Buffalo II - Assembly for the Electronically Bewildered.

[Suffolk Tony]

Well, my Buffalo 2 DAC box of bits arrived yesterday so I thought I'd start a thread detailing my attempts to put it together into something that actually works.

This is a major step up in complexity (and worry) for me but thankfully, in addition to the enormously helpful folk on the forum, there is a wealth of information on the Twisted Pear website and forum.

As usual with Twisted Pair Audio, everything arrived nicely packaged and clearly labelled -

The various bits are (clockwise from top left) Transformers (1 for analogue, 1 for digital), Placid Bipolar power supply, Placid supply, MUX 4:1 unit (for adding up to four digital inputs, then connects directly to the Buffalo via 12S connections. Apparently..), SP/DIF optical input kit, Legato I/V stage. I've also got three Trident regulators which arrived a couple of weeks ago, more of these later...

After opening this little lot and panicking for a couple of hours I sat down and carefully went through the units to familiarise myself. Where I saw something that puzzled me I found out the answer and the initial terror subsided a bit.

My initial plan is to assemble and populate the individual items, adjust the settings where stipulated, then lay everything out on a board the same size as my case. The latter's a Modushop Galaxy Maggia-wotsit 330x280x80 which seems to be fine sizewise.

I'd originally planned to fit the Tridents as I went but there's some doubt whether the Placid will have sufficient grunt to power these in addition to the other stuff so I think I'll get the DAC up and running with the standard jobs in place.

Job for today - solder up the Legato. It's got the most components so once that's done the rest should be plain sailing. Well, that's my theory anyway.

Here're the bits for the Lagato laid out. Sorry it's not in focus but I've moved it all around now -

OK, soldering iron's hot...Wish me luck!

 

[Uzinusa]

Ace. You do right to check things out first. Find yourself an interrupted time. Try not to have to de-solder anything, e.g. because you got the cap polarity the wrong way round, as de-soldering can damage some pcb if you're not careful. Soldering can actually be a pleasure
Andy

 

[James Evans]

Good luck! Should be fun. Bear in mind that if you're only using the single ended outputs from legato you don't need to fit the green nichicon muse caps - you can just put wire links in place, which gives a decent improvement.

 

[Suffolk Tony]

Just having a coffee break; all's going well so far but luckily I looked at the photo of the finished board on TP's website & noticed I was about to solder the four red square caps in the wrong holes. Confusing because there are several holes & they don't show which are the correct ones to use. At least, not to my uneducated eye!

Thanks for the info. James, although I don't quite follow. Presumably by single-ended you mean unbalanced outputs? The board output's labelled; - GND + GND SE on both channels. Presumably I'll only need to connect + and - on each side? Or + and GND?

Sorry for the simplistic questions; I'll be asking lots of these as things progress, not just for my benefit. I know there are some silent folks watching this thread who know even less than me! if that's possible...

 

[James Evans]

Yes, unbalanced, ie: GND and SE. You will need to put wire links in place of the green caps as they are directly in the signal path, so you'll get nowt out wi nowt in there. Don't want to start suggestions on modding the board as keeping it stock is the best way, but if you're not going to use the balanced outs there really is no need for those caps.

 

[Suffolk Tony]

Ta James, 'tis done!

 

[Suffolk Tony]

Time to knock off. Everything seems to have gone well enough so far & I've put together the Legato, Placid BP & the various bits needed on the Buffalo -

I love the way the Legato, Buffalo & AVCC module all plug together so nicely.

Hopefully I'll be able to finish off the other units tomorrow & maybe power up the Placids.

 

[avr300]

When you do power up the Placid, be careful not to make the common mistake.

When you measure the voltage across R1(2), don't let the probe pin slip and short to ground plane. If done, you will burn the VR1(2) pot.

 

[cutting42]

Looks great Tony.

I had my Twisted Pear bits out tonight as well. Pic not as clear as yours but I laid out for box information.

The Legato I purchased had been configured without the buffer or the BAL/SE stage so it is looking emptier than yours. However I will need the single ended so will be adding the bits, but not the buffer.

I have a Optical adapter to make as well and am thinking of using the generic reg cards to supply the Placids - thoughts anyone?

Cheers

Gareth

 

[Suffolk Tony]

Hi Gareth, I was also wondering whether I could use one of the generic rectifier boards to power my MUX 4:1 receiver. I haven't got a clue how to do this (well, not much of one anyway) presumably we'd also need a regulator?

I forgot to mention that the recommended change on the Legato board from 12 x BS250KLs semiconductors to TP0604s has already been done by TP. I'd already bought the TP0604s from Mouser so these are now going spare if you want to upgrade your Legato.

I'm off now to complete the other units - a hot soldering iron waits for no man!

PS, I'm struggling a bit with the various abbreviations used on the boards. I know some obvious ones but others I'm not sure of. I'll have to search the internet for an Electronics - English directory!

 

[James Evans]

Gareth, generic psu boards will be fine, but you'll have to remove the rectifier bridges, and probably smoothing caps from the placids. Just then need to see if you need to put any wire links in place. Someone I think built their buffalo this way and noticed an improvement using the psu boards.

Tony, you would need a regulator to drop the raw voltage off the psu board if going that way with the mux. I assume for the moment you're looking at daisychaining off the placid supplying buffalo? If you install tridents watch for total current draw. Can't remember offhand what mux uses, don't think it's much.

 

[cutting42]

Hi Gareth, I was also wondering whether I could use one of the generic rectifier boards to power my MUX 4:1 receiver. I haven't got a clue how to do this (well, not much of one anyway) presumably we'd also need a regulator?

I forgot to mention that the recommended change on the Legato board from 12 x BS250KLs semiconductors to TP0604s has already been done by TP. I'd already bought the TP0604s from Mouser so these are now going spare if you want to upgrade your Legato.

I'm off now to complete the other units - a hot soldering iron waits for no man!

PS, I'm struggling a bit with the various abbreviations used on the boards. I know some obvious ones but others I'm not sure of. I'll have to search the internet for an Electronics - English directory!

Hi Tony

I would love the TP0604 and will PM you, many thanks.

Re the MUX and the TOSLINK yes you do need a separate PSU of 5-12vdc. You will need another transformer and regulator. The generic card will certainly do the job but is somewhat overkill. I dont have the MUX yet but may add one later so will have the same issue to power the TOSLINK card.

Cheers

Gareth

 

[cutting42]

Gareth, generic psu boards will be fine, but you'll have to remove the rectifier bridges, and probably smoothing caps from the placids. Just then need to see if you need to put any wire links in place. Someone I think built their buffalo this way and noticed an improvement using the psu boards.

Hi James

Thanks for that, I was having a look at the cards last night and came to that conclusion so good to have it confirmed. Might have a quick search on DIY for anyone else that has done it.

Cheers

Gareth

 

[Bemused]

Great thread am missing here, I need to get my mits on some hardware

Taking the rectifiers out of the Placids and using Carls boards seems like a good idea if not a little overkill. I would tend to expect the TP would have put CR stages in the primary filter if they thought the Placids were lean on rejection but I believe Carls boards could only improve things, but probably not by a lot. Placids seem to have good enough rejection as they have not even found the need for a center tap transformer winding configuration. You may be gilding something that is already made of gold. Maybe worth asking the TP for there thoughts.

Meanwhile I just need a chance to bid ten I will join you guys for some fun.


Hows the Ergo progressing Gareth?

Tony

 

[Paul R]

Re the MUX and the TOSLINK yes you do need a separate PSU of 5-12vdc. You will need another transformer and regulator. The generic card will certainly do the job but is somewhat overkill. I dont have the MUX yet but may add one later so will have the same issue to power the TOSLINK card.

I'm running a Toslink adaptor, Volumite and mux card from the same Placid that supplies the Buffalo 2. I don't have Tridents.

When I rebuild I may add another digital supply, but this arrangement has worked since I installed the Buffalo 2 and found that the in place LCDPS was dropping out under the load.

Paul

 

[Suffolk Tony]

When you do power up the Placid, be careful not to make the common mistake.

When you measure the voltage across R1(2), don't let the probe pin slip and short to ground plane. If done, you will burn the VR1(2) pot.

Thanks for the good advice avr300, I'll be extra careful!

I've completed the individual units -

I've done the pre-powerup adjustments to the Placids. Now I confess I'm getting rather lost regarding how the individual bits are powered up and would appreciate some advice.

I've the two TP transformers, one producing 9V/ 0.83A on its two secondaries, the other 15V/1A. I've sussed out I need to join two of the wires (in this case, Violet and Grey) to get the 230V for input. The Placid BP takes the four secondary wires in its 4 AC inputs, but from which transformer?

The three outputs from the BP (V-, V+ & GND) presumably go into the Legato.

The Placid only has two AC input terminals, so do I just double up the secondaries from one of the transformers, or just use a single secondary? Again, which transformer?

I've then got the Buffalo itself, the MUX 4:1 input module and the TOSlink module. Can the single Placid power all these OK? the Legato's 360 mA constant, Buffalo 290 mA and MUX 60 mA; no figure for the TOSlink but I imagine it's pretty insignificant.

It would seem that I've more than enough power to handle everything (although I've not fitted the Tridents yet just in case)

As usual, any and all help and advice gratefully received! Or if any of you happen to be in Suffolk at the weekend, SWMBO's a pretty mean cook.

 

[James Evans]

Ok, placid bp powers legato. 15v transformer is for placid bp. 9v one for single placid. Use a single secondary for this and I'd probably wire the spare secondary into a chokblok (spelling?). Either that or securely insulate the ends, separately, and coil the wires up to keep them out of the way. From memory the placid single is going to max out somewhere around 350mA, but the newer one may go higher, not sure if they've made any changes there. I would set it to the max current you can get out of it, connect up buffalo, mux and toslink, daisy chained, and measure the current draw. Make sure voltage is set to whatever is recommended for buffalo - 5.2v sounds about right. Connect your multimeter in the +ve supply wire between placid and the first component being powered - croc clips are ideal here - and set the meter to mA. When powered up you should see the total current draw. If it's higher than placid can supply you'll probably see placid output voltage drop. If you have headroom, adjust the placid current to about 80mA above total current draw. If you do run out of juice then I'd probably just run the buffalo and toslink board for now and get a single input working. Add the mux in later when you have another supply available, and then put the toslink board on this supply as well, to keep the buffalo on its own.

Likewise for legato - measure the current draw in each rail and adjust the placid supply on both to about 80mA above measured current draw.

Hope that helps, and I hope I've got it all correct. Been a while since I dived inside!

I have a fairly early placid and it was maxing out on buffalo when tridents were added, so I've put a LCDPS supply in there now (with current limiting resistors removed) - one rail supplying buffalo, the other the mux, toslinks, volumite. When placid HD is available I may get one and try that supplying the buff with tridents.

 

[Suffolk Tony]

That's really great James, many thanks!

I did ask a question on the TP Forum a while back about powering the MUX & I was advised "If the Placid is one of the latest versions you shouldn't have any trouble getting it to work with a B2 with Tridents and a Mux". Russ White advised I "Might want to use two Placids". I'll play safe & leave out the Tridents for the time being.

 

[avr300]

I'm using both secondary windings in parallel to feed the single Placid.

You have to phase them correct, ie. red||yellow / black||orange.

With the Tridents in, the single Placid will have to go 105% (or slightly less).

I would consider a LCDPS to power the mux.

 

[Suffolk Tony]

Whew! Got things powered up this morning -

Don't you just get a nice warm glow when there's no bang or spooky little plume of smoke?

A couple of problems - first off, one side of the Placid BP didn't light up. Double-checked the soldering underneath and although it all looked OK through a magnifying glass I ran the soldering iron over the pads & all was well. Then doing the adjustments to obtain ~ 0.35V across R1 & R2 I got a bit nervous because the variable resistors needed quite a few turns from their initial settings to get the right value.

No problems with the Placid; connected up to the Buff., MUX and TOSlink and no voltage drop, all measures well.

Anyway, time to stop or SWMBO will get a bit cross (and you wouldn't like her when she's angry...). I'll carry on with the connections to Legato, outputs & inputs on Monday.

I've decided to buy another Placid (when the TP chaps are back & running again) to power the MUX & TOSlink module, then I can fit the Tridents.

Thanks again for all the help you folk have given me.