[mmx3]

    my opinion is - after any no-fold (eg, 44.1 - 96) re-discretization sound quality is down.   
 These DAC's  contain 8x (sync, fold)   digital filter, that already multiply frequency at 8x.
 
Yes,  digital volume control - way to degrade the resolution on lowest and middle levels.

 
Quote:

upsampling supposed to sound better isnt? digital volume tends to degrade the resolution on lowest volumes?

   You can make simple experiment -
on computer with good  pro soundcard  play test music with 44.1 kHz,   resamplinig to 48 / 24bit,  88/ 24, 96 / 24, 192/ 24.
On player with very good re-discretization plugin  (foobar + ssrc x), of couse.
 
If your acoustics/amp or headphones are good,  you may hear the difference -
very slight turbidity after no-fold (44 - 96 , 192) increase in the frequency.

And almost nothing after the 44.1 - 88.2.

for the bad records this turbidity can, may be good ... matter of taste. I do not like.
 
Also pls remember,  that even very good delta-sigma DAC's   works better on 44/48 kHz, than on 176/192 kHz  (see datasheet for pcm1792, for example. and measurements is for 20hz-20khz for all cases)
 
 
 

 

[mmx3]

  Can I change mode of digital filter of pcm1792a in  SMK-III  mod  (sharp <->  slow ) ?

 

[david-gao]

Quote:

how is this compared to matrix mini i dac?

     Sound is similar to Matrix mini
     Matrix mini is good DAC with a small chassis, But HLLY SMK3 is easy for MOD
     (I mean you can replace the OP AMP or capacitors)
 

 

[david-gao]

Quote:

  Can I change mode of digital filter of pcm1792a in  SMK-III  mod  (sharp <->  slow ) ?

     I think it is difficult to change the mode of digital filter
 

 

[mmx3]

     USB signal, received by tenor 7022,  go to spdif chip 9001  or  directly to pcm1792  ?
 
Quote:

Originally Posted by david-gao /img/forum/go_quote.gif
     I think it is difficult to change the mode of digital filter
 

 

 

[jackmccabe]

The matrix mini-i is prettier and has a remote as well.

 

[david-gao]

Quote:

     USB signal, received by tenor 7022,  go to spdif chip 9001  or  directly to pcm1792  ?
 


 

     Yes, correct!
 

 

[mmx3]

What is correct ?  8=-)
" USB signal, received by tenor 7022, go to spdif chip 9001"  or  "directly to pcm1792" ?
 
Can you send to me scheme of SMK-III  ?   (at Monday  I 'll   receive it. )
 
Quote:

     Yes, correct!  

 

 

[jackmccabe]

I have a hlly smk-III for sale, if any one is interested please pm me.
 

 

[mmx3]

Receive SMK-III mod.


Good case, carefully assembled.

Overally good ( but slightly... ragged), smooth sound with my Beyerdymamic 990.

Articulated bass, good rock sound (without specififc treble problems as for some CirrusLogic dac's , for example).

Not so good with Sennheiser px100;   yes, I know about level (much below B990) of px100,

but It seemed to me that SMK-III amp works with 32 Ohm not so good, such as with 250 Ohm.



Changed opamp from op275 to bb opa2132p.

Sound became more clear, smoother and rather .




 

 

[david-gao]

     If you have philips big caps, you can try to replace the main power caps and the sound will be better!
also you can try to replace the OP275 with OPA627
 
Quote:

Receive SMK-III mod.


Good case, carefully assembled.

Overally good ( but slightly... ragged), smooth sound with my Beyerdymamic 990.

Articulated bass, good rock sound (without specififc treble problems as for some CirrusLogic dac's , for example).

Not so good with Sennheiser px100;   yes, I know about level (much below B990) of px100,

but It seemed to me that SMK-III amp works with 32 Ohm not so good, such as with 250 Ohm.



Changed opamp from op275 to bb opa2132p.

Sound became more clear, smoother and rather .




 

 

 

[mmx3]

What caps ?   I have   mod version.
opamp in I/U   or in filter ?
 
front pair  of opamp  (closer to  pcm1792 chip) - I/U  or filter ?
 
Quote:

     If you have philips big caps, you can try to replace the main power caps and the sound will be better!
also you can try to replace the OP275 with OPA627
 


 

 

 

[ballcall2]

I suggsest that the next DAC  from Hilly will be asynchronous usb...

 

[EarlyBird]

I'm still testing the smk III (Mod) with different opamp combinations. I tried all possible combinations of opa2604s, op275s, and opa2132ps. My favorite so far is a combination of op275s as filter and opa2132ps for I/V (larger soundstage, somewhat darker but still very refined bass and more balanced than just op275s), followed by opa2132ps for both filter and I/V (extremely broad soundstage, somewhat less refined bass, somewhat less detailed? -  but I'm not sure about the last point). The 2604s seem to cause oscillation problems and don't sound as good as the other two in combination (larger soundstage than just 275s, even a bit darker but the worst detail grade).

 
MMX3, how about your opa627s, did it work out? Should i try those, too?

 

[EarlyBird]

David,
 
which chip and which opamps will the hlly smk IV use?