Follow Up Thoughts Re Sigma Power Cord Review

As far as I see the question, this is not at all a subjectivist versus objectivist question at all.

In objective terms power cables can not change gain. However sound quality affects our perception of loudness - a known subjective effect. For me the only question that astonished me was the enormous compensation you were reporting in level - something like 4dB if I remember well, that was never measured. Please correct me if I am wrong.

BTW, knowledgeable objectivists will tell you that subjective findings of a few correlated people in non formal experiments are objective, but they will also tell you that the error bars will be enormous.

I am waiting for Marty report with great interest.

Well Steve, you've put me in a spot. I didn't realize you'd share our conversation earlier and the truth is, I don't like commenting on something I don't fully understand. However, in this case, it probably doesn't matter when I would have replied. I'm not sure I will ever understand the phenomenon I am experiencing with the Sigma digital cable. To rephrase the paradox discussed above, it goes something like this. I (and others) have inserted this marvel called the Sigma digital cable and have noticed several aural differences as a result- all of them positive. The most obvious one is indeed that the base seems to be quantitatively increased in level (and qualitatively better). On the surface, not a big deal, right? Except for one glaring problem, which is namely, how the hell can a cable be capable of changing gain? Even more perplexing, its not total audio bandwidth gain but in this case, relative bandwidth gain (at least for me); that is, most prominently in the range from 20-60Hz?

How much "increased gain" are we talking about? The difference in gain, as assessed by the negative correction I have to add to my DSP filter to correct for the apparent gain in bass frequencies due to the cable, ranges from approximately 0.5db (30-60 Hz region) to nearly 1.0dB at 20Hz. It should be obvious that for most individual and most systems, this degree of change will hardly be meaningful. Most systems have a frequent response below 100 Hz that is characterized by large excursions in amplitude, typically with variances of 5-10 dB or more from "flat" and often as much as 20dB!. In that regard, deviations of 0.5-1.0 dB will be essentially inconsequential as its effect will typically be folded into those 5-10dB peaks and troughs so as to be essentially imperceptible. However, if one's system is generally linear in the bass region or perhaps fully elevated for bass frequencies in a certain range, the addition of even tiny amount of increased bass gain might be noticeable, and cause one to remark that there is "more bass" in their system with the Sigma digital. My guess is that some or even most folks might even like that effect! On the other hand, in a system where bass already fully "maxed" out, some may not prefer it. if that were the case, its often relatively easy to do something about that, especially if the system uses subwoofers. Just turn the subs down a hair. Problem solved. For a full range speaker, a tiny change in position might be all that is need. If one uses a precise DSP algorithm to provide optimal low frequency response, any newly imparted changed of 1 dB might not only be noticeable, but again, in my case, was very noticeable. OK, so I'll just modify by DSP algorithm to remove some gain (0.5bD or 1.0dB of gain from 20-60Hz to my system), and the problem is solved. In summary, I do believe the Sigma digital adds some bass weight to any system, and for the most part, if it is noticed, it will probably be appreciated and enjoyed, and if it is not, it is rather straightforward to address this by turning down the subs a tad, adjusting speaker location, or perhaps altering ones DSP target curve. Put another way, the increased bass gain is not really a big deal in most cases and in fact might even be considered beneficial in many systems. Keep in mind that we have only been talking about a very small increase in increase in bass amplitude. I believe that owners of the Sigma digital would unanimously enjoy the qualitative benefits of the bass without reservation, which is greater immediacy and tautness of the bass signal.

Now the hard part. What could possibly account for the effect I and others have observed? Here, I'm at a loss and would turn this question over to Caelin. I suspect the answer might have something to do with signal to noise, as we have hypothesized before for the changes in perceived loudness that one can experience with the Typhon. But in the case of the Typhon, we were discussing perceived loudness of the entire frequency range, not just a range of frequencies within it. And since we keep going back to the hypothesis that cable has no gain of its own, I remain totally clueless about what is going on. In short, I believe my perception of increased relative bass gain is real, but for the life of me, I have no clue as to why it occurs with the Sigma digital. It should be emphasized that regardless of my inability to either understand what is happening, that should not detract from one very important observation which is namely, I believe the addition of the Sigma digital was revelatory in my system (as it was for Steve). The changes it imparts in bass weight, midrange clarity and overall quietness have made this an indispensable addition to my system. I am trying to exercise discipline by waiting a full 3 weeks before I add my second Sigma digital so i can assess its benefits separately from adding the first. Truth is, I'm almost frightened to find out what it does. Stay tuned!

Thank you Marty and Steve for your observations and measurements. While I agree with microstrip's statement about perceptual influences ..

However sound quality affects our perception of loudness -

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It is also true that a reduction in AC supply voltage or of current delivery can and does affect the signal output, gain and many other measurements. (This is highly dependent upon the specific component's design and also depends upon the range of tolerance for voltage and current deviation.)

marty said:

I am trying to exercise discipline by waiting a full 3 weeks before I add my second Sigma digital so i can assess its benefits separately from adding the first. Truth is, I'm almost frightened to find out what it does. Stay tuned!

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Well that time is here. I was finally at a place where the full glory of the Sigma digital has shown itself. Almost too uncanny, is that the break-in of the Sigma digital was very similar in duration to the Alpha digital which it replaced. Both cables were at their worst on day 4, and opened up dramatically on day 17. In each case, a new level of clarity was preceded by a very unpleasant sonic signature on day 16 in which the bass was ill-defined and bloated. Oh well, such are the joys of break-in. However, the end results are more than worth it, and at 3 weeks, the cable is a stellar performer and a permanent fixture in the system. As I suspected, I should have reserved my comments above until full break-in, but in fact, the final amount of offset I had to program into my DSP to accommodate the Sigma digital was similar but slightly less to what I reported earlier (day 12), and now ranges from 0.25 at 50Hz to about 0.75 dB at 20Hz. In any event, the second Sigma digital is in the system powering the Meitner XDS1v2. It will be really interesting to see if the DSP curve requires further change, or will the changes I made for the first Sigma digital be all that is required once the second one breaks in. We shall see.

marty said:

Well that time is here. I was finally at a place where the full glory of the Sigma digital has shown itself. Almost too uncanny, is that the break-in of the Sigma digital was very similar in duration to the Alpha digital which it replaced. Both cables were at their worst on day 4, and opened up dramatically on day 17. In each case, a new level of clarity was preceded by a very unpleasant sonic signature on day 16 in which the bass was ill-defined and bloated. Oh well, such are the joys of break-in. However, the end results are more than worth it, and at 3 weeks, the cable is a stellar performer and a permanent fixture in the system. As I suspected, I should have reserved my comments above until full break-in, but in fact, the final amount of offset I had to program into my DSP to accommodate the Sigma digital was similar but slightly less to what I reported earlier (day 12), and now ranges from 0.25 at 50Hz to about 0.75 dB at 20Hz. In any event, the second Sigma digital is in the system powering the Meitner XDS1v2. It will be really interesting to see if the DSP curve requires further change, or will the changes I made for the first Sigma digital be all that is required once the second one breaks in. We shall see.

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If i were to add a second Sigma Digital to my system, I think I will follow Marty's where he Sigma-lised his CD Player before he does his DAC. I also use Meitner DAC and plugging the first Sigma into DAC made the sound to be too dark to think that it is the right way to do it. Sigma is now into my McIntosh CDP.

Have heard from another user that first Sigma Digital is best to power CDP instead of DAC.

All in all, I love Shunyata products. Have just ordered and now waiting for my Triton, Typhon, Sigma Analog and Sigma HC to come in two weeks *among the longest 2 weeks in my life*.

Best,
Adam

adg243 said:

If i were to add a second Sigma Digital to my system, I think I will follow Marty's where he Sigma-lised his CD Player before he does his DAC. I also use Meitner DAC and plugging the first Sigma into DAC made the sound to be too dark to think that it is the right way to do it. Sigma is now into my McIntosh CDP.

Have heard from another user that first Sigma Digital is best to power CDP instead of DAC.

All in all, I love Shunyata products. Have just ordered and now waiting for my Triton, Typhon, Sigma Analog and Sigma HC to come in two weeks *among the longest 2 weeks in my life*.

Best,
Adam

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Do you know there is a new version of Triton coming out? Maybe you should wait for the new version.

adyc said:

Do you know there is a new version of Triton coming out? Maybe you should wait for the new version.

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well it is always a strong maybe, right. But timing will always be unknown whilst my ears cannot wait that long. ;-)

Best,
Adam

Steve, do I take it that the recommended option is to use a Sigma Digital on one's transport and a Sigma Analogue on the DAC? I am considering Sigmas and have until now always used the original Anaconda Vx (Constellation series) on my transport and an Anaconda Alpha on my DAC..........I have never tried using an Anaconda Vx on both transport and DAC?

Thanks for welcome...........I am a long term Lamm ML2/L2 R/LL2 D user (17 years), recently changed up to ML2.2 and included an LP2.1 D . Also have had Shunyata products for 10+ years, so my interest in your site is obvious.

I actually thought you might have been using a DAC as well. I was wondering whether those using Shunyata powercords used Sigma Digital cables on both transport and DAC or Sigma Digital on transport and Sigma Analogue on DAC - I would appreciate any comments or is this question better in it's own thread perhaps?

Smp said:

Thanks for welcome...........I am a long term Lamm ML2/L2 R/LL2 D user (17 years), recently changed up to ML2.2 and included an LP2.1 D . Also have had Shunyata products for 10+ years, so my interest in your site is obvious.

I actually thought you might have been using a DAC as well. I was wondering whether those using Shunyata powercords used Sigma Digital cables on both transport and DAC or Sigma Digital on transport and Sigma Analogue on DAC - I would appreciate any comments or is this question better in it's own thread perhaps?

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If you are considering Sigma, it would be fine to use a Sigma Digital or Analog on a DAC. Both power cords are similarly filtered, with the Sigma Digital having slightly higher-frequency filtering--many dealers have compared both and they split on which they prefer-- the differences are subtle. If you were considering the lower priced Alpha models, then I would recommend moving up to the Alpha HC because DAC's are peak-current sensitive and the added wire gauge in the Alpha HC definitely benefits all DAC's. From my perspective and experience, either model will work well on a DAC, but DAC's are lower in noise-output than Transports, NAS, Servers etc, so I'd be tempted to say try the Sigma Analog there first.

Best regards,

Grant
Shunyata Research

Thanks very much Grant - your response is appreciated.

Steve Williams said:

Last year when I introduced 4 Hydras into my system I found that there was an apparent increase in signal gain (only because many of my demo tracks, I know exactly where on the gain control of my preamp to listen). I know that this generated much discussion as to the typical objectivist vs subjectivist debates as to how this could be so.

Having my entire system now wired with Sigma Series PC's (3 HC. one digital, 4 analog) as well as 2 alpha HC's for my subs, I feel that having listened now for well over 6 weeks (and having introduced each PC prior to that serially over the course of the previous month that I can reasonably and safely say the following......"with each Sigma PC or a pair thereof I found that there was an apparent boost in the bottom end of my system. By the time the last pair of Analog Sigma PC's were added (to my preamps) I can say that the boost in gain was no longer a suspicion but fact. It is easy to hear the difference both before and after the introduction of each Sigma PC. Now of course I have opened the flood gates of prove it to me and all I can say is that is an observation that can be easily heard. In fact the bass response I was getting in my room made me stop and wonder how this is so with my 30 wpc amps."


Now this is obviously not a proper way but at least it is my way, "I use my ears" and have let them guide me in this hobby. For those who have heard my system before and after the change everyone always comments about the bass response in my room. Now of course this could be a case of the "Emperor's New Clothes and perhaps everyone was being kind.

So hear is the reason I started this thread. I was just speaking to my good friend Marty who has just introduced a single Sigma Digital for his TacT and is burning in a second for his Meitner player. Most of you here know that Marty has a TacT corrected room and IMO it is one of the best rooms I have ever heard. Having visited Marty on many occasions I have watched him correct small parts of his room frequency response and know how zealous he is about this. Well Marty told me that his room response had to now be corrected for bass because of the significant change in bass response.

So after reading all of this..."Is it possible that a Power Cord can alter gain in a sound system?"

I felt that Marty's observed change in his TacT room curve gave at least some credence to my observations that each time I made a change the bass in my room improved to the point that made me wonder how a 30 wpc amp can create this change

I don't know if it is the filters that Caelin uses or his comments re DTCD or just ?????

Perhaps Caelin and Marty might chime in


BTW, the final change to my system was adding the Alpha HC to my subs so people can't accuse me of changing the subs first

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Excellent post Steve.

Lee said:

Excellent post Steve.

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I thought so too...so much I now have 1 Sigma HC and 3 Sigma Analogs. Pretty much back up what Steve/Marty are saying above... Soon a few Sigma Digitals...