AYA II DAC

[audio kutak]

citiram joea, pročitaj zadnju rečenicu! :

Taj dio nemam namjeru koristiti, ali da radim izbjegavao bi elektrolite na direktnom putu signala gdje god je moguće.
A tu je 23,5uF (serija 47+47uF) previše po meni. Ja bi tu puknuo neki kvalitetan folijski kond od par uF.
Najbolje što mi je dostupno. Može i neka MKP Wima i sl. Mundorf, Jenzen, Solen, Audyn, Epcos itd.

Taj kondenzator sa ulaznim otporom slijedećeg stupnja čini visokoporopusni filter.
Ako je ulazni otpor slijedećeg stupnja 10k (u praksi najčešće i više, kod cijevi pogotovo) uz vezni kond 1,5uF je granična frekvencija filtera oko 10Hz.
Po meni sasvim dovoljno. Sve više od toga super.

[yoke]

Ekipa imamo problemčić. SB160 diode su malo prevelike za pločicu. Stanu ali su malo nagurane i ostaju u "zraku":



Da li montirati ovako ili nabavljati 1N5819 koje su sigurno manje?

bas sam jucer probao staviti jednu diodu iz paketa koji si mi poslao...
mislio sam se dali da narucujem druge, ali ako su ove u paketu iste kao ove na slici onda nema potrebe...
diode stanu bez problema, samo se nogice trebaju savinuti odmah uz tijelo (sto kao nije preporucivo) ali onda finu legnu...(nije me strah da ce se odvojiti od tijela)

[yoke]

Da jos razrijesimo greske na tiskanoj

AD1

Hello,

Unfortunately, there is a small but significant error at PCBs revision 0, which are regrettably already sent. It was one of those small things that were added last, prior to sending the design into series fabrication, and once was made the error was impossible to discover prior to putting complete kits into work. Still, I owe "thank you" to Antonio who was one day faster.

The problem appeared with lately added four pads (double sided, so vias) that provide direct current output from TDA1541A. These are located between TDA1541A and capacitors C405/C406. Pad (via) marked as LIO shorts TDA1541A left output (trace at top side) to ground (just beneath). Obviously, this one had to be one (top) sided pad, and not via.

Essentially, the solution would be to cut the connection that goes through the board. This could be done by small needle file or diamond file. It can be done with no major traces, but it would be still recommend to do this from the bottom board side. For the record, this hole itself is 1 mm in diameter, so the tip of the file should be smaller than that. Once you do this, please use DMM to make sure there is no connection anymore between pads at two sides.

It is important also to remember that, when using these pads to connect TDA1541A to external output stage, to make this connection at top side only, not going through the board with wire.

This information will be of course added into the next revision of assembly manual.

Please don't hesitate to let me know if you need any further help in this.

Apologies for inconvenience caused

and regards,

Pedja

AD2

Hello,

With quite an embarrassment, I have to inform you about another pad that has to be cut / removed at PCB rev.0. This error was another "last minute" change, and this one is associated to the output stage ground plane (should I say, that could be left as it was...). So the one pad that had its purpose in the original AYA II (2007) is now nuisance, and must be cut in order to let output stage negative supply work properly. This pad is located between capacitors C6 and C7, and it must be cut the same as pad described in the previous errata notice.

Hopefully, it shouldn't be that hard to do this for anyone, certainly not considering all the work required to populate the board, and it is possibly about one minute of work. As suggested in previous mail, file or any similar tool will work, and no major traces of surgery should remain, either.

Attached picture shows the file in the pad mentioned in previous mail, while red arrow marks this second pad. Two or three turns done with file inside the pads will cut the connection and do the work. Once you do this, please use DMM to make sure the connection is cut.

I hope the picture is more instructive than bare text, but should you need any further guidance, don't hesitate to let me know.

Regards

SLIKA




PS: trenutno nemam tiskane kod mene, ali kad ih se dokopam, volio bi da se preko slike prikaze sto treba izmjenit/prekinuti...ne znam dali su na gornjoj Pedjinoj naznacene sve potrebne izmjene ili treba jos nesto (malo sam u guzvi pa nisam s paznjom procitao oba Pedjina maila...samo sam ih na brzinu kopirao da se nadju u ovoj temi)
ali koliko vidim na prilozenoj slici, Pedja je napisao da su naznacene obe izmjene...onom turpijom (ili cim vec) je naznacena prva izmjena i crvenom strelicom druga

[audio kutak]

da, to je to.... bar za sada...

[Dean]

Iskoristio sam Marantza CD60 da provjerim TDA1541A. U to svrhu uskočio je S@ki i odlemio oriđinal i stavio podnožje.




Na probi su bili čipci iz "Yoke edicion". To su oni koji nemaju krunice, ni S-ove....



Onaj čipac gore je "orginal" iz Marantza, a ostatak je redom: moj, daltonov, zendrin i šulcov... Tim redom jer sam najbolji ostavio sebi, a najgori šulcu. ( jbg. šule, ali je zendra bio tamo, pa nisam mogao njemu uvaliti fejk)

[s@ki]

srecom pa sam si odmah ostavio tvoj orignal i uvalio ti fejkaru a da nisi ni skuzio

[Dean]

Budno oko forumaša pratio je specifično mjernje čipaca...



S ljeva na desno; Audio kutak, Zendra...

Nakon opetovano ponovljenog testa na svim čipcima, tročlani test žiri dao je ocjenu....



Svi čipci su radili....

[Dean]

E sad jesu li fejk? Jest da je Kutak rekao da njegov radi bolje (veli da on to čuje), no ja mislim da je jedini mjerodavni Tom-hifi, ali njega nije bilo, pa smo proglasili testiranje gotovim....

[yoke]

Sta ste mjerili ?
volumen ?
uranjanjem cipca u solju vode ?

[Schultz]

Čim svira nije fejk...

Allahu Ekber.... Ne bacamo novce totalno bez veze... Bacamo ali ne totalno.