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BII at least damaged maybe faulty: Reverse fix possible?
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Hello folks,
prior to start the technical stuff I find polite to ask if the way I think it needs to be done is OK for you.
I've bought an used complete Buffalo II, supplies and parts from TPA. It seems it was working nicely, but that was before shipping company exploded it. There are obiousely damaged parts, like a chopped down capacitor or flying toroidal.
So I may need help to mind what needs to be checked, in wich order -and maybe fixed/adjusted- on that already built and cased Buffalo, like reverse engeenering for me as I did not built it.
Does that sound good for you people?
Thanks
Matthieu
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Start posting pictures. Lots of pictures.
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Hi Brian, I like your style: right to the facts :) here is the picture of actual state. I may not be able to work all day long on it, take it with a DMM off for holidays, that may be a rainy day work. I see 2 options, try to bed it in this case to make it works, or remove parts and rebuild it step by step on a wooden board. (fast recovery or slower one but with short twisted wires and better care... ). I also want not to be rude to original builder, we each have our ways to do things, he's done it its way and I don't intend to make fun of anyone. That been said first picture, a second one with things back in place a bit later (no power up, a toroidal seems deeply damaged so maybe windings shorts):  nb: external hosting for a larger image. Edited by user Tuesday, August 11, 2015 9:55:07 AM(UTC)
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Hi, in fact that may not be that hard, seems. We wired back the PSUs, a Placid HD BP and a Placid. Both have a 30VA TX, the Placid having more current as the two secondaries are paralleled. Enough juice 1A per side for the Placid HD PB?Loads are disconnected for now. They give: +13.8V / -14.3V for the PlacidHDPB and 5.0V For the Placid. Fine tuning needed? I wonder why so many pots on the Placid HD BP... There are three regulators left alone, wich is which going where? 3.3 and 1.2 written on back, that's voltage? Thanks! Matthieu Malefoda attached the following image(s):  Placid.jpg (166kb) downloaded 35 time(s). PlacidHDBP.jpg (243kb) downloaded 25 time(s). PCBs.jpg (243kb) downloaded 39 time(s). Trident.jpg (157kb) downloaded 31 time(s). Volum.jpg (89kb) downloaded 27 time(s).You cannot view/download attachments. Try to login or register.
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The most useless thread of all times.
As said bought over Internet, shipping problems, shipping's insurance claimed to take the refund their side, been refunded, but the seller has been charged despite what the shipping company said... in short I send it back as-is to the seller, a sudden news. Will never hear a Buffalo :'(
Sorry, so sorry...
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Voltages: They do look ok for a start. Tridents: Look at the DAC board so you can read the word "Buffalo-II" 1.2v goes to the left (VDD), 3.3 in the middle (VDD_XO) and to the right (DVCC) (see my picture, here shown with an old AVCC shunt, but you get the picture) Many trimmers: consult the manual. The Placid is a shunt supply. The one trimmer adjusts the current and the other adjusts the voltage V+(positive) and V-(negative) respectively. This excellent manual is for the 2.1, but the concept is the same. Placid manual by LeonWe will get it running. . Edited by user Wednesday, August 12, 2015 5:32:25 PM(UTC)
| Reason: Not specified avr300 attached the following image(s): cut1.jpg (99kb) downloaded 56 time(s).You cannot view/download attachments. Try to login or register.
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 1 user thanked avr300 for this useful post.
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... yes I know... but I've managed to get a deal with seller. I keep it...
So back to work ;)
Ready to adjust things, manual ready! A terrible drift from cold start to warm state, is that the normal behaviour?
Best adjustments for Legato with buffer on the Placid HD BP, 80mA and 15V?
Best adjustments for BII, three Tridents and something on top (what's that?) 500mA and 5.25V (5.35 cold)?
I'll need another input than the single one OEM, what are the options on sources selections and XMOS-like USB?
Enough for now I guess. After that I'll try it as it is but the "pop-corn" like resistors on the Legato are strange as the wire bridge between Legato and BII.
Thanks!
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Yes, drift is normal and has been documented in the manual (p.10). Also read the BIII manual, as that offers a lot more detail on a lot of aspects of the Buffalo series DACs, including input options.
Note: since you're in France I would suggest getting R-Cores from Selectronic to replace the transformers.
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Thanks Leon,
yep I'll check manuals and fully recase it, will learn that way. I do have some Selectronic R-Core (30VA 12V, too low for Placid HD BP and too much for Placid sadly...) wich... hums like hell! Hope I can cope with that.
Back home today we tried it like that non-secured version: does not lock on S/PDIF of my VRDS10! But it does it flawlessly with cheap DVD player and TV output... another problem in sight...
Matthieu
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I have quite a few of them, and none of them hums. Maybe a ground issue?
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Don't know, maybe a misuse of the screen wire? I this is the only thing connected to earth... but I must admit all TX hums in here, and sometimes with cycle, maybe line is more or less loaded, impedance changed/cos p stories and other DC tales...
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Hi there, questions from things not in manual; first on Placid BP HD, the Leon's manual parts list features ON Semi for both QP1/2 and QN1/2. Mine have giant ST 2STA1962 and Fairchild (TO220) J5200 on QN side. Does that mean the board was damaged/fixed and if yes is it better to get OEM parts to get the most out of the Placid? Also when looking at the Placid vs the Placid BP HD I wonder why 1.000µF vs 10.000µF? Aren't they at the same place after recitifers? now on Legato, on the picture you can see the Dale resistors 150R look new, the surface being smooth like glass. But the 680R look like fried sausages!  Is it normal? I guess they should look the same as the 150R, as on the TPA's main picture in the shop...   Edited by moderator Wednesday, September 2, 2015 6:14:23 PM(UTC)
| Reason: one pic does not show properly... File Attachment(s): Sausages.jpg (272kb) downloaded 171 time(s).Malefoda attached the following image(s): QP.jpg (178kb) downloaded 259 time(s).You cannot view/download attachments. Try to login or register.
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Originally Posted by: Malefoda  Hi there,
questions from things not in manual;
first on Placid BP HD, the Leon's manual parts list features ON Semi for both QP1/2 and QN1/2. Mine have giant ST 2STA1962 and Fairchild (TO220) J5200 on QN side. Does that mean the board was damaged/fixed and if yes is it better to get OEM parts to get the most out of the Placid?
Those are for sure not standard. Originally Posted by: Malefoda
Also when looking at the Placid vs the Placid BP HD I wonder why 1.000µF vs 10.000µF? Aren't they at the same place after recitifers?
Technically yes. The Placid is an old lady. It is generation 1 of the Placid. Thanks to evolution the cap has grown in capacity. Originally Posted by: Malefoda now on Legato, on the picture you can see the Dale resistors 150R look new, the surface being smooth like glass. But the 680R look like fried sausages! Is it normal? I guess they should look the same as the 150R, as on the TPA's main picture in the shop... Post a picture of the so called sausages.
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Rank: Member
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Joined: 8/10/2015(UTC) Posts: 27 Thanks: 7 times
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Hi AVR300 (damn that sounds awful! at least AK47 is shorter), you can't see the file in previous post? I've given up the hope on making it visible, I don't know why it can't be attached as a picture -and then displayed- but as a file to be downloaded. I try again here. Ok for now I put the OEM transistors in my shopping list. And a bigger cap for the old lady, as far as she's competent... BBQ on!  Edited by moderator Wednesday, September 2, 2015 6:15:15 PM(UTC)
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Looks like an awful solder job on some connections, plus non-standard items. I'd order a new one, but that's just me.
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(Fixed images) Looks like the Legato has some "custom" transistors as well. Let me know if you need replacement FJPF5200/1943 for the Placid. I have a bunch I have no use for. Edited by user Wednesday, September 2, 2015 6:17:39 PM(UTC)
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1 user thanked Brian Donegan for this useful post.
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Originally Posted by: LeonvB Looks like an awful solder job on some connections, plus non-standard items. I'd order a new one, but that's just me. Sadly Leon the more we have a close look the more I feel stolen :'( I'll try to fix it, that's all I can do. All odd transistors are QN ones, no brand BC550 with no grade on it. Fairchild Semiconductor BC550BTAR were EOM, shopping list. Originally Posted by: Brian Donegan Looks like the Legato has some "custom" transistors as well.
Let me know if you need replacement FJPF5200/1943 for the Placid. I have a bunch I have no use for. Brian, I welcome the offer as I understand it will be the right parts. I PM you. QN3 and QN4 are also not original parts, same ugly package as the Placid's ones) do you know what it should be? I see BC560C around, maybe Fairchild BC550BTAR as well? No BOM online. Maybe Vishay/DaleCMF60681R00FHEK/CCF60681RFKE36 if they do look like sausages... do they? I'm between trash it all and fix it... A sad but thankfull Matthieu.
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The resistors looks ok. For now forget them. Or try measuring them. I'll think they're ok. Edited by user Wednesday, September 2, 2015 7:14:32 PM(UTC)
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