TR Forums

I've been deeply involved in all things PC for decades now, but I dawned on me today, while looking at other threads, that I really haven't given much thought to PC Audio in the last 10 years or so.

It's weird, I remember the Soundblaster vs Adlib wars, the SB16 clones, terrible MIDI except from Roland, Turtle Beach, and the GUS if used properly. But after the AWE64, PC audio just started to get all homogenized, and took a big backseat to the 3D card wars, the GHz CPU race, and ever larger HDDs.

I hope that AMDs TrueAudio catches on, since it's the biggest chance we've seen in the gamer audio market in ages ( and it being used by the PS4 should help adoption immensely).

With that said, I spotted an ad for a Gigabyte G1.Sniper 5 Motherboard the other day, and it had a few audio related features that caught my eyes, and raised a lot of questions I hope you folks can answer.


1) The Creative Sound Core3D ASIC with "Gold Plated Shielding". Firstly, does gold plating that chip do any good, or is this like gold Monster Audio cables? Secondly, is the Sound Core3D actually worth a damn?

2) Audio Noise Guard with Path Lighting - I'll let gigabyte explain this "...G1-Killer motherboards feature an audio noise guard that essentially separates the board’s sensitive analog audio components from potential noise pollution at the PCB level. LED trace path lighting Illuminates to show the separation of the PCB layers". Sure, it looks really neat, and all, but does it actually do any good?

3) gold plated audio and HDMI connectors - Monster Cables, anyone?

4) Gaming Headphone Amplifier (Front Headphone)
"Specially designed for gamers, GIGABYTE G1-Killer motherboards utilize a high-capacity amplifier which is able to drive 600Ω loads, giving gamers a fuller range of dynamic sound with crisper details and less distortion when using high quality professional headphones." I have no idea how powerful a 600 Ohm load is, in audio terms, but that sounds badass!

5) Swappable OP-AMPs. Sounds good on paper.



Does something like this sound like it would have great audio, or should I stick with getting an EMI shielded Soundblaster or something?

Hz so good wrote:

I spotted an ad for a Gigabyte G1.Sniper 5 Motherboard.

http://techreport.com/review/26113/giga ... d-reviewed

First. Never ever buy anything from Creative. I thought we knew this.

This thing:

http://www.amazon.com/dp/B0093KZWRE/ref ... 1_ST1_dp_1

Destroys any sound card I have ever heard. I still have an ISA bus Pinnacle in the drawer and my son has my M-Audio 24/96 'cause I have no PCI slots. I bought it 'cause it was cheap and my onboard sound was ugly, just a cheap fix, but I think I'm gonna keep this little jewel.

It is a very fine DAC and although I really can't speak to the headphone amp the DAC is golden. I have it hooked up to the beast system. Factory tweaked Sonic Frontiers Signature preamp feeding SFM 75 Monoblocks which are hooked up to original B&W Matrix 1 speakers, with the crap crossovers replaced, with Tara Time and Space, biwired. It is a revealing system.

I have no idea how it compares to the plethora of $100 and change USB DACs but it is very sweet for less than half their price.

I believe that Creative's sound cards are better than those from Asus.
http://www.newegg.com/Product/Product.a ... 6829102054
http://www.newegg.com/Product/Product.a ... 6829102050

Hz so good wrote:

1) The Creative Sound Core3D ASIC with "Gold Plated Shielding". Firstly, does gold plating that chip do any good, or is this like gold Monster Audio cables? Secondly, is the Sound Core3D actually worth a damn?

2) Audio Noise Guard with Path Lighting - I'll let gigabyte explain this "...G1-Killer motherboards feature an audio noise guard that essentially separates the board’s sensitive analog audio components from potential noise pollution at the PCB level. LED trace path lighting Illuminates to show the separation of the PCB layers". Sure, it looks really neat, and all, but does it actually do any good?

3) gold plated audio and HDMI connectors - Monster Cables, anyone?

4) Gaming Headphone Amplifier (Front Headphone)
"Specially designed for gamers, GIGABYTE G1-Killer motherboards utilize a high-capacity amplifier which is able to drive 600Ω loads, giving gamers a fuller range of dynamic sound with crisper details and less distortion when using high quality professional headphones." I have no idea how powerful a 600 Ohm load is, in audio terms, but that sounds badass!

5) Swappable OP-AMPs. Sounds good on paper.



Does something like this sound like it would have great audio, or should I stick with getting an EMI shielded Soundblaster or something?

1) Different metals/alloys reject different emi/rf frequency noise. I don't know how well gold works for this. I know that mu-metal is really good though.
2) I think what this is is just isolation of the DAC from the rest of the system, which protects against system noise. The LEDs definitely make the audio better and your computer faster.
3) Gold has lower resistance than copper/aluminum/tin, which makes it better for connectors. I doubt most people would hear a difference, so it's probably just good for tarnish resistance.
4) Unless they mean that the amp output is buffered, then they probably just mean that the opamps they give have high enough output current to drive 600 ohm headphones. But then again, any amp can drive 600 ohm headphones, but some do so better than others.
5) I always thought it was generally frowned upon to swap out opamps willy nilly, since some are designed for high gain (>5) and some are stable at unity gain while others aren't.

That said, I decided to just build myself a Gamma2 and be done with computer soundcard nonsense until I felt like spending >$1k on a new DAC.

chµck wrote:

3) Gold has lower resistance than copper.

No. From most conductive on down, it's Ag, Cu, Au, Al...

chuck wrote:

It's probably just good for tarnish resistance.

Yes. Also, because gold is malleable, it squishes to make a good high-area connection.

If you want quality audio, invest in a USB DAC and headphone amp combo. I personally have the entry level Schiit stack.

http://schiit.com/products

http://www.amazon.com/Schiit-SCH-07-Mag ... B00CICPMA6
http://www.amazon.com/Modi-USB-Digital- ... B00CICPN0K

I hit up some 24/96 FLAC tracks, and it is soundgasm with my ATH-M50. The entire setup including the cans cost me ~$300.

Don't fall for the gold plated jargon jumble bull.

chµck wrote:

1) Different metals/alloys reject different emi/rf frequency noise. I don't know how well gold works for this. I know that mu-metal is really good though.

I don't know what mu-metal is, but certain agencies embed a fine copper mesh into windows to create giant faraday cage, so what advantage to gold plating an ASIC give, short of "Bling Effect"

2) I think what this is is just isolation of the DAC from the rest of the system, which protects against system noise.

Oh, OK. That makes sense.

The LEDs definitely make the audio better and your computer faster.

Awesome!

3) Gold has lower resistance than copper/aluminum/tin, which makes it better for connectors. I doubt most people would hear a difference, so it's probably just good for tarnish resistance.

That's wrong. Copper is way better than Gold.

4) Unless they mean that the amp output is buffered, then they probably just mean that the opamps they give have high enough output current to drive 600 ohm headphones. But then again, any amp can drive 600 ohm headphones, but some do so better than others.

I dunno. I was just thinking that 600Ohms right into my heads holes sounded neat.

5) I always thought it was generally frowned upon to swap out opamps willy nilly, since some are designed for high gain (>5) and some are stable at unity gain while others aren't.

If you check out their "premium OP-AMP upgrade kit", it's rather silly. Each of the 3 are better suited to certain types of music, so it seems like it would be a pain, if you liked a wide range of music. I do like the cheap IC puller, straight out of a bargain bin A+ course tool kit. So they've got that going for them...

That said, I decided to just build myself a Gamma2 and be done with computer soundcard nonsense until I felt like spending >$1k on a new DAC.

What's that? I'd be content with just a good 2.1 system, and nice rich audio in the ~$200 range. Your kit sounds like my audiophile brother-in-law. 10K DAC, no lie. He has two insane speakers, and each one has an amp so heavy that it's bowed the hardwood floor.

LASR wrote:

If you want quality audio, invest in a USB DAC and headphone amp combo. I personally have the entry level Schiit stack.

http://schiit.com/products

http://www.amazon.com/Schiit-SCH-07-Mag ... B00CICPMA6
http://www.amazon.com/Modi-USB-Digital- ... B00CICPN0K

I hit up some 24/96 FLAC tracks, and it is soundgasm with my ATH-M50. The entire setup including the cans cost me ~$300.

Don't fall for the gold plated jargon jumble bull.

I've been wondering how well processing the audio outside the case would work (less EMI). I'll have to check into it, since I've got roommates at the moment. Thanks for the links!

Hz so good wrote:

That said, I decided to just build myself a Gamma2 and be done with computer soundcard nonsense until I felt like spending >$1k on a new DAC.

What's that? I'd be content with just a good 2.1 system, and nice rich audio in the ~$200 range. Your kit sounds like my audiophile brother-in-law. 10K DAC, no lie. He has two insane speakers, and each one has an amp so heavy that it's bowed the hardwood floor.

It's a DIY DAC that is on par with DACs in the $1000+ range. It can be built for about $200 in parts, or more if you want a better power supply or more boutique parts.
http://www.amb.org/audio/gamma2/
I think I wasn't clear with my previous statement. I meant that I recently built the Gamma2 DAC to replace my sound card, and that I plan to use this Gamma-2 until I feel like it's the limiting factor in my audio chain, at which point I may buy a more expensive DAC.

LASR wrote:

If you want quality audio, invest in a USB DAC and headphone amp combo. I personally have the entry level Schiit stack.

http://schiit.com/products

http://www.amazon.com/Schiit-SCH-07-Mag ... B00CICPMA6
http://www.amazon.com/Modi-USB-Digital- ... B00CICPN0K

I hit up some 24/96 FLAC tracks, and it is soundgasm with my ATH-M50. The entire setup including the cans cost me ~$300.

Don't fall for the gold plated jargon jumble bull.

Does your modi have the issue where the sound cuts out if you touch it?

Haven't seen it happen once on my Modi. But then again, I never touch it. Not without taking ESD precautions anyway.

The reason you haven't heard about PC audio much is it became a solved problem about that time and then no one cared except for those people who somehow think there's something wrong or read too much Audiophile sites/magazines.

keltor wrote:

The reason you haven't heard about PC audio much is it became a solved problem about that time and then no one cared except for those people who somehow think there's something wrong or read too much Audiophile sites/magazines.

Well that's kind of a silly way of putting it. PC audio involves more than just audio quality which is what you're talking about, it involves the software and hardware for real-time positional sound and effects. I do think that this has mostly been 'solved', Aureal and Creative X-Fi positional audio zealots romanticizing the past notwithstanding, so that specifically leaves analog output quality as a key differentiator.

keltor wrote:

The reason you haven't heard about PC audio much is it became a solved problem about that time and then no one cared except for those people who somehow think there's something wrong or read too much Audiophile sites/magazines.

This. I'm a bit picky with audio as well, and as someone who's actually done listening tests between my Sound Blaster X-fi and the Realteks that have come my way, I can tell you that even compared to my Realtek ALC889 (which is about as good as it gets when it comes to cheap audio codecs), the X-Fi really does sound a bit richer, clearer and punchier. But... I'm actually sticking with the ALC889. I know it sounds weird, but really, it sounds just fine. It's not like it sounds dull and raspy and pops and clicks happen all the time, no. I grew up with cassette tapes and saw the advent of compact discs, and quite honestly I'm satisfied with onboard audio. And the fact that adding audio to a motherboard using such a tiny chip that's practically free makes it even more interesting. I might plug my X-Fi back in at any time but I guess I'll stick with the ALC889 for a little bit longer.

The thing about external DACs is that you only use the optical out, which in the case of onboard audio is actually pretty good. Now, I'm a headphone convert, and getting sound to your ears through some external DAC that you plug into mains power is A Good Thing(TM). I've not heard the Asus Muse, but the Bryston and Benchmark DACs are the best there is. Work your budget!

Hz so good wrote:

With that said, I spotted an ad for a Gigabyte G1.Sniper 5 Motherboard the other day, and it had a few audio related features that caught my eyes, and raised a lot of questions I hope you folks can answer.

Briefly, TR reviewed the board and said it had great audio compared to other built-in solutions, but paled in comparison to an add-on card like the Xonar.

1) The Creative Sound Core3D ASIC with "Gold Plated Shielding". Firstly, does gold plating that chip do any good, or is this like gold Monster Audio cables? Secondly, is the Sound Core3D actually worth a damn?

Gold plating won't tarnish like nickel plating, but the effect is not noticeable. Simply plugging in the regular nickel plugs usually strips the tarnish, anyway. SoundCore3D is ok, but nothing special, and far from the best out there.

2) Audio Noise Guard with Path Lighting - I'll let gigabyte explain this "...G1-Killer motherboards feature an audio noise guard that essentially separates the board’s sensitive analog audio components from potential noise pollution at the PCB level. LED trace path lighting Illuminates to show the separation of the PCB layers". Sure, it looks really neat, and all, but does it actually do any good?

'Path Lighting' is a useless bling feature. Separating the paths is a good idea, but based on reviews of the board, there is still significant interference compared to add-on sound boards. It's probably impossible to sufficiently isolate the audio circuitry on a consumer mobo.

3) gold plated audio and HDMI connectors - Monster Cables, anyone?

See above. Gold plating is nice, but shouldn't be a selling point.

4) Gaming Headphone Amplifier (Front Headphone)
"Specially designed for gamers, GIGABYTE G1-Killer motherboards utilize a high-capacity amplifier which is able to drive 600Ω loads, giving gamers a fuller range of dynamic sound with crisper details and less distortion when using high quality professional headphones." I have no idea how powerful a 600 Ohm load is, in audio terms, but that sounds badass!

Again, a headphone amp is better than a regular audio port like you get with most on-board audio, but you'll get better sound from a good discrete add-on card like the Xonar.

5) Swappable OP-AMPs. Sounds good on paper.

According to the TR review, the different op-amps sound different, but none make it as good as the Xonar. I suppose if swapping op-amps is fun for you, you would enjoy tinkering with the the board, but then, you could swap op-amps on a discrete sound card, or nearly any USB audio device, and get better sound to boot.

Does something like this sound like it would have great audio, or should I stick with getting an EMI shielded Soundblaster or something?

Stick with a Xonar.

JustAnEngineer wrote:

I believe that Creative's sound cards are better than those from Asus.
http://www.newegg.com/Product/Product.a ... 6829102054
http://www.newegg.com/Product/Product.a ... 6829102050

Since I do not have a Zonar DSX, but I do own and love my Sound Blaster X. As of right now I am using it in stereo only with a 15-20 year old pair of Advent 750's powered partners Studio Monitors and they sound fantastic. I have no Zonar DSX to compare the SB X to but from what I have read in the AVS forums and other audio forums is that the SB X is a fine sound card.
Besides having great sound one good feature is you do not have to plug and unplug your headphones in every time you wish to use them. The sound blaster Control panel has a switch that will go from speakers to headphones. It sure does save beating up the connections by plugging and unplugging your headphones in and out.

Once again I think TR needs to do a Mainstream sound card review so people can see what the different cards have to offer to fill a builders needs.

But I do think the Regular Sound Blaster Z has a undeserved bad rep just because older cards have had driver problems.

1. Gold is one of the best electrical conductors, but copper and silver are still better. The advantage of gold is that it does not tarnish. I do not think gold plating makes any difference from a shielding perspective, since a microscopic layer of tarnish will not affect the shielding properties. A simple copper shield would likely be just as effective, if not better.

2. The actual electrical isolation, if done properly, is worthwhile. Careful component selection and PCB design should allow onboard to perform nearly as well as a discrete soundcard. The LEDs, OTOH, are totally pointless.

3. There *is* a point to gold plated connectors. Connectors made from other materials will eventually tarnish (see my explanation for #1). Tarnished connectors potentially add resistance (reducing signal levels), and/or act as a crude diode (introducing significant distortion, or even causing the audio path to inadvertently pick up nearby radio broadcasts).

4. Only really matters if you happen to have 600 ohm headphones. I was under the impression that most headphones are 32 or 250 (someone with more of an audio background can correct me if this is wrong). Furthermore, unless the boost feature is user selectable, you may find that it tends to over-drive (or even damage) normal headphones unless you set the volume very low.

5. Swappable op amps has been a feature of many "high end" soundcards for a few years, but I'm not convinced it is a net win. Swappable op amps means the op amps must be socketed instead of soldered directly to the PCB. Use of a socket means additional mechanical contacts, which have their own issues (see #3... I've never seen an op amp with gold plated pins). Furthermore, the contacts of the socket itself, and the larger pins of the socket-compatible op amp create additional opportunities for pickup of unwanted EMI since they are effectively tiny antennae.

I am a fan of Asus sound cards - have the Essence in my main box.

For what its worth (since this is all ultimately subjective) Stereophile lists the Xonar Essence as a Class D product - worth buying. I'd agree. http://www.stereophile.com/content/2013 ... processors

(The Dragonfly is rated as Class B in DACs).

Alas, between the ears sound is no match for between the speakers in a room with good acoustics.

just brew it! wrote:

1. Gold is one of the best electrical conductors, but copper and silver are still better. The advantage of gold is that it does not tarnish. I do not think gold plating makes any difference from a shielding perspective, since a microscopic layer of tarnish will not affect the shielding properties. A simple copper shield would likely be just as effective, if not better.

2. The actual electrical isolation, if done properly, is worthwhile. Careful component selection and PCB design should allow onboard to perform nearly as well as a discrete soundcard. The LEDs, OTOH, are totally pointless.

3. There *is* a point to gold plated connectors. Connectors made from other materials will eventually tarnish (see my explanation for #1). Tarnished connectors potentially add resistance (reducing signal levels), and/or act as a crude diode (introducing significant distortion, or even causing the audio path to inadvertently pick up nearby radio broadcasts).

4. Only really matters if you happen to have 600 ohm headphones. I was under the impression that most headphones are 32 or 250 (someone with more of an audio background can correct me if this is wrong). Furthermore, unless the boost feature is user selectable, you may find that it tends to over-drive (or even damage) normal headphones unless you set the volume very low.

5. Swappable op amps has been a feature of many "high end" soundcards for a few years, but I'm not convinced it is a net win. Swappable op amps means the op amps must be socketed instead of soldered directly to the PCB. Use of a socket means additional mechanical contacts, which have their own issues (see #3... I've never seen an op amp with gold plated pins). Furthermore, the contacts of the socket itself, and the larger pins of the socket-compatible op amp create additional opportunities for pickup of unwanted EMI since they are effectively tiny antennae.

1/3. Unless you live by the ocean and keep the doors/windows open, in reality there's no need for anything other than nickel - it's not like under any normal situation nickel will tarnish.

2. The audio circuits will all be isolated by the DAC/Codec IC, how could they not be? Power is the main issue and it's not like there's whole lot of audio that takes external power (which funny enough are generally dirtier than computer power supplies.)

4. If you have 600Ohm headphones you know it and you carry your headphone amp attached to your phones - seriously if it's loud enough, you don't need additional amplification. If not, get an amp, they are cheap.

5. The reason they are not gold is because there's no reason. IC manufacturers are super cost sensitive, so unless there's actually a real reason, they aren't going to do it. It only matters in much higher frequency chips than opamps.

keltor wrote:

1/3. Unless you live by the ocean and keep the doors/windows open, in reality there's no need for anything other than nickel - it's not like under any normal situation nickel will tarnish.

Experience says otherwise. I don't live near the ocean, and have definitely experienced problems with noisy/intermittent audio cable connections on multiple occasions.

keltor wrote:

2. The audio circuits will all be isolated by the DAC/Codec IC, how could they not be? Power is the main issue and it's not like there's whole lot of audio that takes external power (which funny enough are generally dirtier than computer power supplies.)

The post-DAC signal path can still pick up EMI from other circuits on the motherboard. Ground loops/bounce on the motherboard can also be a significant problem. If isolation was as simple as you seem to be implying, we wouldn't have had all the godawful-sounding onboard audio implementations that plagued the industry prior to around 2005 or so.

chµck wrote:

Hz so good wrote:

That said, I decided to just build myself a Gamma2 and be done with computer soundcard nonsense until I felt like spending >$1k on a new DAC.

What's that? I'd be content with just a good 2.1 system, and nice rich audio in the ~$200 range. Your kit sounds like my audiophile brother-in-law. 10K DAC, no lie. He has two insane speakers, and each one has an amp so heavy that it's bowed the hardwood floor.

It's a DIY DAC that is on par with DACs in the $1000+ range. It can be built for about $200 in parts, or more if you want a better power supply or more boutique parts.
http://www.amb.org/audio/gamma2/
I think I wasn't clear with my previous statement. I meant that I recently built the Gamma2 DAC to replace my sound card, and that I plan to use this Gamma-2 until I feel like it's the limiting factor in my audio chain, at which point I may buy a more expensive DAC.

Well, you could just buy a DAC of equal size/quality (implementing the same top-end Wolfson chip) for less than $270 shipped if you don't want to assemble yourself. This one also comes with a decent enough headphone amp..

cynan wrote:

Well, you could just buy a DAC of equal size/quality (implementing the same top-end Wolfson chip) for less than $270 shipped if you don't want to assemble yourself. This one also comes with a decent enough headphone amp..

Building it is half the fun. Those SMD parts are crazy!
And from my (basic) engineering knowledge, the PCB layout is half of where the sound quality comes from, and the Gamma2 has a very nice layout.
I can't comment on if mine would sound better, since I have no experience with audio-gd products.

FireGryphon wrote:

5) Swappable OP-AMPs. Sounds good on paper.

According to the TR review, the different op-amps sound different, but none make it as good as the Xonar.

Unfortunately, this is one of those cases where knowing the difference, IS the difference, or else there is an incorrectly controlled third factor, such as a change in output level (when comparing two sources, people will often identify a slightly louder source as a slightly higher quality source).

A certain type of audiophile will swear up and down that they can hear the difference, but It has been shown repeatedly that in a true double-blind A/B test, effectively nobody can tell the difference between op-amp types from a cheap TL072 on upwards, unless there is an actual defect in the hardware. If the ability to tinker is amusing to you, then it might be a useful feature, but otherwise, focus on the features that matter.

chµck wrote:

cynan wrote:

Well, you could just buy a DAC of equal size/quality (implementing the same top-end Wolfson chip) for less than $270 shipped if you don't want to assemble yourself. This one also comes with a decent enough headphone amp..

Building it is half the fun. Those SMD parts are crazy!
And from my (basic) engineering knowledge, the PCB layout is half of where the sound quality comes from, and the Gamma2 has a very nice layout.
I can't comment on if mine would sound better, since I have no experience with audio-gd products.

Yeah. DIY can indeed be fun/rewarding. But some people find it a bit intimidating. I upgraded the USB receiver chip on my DAC - only required about half a dozen solder points and that was almost challenging enough for me (It was also the risk of breaking something that I'd payed a significant amount for that was already in working order).

And you're correct, the y2 may be a better sounding DAC. It does reputedly have a pretty good anti-jitter implementation (for what that's worth). That said, I have some experience with Audio-gd DACs, and, whether or not they're the best, they have been very good bang/buck. The cost of the parts in those DACs alone (for us to buy them here in small quantities) is not much less than the price of the Audio-gd DACs, even with shipping.

For someone looking for a first stand alone DAC that's not too much $$, something like the Audio-gd is pretty hard to beat in the value department.

ludi wrote:

FireGryphon wrote:

5) Swappable OP-AMPs. Sounds good on paper.

According to the TR review, the different op-amps sound different, but none make it as good as the Xonar.

Unfortunately, this is one of those cases where knowing the difference, IS the difference, or else there is an incorrectly controlled third factor, such as a change in output level (when comparing two sources, people will often identify a slightly louder source as a slightly higher quality source).

A certain type of audiophile will swear up and down that they can hear the difference, but It has been shown repeatedly that in a true double-blind A/B test, effectively nobody can tell the difference between op-amp types from a cheap TL072 on upwards, unless there is an actual defect in the hardware. If the ability to tinker is amusing to you, then it might be a useful feature, but otherwise, focus on the features that matter.

It may be harder to distinguish between OP-AMPs in some implementations vs others. And some implementations are better than others. I have sound card that uses four separate OP AMP chips for right and left stereo channels - one for each polarity. I could definitely tell the difference when changing them. Now, of course it wasn't a major difference, and likely not one that would matter to 99% of people.

Also, I doubt I'd pay the $80 for the OP AMP kit. I don't know if you can any longer, but some manufacturers used to offer free samples. I remember getting a couple of sets of OP AMPs to swap in, and all I had to pay was shipping.

From my limited experience, I tend to prefer implementations that don't use any OP AMPs in the analog output stage. But again, implementation is key...

cynan wrote:

From my limited experience, I tend to prefer implementations that don't use any OP AMPs in the analog output stage. But again, implementation is key...

Is there any particular reason why?
The output on my Gamma-2 goes through a CMOS rail-rail opamp, which acts as a lowpass filter and pre-amp. I have though of wiring the DAC straight to my headphone amp, but I'm not sure it'll be worth it.

Also, I doubt I'd pay the $80 for the OP AMP kit. I don't know if you can any longer, but some manufacturers used to offer free samples. I remember getting a couple of sets of OP AMPs to swap in, and all I had to pay was shipping.

It's $80??? You can get all of them off ebay for less than half that. And while those opamps are great, they're hardly "premium"

chµck wrote:

cynan wrote:

From my limited experience, I tend to prefer implementations that don't use any OP AMPs in the analog output stage. But again, implementation is key...

Is there any particular reason why?
The output on my Gamma-2 goes through a CMOS rail-rail opamp, which acts as a lowpass filter and pre-amp. I have though of wiring the DAC straight to my headphone amp, but I'm not sure it'll be worth it.

Also, I doubt I'd pay the $80 for the OP AMP kit. I don't know if you can any longer, but some manufacturers used to offer free samples. I remember getting a couple of sets of OP AMPs to swap in, and all I had to pay was shipping.

It's $80??? You can get all of them off ebay for less than half that. And while those opamps are great, they're hardly "premium"

Yup. No joke. $80 at the Egg

Well, modern DAC chips such as the Wolfson WM8741 already have built digital filters that can be implemented with jumpers, but even more elegantly with software. Given, this, it kind of makes sense to me that the less additional components in the output stage path, the better, as a rule.

And, back to Audio-gd DACs and integrated headphone amps, as far as I understand it, gain is applied in the output stage in the current domain (some explanation here if you can get past the english), partly explaining why traditional application of OP AMPs are not required. The signal is converted to voltage after the fact. With the WM8741, this requires converting the voltage signal to current prior to the output stage, as the WM8741 can only output a voltage signal. However, the Sabre ES9018, for example, can output a current signal, therefore requiring even less manipulation of the output stage.

But what real world benefits this gets you at the end of the day, is lost on me. I just know what I think sounds good.

Random observations, don't feel like quoting. Too lazy.

Gold plating - offers corrosion resistance. Conductivity is not an issue, as you're never passing much current through one of these connectors. The corrosion resistance is important though, as metal-to-metal contact is key. If there's an oxide in the conduction path, you have capacitance and the potential for rectification at much higher frequencies. As JBI said, picking up AM radio on a connection - it happens. Also, since you probably don't move these connections around a lot and don't have a wiping/cleaning effect, you want a gas-tight, metal-to-metal connection to prevent corrosion from creeping in. For very high frequency signals like HDMI, a good corrosion-free connection is critical. Less so with audio frequencies. Gold is probably better than anything at being purely resistive, regardless of the current levels or frequencies involved.

Headphone impedance - if you want the most efficient power transfer, you want your amp's output impedance to match the impedance of the load. But with headphones, efficient power transfer is not really all that important. What's important is that your output is not the limiting factor in your voltage swing. In other words, as long as the amp's output impedance is less than the headphone impedance, you've done about all you need to do. A 600 ohm headphone is a very easy load to drive and your choice of op-amps is less critical. A 32 ohm headphone is more difficult (electrically) and will probably show more differences with different op-amps. A motherboard bragging about having "a high-capacity amplifier which is able to drive 600Ω loads" is not saying much, really.

Separation of analog and digital signals - nice to do, but usually not sufficient by itself. You also have to provide separate power supplies and grounds for the analog and digital parts, and this can be trickier, since eventually they all return to the same place. You just want that place to have a very, very low impedance path to ground for audio band noise. Every codec circuit has analog and digital signals; the codec is where they meet. So you can only keep the signals physically separate up to a point.