[TheManko]

I got a SPL Auditor recently and really noticed the difference between the headphone and line-out exactly as described in the thread. I want to do the dc coupling mod, but is a bit of a newb. So I rip out the caps and solder wires between the points the caps are connected to now? I have the tools and it seems simple enough even for me. Just want to make sure I got it right.

EDIT: I went ahead and did it and noticed that I absolutely suck at soldering, but on my second attempt I actually got both channels working and now the line out sounds better than ever! Despite my lack of skills I do get excited at the prospect of modding my stuff since I tried to mod my old 701s and broke them (now I have new ones!) and I did the markl mod to my d5000s. Thanks for mentioning the mod!

 

[ROBSCIX]

Good for you! You tried it out and it worked out great for you.
Maybe some new high grade opamps?
So you easily noticed the difference between the modded and non modded line outs?

 

[TheManko]

The difference between the unmodded line-out and using the headphone out to the Auditor had an obvious difference in sound and the modded line-out sounds like the headphone out now except a bit better. So before the sound was a bit dull in comparison as it now sounds like it has opened up and especially the bass has more life to it with the 701s.

 

[leeperry]

OMG they're pulling the caps now(and kill the warranty)

but yeah, these caps sound agressive anyway.

 

[ROBSCIX]

Quote:

Originally Posted by TheManko /img/forum/go_quote.gif The difference between the unmodded line-out and using the headphone out to the Auditor had an obvious difference in sound and the modded line-out sounds like the headphone out now except a bit better. So before the sound was a bit dull in comparison as it now sounds like it has opened up and especially the bass has more life to it with the 701s.

These caps are a necessary evil some say. They block DC from leaving the circuit but if the device has negligable DC, they are there for nothing and are a detriment to the sound quality. Some also recplace caps in this circuit position with higher quality units, to make the negative influence as minimal as possible.

 

[GWorlDofSPACE]

I just want to comment the title.
In my opinion is the line out the way to go whit. Especial if you have some boutique op-amps on it. The headphone amp on the board is sounding average. For the designers of the card would be better to leave it out and instead of it install an additional DAC chip in mono mode.

 

[ROBSCIX]

The can amp is OK considering the price of the entire unit. It will not surpass a good quality external unit. There is no onboard can amp circuit that will keep up with a good external but the price of the good external is also a factor.
I have always prefered the line out on this card when I was testing it. Dual mono mode DAC's are common in higher end designs as the specs of the DAC will go up considerably. Most spec sheets of higher end DAC's will have refenece designs for such circuits.

 

[TheManko]

I bought three LME49720HAs earlier this year and found that they made everything sound more open but also made the bass impact so weak that most recordings didn't sound very convincing as they were too weak and didn't feel as solid in the soundstage. Of course I have to try them out again without the caps and see if I feel different about that now.

 

[germanium]

Quote:

Originally Posted by TheManko /img/forum/go_quote.gif I bought three LME49720HAs earlier this year and found that they made everything sound more open but also made the bass impact so weak that most recordings didn't sound very convincing as they were too weak and didn't feel as solid in the soundstage. Of course I have to try them out again without the caps and see if I feel different about that now.

You will not hear any improvement in the depth & power of the bass with the removal of the caps but the bass will become more defined. The caps are large enough to support the depth of the bass but they do muffle the overtones a bit & lose some of the quick attack on hard bass drum hits. The sound will be ever so slightly brighter, not as much though as changing the opamps though it apears & the bass will take on new found definition & is easier place in the soundfield as a result. It will also sound more spacious as will start to hear the room acoustics all the way down into the bass. Bear in mind though the bass is not actually rolled off at all, just the increased definition will bring out the overtones & room acoustics of the studio. The bass is still rich & full with more power in its attack.

The LME49720HAs may actually work against you as there seems subtantial boost in the mid & upper frequency range with them causing them to sound bass shy. This will slighly be accentuated by the removal of the caps. This often gets mistaken for higher definition as will bring out details that you may not have heard before but only because of the imbalance caused by the upward tilt of the frequency response. These frquency responce shifts are very difficult to measure as the they still measure flat when running a frequency sweep, but the sound of music tells a different story. Measuring frquency response with a complex waveform is probably more revealing of this characteristic. The other way is to run a null test using a complex waveform such as pink noise or music even. Any difference would then be easily heard & measured.

 

[TheManko]

Yes I tried 3x LME49720HA for a little while and then switched back to stock because it sounded absolutely terrible. Way too much of a focus on the mid and highs.

 

[ROBSCIX]

I wouldn't have went with three. Not in the configuration used on the ST(X).
Using them for I/V or buffer is ok but not for both. Personal tastes also vary quite a bit..

 

[TheManko]

Yes of course. I used the AKG 701s when I did my most recent test with the 3x configuration without caps and those particular headphones already focus on the mids and highs a lot so it really became too much for them. If you had some headphones that have way too much bass I could imagine that the 3x configuration could work.

 

[ROBSCIX]

Yes, just a case of bad synergy. You have a bright device for the I/V buffered by another bright device driving heapdheons that are bright. See the problem?
The differential I/V section tied to a single ended buffer is actually very handy for tuning your sound to the way you like. Generally using opamps of the same type in this configuration is usually frowned upon but it depends on the unit.

 

[Bizarro]

Hi all and thanks for great advices concerning this card.

Now to the point. So I would like to try out this mod but I'm wondering could it damage my amp? I have connected STX line out to my NAD C 315BEE. I would appreciate your opinions.

BTW leeperry, in some other thread you were interested about ATX PSUs with low noise and ripple. Check out Seasonic X-650. It got some impressive results in SilentPcReviews tests. X-650: Seasonic hits Gold page4

 

[ROBSCIX]

Quote:

Originally Posted by Bizarro /img/forum/go_quote.gif Hi all and thanks for great advices concerning this card. Now to the point. So I would like to try out this mod but I'm wondering could it damage my amp? I have connected STX line out to my NAD C 315BEE. I would appreciate your opinions. BTW leeperry, in some other thread you were interested about ATX PSUs with low noise and ripple. Check out Seasonic X-650. It got some impressive results in SilentPcReviews tests. X-650: Seasonic hits Gold page4

Truth be told, yes it certainly can!
The caps in this position are used for blocking DC, which is not good for audio components. However, if you remove the caps and measure the outputs and the DC is a negigable amount then you are good.
Also, these types of caps are used on input section aswell as output section so your amplifier MAY have the same thing on the input, making their use on the output redundant. There is many things that need to be right to use this type of a mod. If your not sure of how to check on any of them...maybe you should leave the caps where they are. You can always go with a set of caps that are of higher quality. Making the negative effects much less then what they woudl be with the stock caps.
Just my opinion.