional Tridents current draw! With 50ma headroom, you need to adjust the power supply to about 500ma!

Hope this helps,
Milton

Yes, ferrites all removed. I did increase the current output of the Placid. It's delivering 5.3V with the Buffalo/Tridents connected. It measures 0.38V across R8.

As already mentioned .38V is not enough. Your Buffalo/Tridents are starved. The Placid needs to shunt current above and beyond what the Buffalo with the Tridents is pulling. This is measured across R3. Please see the Placid schematic. If I'm not mistaken Buffalo pulls ~350mA, Tridents another ~100mA. Your Placid needs to be adjusted to pull another ~50mA or so above the load for proper operation. The voltage across R8 is measuring the total current. 1 ohm resistors at R3 and R8 make the current calculations easy (I=E/R). With Placid disconnected, adjust CCS pot until you measure .5V across R8, double check output voltage, 5.3V. Reconnect Buffalo and adjust the CCS pot until you have .05V or so accross R3, measure carefully as not to short anything.

Oh dear. No luck I'm afraid.

I've followed William's instructions - the Placid's putting out exactly the values he stipulates, the heatsink's getting hot (a bit hotter than when the Buffalo was running successfuly less the Tridents), all LEDs on AVCC module & Tridents alight but now neither the Lock nor Mute LEDs are alight.

Help...

Edited by user Sunday, April 24, 2011 1:02:33 AM(UTC)  | Reason: Not specified

Thought I'd try & disconnect one of the Tridents - the one on the extension which doesn't require unsoldering, & re-bridge the relevant link. No difference but I notice the mute and lock LEDs behave erratically. If I cycle the power sometimes none come on, once both came on quite brightly, then just the lock one, dimly.

Ah-Ha! Measuring the Tridents revealed DVCC & VDD_XO were in the right position and delivering 3.3V but although VDD's LEDs are illuminated it wasn't producing any output!

I've just removed it, reinstalled the ferrite bead and, by golly, the Buffalo works! Whew!

What to do with the faulty one please? There's nothing visually amiss. Also, I've now powered everything down but is it OK to leave the Placid set at its current power level please?

Thanks avr, job done. It's sounding very good, even minus one of the Tridents.

Many thanks for all your help avr. I'm afraid I'm not up to owning a labs supply yet, but wonder if I could use the Placid's output to check?

All's well now; I checked the Trident (it was the 1.2V one) & discovered there was no output even off the board. I looked at it carefully with a high-powered loupe but again there was nothing obvious. I then ran the soldering iron over the bits I'd soldered, cleaned round, rechecked and bingo! Don't know what it was but, hey, I don't care now...

I've still got the bits mounted on a ply board the same size as the case. I'm just enjoying listening to it whilst it runs in & then I'll pop it in its case with the components positioned as the folks over on Pink Fish Media have advised.



No doubt it'll sound even better when properly wired and enclosed but it sounds pretty damn good now! Adding the extra Trident seems to have made a greater difference to the sound quality than adding the first two.

I'll order another Placid when they're back in stock to power the MUX 4:1 & TOSlink module but there's no rush.

CD 555 still wins?
Why don't you post also here a picture of your modest music rig