[germanium]

Quote:

Originally Posted by johnzz4 /img/forum/go_quote.gif Germanium, I'm guessing that the DC offset of the ST should be very close to the STX you tested. Safe assumption? If so, I will be bypassing caps since I can't go back to the line outs with the lesser soundstage and detail. Right now, I'm favoring the headphones by sending the headphone out to my headphone amp, and the line out is feeding my monitors... I would like my monitors to have the same quality signal that I have going to the headphones. Let me know your best guess on the DC offset of the ST in comparison to the STX and I'll get soldering.

Your assumption is probably correct however I always measure it anyway both before & after removal of the caps. Measure at the input side of the caps before removal.

The caps only effect the line out. The headphone amp is already D.C. coupled, however the headphone amp has more D.C offset than the lineout opamp does & that can be a problem for high gain D.C. amplifiers so the line out is still the best option for driving D.C. coupled amps. This remains true even with the caps removed assuming that the D.C. offset is similar to what I read on mine.

 

[germanium]

Fotios.

Metalized film caps in & of themselves do not cause D.C. offset. They can however block D.C. offset generated by the input circuitry from being cancelled by the previous amp stage which can cause excessive D.C. offset at the output of the amplifier. By D.C. coupling the input & driving the input with an amp that has intrinsically low D.C. offset at its output the output of the previous stage can cancel most if not all D.C. offset of the following amp stages input. However if you adjust the D.C. offset correction for the presence of D.C. offset then you remove the cap & the D.C. offset at the output will go up in proportion to the correction applied as the D.C. offset that was at the input is no longer there hence you will need to recorrect the D.C. offset at the output of your amp.

 

[Apocalypsee]

So, after doing this mods does this make the soundcard worth to buy? I worry that it might sound too 'digital' for my liking, when I mean digital its sounds cold, shrill and bright, my system already sounded bright so I looking for a soundcard to balanced it out. The other similar DAC that needs I/V conversion and buffer stage afterwards is AK4396 from Prodigy HD2, it sounds so bad that no amount of modding cure that bright sound. Although this card do have spikes on 5kHz judging from here

I've checked the other thread that glingrem on Making Decent HiFi PSU for Xonar thread increase the voltage supply to the opamp, because most opamp runs better at a higher voltage (AFAIK the stock opamp voltage supply is 9V, correct?)

 

[germanium]

Quote:

Originally Posted by Apocalypsee /img/forum/go_quote.gif So, after doing this mods does this make the soundcard worth to buy? I worry that it might sound too 'digital' for my liking, when I mean digital its sounds cold, shrill and bright, my system already sounded bright so I looking for a soundcard to balanced it out. The other similar DAC that needs I/V conversion and buffer stage afterwards is AK4396 from Prodigy HD2, it sounds so bad that no amount of modding cure that bright sound. Although this card do have spikes on 5kHz judging from here I've checked the other thread that glingrem on Making Decent HiFi PSU for Xonar thread increase the voltage supply to the opamp, because most opamp runs better at a higher voltage (AFAIK the stock opamp voltage supply is 9V, correct?)

This mod does make the sound more lively & slightly brighter but only slightly. I don't know how the HD2 sounds but leeperry has said he liked it more than the Essense ST or STX as suposedly it wasn't as bright but he changes his opinions frequently. This card to my ears starts out on the neutral to ever so slightly warm sound compared to my modded X-Fi Elite Pro. Niether sound digital to me compared to the early C.D. players & soundcards but the Essenses sound was definately more inviting to me compared to the X-fi. It is substantially more detailed in spite of the warmer fuller sound than the X-Fi meaning there is more true resolution here.

With the mods there is improvements across the board (all frequency ranges). Bass is tighter sounding & more resolving of space around the instrument as well as improved placement within the sound field. Mids are way more detailed yet smooth on good recordings but forget low bitrate compressed digital recordings as you will hear the digititis on those. This is not a fault of the card as much as the resolution revealing deficiancies in the format. Cymbals sound more natural with the mod as the shimmering quality is not lost compared to the more spikey elements of cymbal sound which can be somewhat of a problem with the stock line out sound.

Many of these benefits are lost when playing poorly mastered & mixed recordings. The benefits I should say are still there but they become a two edged sword cutting both ways. you still hear the benefits but the revealling nature of this card especially modded will not sound it's best on over limited over compressed studio recordings, even direct from the CD sources. It's the everything louder than everything else syndrom out there in pop & rock music & even the long time holdouts such as the group called Rush has finally fell into that trap. At least thier Snakes & Arrows album though in spite of being maxed out to the hilt volume wise still sounds relatively clean even on this card but many with even less compression & limiting do not sound clean.

Stock power supply is +/- 12 volts to the opamps on the Essenses. The rise @ 5KHz in the noise flore of the HD2 should in most cases be inaudible unless you have high sensitivity earphones such as many balanced armature IEMs. This should not impact the sound you hear out the card unless you are listening to very wide dynamic range music even on IEMs.

 

[Apocalypsee]

Quote:

Originally Posted by germanium /img/forum/go_quote.gif This mod does make the sound more lively & slightly brighter but only slightly. I don't know how the HD2 sounds but leeperry has said he liked it more than the Essense ST or STX as suposedly it wasn't as bright but he changes his opinions frequently. This card to my ears starts out on the neutral to ever so slightly warm sound compared to my modded X-Fi Elite Pro. Niether sound digital to me compared to the early C.D. players & soundcards but the Essenses sound was definately more inviting to me compared to the X-fi. It is substantially more detailed in spite of the warmer fuller sound than the X-Fi meaning there is more true resolution here. With the mods there is improvements across the board (all frequency ranges). Bass is tighter sounding & more resolving of space around the instrument as well as improved placement within the sound field. Mids are way more detailed yet smooth on good recordings but forget low bitrate compressed digital recordings as you will hear the digititis on those. This is not a fault of the card as much as the resolution revealing deficiancies in the format. Cymbals sound more natural with the mod as the shimmering quality is not lost compared to the more spikey elements of cymbal sound which can be somewhat of a problem with the stock line out sound. Many of these benefits are lost when playing poorly mastered & mixed recordings. The benefits I should say are still there but they become a two edged sword cutting both ways. you still hear the benefits but the revealling nature of this card especially modded will not sound it's best on over limited over compressed studio recordings, even direct from the CD sources. It's the everything louder than everything else syndrom out there in pop & rock music & even the long time holdouts such as the group called Rush has finally fell into that trap. At least thier Snakes & Arrows album though in spite of being maxed out to the hilt volume wise still sounds relatively clean even on this card but many with even less compression & limiting do not sound clean. Stock power supply is +/- 12 volts to the opamps on the Essenses. The rise @ 5KHz in the noise flore of the HD2 should in most cases be inaudible unless you have high sensitivity earphones such as many balanced armature IEMs. This should not impact the sound you hear out the card unless you are listening to very wide dynamic range music even on IEMs.

Thnak you for lengthy comment, just what I wanted to hear from you

I've used X-Fi Elite Pro before and it got a great synergy with my system, what I like the most is the vocal and how it handle treble, its smooth yet very detailed. If you say STX is an upgrade then thats good news for me

Most of my music collection are FLAC and WAV, only the track I don't listen much are encoded to mp3 to save space.

If everything's well I would bought it tomorrow

But still I'm waiting for the bitperfect driver to come out, or maybe ROB could give the beta ones

 

[ROBSCIX]

The drivers are currently bit perfect. You just need to set the sample rate manually.
The term you are looking for is auto sample rate adjust.

 

[leeperry]

Quote:

Originally Posted by Apocalypsee /img/forum/go_quote.gif The other similar DAC that needs I/V conversion and buffer stage afterwards is AK4396 from Prodigy HD2, it sounds so bad that no amount of modding cure that bright sound.

humm? AK4396 doesn't need any I/V(only LPF), and is anything but bright:

you only heard it on the stock HD2 I think? which has pretty crappy caps in the first place...you clearly haven't heard the Deluxe version w/ Bursons! it's ANYTHING but bright, and all my friend who heard it sold their STX in the blink of an eye

the only real issue on the HD2 is that the ground shielding sucks, so the dirty chassis ground shows up into the signal path...which is a big nono, and even ixbtlabs warned about this major issue upfront.

anyway, we all know what plagues internal soundcards...dirty ground that only top designs like the STX/Bravura don't allow to get into the audio path, high ripple 12V due to the other components..such as your GPU/HDD(and this can only be cured by an external linear regulated PSU), major EMI/RFI within the computer case, and last but not least....crappy opamps expected to do miracles on a very dirty SMPS.

output toslink from your "noise factory" PC, run on a proper dedicated PSU, use high grade opamps...and any recent DAC chip will sound friggin'good

this said, ditching the caps that are in the audio path on the STX might improve on the edgy/agressive/fatiguing upper spectrum of this card...but I honestly think that they're mostly due to the noisy ATX SMPS and EMI hell....and be careful w/ DC offset, as Asus prolly put those caps on purpose hah.

 

[ROBSCIX]

@Lee
No, incorrect, IIRC, ALL DAC's need I/V sections. They are either internal such as the one mentioned above or the conversion is done externally.

You really need to do some quality studying, not just regurgitating the same blurbs of information in every thread, instead of staying on topic. If you think External is the way to go, knock yourself out and get ready for a whole slew of new issues.

 

[Vandal]

Quote:

Originally Posted by Apocalypsee /img/forum/go_quote.gif Thnak you for lengthy comment, just what I wanted to hear from you I've used X-Fi Elite Pro before and it got a great synergy with my system, what I like the most is the vocal and how it handle treble, its smooth yet very detailed. If you say STX is an upgrade then thats good news for me Most of my music collection are FLAC and WAV, only the track I don't listen much are encoded to mp3 to save space. If everything's well I would bought it tomorrow But still I'm waiting for the bitperfect driver to come out, or maybe ROB could give the beta ones

The ST/STX is a huge upgrade, in fact you'll find the X-Fi warm after using this, although the ST does have a bit of warmth too, it has a nice top-end.
BTW super sexy profile pic

 

[germanium]

Quote:

Originally Posted by Apocalypsee /img/forum/go_quote.gif Thnak you for lengthy comment, just what I wanted to hear from you I've used X-Fi Elite Pro before and it got a great synergy with my system, what I like the most is the vocal and how it handle treble, its smooth yet very detailed. If you say STX is an upgrade then thats good news for me Most of my music collection are FLAC and WAV, only the track I don't listen much are encoded to mp3 to save space. If everything's well I would bought it tomorrow But still I'm waiting for the bitperfect driver to come out, or maybe ROB could give the beta ones

Let me know how it goes , ok.

 

[germanium]

Leeperry is correct in that the AK4396 does not need external I/V conversion as it is done on chip. The 3 chip configuration seen on the HD2 is strictly low pass filtering, not I/V conversion. AKM does also recommend a single chip low pass filter as well as the three chip version on the HD2.

All the recommended filters for the AK4396 contain positive feedback loops which can present a problem if poorly implimented. None of the filters recommended for the PCM1792 when filtering PCM analog output contain positive feedback loops. Only the ones for filtering DSD analog out for the PCM1792 have any positive feedback loops acording to the spec sheets for both DA converters.

These positive feedback loops if implimented on the HD2 could be the source of the trouble your hearing on the HD2 Apocalypsee.

I have a SACD player that had such filters. I reconfigured it to work without positive feedback loops. The sound with these filters was dead in the mids but overly lively in the lower treble. Kind of like the twangy sound you get by going through a flanger. I could tell that part of the sound came from the positive feedback loop & the dead mids were a result of starting the rolloff too early so I moved the cutoff frequency up, converted the filter from a 18db/octave to to 2 cascaded 6db/octave filters for a total final slope of 12 db/octave without any positive feedback loop. Without moving the cutoff frequency up the sound was totally dead when the positive feedback loop was removed. This cleaned up the deficiancies in the sound very well. Now the sound sigature was consistanly lively but without the twangy flanger like effects which can make it sound like some of the early digital or low bit rate compressed digititis, particularly low bitrate WMA's though very low bitrate MP3s can sound this way too.

 

[Apocalypsee]

I see, interesting read. I never could have thought that the triple opamp design is just for LPF, no wonder I feel weird why the datasheet have two design for its analog filter. One thing for sure is I would never bought another HD2 ever again although I never stop anyone to buy it, it just don't get the synergy with my system.

I haven't have time to bought STX today sadly, I'll update if I bought it. Still using old SB Live! 5.1 SB0100 with kX driver and OS-CON caps with LT1364 opamp on rear Phillips DAC since my Elite Pro suddently went bust. I just hope STX would sounds great with my system. Note that I don't use headphones too much, 90% of the time I use speakers.

 

[sagatman]

Well, I just did the mod suggested by germanium and got the exact improvement described in this thread. I think it is a worthy mod.Even before the mod the ST sounded great and now it become more lively.
Thank you germanium ^_^

My rig: Essence ST (OPA: LME49720HA X 2 + OPA 2107SM) + Stax 4040 Signature

 

[germanium]

Quote:

Originally Posted by sagatman /img/forum/go_quote.gif Well, I just did the mod suggested by germanium and got the exact improvement described in this thread. I think it is a worthy mod.Even before the mod the ST sounded great and now it become more lively. Thank you germanium ^_^ My rig: Essence ST (OPA: LME49720HA X 2 + OPA 2107SM) + Stax 4040 Signature

You welcome sagatman.

Kool headphone rig too!!

 

[ROBSCIX]

Quote:

Originally Posted by sagatman /img/forum/go_quote.gif Well, I just did the mod suggested by germanium and got the exact improvement described in this thread. I think it is a worthy mod.Even before the mod the ST sounded great and now it become more lively. Thank you germanium ^_^ My rig: Essence ST (OPA: LME49720HA X 2 + OPA 2107SM) + Stax 4040 Signature

These caps in this circuit position are always bad from a design standpoint. No good as they always impact the signature in a negative way. However, from a design standpoint they offer protection on the outputs from DC which can damage the next unit in the chain. If you check your unit and the DC is negligible you can bypass them and you will almost always notice an improvement in sound quality.
In many cases they are redundant also as they are used on input sections also.
I haven't seen too many using OPA2107SM modules. Nice!