Howdy gents,-- another no lock problem, the tridents voltages seen correct (as gleaned from previous posts) but prior in to getting photos etc can I ask a simple basic question?--good-

According to the integration a buff 3 with full trident set consumes around 430 ma of current , so i have set my placid CCS to 0.430v (430 Ma) and the output voltage set to 5.25v-- is this correct and am i giving enough current to drive the buff/trident combo?-- I don’t want to assume anything at this stage! (The buff3/trident is currently not connected to IVY)


Does the volume control plug orientation effect lock? -could it be a problem if fitted wrong way round?.

All voltages on trident ok, all led’s on all links correct/jumpered / continuity tested where required and not jumpered as per use with 4 channel input module, i have checked the continuity of my SPDIF leads and every strand of the the ribbion cable connecting the buff to the 4 channel input module.

Cheers boys

Johnny

Hi LenovB, Thanks for the quick reply, so as i understand it(?) as i look at my Placid PSU i adjust Rv1 with my DVM across R2 (TP_SHUNT test points) till i get 50mA (.O5 volt) then adjust the output voltage to 5.25 volts, hence shunt the rest of the uneqeuired across R1 (TP_CCS) is that correct sir?.

regards

Johnny

Hi Lenov B,

OK, sorry think I got my resistors Shunt and CSS mixed up when talking to you! – I have re read the Placid manual and the integration guide (twice!)

From the start I set up the Placid in accordance with the Placid manual- With no load attached-I set the voltage to 5.25 and TP_CSS to 300Ma (low just for safety)- switched PSU off then with only the Buff III attached switched on.
Voltage about 2.6 volts, no tridents lit, (initially worrying but we have to adjust the PSU for load don’t we?) I slowly increased the voltage whilst monitoring both V out and CSS, at 5.25 volts CSS is 0.470 v (470Ma) which seems ideal? (based on buff III current consumptions figures in the integration guide)
No bangs no smells- All nice.
at the tridents: 5.25 IN/ 3.49 OUT (both tridents)
AVCC 5.22 IN/3.48 out +/5.25 IN /3.49 OUT (the Pair logo on the DAC and the pair logo on the AVCC are both point the same direction so its orientated correctly)
“Top regulator” don’t know its name! 5.24 in/1.18V out

Rechecked with forum photos prior to powering up, all is as should be, R7 is not shorted,L5 is fitted, SW1 and SW2 all off, jumpers J1 to J12 closed JPMC 1-3 open ,JSD 1-2 open.

Cold checks show the voltage input is not shorting to earth nor is the output.

I have checked the headers are not shorted and the I/O is also not shorting (all joints cleaned with Iso wotsit alcohol) there are no visual nasty’s on the boards.

The lock LED lights when placed in the mute position and is correctly orientated in the Lock position.
Switched it all off and attached the SPDIF 4 input board – I tested the ribbon cable for continuity on prior installation, all well) I attached the SPDIF input the first input on the board with Signal to + and shield to – (ground not connected) no lock LED , I turned the rotary selection switch to make sure I had the correct input selected just in case,-

I tried two separate SPDIF sources on the same SPDIF input.
I have tried some different switch positions on SW1/SW2 (DLL bandwidth/SPDIF auto detect) all switches currently now OFF.

I have tested my SPDIF input leads for continuity still no lock LED., that’s as far as I have got, I am hoping its still something silly (Silly is good!)

Thank you.

Exactly my question.

You've added the SPDIF 4 input board after setting the CSS. As it is fed through the BIII board, it might be you're running out of shunt current. Please see page 39 to make a rough estimate of what your current should be with all modules attached. Obviously you have to fine tune the shunt current after attaching all of the modules to the PSU.

Under load you have to have ~50mV across R2, if less (and you have less) you have to juice up the current (by turning VR1).

VR1 is the trim of the current. It has no effect on the voltage (unless you shunt to little current).

Dear LeonvB and avr 300,

Thank you so much for the advice, sorry to be a pain,- but i was hesitant to go over 500Ma "just in case" if fried the board and took the CSS reading as the only indication that mattered, clearly not the case!

i will try this when i get home from work, keep you posted, My gratitude to you all.

regards

Johnny

Can you post some pictures of your setup?

[HI boys,

I am back on line refrence my above no lock LED issue, however i am unable to post pictures as requested (I have ticked the attach files to this post box and tried the insert image icon on the top of the box)

However i cannot get acess to roam to any picture files, can anyone suggest a "cure"

ta
Johnny

2 suggestions:

1. Try to connect both sources at the same time with both powered on.
2. Try a different cable between the dac and the sp-dif board. You only need D1 + GND, D4 + GND and VD at the end.

Best of luck.
Regards
Gunnar

I have little experience with your current issue. As far as I can tell you have never had the lock led light up? edit:***

I can only suggest (in order to test the less costly alternative problems) for you to:

1. Make sure that the front panel switch works as it should (place link cables directly on the appropriate pins on the B3)*** edit: use the dil switches to select the input.

2. Try D1 and D2.

Best regards
Gunnar

Edit: *** your input is not awailable to the dac unless you specify it by either the dil selector row or by a working front panel switch selector.

Edited by user Friday, September 7, 2012 5:49:34 PM(UTC)  | Reason: Not specified