DACs and bass response?


I'm auditioning dacs in my system. One (COS) was way to analytical, overall, but had very tight bass. Another (Aqua La Voce) is what some would describe as "musical"  and sounds  terrific in all aspects except bass. My cdp alone does better in that regard. I have monitors and no subs. Can I expect that dacs that are hyper-detailed will also offer tighter bass as a rule?
stuartk
Hi yes you are right the tighter the bass the better. Remember tighter bass usually means more accurate also.
Jitter affects bass quite a lot. Especially as most DACs have a phase lock loop that creates low frequency jitter. Bass should be neither tight nor muddy but articulate. Tight can be a jitter effect - it can be unwanted overtones. Jitter can easily be misconstrued as detail to the untrained ear.
Looking at the inside of the Aqua La Voce, it’s looks to me as it has a capacitor coupled output stage, as many owners are doing cap change mods to it.
Being an opamp based output stage on it from what I saw, it is very possible with a tech who knows what he’s doing to trim out any dc offset to make this a direct coupled output stage, remember for everything not just for bass the best cap is no cap.

Cheers George
Seems like my choice of words is not skillful. With the COS, the bass, whether electric or acoustic, was very evident. Although it varied from one cd to another, I never had to struggle to hear it. And it was well-focused, not dispersed with too much bloom as I used to hear from my old Jolida tube integrated.  With La Voce, the bass was simply not very present on the majority of cds I played. It seemed to be buried in the mix or recessed. I don't really know how else to describe it. 
I'm using an Ayre QB 9 DSD and I've added a Regen ISO with the the optional linear power supply. I replaced the fuse with a Synergistic Research Black and attached an Akiko Audio XLR tuning stick to the Ayre DAC. These tweaks have made my DAC sound (to me) more natural, more balanced and with a greater degree of presence. I never up-sample, as it isn't necessary nor is it preferable. 
Doing this would probably alarm many however, I've tailored these tweaks to my own hearing. I would however appreciate slightly faster bass with more melodic structure whenever I'm listen to music options other than classical music and so I'm considering the new Synergistic Research Blue fuse for the Ayre. Is anyone using the Blue fuse?
@stuartk 

I am not familiar with the La Voce, but it sounds as though it may not have had enough burn-in time. Could it be the case? Also, did you notice any significant difference between balanced and single-ended outputs?

Best,

Luiz
Capacitance. A look inside a DAC will tell you. If it has allot of electrolytics it will typically have good bass.
I've owned several DAC's to date and some were more on the "thin" side in terms of Bass and others were a bit "thicker".

I have a hunch that the power supply design and how well its isolated from the rest of the sensitive pieces play a pretty big role here.

Of all the DAC's I've tried to date the best ones have been from EMM Labs/Meitner when it comes to deep/textured and clean bass output. I hear DCS is also very good in this area but I've not had the opportunity to hear that for myself, yet.
Totaldac has the best and most focused bass I have ever heard. It is also the most analog sounding digital I have heard.
@luizfcoimba: this is a demo unto supplied by a dealer who assured me it was well burned in. Overall, it sounds wonderful. . . except for the lack of bass, that is. 

@eniac26, paul79, I'm pretty sure I cannot afford Totaldac, Meitner or DCS but thanks for the suggestions. 




@paul79. caps?  how about a Denafrips Terminator.
Does every component in a system have to add the designers interpretation of accuracy ? Is there not a measurement for bass so we are getting the correct amount of bass on a recording ?

Tight bass in a DAC is achieved by a combination of low jitter of the interface or input signal to the DAC as well as power delivery that enables this in the DAC.

Power delivery includes power supply, voltage regulators, power storage caps and power decoupling caps.  These all must be good designs and high-quality parts of optimum values.  The caps in particular must have high "Q".  Bass dynamic response depends on it.

The output caps affect on bass response will be minimal as long as the load is high-impedance, like 25K ohms. Even 1uFd is sufficient to get good bass.   If you plug 100 ohm headphones into the DAC output, it will probably not have any bass, but any preamp or amp will be 25K ohms or higher.  Not an issue.

I make a very detailed DAC, the Overdrive SX, but it also has superb bass response. Ultra-clear imaging and liquid vocals.  If you don't care about DSD, the Overdrive SX is the one to beat. It does not decode DSD.

One thing that will make it difficult to compare DACs is if you are not using the same interface, for instance comparing one DAC driven from a CD transport to another using USB from a computer for instance.  The first thing is to achieve a really low jitter source.  Then, feed all of the DACs with this same source.  Your CD transport can become this, but it will need some help.  A Synchro-Mesh reclocker can reduce the jitter to around 20psec.  Typical Transports have about 800psec of jitter.  See these jitter plots:

http://www.audiocircle.com/index.php?topic=154408.0

Steve N.

Empirical Audio

@audioengineer: Steve: I've read many favorable reviews of your dac. Unfortunately it's beyond my financial reach at this time. Thanks for the info and suggestions. 
@audioengr,

Speaking of your Synchro-Mesh reclocker, what about DAC’s internal jitter control? Is it not good enough to reduce jitter on a incoming digital signal? I am just trying to understand the need for external reclocker.  

My DAC is equipped with a high resolution, low jitter clock. The measurements show Intrinsic Jitter <10 pS.  

In my setup, I always used balanced analog outs on my CD player straight into my preamp. The DAC digital inputs (SPDIF and AES/EBU) are being used for two dedicated steamers only. And then DAC analog outs (XLR) to my preamp. 

After trying over 70 different digital front ends including Total Dac/Total dac server combo, which were stunning, I now believe the source is more important than the actual dac. Two years ago when I was trying dac after dac, I would have said the dac had the most effect on my system but after playing with several different servers, including most of the top servers on the market, I now believe, in my system the server has more of an effect than the dac. I have also tested all Aqua dacs and both COS dacs. Now that I have a great server, great CAT 7 cables and a great USB cable, I can truly hear the differences between dacs.

 

Cheers and just my opinion.


bass in a dac is a somewhat complicated question. it can relate to multiple factors, including rack interface and power cords. and three dacs I’ve owned were quite high resolution, two with what i’d call ’hyper-detail’.......the Trinity dac and my current MSB Select II. that hyper detail did nothing to restrict bass. likely they did allow for super articulation. possibly some dacs do a bit of ’rounding’ and that can be perceived as having a ’heavier bass. but is that an artifact? or reality?

http://www.msbtechnology.com/dacs/select-features/

but my experience with my current dac, the MSB Select II, really hit home on how much the power supply can affect the bass and the overall sense of authority and ease in the bottom octaves. when i first purchased the MSB in June it had only a single power supply; which powered both the analog and digital circuits. then in August i added a second power supply. i had to send in my dual single box power supply and the manufacturer used the case of that dual unit and added another case and put a single power supply in each; one box for the analog circuits, and one for the digital circuits. I now had two power supplies each with it’s own power cord.

wow!!

the effect on the lower octaves and overall ease and authority was astounding. a huge difference. nothing else changed. the level of detail increased with greater expressiveness and overall levels of information was better.....lower noise.....greater nuance.

is this surprising? maybe not. we know that power supplies are a significant part of the overall performance of all electronics.

the bass in my dual power supply MSB Select II now compares favorably with my vinyl and Studer A-820 RTR deck bass. those are my references.

@worldwidewholesales What server are you using ?
Wow 800 psec of jitter would easily be audible. Even 20 psec jitter may be audible. This shows the importance of

1) A good modern asynchronous DAC that rejects the always present incoming jitter entirely - so you are left with inherent jitter of the DAC itself (for example Cranesong Solaris claims less than 0.5 psec jitter)
2) If you use a DAC that is not known for good incoming jitter immunity or rejection (perhaps a classic older DAC or something which just sounds good to you) then for goodness sake get Synchro-Mesh reclocker!

Be careful of asynchronous DACs that dont fully explain how they achieve a PLL. The very fact of gently adjusting the timing of a secondary clock to rapid fluctuations in the incoming clock can easily create low frequency jitter!! Some DACs have implemented a control filter on the timing adjustments that limit adjustments to less than 10Hz. Only a DAC that limits master-slave timing adjustments to BELOW the audible range (less than 10 Hz) can guarantee to eliminate all audible incoming jitter.

A poorly designed PLL may reduce jitter but create more audible jitter than a high level of random incoming jitter. The key is to understand that signal correlated jitter is much more audible than random jitter by several orders of magnitude. 20 psec jitter that is highly correlated could be much worse than 200 psec of totally random jitter. So a PLL may actually be a significant source of audible jitter!!! (sounds crazy but it is true)
Bass and power supply are linked in every way. This is because they share the same frequencies. The latest DACs are now using switched mode power supplies to great advantage at ultra high frequencies in order to get power supply noise far far away from the audible range. 

The weak link in any Linear Power Supply (no matter how massive) is that it runs on 60Hz (or 50 Hz) and this is a fundamental bass frequency!!!!!
@worldwidewholesales: RE: source, I plan to move to a server. For now, my Jolida cdp is no doubt, less than ideal, but this didn't keep the COS dac from serving up appealing bass. The difference between it and the Aqua were not subtle. What are you using for a server, BTW ? 

@shadorne: your technical understanding is way beyond me. I'm wondering if you could suggest some dacs that "limit (s) master-slave timing adjustments to BELOW the audible range (less than 10 Hz)". I will start paying attention to whether dacs I consider have switched mode power supplies. 

@mikelavigne: I wasn't suggesting that hyper-detailed dacs restrict the bass-- I was wondering whether they, in fact, might have the opposite effect. Sorry if that wasn't clear. 
   
 
@stuartk


As far far as I can tell, Weiss, Cranesong and Benchmark use similar methodology to handle jitter.

This article explains how digital processing is done on the Benchmark DAC2. There is a paragraph explaining how timing adjustments are done at always less than 1Hz in the Ultralock 2 approach. Note that adjustments are done in the digital domain which allows very small 4 psec tweaks.

https://benchmarkmedia.com/blogs/application_notes/inside-the-dac2-part-2-digital-processing

I have the DAC3 and it seems to do what they claim and Stereophile gave it a thumbs up recently as they did the Weiss DAC a few years ago.

lalitk wrote:

Speaking of your Synchro-Mesh reclocker, what about DAC’s internal jitter control? Is it not good enough to reduce jitter on a incoming digital signal? I am just trying to understand the need for external reclocker.  

My DAC is equipped with a high resolution, low jitter clock. The measurements show Intrinsic Jitter <10 pS.

  

I have yet to hear a DAC that is not sensitive to incoming jitter, even those with reclocking inside.  The easy way to tell is to use a cheap S/PDIF cable from a good low-jitter source and then a really good cable.  If you hear ANY difference, then it is sensitive to jitter.  I routinely ask my customers to do this test and 100% of the time they hear a difference.  Jitter almost always matters.

Intrinsic jitter is not a good indicator either.  This usually means that the internal clock jitter has this jitter specification.  This has little bearing on the actual jitter you hear from your DAC.  The associated circuitry and power delivery to that circuitry makes all the difference and usually increases that number 10-100 times.

I recently did jitter measurements on a device that advertised "intrinsic jitter" of less than a picosecond.  The measurements at the S/PDIF termination into 75 ohms showed jitter of 60-80 psec.  Lots of manufacturers say they eliminate all jitter.  Not possible.

Here is some really low jitter at the 75 ohm termination inside the DAC:

http://www.audiocircle.com/index.php?topic=154310.0

Steve N.

Empirical Audio

Shadorne wrote:

Bass and power supply are linked in every way. This is because they share the same frequencies. The latest DACs are now using switched mode power supplies to great advantage at ultra high frequencies in order to get power supply noise far far away from the audible range.

Well, sort-of.  The real story is that the regulation on SMPS responds much faster than most LPS.  It has little to do with the 50 or 60Hz, more to do with the devices used, the "Q" of the storage capacitors and the technology used for regulation. 

LPS can also respond very fast, if the circuit is designed for it and the output device is really fast.  I provide such a fast LPS for my converter and reclocker products.  I also use SMPS in my Overdrive DAC.  They both can work for digital.

Steve N.

Empirical Audio


@shadorne: the reasons I haven't tried the benchmark are 1) complaints that it's a very complex component (not exactly plug in and play) and 2)  that it sounds thin/lean. You seem to be very technically competent, so let's set aside complaint #1 and focus on #2. I'll assume that you haven't found the sound to be wanting in this regard. Would you mind listing the source, amplification and speakers you're using in conjunction with the Benchmark? 
@audioengr,

Thank you for your feedback and sharing the link. I guess that’s one way to promote external reclocker by taking a subpar DAC/Streamer. I do not know about anyone else but IMO, SONOS connect box is a piece of crap. It’s also one of the most antiquated streamer/DAC in their lineup.

May be you can post some measurements with Bluesound Node 2 or Aurender N100 and Synchro-Mesh reclocker.  Also, what degree of improvement justifies the cost of external reclocker and digital cables?

Having said that, I do recognize the importance of a quality digital source and DAC that employs best designs attributes to minimize or eliminate jitter within digital domain.

I would be open to try an external reclocker between my two sources Aurender N10 / Bluesound Vault 2 and ARC DAC9 in near future. At this time, I am very content and happy with fabulous sound output of my digital setup.



Thank you for your feedback and sharing the link. I guess that’s one way to promote external reclocker by taking a subpar DAC/Streamer. I do not know about anyone else but IMO, SONOS connect box is a piece of crap. It’s also one of the most antiquated streamer/DAC in their lineup.


The final jitter will be exactly the same, no matter what the source is. you can literally compete with a $20K transport using a $300 transport and a $1400 Synchro-Mesh and Dynamo power supply.  The input jitter to the Synchro-Mesh is totally unimportant. 

The Sonos is very popular and many folks like the interface well enough.  With the Synchro-Mesh reclocking, the Sonos actually sounds as good as any of my $3K digital interfaces, including USB and Ethernet.


Maybe you can post some measurements with Bluesound Node 2 or Aurender N100 and Synchro-Mesh reclocker.  Also, what degree of improvement justifies the cost of external reclocker and digital cables?


I would be happy to if I had one of these on hand.  So far, everything I have compared with the Synchro-Mesh has much higher jitter.


Having said that, I do recognize the importance of a quality digital source and DAC that employs best designs attributes to minimize or eliminate jitter within digital domain.

I would be open to try an external reclocker between my two sources Aurender N10 / Bluesound Vault 2 and ARC DAC9 in near future. At this time, I am very content and happy with fabulous sound output of my digital setup.


When you are ready, I have 30-day money-back on most of my products, less shipping. BTW, I also now offer a truly world-class S/PDIF BNC/RCA cable for $499. My whole career in audio has been devoted to achieving the lowest jitter.

Steve N.

Empirical Audio

Steve,

“The final jitter will be exactly the same, no matter what the source is” - Agreed.

“You can literally compete with a $20K transport using a $300 transport and a $1400 Synchro-Mesh and Dynamo power supply”
- That’s a pretty bold statement, what have you tried and compared in that range to arrive at this conclusion.

“Input jitter to the Synchro-Mesh is totally unimportant” - Agreed.

“The Sonos is very popular and many folks like the interface well enough. With the Synchro-Mesh reclocking, the Sonos actually sounds as good as any of my $3K digital interfaces, including USB and Ethernet”
- Wyrd 4 Sound offers an somewhat similar internal upgrade for lot less. Once you add the cost of Connect, Mesh w/Dynamo PS, extra digital cable, you are already at $2250. It would be interesting to compare this setup with let’s say Aurender N100.

I wonder if anyone else from our esteemed community can chimed in with their experience with Mesh / Dynamo PS.


@stuartk


You asked about my setup.

Here is a link https://systems.audiogon.com/systems/6257

I think the DAC3 sounds like one of the cleanest and clearest windows to the recording that I have heard so far. Apparently it compares well to PS Audio (see recent Stereophile article). I have heard it against ARC DAC 8 and a Gustard Pro with reclockers/bridge (Singxer SU-1) and it doesnt need or benefit from special cables or reclocking although those other devices did. I would not call it thin. Transparent is the best word. It has an extremely low noise floor so details are highly audible but it remains smooth like vinyl. First device I have heard without the slightest hint of digital glare. I think the latest Weiss, Cranesong Solars and Mytek Brooklyn DAC+ will be similar and equally enjoyable. These latest DACs are astonshingly good and not expensive. Technology Progress is wonderful. If you prefer something euphonic then none of the DACs I have mentioned above should be on your short list.

Per Steve’s recommendation, once you settle on a DAC I recommend you try a bridge/reclocker and different cables/inputs yourself. I found no benefit in the Singxer SU-1 and no difference between various digital inputs but YMMV and certainly many DACs do need a reclocker or a bridge to sound their best.
“You can literally compete with a $20K transport using a $300 transport and a $1400 Synchro-Mesh and Dynamo power supply”
- That’s a pretty bold statement, what have you tried and compared in that range to arrive at this conclusion?


I have heard plenty of megabux transports at tradeshows for 15 years.  I don't like to name names.

- Wyrd 4 Sound offers an somewhat similar internal upgrade for lot less. Once you add the cost of Connect, Mesh w/Dynamo PS, extra digital cable, you are already at $2250.

The Synchro-Mesh plus Dynamo LPS plus BNC reference cable is $1897.  Less than the cost of most high-end S/PDIF cables alone.

Doing mods inside a transport will not get you there.   I used to do mods on transports and DACs myself, for 10 years.

Steve N.

Empirical Audio

@shadorne: RE: euphonic sound. I guess different people would define that term differently. My SS Wells Majestic integrated has no need of "fattening up". I listened to the Metrum Adagio today and it seems a poor match with the Wells-- to much weight/body, but the bass was quite good. I had no idea it would be this challenging to find a dac I like. The Aqua La Voce did everything right, except for the weak bass. Otherwise, I'd be done. The COS has made me very wary of dacs that serve up detail to such a degree that the sense of the "forest" is lost amid the hyper-emphasis of the "trees". Seems to me, a worthwhile musical performance is one in which the whole equals more than the sum of the parts. I don't want to be presented with a field of disembodied parts floating in space, so I tend to view detail as a double-edged sword. 
Stuartk,
Reading various post by listeners who’ve heard the Benchmark Dacs some have described them as having a "thin" or somewhat clinical sound character. Subjective to be sure and some listeners love its sonic character.

If at all possible listen to it yourself . It’s impossible to predict accurately what someone else may like based on another’s taste. You may find this DAC to be excellent or you could find it somewhat sterile, amusical  and unengaging. I hope that you are able to audition the Benchmark in your system.
Best of luck,
Charles
@stuartk  

Euphonic would be a tube like sound - richer in even harmonics than is on the recording and can sound wonderful. Your choice as to what you prefer. There is no wrong choice.
Reading various post by listeners who’ve heard the Benchmark Dacs some have described them as having a "thin" or somewhat clinical sound character. Subjective to be sure and some listeners love its sonic character.

True. This is because they use delta sigma Sabre ESS series chips, which have a well known/documented signature sound.


@stuartk,

What are your source components? I am thinking may be there is a room for improvements elsewhere in your system. 

Hi,

The servers we have tested include all the Lumin servers, 2 Antipodes server, DS and DX, 3 Aurender servers but not the top Aurender, Total dac server (very nice but only when using the matching Total dac) and several units like Cocktail and Auralic. Our favorite servers we have tested are the Sonore products. My reference server is the Sonore Signature Rendu SE model but even the smaller ultraRendu with an aftermarket linear power supply tested above many of the more expensive servers that we tested.

 

When we did our testing we did it on several higher end, very sensitive systems. We were testing for a lower noise floor, better soundstage, better harmonics and less digital glare. The Sonore products just produced a more natural music flow and sounded much more analogue than the other servers.

 

The other factor that really effects the sound of the server is the quality of the CAT 7 cable that you use and the quality of the USB cable that you use. Inakustik USB Reference cable and the Inakustik Reference CAT 7 cables are our reference cables. We have blind tested slightly over 400 different cable models over many years of testing cables.

 

Just a quick note; we are the Canadian and North American distributor for some of these products but we never take on new lines unless they beat our previous reference lines.

 

Cheers and enjoy your holidays.
@lalitk : My source is probably the weakest link in the chain: an aging Jolida JD100 tubed cdp.  To be honest, I've been very confused by the claims and counter-claims in these forums re: the degree to which any transport feeding a dac affects the sound. I've gone back and forth between thinking I should put all my $ into a dac (which I can continue to use with a server once the Jolida breaks down), and dividing my $ between a better transport and a less expensive dac, The latter would mean allocating about $2500 per component. The Heed obelisk is one transport I've considered, as it has an internal buffer. Of course, the PS audio transports do as well. 

@worldwide wholesales: thanks for the detailed response. 
@shadorne: Well, my cdp has a tubed output and I was concerned that using a separate dac and bypassing the tubes might be a problem, but so far, with the 3 dacs I've tried, it hasn't been an issue. The SS  Majestic integrated provides plenty of "tube-like" warmth. In fact, coupled with the Metrum Adagio, it seems like too much weight/thickness. I know these are not audiophile terms-- sorry for my ignorance. Darko described the Aqua La Voce as "cool" but it sounded terrific in my system, except that I found its bass response severely lacking. 
Bass in general should be more articulate or nuanced with better devices.

Stuartk - I think you should address the CD transport before you get a new DAC.  The source is at least as important as the D/A, maybe more.  Before you drop $2500 on a new transport, consider a reclocker that will actually get you much lower jitter in the S/PDIF signal than a transport at a lower cost, and also provide for galvanic isolation to break ground-loops.  You can still use your existing transport. The Synchro-Mesh with Dynamo power supply and BNC reference cable combination will do this.  You could start with the Synchro-Mesh OTL and the reference BNC cable for $1100.00.  This will get you jitter in the 25psec range.

Here are some jitter plots comparing the SM to a popular transport:

http://www.audiocircle.com/index.php?topic=154408.0

Steve N.

Empirical Audio

stuartk 
  Darko described the Aqua La Voce as "cool" but it sounded terrific in my system, except that I found its bass response severely lacking.

As I mentioned in my first post, it has output coupling caps, that's why many owners on the net are changing that cap.
  
If that cap is too small in uF (microfarads) it will roll off the bass too early giving a shallow subdued (cool) bass, increase this cap 3 x in uF and it should fix the problem and give you a deeper stronger bass.

Or my preference is to direct couple, but you need a tech for that. 

Cheers George
BTW, there are many different ways to implement ESS series chips, so can't just look at the chip used and say it sounds a particular way.

Then there is the circuit layout, the section of and matching of various discrete components, etc.

all can have effects on SQ - not like a speaker, but something you can hear in a spendy system
Steve,

What is your opinion on the stereophile J-test?

It measures analog out of a DAC to a test signal - so it checks for both incoming and intrinsc jitter.

What do you think of the typical SOTA DACs that have a noise floor at -150dB when tested for jitter?

How can perfect performance be improved upon and what do you look for when testing an asynchronous DAC of this level and how could Synchro-mesh or another cable improve upon perfect?

GeorgeHIFI wrote:

As I mentioned in my first post, it has output coupling caps, that's why many owners on the net are changing that cap.
 
If that cap is too small in uF (microfarads) it will roll off the bass too early giving a shallow subdued (cool) bass, increase this cap 3 x in uF and it should fix the problem and give you a deeper stronger bass.

If its 1uFd or more, this should be sufficient for most preamp and amp loads to deliver bass.  No bass roll-off will occur. 

The real issue is the quality and combination of these caps.  For all caps I have tried with my own DAC, one must add a smaller cap in parallel to get the full range out of it.  Highs are ultimately compromised by using larger caps only.  The best names, Duelund, Mundorf and V-Cap all need this.

Steve N.

Empirical Audio


What is your opinion on the stereophile J-test?

It measures analog out of a DAC to a test signal - so it checks for both incoming and intrinsc jitter.

Much better to measure the jitter directly, although this is all you can do if the Master Clock interface is inside the DAC.  Mildly interesting and only gives you part of the picture IMO because the stimulus is not a true music waveform.


What do you think of the typical SOTA DACs that have a noise floor at -150dB when tested for jitter?

Those are good numbers, but what stimulus is used?  A single frequency?  Not good enough.


How can perfect performance be improved upon and what do you look for when testing an asynchronous DAC of this level and how could Synchro-mesh or another cable improve upon perfect?

I have yet to see or hear "perfect performance".  Every time I make an improvement to my own DAC or converter, I think that it cannot possibly get better, but then it does.  If I had to choose the best DAC for a demonstration, cost no object, I would choose mine, even though it's not the most expensive or even DSD capable.

Performance can always be improved.  If you can drive this DAC with S/PDIF signal and hear a difference with different cables, then it is not jitter immune. A simple test. The Synchro-Mesh and a reference BNC cable would likely improve the SQ from it.

If it is an internal Ethernet or USB interface, making changes to the power delivery to the clock circuits and buffers will likely improve it. Sometimes even making changes to the ground-plane or voltage regulators will improve it.  Performance in high-end audio is mostly about good power delivery, which includes optimum board design, power supply, regulators and decoupling caps.

I modded DACs and other digital gear for 10 years and I was able to improve any product a customer would send me.  This is precisely what gave me the bag of tricks that I use on my own products. Given enough time tinkering, I can probably improve them even more too.

Steve N.

Empirical Audio



If its 1uFd or more, this should be sufficient for most preamp and amp loads to deliver bass. No bass roll-off will occur.
Your assuming it's 1uf if it is (and it's plastic looking at the net pics) and it's look at maybe a class-D which many are 5kohm input the the bass roll off is going to be -3db at 32hz. If the cap is only .47uf the the bass roll off is going to be around -3db at 64hz.

As I said before there are many owners putting in big plastic caps in place of what there from the factory which seem to be small in physical size, but still plastic.  

Cheers George  
As I understand it the J-test was developed by Julian Dunn in the mid 90’s.

It appears to be the best test found so far and is used by AP in their lab test gear. (I dont agree with probes on legs of DAC chips as the probe itself is likely to affect the device itself when measuring timing to such accuracy. I think the J-test known test signal in and a careful look at the perfection of the analog out is much more representative as it tests the DAC as a whole as it is designed to function and including the clock timing accuracy)

A LSB square wave at Fs/192 which produces harmonics right across the audio range. This square wave is coupled with a high level sine wave at Fs/4. The sine wave being a very intense digital full on/off work out (nasty stuff that should produce logic Induced modulation in anything but stellar equipment)

Looks like an extreme DAC jitter work out or jitter stress test to me!

No doubt jitter is still there even on the best devices but to have analog artifacts of jitter sitting below a -150dBfs noise floor seems exceptionally good to me.

https://www.stereophile.com/content/case-jitters
@georgehifi: forgive my ignorance, but would installing such a cap likely void warrantee? Also, is this something I could purchase from say, parts conneXion?  Briefly, what is involved in installation? Thanks. 

BTW, I swapped out power cord and coax cable for another brand and it substantially helped the La Voce's bass. Disappointingly, swapping out cables did nothing to improve the muddiness of the Adagio in my system. There must be a profound lack of synergy. It's going back. 
@audioengr

I believe your Synchro-Mesh works as you claim from your measurements. I have no hesitation recommending it as I know others with excellent DACs that benefit from source jitter reduction devices including cables.

I also believe many (most) DACs are not at all good at jitter rejection and also have high intrinsic jitter (despite claims to the contrary). So the Synchro-Mesh is a great product for improving sound quality of most DACs.

Since you are clearly able to build a device that takes 800 psec jitter from an Oppo and turn that into 20 psec jitter with your Synchro-Mesh, then why do you believe that nobody else has a DAC that can correct incoming jitter to completely inaudible levels - around 20 psec or less?
stuartk OP158 posts
georgehifi: forgive my ignorance, but would installing such a cap likely void warrantee? Also, is this something I could purchase from say, parts conneXion? Briefly, what is involved in installation? Thanks.

Hi Stuart, if you need to ask this. Better off getting some one to do it, it’s not hard.

Cheers George

PS Stuart just found a good internal pic, click on the pic and it enlarges again, and the two blue plastic caps are the ones near the output rca's, but unfortunate they are already 3.3uf and are quite big enough, but of cheap industrial quality, this is why some owners are changing them for more upmarket caps, maybe this also could help the bass??
http://www.6moons.com/audioreviews/aqua/9_big.jpg

Cheers George