[leeperry]

build a DIY DAC then if you really like the smell of burning lead in the morning?
 
it's like the ppl who spend more money on a sh***y mono-LCD based DIY projector than in a brand new off the shelf much superior triLCD/DLP commercial projector

 

[superrobin]

I've considered that option, but it takes time, and I was in urgency to replace my defunct previous DAC
 
The point is: I love music, but I can't afford the cost of a really good off the shelf dac, so I start from something cheaper and try to improve it
 
Often the difference in sound quality between a good and an average product lies in few dollars of better quality components
 
Anyway, if I could buy a really good dac for around 200$, one that doesn't make me think about possible improvement, I would be very happy to leave my soldering iron in the box
 

 

[Groundloop]

Quote:

I would be very happy to leave my soldering iron in the box
 

What's the fun living then?
 

 

[ROBSCIX]

The more you use your iron the more fun they become. 

 

[leeperry]

 

Originally Posted by superrobin /img/forum/go_quote.gif
 
The return policy in Italy doesn't include money back

Order from another european country next time? Germany and France provide a 2 weeks cooling-off period, no question asked.
 

Originally Posted by superrobin /img/forum/go_quote.gif
 
There were so many people swearing for STX, claiming it was the best value for money available on the market with few mods

Originally Posted by superrobin /img/forum/go_quote.gif
 
 if I could buy a really good dac for around 200$, one that doesn't make me think about possible improvement, I would be very happy

 
Well, subjective impressions are completely dependent on what the reviewer heard before, if you come from a crappy internal soundcard the STX will blow you away...and there's also the new toy syndrom at play. If you own a 4 figures DAC, the STX will sound like a shrill realtek to you.
 

Wow, that NFB-12 looks really interesting

 
It's an entry level discrete DAC+headamp, it won't do miracles but it will outshine any internal soundcard in a hearbeat. It was only an example, I'm not too up to date on entry level DAC's.
 

Often the difference in sound quality between a good and an average product lies in few dollars of better quality components

 
I don't agree at all, you're only as strong as your weakest link...and the STX is being a fed a very noisy PSU and has a high jitter DSP(its datasheet talks about 700ps) and a 24.576MHz(48kHz*512) low resolution clock...so its performance at 44.1kHz is severely compromised(hence the CS2000 75ps reclocker in the ST, but it doesn't do miracles either).
 
Their new 400€ "Essence One" DAC is a major step up the food chain, though

 
I recently quoted an EE who told me that it's fairly easy to get killer measurements with opamps, but it doesn't prove that it'll sound good: http://www.head-fi.org/t/542563/asus-essence-one-headphone-amp-dac-cebit-2011/420#post_7952126

 

[superrobin]

You put me in severe trouble, leeperry
 
While looking at audio-gd site for NFB-12, I discovered NFB-2 and NFB-3, complete discrete output section, top quality components ...
 
I can't resist, my wife could kill me...
 
I guess both are superior to asus essence one 
 
Anyway my previous dac was a beresford caiman upgraded with discrete output stage
 
It was a little marvel, at first STX couldn't compete with it, only after all the mods it reached same level
 
I would be curious to do an A/B comparison between them right now, but is not possible
 
 

 

[leeperry]

 

You put me in severe trouble, leeperry

Well, the rabbit hole goes as deep as your pocket. Leave while you still can

 

 

[germanium]

Some people claim the Essense ST/STX cards harsh but in my situation it is only harsh on certain music with certain phones. Interestingly not harsh on the very ones you would expect to sound harsh with such as the ER4p with p to s converter. Very well balanced with these & with my modded speakers which are also very revealing. Denon AH-D1001 sounds somewhat harsh but only on certain music not all  these phones sound the same on other sources with the same music I have so can't blame the STX I have for sounding harsh in & of itself.

 

[PurpleAngel]

SuperRobin.
For better sound, you might try installing 3 LME49860NAs op-amps, my three only cost me only $15.
They are the same op-amps as the LM4562s, but with a better voltage range.
 
I'm gong to try replacing the buffer (LME49860NA) on my STX with the OPA2107AP in the near future.

 

[superrobin]

PurpleAngel, LM49990 are on the way right now, I've ordered them soldered on dip 8 adapters (two chips for each adapter) 
 
I can tell a little story here about STX harshness: this problem is really apparent through my main system (DIY amp based on TA3020) than my headphone (sennheiser HD540)
 
That's because the TA3020 is very very revealing, given a proper source it will deliver a fantastic sound, dynamic, fast, super detailed, strong bass, but it show any flaw in the source, and can't tolerate HF noise
 
This is common to all high speed wide band amplifiers, they amplify also HF noise, running hot and deteriorating performance in audio band
I discovered this is the same reason for blamed poor bass performance of LM4562; try to clean out the signal from HF noise, and it will deliver a spectacular strong, heavy and punchy bass, without that sense of coldness in the treble
 
I had major benefits working around output stage feedback loop (that is an active filter in the end) and filtering the PS, particularly the 3.3V supplied by PC mother board that fed also the oscillator
Next to the PCI-ex slot pin there is a little ferrite bead to filter the 3.3V; I replaced it with an hand made coil with toroidal ferrite core, and I added a 47uF X5R ceramics cap in parallel to the line
 
This mods removed A LOT of the harshness and provided better instrument definition and sound stage, maybe a lower noise power reduce oscillator jitter ?
 
 

 

[PurpleAngel]

Quote:

PurpleAngel, LM49990 are on the way right now, I've ordered them soldered on dip 8 adapters (two chips for each adapter) 
I can tell a little story here about STX harshness: this problem is really apparent through my main system (DIY amp based on TA3020) than my headphone (sennheiser HD540)
That's because the TA3020 is very very revealing, given a proper source it will deliver a fantastic sound, dynamic, fast, super detailed, strong bass, but it show any flaw in the source, and can't tolerate HF noise
This is common to all high speed wide band amplifiers, they amplify also HF noise, running hot and deteriorating performance in audio band
I discovered this is the same reason for blamed poor bass performance of LM4562; try to clean out the signal from HF noise, and it will deliver a spectacular strong, heavy and punchy bass, without that sense of coldness in the treble
I had major benefits working around output stage feedback loop (that is an active filter in the end) and filtering the PS, particularly the 3.3V supplied by PC mother board that fed also the oscillator
Next to the PCI-ex slot pin there is a little ferrite bead to filter the 3.3V; I replaced it with an hand made coil with toroidal ferrite core, and I added a 47uF X5R ceramics cap in parallel to the line
This mods removed A LOT of the harshness and provided better instrument definition and sound stage, maybe a lower noise power reduce oscillator jitter ?

Where did you order the LME49990 from?
 
 
 

 

[superrobin]

From a NY guy, he sell on ebay
 
I don't know if posting link to vendors is permitted here
 

 

[superrobin]

Quote:

 
Their new 400€ "Essence One" DAC is a major step up the food chain, though

 
 

The essence one was in my plan, but for the same price there is the NFB-2...
 
It would be very nice to have a comparison

 

[PurpleAngel]

Quote:

From a NY guy, he sell on ebay
I don't know if posting link to vendors is permitted here

Found him on eBay, but not selling the LME49990 right this second.
 
 

 

[germanium]

Quote:

 
 
That's because the TA3020 is very very revealing, given a proper source it will deliver a fantastic sound, dynamic, fast, super detailed, strong bass, but it show any flaw in the source, and can't tolerate HF noise
 
This is common to all high speed wide band amplifiers, they amplify also HF noise, running hot and deteriorating performance in audio band
I discovered this is the same reason for blamed poor bass performance of LM4562; try to clean out the signal from HF noise, and it will deliver a spectacular strong, heavy and punchy bass, without that sense of coldness in the treble
 
 

Note that the amplifier that you are using is not a wide band amplifier but a switch mode audio frequency amp so I can see why it can not tolerate radio frequency noise of any kind.The noise would be more than half the switching frequency of the swich mode amplifier so you would have aliasing that would cause this noise to dump down into the audio band if sufficiantly close to the operating frequence of the switch mode amp which it may be & said amp would not be linear under those conditions either. A true wideband amplifier would not have difficulty with the noise level coming of the STX card as the amp even though it would amplify the noise would do so in a linear fashon & not create excessive distortion. It certainly would not cause a true wide band linear amp to produce excessive heat nor cause problems for sensitive tweeters as even though there is RF noise present it is not of sufficient level to cause problems with wide band linear analog amps. The headphone amp inside the ST/STX cards is one such wideband linear amp. It is flat with low distortion all the way out to 10MHz! This is true of all current mode feedback amps that they are very wide band amps & this trait does not change with gain unlike voltage feedback amps which gain level does change bandwidth.