BUFF III No lock led (again!)

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BUFF III No lock led (again!) - When connecting SPDIF from my Hag DAC or CD player , no lock.

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sawman		#1 Posted : Saturday, August 4, 2012 8:36:54 AM(UTC)
Rank: Member Groups: Member Joined: 6/10/2012(UTC) Posts: 22 Location: sandpit Thanks: 6 times		Howdy gents,-- another [i]no lock problem[/i], 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


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LeonvB		#2 Posted : Saturday, August 4, 2012 9:39:05 AM(UTC)
Rank: Member Groups: Member Joined: 5/23/2010(UTC) Posts: 708 Location: Netherlands Thanks: 2 times Was thanked: 48 time(s) in 45 post(s)		No, that is not correct. The Placid is a shunt regulator. By setting the CCS to your expected usage there is nothing left to shunt which results in a voltage drop as you run out of current. Please read the guide carefully: "We recommend using either a Placid HD tuned for shunting about 50mA (approx. 490mA CCS current) or half of a LCDPS.". And always check your shunt current afterwards and fine tune your shunt regulators as per manual.


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sawman		#3 Posted : Saturday, August 4, 2012 3:41:02 PM(UTC)
Rank: Member Groups: Member Joined: 6/10/2012(UTC) Posts: 22 Location: sandpit Thanks: 6 times		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


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LeonvB		#4 Posted : Saturday, August 4, 2012 5:43:37 PM(UTC)
Rank: Member Groups: Member Joined: 5/23/2010(UTC) Posts: 708 Location: Netherlands Thanks: 2 times Was thanked: 48 time(s) in 45 post(s)		No. Follow the Placid manual: set the voltage (VR2), set your rough estimate of CCS (VR1). Then measure your shunt current and fine tune CCS so your shunt current is about 50-60mA. If you adjust the voltage you have to start all over again.


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sawman		#5 Posted : Sunday, August 5, 2012 1:03:03 PM(UTC)
Rank: Member Groups: Member Joined: 6/10/2012(UTC) Posts: 22 Location: sandpit Thanks: 6 times		:-" 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.


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Russ White		#6 Posted : Sunday, August 5, 2012 1:11:45 PM(UTC)
Rank: Administration Groups: Administration, Customer Joined: 10/24/2006(UTC) Posts: 3,979 Location: Nashville, TN Thanks: 25 times Was thanked: 89 time(s) in 83 post(s)		Under load how much current is being shunted (not CCS)?
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LeonvB		#7 Posted : Sunday, August 5, 2012 1:40:06 PM(UTC)
Rank: Member Groups: Member Joined: 5/23/2010(UTC) Posts: 708 Location: Netherlands Thanks: 2 times Was thanked: 48 time(s) in 45 post(s)		Originally Posted by: Russ White Under load how much current is being shunted (not CCS)? 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.


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sawman		#8 Posted : Sunday, August 5, 2012 4:49:40 PM(UTC)
Rank: Member Groups: Member Joined: 6/10/2012(UTC) Posts: 22 Location: sandpit Thanks: 6 times		HI BOYS, thanks for getting back, with the 4 input SPDIF (with regard to page 39) I have 5.25 volts with CCS 480Ma, with respect to the shunt I have : between TP_OUT+ and TP_GND2 = 5.25V TP_OUT+ and TP_SHUNT+ = 0V TP_SHUNT+ and TP_GND2 = 5.26V I also note that whilst the Placid sets up as per the Manual with no load attached,- with a load attached (buff III or buff III+4 input SPDIF module) Vr1 has no effect on voltage adjustment, only adjusting Vr2 has any effect on voltage output. (and is currently 5.25v with CCS 470 Ma but nothing shunted across R2 ?) Yet- the correct voltage is being applied between v+ and Gnd (5.25 v) and enough current at 470 ma is being provided in CSS.?- is it not getting enough voltage and current despite having nothing shunted across R 2…..or am I missing something fundamental about shunt supplies Cheers and thanks Johnny


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avr300		#9 Posted : Sunday, August 5, 2012 8:19:32 PM(UTC)
Rank: Member Groups: Member Joined: 6/17/2008(UTC) Posts: 921 Thanks: 1 times Was thanked: 70 time(s) in 69 post(s)		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).


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LeonvB		#10 Posted : Sunday, August 5, 2012 8:39:57 PM(UTC)
Rank: Member Groups: Member Joined: 5/23/2010(UTC) Posts: 708 Location: Netherlands Thanks: 2 times Was thanked: 48 time(s) in 45 post(s)		Step back an re-read page 39, esp. the paragraph "Shunt power supply". 440 (DAC) + 30 (input board) + 50 (shunt current) does not equal 470. Your shunt current is 0mA (OUT-SHUNT = 0mV). So there's clearly not enough current. Adjust VR1 on your Placid until the voltage across OUT-SHUNT equals 50mV.


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sawman		#11 Posted : Monday, August 6, 2012 3:53:00 AM(UTC)
Rank: Member Groups: Member Joined: 6/10/2012(UTC) Posts: 22 Location: sandpit Thanks: 6 times		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


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sawman		#12 Posted : Monday, August 6, 2012 3:01:39 PM(UTC)
Rank: Member Groups: Member Joined: 6/10/2012(UTC) Posts: 22 Location: sandpit Thanks: 6 times		Evening lads, Johnny here,- in accordence with you advice i have adjusted the Placid thus: TP+Shunt (R2) = 0.050v CCS = 0.530 V V OUT=5.28V So i am at last shunting 50 mA, however i still have no lock LED with a SPDIF source selected via the 4 channel input module, i was hopeing that the supply the correct current was the issue, it appears not to be?, can you suggest any further idears? is the DAC damaged? cheers and thanks Johnny


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LeonvB		#13 Posted : Monday, August 6, 2012 6:10:06 PM(UTC)
Rank: Member Groups: Member Joined: 5/23/2010(UTC) Posts: 708 Location: Netherlands Thanks: 2 times Was thanked: 48 time(s) in 45 post(s)		Can you post some pictures of your setup?


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sawman		#14 Posted : Wednesday, August 8, 2012 2:01:09 PM(UTC)
Rank: Member Groups: Member Joined: 6/10/2012(UTC) Posts: 22 Location: sandpit Thanks: 6 times		HI all, I have been called away for 12 days (family breavement) i shall follw up again on 20th Aug, sorry to cut and run. (i attempted to quickly cut and past the photos of the DAC to the forum but the "paste" function is grayed out on the reply post page. I ticked "attach files to this post page?")- so i am not sure how that works? johnny


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sawman		#15 Posted : Tuesday, August 21, 2012 4:50:10 AM(UTC)
Rank: Member Groups: Member Joined: 6/10/2012(UTC) Posts: 22 Location: sandpit Thanks: 6 times		[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


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sawman		#16 Posted : Tuesday, September 4, 2012 11:02:19 PM(UTC)
Rank: Member Groups: Member Joined: 6/10/2012(UTC) Posts: 22 Location: sandpit Thanks: 6 times		] Hi again, I have returned from my “vacation” and am able to once more look at the buffalo III with no lock issues and ask for assistance if I may. I have removed the IVY for now. I can confirm I have V shunt of 50 Ma across R2 and CCS of 530 mA, @ 5.25 volts, additionally I have tested the DAC on a bench power supply and still achieve no lock when 2 different SPDIF sources are applied via the 4 input SPDIF module, I am confident the Power supply is correctly tuned to the Buffalo III and 4 input SPDIF module current sinking requirements. I have opportunity to use an oscilloscope at work and have scoped the SPDIF outputs of both my sources ( A USB Hag DAC from a PC and the consumer level output of a CD Pro 2) and all seems normal with regard to the outputs produced, ( the CD Pro 2 seems particularly good) and I am confident the consumer level inputs offered to the 4 input SPDIF module are serviceable and are put selected on the off board selector switch to the appriopate SPDIF connector between + and – .. I have with a scope followed the SPDIF output from the source through the 4 in put SPDIF board and to the input pins of the buffalo DAC (SPDIF input D4 to PINS 8/9 on the DAC) My Tridents measure as follows both , Vin 5.248 v out 3.17 and 3.29 respectively The “other” trident closest to IC 8 Vin 5.247 V out 1.166v AVCC Vin 5.24 v out 3.5v (both sides) I have carefully checked the trident voltages under the pins and voltage continuity is OK The Tridents are version 3 so don’t have theR4 resistor omission issues the sometimes catch people out. The Underside links JPCM 1 to 3 are not connected JSD1 to 2 are likewise not connected. Links J1 to J12 are bridged with the supplied links and have each been tested for continuity. There are no physical shorting problems on the headers and all DIL switches on Sw1 and Sw2 are currently all off (though I did adjust the bandwidth settings and the SPDIF bypass to no effect) I have physically checked the ribbon cable with an ohm meter and have continuity with every strand of the cable. To date the lock LED remains off when consumer level SPDIF is applied to the 4 channel SPDIF board with th einput correctly selected. Thank you Edited by user Tuesday, September 4, 2012 11:07:07 PM(UTC) \| Reason: Not specified sawman attached the following image(s): IMG_0001.JPG (161kb) downloaded 51 time(s). You cannot view/download attachments. Try to login or register.


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gwikse		#17 Posted : Wednesday, September 5, 2012 10:41:19 AM(UTC)
Rank: Member Groups: Member Joined: 1/19/2011(UTC) Posts: 332 Location: Oslo, Norway Thanks: 14 times Was thanked: 17 time(s) in 17 post(s)		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


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sawman		#18 Posted : Friday, September 7, 2012 4:54:21 PM(UTC)
Rank: Member Groups: Member Joined: 6/10/2012(UTC) Posts: 22 Location: sandpit Thanks: 6 times		Hi Gunnar, I have done that last night, and still get no lock with two independent sources, so for now i have reverted back to the original configuration with a ribbon cable i have confirmed serviceable by testing every connection/line with an ohmmeter. Given that i have two good SPDIF sources (i have scoped them both) and i have ascertain they are leaving the 4 input SPDIF module (again with a scope) i am forced to think its got to be on the DAC where the problem resides, i believe thee is a cold DC check between the DAC earth and its output one can do to ascertain if the DAC is serviceable, i can see the earth pad (by IC 8) but where is the best location to check the DAC output and what should a healthy Resistance be for a normally functioning DAC please ? Can any other definitive DAC checks be suggested as i have sifted the forum and believe i have tried everything already suggested (apart from the cold DC check) i don't want to think its s dead DAC but its leaning in that direction? best regards and thanks to all Sawman


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gwikse		#19 Posted : Friday, September 7, 2012 5:45:38 PM(UTC)
Rank: Member Groups: Member Joined: 1/19/2011(UTC) Posts: 332 Location: Oslo, Norway Thanks: 14 times Was thanked: 17 time(s) in 17 post(s)		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


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sawman		#20 Posted : Friday, September 7, 2012 11:40:35 PM(UTC)
Rank: Member Groups: Member Joined: 6/10/2012(UTC) Posts: 22 Location: sandpit Thanks: 6 times		Hi Gunnar, Thanks for that, I replaced all the 4 switch wires with ones with crimped ends that grip the header pins and headshrinked them on for a secure grip, (the original connector was getting a bit ropey anyway what with all the testing etc!)-- still no lock, (i had the 4 pins on the wrong header pins on the buff (on front row 1/3/5/7 instead of on the correct row 2/4/6/8/ "behind the front row" as it were- i don’t know if that could damage anything?? Any how- with new wires correctly connected to input header pins 2/4/6/8 (as per page 13 of the integration guide) and two separate SPDIF inputs in inputs A and B of the 4 input SPDIF board i got no lock when switch from A/B on the selector switch, on switch 2 switches 1 and 2 were toggled (all up /1 up 2 down/2 down 1 up and both down) no joy-- I switched off removed the 4 wires of the 4 channel switch, switched on (checked PSU 5.6 V shunting 51 mA) and toggled switch 2 ( 1 and 2) to no avail. During this time i also switch 1 5/6/7 (DLL bandwidth) but still no Lock LED switch 2 sw 5 (SPDIF auto detect) I am confident that an serviceable SPDIF signal is being selected (by switch or via Switch 2 (sw 1 and sw 2) to the DAC (but as previously stated i did have the input selector on the wrong header row previously- but now that put right!) and the PSU is shunting enough current to power it all. The DAC currently has 2 separate SPDIF inputs connected, SW1 and SW2 all off, with mute LED on but no Lock LED (yet!) Did you have a simular expearence Gunnar? Cheers Gunnar your a gent, any suggestion other for other checks anyone (cold DC check on the DAC?) REGARDS AND THANKS John


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