[Lil' Knight]

I'm thinking for 'upgrading' the caps in my DAC but still not sure which to use. My choices now are the Black Gate NX HiQ 47uf and Black Gate FK 47uf.
The replaced caps are Sanyo OSCON around the DAC chip in the pic:
 

 
The NX HiQ is really, really to find now while the FK is still available. My question is which one would be better for this application?
 
Thanks!

 

[qusp]

neither, IMO the oscons are much more suitable for this application. blackgates are good caps thats for sure, but oscons are pretty much made for decoupling digital circuits. u could also add some small poly film caps in parallel to the oscons. 

 

[Lil' Knight]

Hmm, I thought I've seen many mods using the NX Hi-Q as decoupling caps in digital circuits.

 

[spritzer]

Just because people do it, doesn't mean it is a good idea.  I've seen people put V-caps in Stax amps where they will do aboslutely nothing since the amps are DC-coupled...

 

[MASantos]

Sanio oscon's are probably the best caps you could use there for that application.

 

[nikongod]

What do those caps do? How can anyone possibly give a worthwhile recommendation if they dont know what its for?
 
It is quite possible that the oscons in there now are awesometoast. If they are power supply decoupling caps oscons are borderline unbeatable, and black gates are borderline worthless.
 
As an aside: with all the black-gate hate, has anyone measured the THD of the cap? I have seen information on other audiophile caps (elna in specfic) that they have lower THD than "general purpose" caps. food for thought.

 

[Lil' Knight]

Here's the schematics:
 

 

 

[qusp]

errm its pretty likely from the picture that they are decoupling inputs and acting as local reservoirs for the supply lines of the receiver and dac chip. the application calls for a lowZ, low leakage cap, oscons are pretty much unmatched for the position they are used here (only thing better would be the SEPC version or otherwise SMD type package of same). they have about the best spec for lowZ at HF (for electrolytics) going apart from NPO ceramic and some films, which the PCB seems to even have placement for too. those through-hole thin rectangular positions on the component layout there seem to be there for adding wima/evox/vishay MKP or similar to bypass the sanyos, that would be what I would do anyway and it seems they have made it easy for you.
 
I see mods all the time on here and around the net, basically removing suitable caps, only to replace them with ill-suited, ill-fitting inductive nightmares, replacing very low capacity (20pf or whatever) SMD NPO ceramics decoupling very HF signals with a comparatively slow and ineffective 100uf BG, without regard for (and most often knowledge of) what the caps are they are replacing; simply because they are SMD or not a brand that is as 'audiophile approved' as blackgate. hell sometimes its done with a complete DIS-regard for what is called for in the datasheet
 

 

[qusp]

haha the above reply was composed before the above schema was posted (nut I only just hit send) and it seems was accurate anyway. yep, leave the oscons in and bypass them in the positions provided, with a small 10nf or 100nf MKP or PPS type box film cap like wima MKS2 or MKS10, vishay MKP, or my personal favorite at the moment, Evox/Rifa MKP or PPS. they call for 100nf (0.1uf) but you could use 10nf pretty effectively too. even 47nf to match the 47uf oscon (purely superstition )