I have listened to Jeff Rowlands integrated with the Aeris DAC. And the VAC Sigma integrated with the Aeris DAC.... I have heard the VAC Sigma 160iSE and the JR 625 upgrade both with the Aeris as the DAC.
Am I correct in inferring that you have not heard either amp with the Wilson Sabrinas? While I am a big VAC fan, I would have some concern about how well suited the Sigma integrated (and many other tube amps, especially those which use minimal amounts of feedback) may be for use with that particular speaker. Per John Atkinson's measurements:
My estimate of the Sabrina's voltage
sensitivity on the tweeter axis was 88.2dB/2.83V/m, slightly higher than
the specified 87dB. Wilson specifies the Sabrina's electrical impedance
as 4 ohms, with a minimum magnitude of 2.53 ohms at 139Hz. My
measurement of the impedance is shown in fig.1: the value (solid trace)
varies between 4 and 6 ohms between 250Hz and 4kHz, and the minimum
magnitude is 2.44 ohms at 135Hz. However, there is also a combination of
4.44 ohms and a capacitive phase angle of –58° at 72Hz, a frequency
where music can have considerable energy; this will place a significant
demand for current on the partnering amplifier. Although the output impedance of the VAC integrated is not specified, I suspect that it is not particularly low, because I would expect a VAC design to avoid heavy-handed application of feedback. Given the speaker's impedance variation from about 2.4 ohms in important parts of the bass region to substantially higher values at higher frequencies, especially in the treble region (as shown in Figure 1 of JA's measurements), the result of that combination is likely to be some degree of weakness in the bass, and some degree of over-emphasis of part or all of the treble region. Also, given the speaker's 4 ohm nominal impedance be aware that the measured sensitivity of 88.2db/2.83V/1m corresponds to only 85.2db/1 watt/1 meter. Which suggests that 86 watts of amplification may not be enough, especially if your listening includes material having wide dynamic range, such as well recorded minimally compressed classical symphonic music. Good luck, however you decide to proceed. Regards, -- Al |
Do you have suggestions for other amp pairings with the Wilson Sabrinas? I am open-minded at this point. I suspect that Knghifi’s suggestion of the VAC 200iq would avoid the concerns I expressed about pairing the Sigma with the Sabrina. Especially if two of them were used as monoblocks, but possibly also using just one in stereo mode. I say that in part because the 200iq includes a third output tap, designated as being for 1 to 2 ohm loads. That in combination with the reference in its description to 6 db of feedback suggests that the output impedance of that tap is low enough to avoid the tonal issue I referred to. It is also more powerful than the Sigma, of course. A risk of going that route, however, would be the possibility that having a preamp in the chain might ultimately prove to be sonically desirable, and a preamp that would do justice to the rest of the equipment would add up to very big $ in combination with two or even one of those amps. See this thread for some discussion of using the Aeris with and without a preamp. From a technical standpoint I would also expect something like an ARC Ref150SE to be a compatible pairing. ARC tube amps tend to have lower output impedance than many or most other high quality tube amps, as well as having very robust power supplies. However its size, complexity, heat generation, cost, and again the possible desirability of a preamp may rule it out. And I have no knowledge of how well its sonics would synergize with those of the Sabrina. I’m not particularly knowledgeable about VTL products, but the fact that most of their amps have only a single output tap, nominally rated for a 5 ohm load although claimed to be suitable for 2 to 8 ohm loads, would give me pause. Regarding Rowland solid state amplification, I have no experience but FWIW a number of members here whom I consider to be particularly credible, including Ricred who posted above, use it with great results. As far as I know there are no technical issues that the Continuum S2 or the Rowland power amps would present in your application. Good luck. Regards, -- Al |
Although the specs on the Phi 200 aren’t complete enough for me say with any certainty, I suspect there is a good chance it would avoid the issues I raised about pairing the Sigma with the Sabrina. For that matter, I can’t be sure that the issues I cited would be problems with the Sigma either, but they are certainly significant concerns IMO.
Probably the best thing to do if you want to consider the Phi 200 is to call Kevin Hayes at VAC and discuss it with him. In doing so, be sure to point him to the Stereophile measurements of the Sabrina that I linked to. The question, basically, is not whether the amp can drive the speaker, it is whether or not impedance interactions would cause the pairing to not be a good one in terms of sonics.
However another concern that just occurred to me, that is applicable to the Phi 200, the 200iq, and most or all of the other VAC power amps, is that they have particularly high gain, while the Aeris DAC has a specified maximum output level of 7 volts, which is extremely high. (It isn’t clear, though, if the 7 volts applies to the balanced output, the unbalanced output, or both).
The gains of the VAC amps are about 5 db more than the gain of the Rowland 625 S2, assuming balanced connections are used in both cases, even though the Rowland is much more powerful. (And the gains of the VAC amps from their unbalanced inputs are even higher). The combination of high amp gain, very high DAC output, and the additional gain of an active preamp (if one is used) may cause you to have to set the volume control(s) on the DAC and/or preamp to settings that are undesirably low in their ranges. Which, in addition to possibly compromising the resolution of the volume adjustment, might degrade the sonics of the DAC, especially if its volume control function is performed in the digital domain.
Although on the other hand the somewhat low sensitivity of the Sabrina will be helpful in that regard, to some extent.
Apologies for citing so many concerns and negatives in my posts, but as I see it these are things that should be considered before making such a significant investment.
Regards,
-- Al
|
Thank you, Ricred. Good info. Is the adjustment you are referring to internal to the unit, or is it the volume control that is on the front panel?
Rinpoche, gain is the relation between the output voltage of a circuit or component, and the input voltage that is provided to that circuit or component. In the case of a component having a volume control, such as a preamp, it is usually specified based on the control being at its maximum possible setting.
Although for a source component such as a DAC it is probably more proper to refer to maximum output level, or maximum output voltage, rather than gain, since the component is not being provided with an input voltage in the usual (analog) sense.
Best of luck as you proceed. Regards,
-- Al
|
Thanks, Rick.
Part of the concern I expressed about that issue was the possibility that if the DAC's volume control would have to be set in the lower part of its range, and if the volume control function is implemented digitally (I don't know whether or not that is the case in the Aeris), its sonics might be adversely affected as a result of what is referred to as "bit stripping." Which can occur to a greater or lesser degree, or not at all, depending on the design of the particular DAC as well as on the particular volume setting. And I raised that point in connection with the particularly high gain that most VAC amps provide, which (everything else being equal) would necessitate a lower setting of the DAC's volume control.
I see that your Rowland Corus preamp provides overall gain that is "Independently Programmable 0 to 20 dB on each input." It would be relevant to the discussion to know what you have that set to in your system, or if it is set to some default value, what that default value is. If that gain is set to a high value it would necessitate a correspondingly lower setting of the DACs volume control, to enable the preamp's volume control to be used in a desirable part of its range. Thereby increasing the possibility of adverse sonic effects due to bit stripping, if the DACs volume function is implemented digitally.
Pending knowing how that is set in your system, though, my guess is that the high gain of the VAC amps would not be a problem for Rinpoche. I say that based on your results together with the fact that the 5 db or so higher gain of the VAC amps, relative to the gain of your Rowland amp, closely corresponds to the approximately 6 db lower efficiency of her speakers compared to yours. Which would result in essentially the same overall system gain, aside from preamp differences.
In any event, though, I would suggest to her that if she obtains a high gain amp such as one of the VACs, and also eventually purchases a preamp, that high gain preamps be avoided. Examples of high gain preamps include many Conrad Johnson models, which provide gains in the area of 25 db or so. A preamp providing a gain in single digits, or at most around 12 db or so, would be a much more suitable choice.
Best regards,
-- Al
|
I am back to being nervous about tubes — vs. SS — where this thread started. I am not sure if I am up to it?
The VAC 200iq that Knghifi had suggested provides automatic biasing of the output tubes, which is a feature that makes using a tube amplifier a good deal more convenient than would otherwise be the case. The Phi 200 and the Sigma integrated do not provide that feature, although the manual biasing they would require from time to time can be performed more conveniently than in a lot of other designs.
Do you think that a SS amp with a tube preamp will give me the 'sound' I am looking for? Engaging, warm, and magical?
I guess I have to hear it for myself.
There are always multiple paths to success in audio, including both tube power amp/solid state preamp combinations and tube preamp/solid state power amp combinations. There are also multiple paths to failure, of course. So, yes, there's no substitute for hearing it yourself. If you do eventually have an opportunity to audition a VAC amp with your Sabrinas, per one of my comments early in the thread make a point of checking for any signs of bass weakness, treble over-emphasis, or lack of power on brief high volume low frequency dynamic peaks (such as strong bass drum beats). As I indicated earlier, while I'm a big fan of VAC products, and in general I don't consider them to have any intrinsic weaknesses, I see those things as **possibly** being consequences of the interaction between their output impedance characteristics and the specific impedance characteristics of the Sabrina. Aside from that possible concern, and provided of course that its cost is acceptable to you, I would have high confidence that you would be very happy with the 200iq. Best regards, -- Al |
Rinpoche 5-15-2016
I am feeling bad though because I was reading a thread that totally trashes Wilson speakers. I think the Sabrinas are really perfect in so many ways. I had to save space so they fit in really nicely. But the thread I read makes it seem as if people who purchase Wilson’s have no soul. I am not sure why people disparage others for their choices, but in my mind they are really lovely. While there are of course many high end audio products that tend to be controversial and polarizing, my perception over the years has been that Wilson speakers tend to be a bit more polarizing than average. But as you’ll see in many threads here and elsewhere there are a great many highly experienced audiophiles who use and love them, and whose comments are the exact opposite of those you referred to. And it would seem to say something that Wilson has been among the most successful of high end speaker manufacturers for something like 40 years now. My suspicion is that significant contributing factors to that polarization of opinion are greater than average sensitivity of Wilson speakers to differences in ancillary equipment (especially the power amplifiers used to drive them), due to a combination of their impedance characteristics and their resolving power, and perhaps also greater than average sensitivity to room differences and setup. So although it is understandably unsettling to see the kind of negative comments you referred to, they are best ignored. Partly because there are at least as many and probably many more strongly positive comments that can be found, but much more importantly because all that really matters to each of us is our own satisfaction with our own system. Best regards, -- Al |
Rinpoche, the 200iq and the 170 (which incorporates "iq" functionality but omits those letters from the model name) are linked to on this page. Ricred, thank you. In this case I don’t see any technical issues that would arise in using the Aeris DAC directly into a VAC or Rowland power amp, or into most other power amps for that matter. However both Ricred and a member who reviewed the Aeris in this thread that I referenced in one of my earlier posts have stated that they found adding a preamp to be sonically beneficial. In the recent past there have also been lengthy discussions of this question pertaining to DACs in general, in situations where the DAC provides a volume control. See this thread, for example. My perception has been that the prevailing (although certainly not unanimous) consensus has been that inserting a high quality preamp into the chain is likely to be sonically beneficial in most cases. FWIW, my own instinct would be to follow Knghifi’s recommendation and go with one of the new "iq" power amp models, initially without a preamp, ***PROVIDED*** that confidence can be established (preferably by audition) with respect to the issues I raised regarding the sonic synergy or lack thereof between a VAC tube amp and your Sabrina speakers. (And btw, the inclusion of a 1 to 2 ohm output tap on these models, that is not provided on the Sigma integrated, could very conceivably be beneficial in that regard). At a time of your choosing, now or in the future, you could then assess whether the addition of a preamp would be worth its cost to you. Perhaps by buying one used and then selling it if it did not provide a worthwhile benefit. Finally, I’ll second the comment Charles provided earlier to the effect that VAC equipment is designed in an extremely robust manner, and can be expected to be very reliable. And their support and customer service is second to none. Best regards, -- Al |
The shop insists a 3-way is a 3-way.
Speaking frankly, this comment by the shop is nonsense. Some 3-ways (and other kinds of speakers) are best suited to be driven by solid state amplification, some are best suited to be driven by tube amplification, and some are equally at home with either. A speaker having a nominal impedance of 8 ohms or more, and having impedance that does not vary greatly as a function of frequency, and having higher than average sensitivity, will usually be suitable for use with either. To the extent that those criteria are not met, things become questionable. Over the years many of the models Wilson has produced have been used successfully with both kinds of amplification, even though many of those models have had 4 ohm nominal impedances (like the Sabrina). However, the graph of impedance vs. frequency for the Sabrina that I linked to in my first post in this thread, coupled with the associated comments that I quoted, as well as a comment in the main body of the review, as well as the Sabrina's somewhat low sensitivity, raised caution flags in my mind as to the suitability of that model for use with tube amplification. However this comment: ...
The Wilson people I spoke to at Wilson Audio love VTL, VAC, ARC, and Nagra tubes with the Sabrinas.
... as well as the comment you indicated earlier that Kevin Hayes had provided, as well as the video Knghifi linked to showing the Sabrina being driven by a VTL tube amp, as well as the inclusion of a 1 to 2 ohm output tap on the VAC iQ models, do provide a fair amount of confidence, albeit obviously not as much as an audition with your speakers would provide. Best of luck as you proceed. Regards, -- Al |
Knghifi, thanks for that input. Do you happen to know which output tap they were using on the 200iq?
Regards,
-- Al
|
I missed the JR when the VAC was on, and the VAC when the JR was on. Perhaps when I go to hear the IQ both of these differences will be captured. Given the Sabrina’s impedance curve that I linked to earlier, as well as the listening experiences with the Sabrina that have been described by some of the others, I suspect that the 1 to 2 ohm output tap of the 200iq stands a significantly better chance of accomplishing that than the 2 to 4 ohm tap, and certainly than the 4 to 8 ohm tap. I presume, btw, that what you listened to today was the Sigma integrated (which does not have a 1 to 2 ohm tap), and that its 4 ohm tap was what was used. Continued best of luck, and best regards, -- Al |
The only thing that I would want more of is power because of my room's dimensions and the size of my speakers.
Rick, the
Monitor Audio PL-500, at least in version ii, has a rated maximum power handling capability of 400 watts, and a nominal impedance of 4 ohms. Your Rowland 625 S2 amplifier can deliver 600 watts into 4 ohms. Best regards, -- Al |
I wonder if you could expand on what you mean by ’ohm tap’ and which amp would be best in that regard with the Sabrinas? Rinpoche, most tube amps drive their outputs via a transformer, which converts the high voltage/low current signal that is processed by the tubes to a lower voltage/higher current signal that is needed to drive a speaker. Usually at least two transformation ratios are provided (i.e., how much the voltage is stepped down and how much the current is stepped up), including one that is theoretically best suited for 4 ohm speakers and one that is theoretically best suited for 8 ohm speakers. Those are provided on different terminals on the rear of the amp, and are referred to as "taps" because the terminals are connected internally to different points on the output "winding" of the transformer. The 200iq provides a third tap, theoretically best suited for speakers having even lower impedances. The circuitry in nearly all solid state amps operates at lower voltages and higher currents than the circuitry in nearly all tube amps, so most solid state amps do not need or have output transformers, or multiple output taps. If you click on the photo of the rear of the 200iq, shown on this page, you will see that their are a total of 8 binding posts/terminals, 4 for each channel. For each channel, one wire from the speaker (usually the black or negative one) connects to the "Com" terminal, and the other wire from the speaker (usually the red or positive one) connects to one of the other 3 terminals, corresponding to the chosen tap. Since most speakers have impedances that vary significantly over the frequency range, a nominally 4 ohm speaker will not always sound best when connected to an amp’s 4 ohm tap, and an 8 ohm speaker will not always sound best when connected to an amp’s 8 ohm tap. It is often best to try each of the taps that are provided. The impedance curves I have seen for several Focal speakers all show a substantial rise in impedance occurring in the upper mid-range and/or the treble regions. Throughout most of the spectrum your Sabrinas also have an impedance that rises considerably as frequency increases. The interaction of relatively high amplifier output impedance with those kinds of speaker impedance characteristics will result in a brighter sound than if the amplifier has a lower output impedance, everything else being equal. Output taps on a tube amp that are intended to drive lower impedances (e.g., 4 ohms) have lower output impedance than output taps intended to drive higher impedances (e.g., 8 ohms). Solid state amps almost always have effective output impedances that are near zero. So that probably explains why you perceived some brightness with the VAC/Focal combination, and I suspect explains why Knghifi perceived some brightness with the combination of the 200iq and the Sabrina (especially if the 1 to 2 ohm tap was not the one that was being used). The brightness was not the result of the amp’s intrinsic sonic characteristics, but rather was the result of a non-optimal impedance match to the speaker, which would be minimized (although perhaps not entirely eliminated) by using the 1 to 2 ohm tap that is provided on the 200iq. As far as power is concerned, considering the sensitivity of the Sabrina and the power capabilities of the VAC amps, as I mentioned early in the thread I suspect that if you were to have a problem it would only be on recordings having particularly wide dynamic range (i.e., particularly great DIFFERENCES between the volumes of the loudest notes and the softest notes). Some well engineered minimally compressed classical symphonic recordings come to mind, such as many of the Telarc orchestral recordings from the 1980’s that were notorious for having very high volume bass drum beats. On most recordings, and **perhaps** even on those, I don’t think you would have a problem, though. This assumes that your listening distance, room size, and volume preferences are not significantly greater than usual. Best regards, -- Al |
Ricred1 5-23-2016 9:14pm EDT
I was originally told to set the attenuation on the DAC so that the left and right volume LED’s are of equal brightness. It could be that that setting would be appropriate for use with a preamp providing significantly higher gain than whatever gain your Corus may be set to. (The gain of the Corus is indicated as being "Independently Programmable 0 to 20 dB on each input"). I would guess that part of the rationale for the adjustment Guido and Mr. Rowland pointed you to might be that it would minimize possible sonic side-effects of the DAC’s volume control mechanism. Such as what is referred to as "bit stripping," if the volume control function is implemented digitally. In any event, glad that the issue is resolved. As I mentioned earlier it would seem, on paper at least, that your 625 S2 can provide much more power than would ever be used with your speakers. BTW, Guido, I think you may have inadvertently misworded the second paragraph of your post just above. I believe the reference to unity value should be for use with a preamp, not "for direct use into amps." Best regards, -- Al |
Thanks for the references, Guido. I read through the one on "DAC-based Volume Control," and many of the others. All of which seemed to me to be informative, meaningful, and technically persuasive, yet concise and well presented.
A model that would be good for other manufacturers to follow on their websites, it seems to me. Assuming, of course, that they have similarly meaningful and technically persuasive information to present :-)
Best regards,
-- Al
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Thanks for that input, RHL. I would point out, though, that the MC-275 in particular, and also most and perhaps nearly all ARC power amps in particular, have considerably lower output impedances (corresponding to higher damping factors) than most other high quality tube amps. And although those numbers are not specified for the various VAC models, I would feel very confident that difference would apply in their case.
And in fact the MC-275 is arguably almost in solid state territory in that respect, with a specified damping factor of "greater than 22" for the latest version, corresponding to an output impedance on the 8 ohm tap of less than 8/22 = 0.36 ohms.
Although the ARC GSi75 integrated which Pokey reported to work beautifully with the Sabrina is something of an exception in that regard, among ARC amps, having a specified damping factor of "approximately 4," which corresponds to a higher output impedance than is typical for their products. But assuming the 4 ohm tap was being used when he listened to it, I suspect the corresponding output impedance was probably still lower than on the 4 or 8 ohm taps of most or all VAC products.
On the other hand, though, there can sometimes be a tradeoff between which tap is most suitable for a particular speaker, and which tap results in the output stage of a particular amplifier seeing a load that it is happiest with (e.g., which results in the least amplifier-generated distortion, or amplifier-generated distortion that is least offensive in terms of its spectral distribution). So, yes, for that reason among others it would be advisable for Rinpoche to try all of the available taps.
Regards,
-- Al
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Rinpoche 5-24-2016 5:18pm EDT
The tap discussion is way above my head but I am writing it down and when I go to the shop to hear the VAC 200 iq system I will ask about it. If the VAC 200 iq is one of the winners, and I get to bring it home to try with the Wilson’s -- I will report back on the combo for sure. But, if I hear you both correctly, the 8 tap is possibly the one to try first? Then the 4? Absolutely not, in my opinion. And my apologies for wording my previous post more technically than I should have. I don’t doubt that the 8 ohm tap may very well be the best tap to use with the Sabrina when it is driven by a Macintosh MC-275 tube amp or by most Audio Research tube amps, as was stated by an exceptionally credible and knowledgeable source (Peter McGrath). However my basic point was that the MC-275 (and other McIntosh tube amps), as well as most ARC tube amps, are COMPLETELY different animals than both VAC amps and the majority of other high quality tube amps, especially in regard to major differences in their output impedances. Which in turn are especially relevant to tap selection. Differences in amplifier output impedance mean differences in the tonal effects that result from the interaction of amplifier output impedance with the variations of speaker impedance over the frequency range. Given all that has been said, I agree with the others that all taps on the 200iq should be tried, but my guess is that the 1 to 2 ohm tap has the best chance of being optimal, the 2 to 4 ohm tap has the next best chance of being optimal, and the 4 to 8 ohm tap has the least chance of being optimal. Among those three taps on the 200iq, by the way, the 1 to 2 ohm tap will come closest to the behavior of a solid state amp (such as the Rowland) insofar as the tonal effects of the interaction of its output impedance with the impedance characteristics of the speaker are concerned. Although of course there will still be differences between the Rowland and the VAC, resulting from both impedance interactions and the intrinsic sonic characters of the two amps. On the two higher impedance taps of the VAC, look particularly for signs of excessive brightness, and/or for weakness in certain parts of the lower bass region, and/or for poorly defined bass. Best of luck, and best regards, -- Al |
Charles1dad 5-25-2016
Based on what Al has written it seems that the ARC tube amplifiers may utilize a larger degree of negative feedback (NFB) than the VAC amplifiers. I say this due to the lower output impedance (higher damping factor ) of the ARCs. Depending on the particular speakers this can be advantageous. It truly is dependent on the speaker design and intent of the builder. The Sabrinas could require amplifiers with more NFB with the resultant lower output impedance. Again, nothing substitutes for actual listening experiences.
Yes, that’s all true and well said, Charles. The VAC 200iq is specified as using 6 db of feedback, while the ARC Ref 150SE, for example, is specified as using 14 db, a considerable difference. I’ve never seen the corresponding number for the MC-275, but its unusually high damping factor (for a tube amp), its somewhat low gain (feedback reduces gain, everything else being equal), and numbers I’ve seen for other classic MC tube amps, suggest to me that it could be in the vicinity of 20 db or so. My older VAC Renaissance 70/70 MkIII amplifier, btw, has a six-position switch that allows the user to select the amount of feedback. The settings range from zero to 7.5 db. I use the zero feedback position, which works well with my particular speakers (which have a particularly flat impedance curve and no dips to low values at any frequency). As you indicated, judicious use of feedback in a design can be either advantageous or disadvantageous depending on the characteristics of the speaker that is being driven. And also on how well the design of the particular amp avoids the sonic downsides that feedback can potentially introduce. Best regards, -- Al |
Rinpoche 6-8-2016 12:10pm EDT
But, from some of the advice I am getting here, it sounds like ’starting over’ from scratch is perhaps preferable. Not at all, IMO. And I strongly second both of the very well said posts Charles has provided today. Onhwy61 6-8-2016 12:07pm EDT
From reading these forums it’s my observation that new audiophiles don’t have long-term success in building truly high end systems in one shot. To Inna’s point, it’s too complex. I’m not sure if this also applies to music lovers and I’m most interested to find the outcome for the OP. My perception has been that in many such situations the audiophiles in question are the type that is probably incapable of ever being satisfied, and who are embarking on a never-ending merry-go-round. And in other cases are persons asking for help only after making outright mistakes in their purchase decisions, due to poor system matching or other factors. Neither of which appears to be the case here as far as I and at least most of the others are concerned. Best regards, -- Al |
What will be the first thing I play on it? Now that is a thread we
should work on. What is the first song you play on your new stereo?
If classical music is of interest, try Dvorak's "New World Symphony," Jascha Horenstein conducting the Royal Philharmonic Orchestra, Chesky CD31. Out of print, but available from various sellers at Amazon: http://www.amazon.com/gp/product/B000003GCZ/ref=olp_product_details?ie=UTF8&me= And if classical music is not presently of interest, it very well may be after you hear this recording, which you will not believe was recorded in 1962! Best, -- Al |
I have eclectic musical tastes that include jazz, classical, rock, world music, and even ... broadway!
One of my favorite Broadway albums, featuring many of the all-time classic songs, performed by a great operatic singer: www.amazon.com/Love-Julia-Migenes-Johnson/dp/B0001XGP28?ie=UTF8It appears to also be available on vinyl, which is what I have. Best, -- Al |
I’ll second Facten’s comment just above. Also, keep in mind that cable effects tend to be particularly application-dependent, and the sonic effects of a given cable may often depend as much or more on what the cable is connecting than on whatever intrinsic sonic character the cable may have. With those dependencies generally not having a great deal of predictability.
That being one reason why it is not at all uncommon for a considerably less expensive cable to outperform a considerably more expensive cable in a given system, as is borne out by many experiences that have been reported here and elsewhere.
Best,
--Al
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Hi Rinpoche, Regarding interconnects, if I recall correctly all of the equipment possibilities that have been mentioned would be suitable for use with balanced XLR interconnects. While opinions about cable selection tend to be all over the map, as you may have seen in any number of other cable-related threads, FWIW my suggestion is that initially, at least, you simply purchase some inexpensive Mogami Gold Studio balanced cables. And who knows, despite their modest price you may find them to be suitable for use permanently. Those cables, by the way, are the de facto interconnect of choice in professional recording studios worldwide. Best, -- Al |
Hi Rinpoche, Regarding the interconnects that would be used at the output of the Aeris DAC, I note the following statement in the Aeris’ description: Transformer balanced XLR line outputs provide outstanding output common-mode noise rejection, eliminate potential ground loops, and ensure compatibility with other equipment. I also note that it has a 120 ohm output impedance, which although not especially low is considerably lower than in many other designs. I suspect that those factors will result in that DAC having somewhat less sensitivity to cable differences (at its balanced analog outputs) than would be the case in many other circumstances. Especially if the length that is necessary is only 1 meter, as most analog cable effects are proportional to length. Best, --Al |
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Hi Rinpoche,
Congratulations on your decision, preliminary though it may be.
To be sure it's clear, is the Roland you have tentatively settled on the 625S2?
Also, just out of curiosity, which speaker make (Focal?) and specific model was it that you listened to in the recent session? And if you know or can determine it during your next visit, which tap on the 200iq was used in connecting to that speaker?
Best,
-- Al
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Guido, FWIW I interpreted your post exactly as Facten did, and in accordance with the clarification you provided just above.
Best regards,
-- Al
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If you see or hear of a used CD player that you think would be good for not a lot of money, let me know. Hi Rinpoche, The Aeris DAC does not provide any analog inputs, so until and unless you purchase a preamp you would want to connect a digital output of the CD player to a digital input of the DAC. Or, alternatively, you could consider purchasing a CD transport, which would not include a digital-to-analog converter function and would only provide digital outputs. It seems that in more situations than not a coaxial S/PDIF digital connection provides better sonics than a Toslink connection, although that is certainly not always the case. The Aeris provides BNC connectors for its coaxial S/PDIF inputs, while most CD players and transports (especially in the lower parts of the price spectrum) provide those signals on RCA connectors. But BNC/RCA adapters are readily available inexpensively, and can provide fine results. Best regards, -- Al |
Well, Jon seems to have posed a mystery for us to have some fun with. I certainly don't have any background in cryptography, but I note that the number of characters in "SWCRABVHWI" is the same as the number of characters in "JRDG 625S2" (including the space).
Rinpoche, best of luck with your choice.
Regards,
-- Al
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Hi Rinpoche, While DarTZeel equipment is generally very well regarded, some things in Stereophile’s review of the NHB-108 would give me pause, taking into account the low impedance of your speakers (4 ohms nominal, dipping to between 2.5 and 3 ohms or so in the area of 100 to 200 Hz, where a lot of music contains a lot of energy. Most notable among several points of concern: The manufacturer strongly recommends using the Lo setting if the amplifier is to be used with low impedances. However, the amplifier then delivers significantly lower power at clipping—43W into 8 ohms (16.3dBW), 68W into 4 ohms (15.3dBW), and 95W into 2 ohms (13.75dBW)—with no reduction in low-power THD. Best regards, -- Al |
Congratulations and happy birthday from me as well, Rinpoche. I have no doubt that your choice will prove to be a source of delight for a great many years to come.
Best regards,
-- Al
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Excellent inputs from Guido, as usual. Some additional comments: Many Nordost and Cardas wires are often thought of as having intrinsic sonic characters that are in opposite parts of the spectrum, with some audiophiles being of the opinion that Cardas tends in the direction of excessive warmth, and some audiophiles being of the opinion that Nordost tends in the direction of a colder and more clinical sound. Of course, different models within each product line will differ in those and other respects, as Guido noted in the case of the Valhalla and Valhalla II. My main point in responding, though, is to point out that with the exception of the Cardas Clear and Clear Beyond speaker cables, what the Cardas, Nordost, and Furutech cables Guido mentioned all have in common (including the Cardas Clear interconnect) is very low capacitance (between 8 and 20 pf per foot in all cases). Which would seem to say that if other cables are considered, preference should be given to those having similarly low capacitance. Unfortunately, though, many and probably most manufacturers do not provide capacitance specs for their cables on their websites (Cardas, Nordost, and Furutech happening to be among a small number of notable exceptions). But in those other cases perhaps an email to the manufacturer would unearth that information. On the other hand, in the case of the Cardas Clear and Clear Beyond speaker cables (but not the Clear interconnect), capacitance is very high (278 and 446 pf/foot respectively). Presumably that is a consequence of those cables having been designed to provide extremely low inductance. The impedance of the Sabrina speaker rises to relatively high values (around 10 ohms or so) in the upper treble region, which is where inductance primarily matters, and that kind of impedance characteristic makes having low cable inductance relatively unimportant. So my instinct would be to avoid those particular speaker cables in this case. BTW, here is a link to a very nicely written review of the Furutech cables which Guido did a while back: http://www.positive-feedback.com/Issue45/furutech.htmBest regards, -- Al |
P.S. to my post above: Even if pins 2 and 3 were interchanged relative to the usual convention in the Aeris and the 625 S2, it wouldn't matter as the two reversals would result in the correct overall polarity. And that would continue to be true even if a preamp were inserted between them, assuming the preamp's polarity convention is the same at its output as at its input.
Regards,
-- Al
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Thanks, Mapman. On June 11 and June 12 I had posted the following in this thread: Regarding interconnects, if I recall correctly all of the equipment possibilities that have been mentioned would be suitable for use with balanced XLR interconnects. While opinions about cable selection tend to be all over the map, as you may have seen in any number of other cable-related threads, FWIW my suggestion is that initially, at least, you simply purchase some inexpensive Mogami Gold Studio balanced cables. And who knows, despite their modest price you may find them to be suitable for use permanently.
Those cables, by the way, are the de facto interconnect of choice in professional recording studios worldwide....
... Regarding the interconnects that would be used at the output of the Aeris DAC, I note the following statement in the Aeris’ description:
Transformer balanced XLR line outputs provide outstanding output common-mode noise rejection, eliminate potential ground loops, and ensure compatibility with other equipment. I also note that it has a 120 ohm output impedance, which although not especially low is considerably lower than in many other designs.
I suspect that those factors will result in that DAC having somewhat less sensitivity to cable differences (at its balanced analog outputs) than would be the case in many other circumstances. Especially if the length that is necessary is only 1 meter, as most analog cable effects are proportional to length. Regarding the comments about low capacitance in my posts earlier today, the capacitance per unit length of Mogami Gold Studio is somewhat higher than in the case of most of the cables Guido suggested, but the short length that is required should make that difference inconsequential. Best regards, -- Al |
Inna, according to rear panel photos I've seen of the Aeris and the 625 S2 , those models conform to the XLR convention that is standard in the USA, Canada, and many other countries of pin 2 non-inverted and pin 3 inverted (with pin 1 being ground). You are remembering correctly that some of the older JRDG designs did the converse.
Regards,
-- Al
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CODA makes some very nice products, Rinpoche.
However I see that the link at their site for the specs on the 15.5, while going to specs that are stated to be for the 15.0, indicates an input impedance of 50K unbalanced/1K balanced. And the link for the manual for the 15.5, while going to a manual that is stated to be for the 15.0, indicates an input impedance of 50K unbalanced/10K balanced.
Presumably it is best to use the balanced outputs of the Aeris. The Aeris may or may not be able to drive an impedance as low as 1K with optimal results, but more often than not a preamp (if you were to eventually purchase one) would not be able to. And many preamp designs, especially those that are tube-based, would not be able to handle 10K with optimal results, either.
Best regards,
-- Al
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My suggestion about the proposed trade: Tell the dealer that before deciding you’d like to borrow the $6000 cables so that you can compare them in your own system to a 1 meter pair of Mogami Gold Studio, selling new for less than 2% of that amount. If she were to agree, and you do that, let us know the results.
Opinions will differ among different audiophiles as to the merits of the proposed trade, of course. But personally I’d no sooner trade my Porsche, which I love, for a pair of Nordost Odins :-)
Best,
-- Al
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I agree completely with the foregoing comments. While I perhaps worded my Porsche/Odin comment more subtly than I should have, my main point (in addition to providing a bit of perspective on the cost of some of the cables that have been mentioned) was that I would not expect the proposed trade to have much likelihood of being sufficiently transformative to make sense. And I would expect that likelihood to be even lower in this case than in many other circumstances as a result of the technical characteristics of the components that are being connected, as I indicated earlier, and by the short length that is involved.
An approach that stands a much greater chance of being sonically rewarding, IMO, would be to sell the Devialet 200 integrated amp (which the last time I looked had a list price in the USA of just under $10K), and applying the proceeds to or toward the combination of a preamp and much less expensive cables.
Just my $0.02. Best regards,
-- Al
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If the Odin loom were found to be truly ’" mind blowimg" transformative in your system would you be tempted to part ways with the Porsche? Think about it, a lover of classical music with "mind blowing " music reproduction in your home. Nope. No chance whatsoever. And I can always go to a live classical concert for even better sonics, in most cases at least. But that’s just me, and I recognize that it comes down to individual preferences and value judgments. Best regards, -- Al |
I'd feel pretty certain that the AQ cable will work fine, but given its very short 0.5 meter length I'd be hesitant to read too much into such a finding. Given also that the Transparent cables and perhaps also Crystal cables that were used initially were probably significantly longer (the degree of most analog cable effects is proportional to length, as I had mentioned), and break-in of one or both components may be ongoing.
Best regards,
-- Al
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Hi Rinpoche,
Apologies for my post not being stated more clearly.
No I was definitely not saying that the 0.5 meter cable would not sound good. As I indicated, "I’d feel pretty certain that the AQ cable will work fine."
In the post just above mine Guido expressed interest in learning from your forthcoming experience how well the AQ WEL synergizes with the Aeris and the 625 S2. When I said "I’d be hesitant to read too much into such a finding" I was simply saying that given the AQ cable’s short length, and given (as I said in that post and also earlier in the thread) that the degree of most (and probably almost all) sonic effects an analog interconnect cable may introduce is proportional to length (meaning that the degree of the sonic effects of an analog interconnect will be proportionately less for a short length than for a longer length), and given that the cable(s) you are in a position to compare the AQ with (the Transparent and perhaps the Crystal) were probably significantly longer, the data point your findings will provide relative to his question will be less than conclusive.
Best regards,
-- Al
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You see, there is a 1 m Wel for sale also. But, of course, it is a bit more money. Other than resale, there is no point spending more as far as I can see. I agree completely. In fact spending more for the 1 meter WEL could very conceivably be sonically counterproductive. As I see it, in general the goal should be for a cable to have as little effect as possible on the signal it is conducting, and to convey the signal it is provided with in as accurate a manner as possible. In the case of cables conducting analog audio signals, it follows from what I have said about the relation between cable effects and cable length that a shorter cable will provide greater accuracy, and introduce less coloration, than a longer cable of the same type. Best regards, -- Al |
Hi Rinpoche,
What you would want would be a "line stage" preamp. The Lamm LP2.1 is a "phono stage" preamp, which as Inna indicated would be used in conjunction with a turntable, and would require a separate line stage preamp.
Note that as in the case of most phono stages the LP2.1 does not provide a volume control. Also, a phono stage would be severely overloaded by the output of a DAC, which is at a much higher voltage level than the output of a phono cartridge. And it would apply frequency response equalization that is only appropriate for the output of a phono cartridge.
Finally, you would want to choose a preamp providing balanced inputs and outputs, on XLR connectors, as well as unbalanced inputs and outputs on RCA connectors.
Best regards,
-- Al
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