Listen to cable directionality

[witchdoctor]

I do admire a lot of what Bob Carver has done, going all the way back to Phase Linear days. The stuff about making one amp sound like another I feel is comprised of equal parts engineering and equal parts (as I've repeated in this thread) A/B testing not being effective for a great many aspects of audio. However, specifically with regard to imaging, Carver put out what is possibly the best example of an amplifier line whose imaging characteristics were eminently predictable from the specs: his "sonic holography" line. See https://en.wikipedia.org/wiki/Bob_Carver

 

 

 

I had a friend who owned one of these, and listened to it for several hours. Flip a switch and the image would come from outside as well as between the speakers. Flip it back, normal stereo image. Fascinating and fun for a while, but as with any such gimmick, eventually I grew tired of every track imaging in the same artificial way.

 

My TG3 processor you see in the pic has sonic holography. It works best in two channel stereo and the speakers have to be with in a one inch tolerance from your listening position. The digital version is different from the analog version and I typically prefer it on in my desktop system. In the HT I preferred the direct mode with no processing for 2 channel.

 

You can find some great vintage Carver gear on Craigslist if you keep your eye out. I scored my AV 505 for $130!!! It was $1000 retail and if you see them on ebay they generally go for around $350-$450. It replaced a Parasound Zamp which was about a year old. The Zamp just didn't have the effortless dynamics but it is only 50 watts a channel and still sounds good. The AV 505 puts out 130 watts in 2 channel mode and is about 10 times bigger.

[semente]

Jud

Respected U.K. E.E Douglas Self has published a series of Audio Power Amplifier design handbooks where his designs end up with an incredibly high performance for all the currently measured areas, including distortion figures with close to 4 zeroes in them, but many found that the stereo image was mainly between the speakers.

However, do quite a bit more work in the PSU area especially , including separately powering the front end, and the designs are then capable of a 3D type performance with good speakers and suitable source material.

Very few amplifier designers, appear to be able to design amplifiers and preamplifiers that also give a realistic impression of height.

The Nelson Pass 100W/Ch. Class A mono blocks are capable of this with material such as "The Storm" from a Chesky Hybrid SACD's red book CD layer, but many other expensive mono blocks fall flat in this area, and don't make you involuntarily jump like the Pass amplifier can with this track.

Regards

Alex

As far as I know the image is supposed to stay between the speakers and this site seems to attest for that :

 

http://www.sengpielaudio.com/HejiaE.htm

 

But depending on the dispersion characteristics of the speakers as well as their distance to side walls and wall reflection index one will get more or less room interaction which will generate phantom images and increase "spaciousness".

 

[Jud]

As far as I know the image is supposed to stay between the speakers and this site seems to attest for that :

 

Visualization of all stereo microphone systems arrays with two microphones ierung aller Stereo-Mikrofonsysteme with equivalence stereo - Stereo recording angle SRA Audio two microphones time difference level difference orchestra angle Visualisator Ca

 

Hi Ricardo. Phase information in the recording can contribute to auditory illusions of height and depth when listening, so an accurate reproduction will transmit these.

[semente]

Hi Ricardo. Phase information in the recording can contribute to auditory illusions of height and depth when listening, so an accurate reproduction will transmit these.

Hi Jud,

 

I understand that, and we've all experienced that impression of height and depth.

The three factors that affect imaging perception are amplitude, phase and time whilst soundstage is the result of reverberation or room interaction.

Here's a good power point on the subject by Le Cléac'h:

 

http://nicolas.davidenko.perso.sfr.fr/outils/distorsion_de_phase.pdf

 

R

[Jud]

Hi Jud,

 

I understand that, and we've all experienced that impression of height and depth.

The three factors that affect imaging perception are amplitude, phase and time whilst soundstage is the result of reverberation or room interaction.

Here's a good power point on the subject by Le Cléac'h:

 

http://nicolas.davidenko.perso.sfr.fr/outils/distorsion_de_phase.pdf

 

R

 

This looks really good. I will have to learn French (unlikely ) or copy and paste a whole bunch of stuff into Google Translate....

[mansr]

This looks really good. I will have to learn French (unlikely ) or copy and paste a whole bunch of stuff into Google Translate....

You don't need much French to understand most of that. If you're familiar with the concepts, it's largely obvious what the words mean.

[esldude]

What Carver was doing is putting info in the right speaker to cancel cross-talk from the left and vice versa. Essentially it would remove crosstalk and you would hear only the left speaker in the left ear, and right speaker in the right ear were it perfect. Of course that also would only work for the direct sound. That is why everything needs to be symmetrical to within an inch. Also better if the sidewalls are symmetrical. Sonic Holography would indeed when it worked push images way out past each speaker.

[esldude]

As far as I know the image is supposed to stay between the speakers and this site seems to attest for that :

 

Visualization of all stereo microphone systems arrays with two microphones ierung aller Stereo-Mikrofonsysteme with equivalence stereo - Stereo recording angle SRA Audio two microphones time difference level difference orchestra angle Visualisator Ca

 

But depending on the dispersion characteristics of the speakers as well as their distance to side walls and wall reflection index one will get more or less room interaction which will generate phantom images and increase "spaciousness".

 

 

Well not necessarily though usually. Try putting in a spacing of 0 meters for the mics. You will see the recorded angle expand wider than the speakers. Microphone spacing and angling for stereo is counter-intuitive when using pairs. Move the mics closer together for wider angle. Further apart for narrower. Same with angling. Narrow angle wide stereo, wide angle narrow stereo.

[sandyk]

Hi Jud,

 

I understand that, and we've all experienced that impression of height and depth.

The three factors that affect imaging perception are amplitude, phase and time whilst soundstage is the result of reverberation or room interaction.

Here's a good power point on the subject by Le Cléac'h:

 

http://nicolas.davidenko.perso.sfr.fr/outils/distorsion_de_phase.pdf

 

R

 

I don't accept that soundstage is solely due to room interaction. You can still get a very real sounding illusion with depth, width and height in much larger and wider rooms. In fact, if the room is too small the image can become squashed.

A good track for showing this is the simulated moth in the Olivia Newton John recording "Moth to a Flame" where the "moth" appears to do an anti-clockwise circular sweep well beyond the rear of the speakers and the listening position. In a small room the circle becomes elongated . As I previously said, "The Strorm" from Chesky is a very good test track, where my own DIY gear also sounds very similar to the Pass Class A monoblocks, but not in the power area, which is not needed in a typical home situation. Another very good test track is "Queen-Another One Bites the Dust" when down mixed to stereo from the DVD-A .Many recordings are capable of filling the entire listening area with sound, even the DVD/Bluray of "Avatar" through a far better than average system from just 2 front speakers.Much of the illusion is due to the encoding, as well as recorded ambience, and with a better than average system you don't need a Dolby decoder to obtain much of the encoded surround information.

It comes down to phase accuracy etc. Well recorded DTV episodes and even many advertisements can give this illusion.

I normally watch TV using my main audio system, where some of the productions have excellent audio, as do many of the USA Late Night shows transmitted in 5.1 audio. Some of these can be obtained via captured and uploaded .ts streams from the Usenet.

[sandyk]

Re above.

Incidentally, to help retain this accuracy, my system is direct coupled (no input capacitors) all the way from the output of my DAC to the actual speakers, and there is no capacitor in the gain setting feedback area of either the Preamp or Power Amplifier either.

The 0 volts ( "earth") from the DAC is switched all the way through as well.

[17629v2]

"Originally Posted by 17629v2 I know you don't like me"

At the very least, lets consider what I've said in complete sentences. I'm not a big fan of chopping up statements, as they sometimes lose their meaning when edited.

 

"I know you don't like me because I called Dennis out on some of his ridiculous posts, and ever since then, you've been trying to trip me up with difficult questions. So I understand that your posts have nothing to do with wanting answers, and everything to do with getting back at me for comments you didn't like."

 

And now, lets look at this.

 

"n fact I happen to agree with you there are important aspects of sound that cannot be determined from a spec sheet (for example noise behavior, which can depend sensitively on individual system topology and environment). Imaging/soundstage was just a lousy example, and I gave several counter-examples, not because I have any personal animosity toward you, but because those obvious counter-examples in fact exist."

 

I can prove you wrong with as many examples you want. I don't say things that I can't back up. As with any claim I make, I can always sit you down in front of my system, and prove it. For example, why is it that when I swap my Ayre v-5 out with my Rowland 112, and make no other changes, the sound stage looses all its depth? And I mean all of it. The system goes from 3d to 2d. I know the amp isn't broken because I compared it to 2 other amps that were exactly the same at my dealer. What in the spec sheet would point that out? (The problem isn't unique to my system. The amp does that in all systems.)

 

Here's another example that I can, and have, backed up more times than I remember. Image size/scale. Looking at a spec sheet, how do you account for the huge images you encounter with most SET type amps? If you've never heard this before, the change in scale is unbelievable when you compare it to more traditional amp designs. I see nothing in the specs that would explain it. (As in my last example, the issue is not system dependent. It happens with all different components, rooms and systems).

 

One last example. Why is it that my systems imaging extends beyond the outside edge of my speakers when my Aesthetix Calypso is in the system, but not when my CJ Premier 18 is used in the same system with no changes? What specs would I be looking for to explain that? (Once again, not system dependent.)

 

If you can explain any of the above with specs, I'm more than willing to hear you out. Or, you can do like some of the other members do here, and pretend these qualities don't exist, even though they're clearly audible to anyone listening. Their excuse being, stuff like this can't be measured. And I would agree. You can't measure imaging properties.

 

 

[esldude]

"Originally Posted by 17629v2 I know you don't like me"

 

I can prove you wrong with as many examples you want. I don't say things that I can't back up. As with any claim I make, I can always sit you down in front of my system, and prove it. For example, why is it that when I swap my Ayre v-5 out with my Rowland 112, and make no other changes, the sound stage looses all its depth? And I mean all of it. The system goes from 3d to 2d. I know the amp isn't broken because I compared it to 2 other amps that were exactly the same at my dealer. What in the spec sheet would point that out? (The problem isn't unique to my system. The amp does that in all systems.)

 

High output impedance

 

Here's another example that I can, and have, backed up more times than I remember. Image size/scale. Looking at a spec sheet, how do you account for the huge images you encounter with most SET type amps? If you've never heard this before, the change in scale is unbelievable when you compare it to more traditional amp designs. I see nothing in the specs that would explain it. (As in my last example, the issue is not system dependent. It happens with all different components, rooms and systems).

Usually quite high output impedance, distortion that varies with output level more than usually is the case, and these also quite often have variable frequency extension based on output level and some may have phase anomalies into the upper octave or two from the lower bandwidth transformers.

 

One last example. Why is it that my systems imaging extends beyond the outside edge of my speakers when my Aesthetix Calypso is in the system, but not when my CJ Premier 18 is used in the same system with no changes? What specs would I be looking for to explain that? (Once again, not system dependent.)

The Calypso also has a high enough output impedance to effect such things depending upon which amp is connected to it. It exhibits enough distortion that varies with level to perhaps effect such things. Also would depend upon what follows it. Noise levels also might border on audible. Barely audible hiss that might not be noticed separately is known to add a sense of air, space and image size.

 

 

If you can explain any of the above with specs, I'm more than willing to hear you out. Or, you can do like some of the other members do here, and pretend these qualities don't exist, even though they're clearly audible to anyone listening. Their excuse being, stuff like this can't be measured. And I would agree. You can't measure imaging properties.

 

 

[esldude]

 

 

 

[/color]I can prove you wrong with as many examples you want. I don't say things that I can't back up. As with any claim I make, I can always sit you down in front of my system, and prove it. For example, why is it that when I swap my Ayre v-5 out with my Rowland 112, and make no other changes, the sound stage looses all its depth? And I mean all of it. The system goes from 3d to 2d. I know the amp isn't broken because I compared it to 2 other amps that were exactly the same at my dealer. What in the spec sheet would point that out? (The problem isn't unique to my system. The amp does that in all systems.)

 

Here's another example that I can, and have, backed up more times than I remember. Image size/scale. Looking at a spec sheet, how do you account for the huge images you encounter with most SET type amps? If you've never heard this before, the change in scale is unbelievable when you compare it to more traditional amp designs. I see nothing in the specs that would explain it. (As in my last example, the issue is not system dependent. It happens with all different components, rooms and systems).

 

One last example. Why is it that my systems imaging extends beyond the outside edge of my speakers when my Aesthetix Calypso is in the system, but not when my CJ Premier 18 is used in the same system with no changes? What specs would I be looking for to explain that? (Once again, not system dependent.)

 

If you can explain any of the above with specs, I'm more than willing to hear you out. Or, you can do like some of the other members do here, and pretend these qualities don't exist, even though they're clearly audible to anyone listening. Their excuse being, stuff like this can't be measured. And I would agree. You can't measure imaging properties.

 

 

 

I have written of this before, but you might well have never seen it.

 

I once thought that gear showing these large 3D images vs smaller less 3D or 2D presentations of other gear meant the 3D gear was better. It would show these characteristics across most or all systems and those that weren't 3D were not as good somehow. Such gear seemed more real, transparent and direct to the source if it painted large, deep spacious realistic musical soundstages.

 

I changed my mind after performing an experiment for other reasons. I took a good VTL triode amp which had these qualities in abundance, loaded the output with an appropriate value of power resistors, tapped that in a way that meant the whole affair was unity gain. 1 volt input and out comes 1 volt output from the triode amp. Made some interconnects and fed it on into a nice sounding Spectral amp that lacked all of these wonderful qualities. The Spectral fed my Quad ESL63 speakers.

 

The result was not anything I expected. I heard all of the wonderful qualities of the triode amp undiminished. So my supposition that solid state couldn't do such a thing was clearly wrong. There it was for all to hear. I then reversed position of the two amps. Spectral feeding VTL connected to Quads. My thinking was if the Spectral was lacking in these qualities it would diminish or completely eliminate them if between the source and the VTL. Instead nothing was effected. You could insert or remove the Spectral and hear nothing change. No difference. The Spectral was as clean as a piece of interconnect.

 

The only reasonable conclusion is these other qualities were colorations of the triode amp added to the source signal. Not all ss amps are as transparent as the Spectral. Some came close most didn't. Some would transmit maybe 2/3rds of the triode quality and add other colorations on top or have colorations that somewhat limited the effect. Still nothing I heard doing this with several different amps did anything to argue against the idea the beautiful wonderful sound of the triode amp is an additive set of colorations. This is not due to superior fidelity. It was and is quite compelling and most would prefer it I think.

[Jud]

There are such tube amps that I didn't like for just the reason Dennis mentioned, though ARC and others have a reputation for accuracy.

 

And then there are the Pass SIT amps, where Nelson says they use those transistors because they sound more like tubes. I haven't heard these, though I have heard Pass amps sounding what I would describe as gorgeous but not inaccurate. Of course that's a subjective impression.

[17629v2]

High output impedance

Usually quite high output impedance, distortion that varies with output level more than usually is the case, and these also quite often have variable frequency extension based on output level and some may have phase anomalies into the upper octave or two from the lower bandwidth transformers.

The Calypso also has a high enough output impedance to effect such things depending upon which amp is connected to it. It exhibits enough distortion that varies with level to perhaps effect such things. Also would depend upon what follows it. Noise levels also might border on audible. Barely audible hiss that might not be noticed separately is known to add a sense of air, space and image size.

 

If you'll read in each example I gave, I made it clear that the imaging qualities on each of the 3 products I mention were consistent with changes in gear. Now, when I read through your responses, its clear that you are giving me your best guess as to what you think accounts for the imaging qualities I mention. That's fine. There's nothing wrong you attempting to explain what's happening. But I see nothing conclusive. My best guess would be that the relationship between all the components is too complex for simple answers. I'm sure output impedance factors in somehow, but not enough to be the single cause.

 

To understand my main point, look at the problem in reverse. Assuming a fairly normal room with no major sonic issues, if I gave you the specs for a CD player, amp, preamp and speakers, can you tell me imaging properties of the system? I can't, and I don't know anyone who can, and that includes the designers themselves.

 

You know my position on this type of thing. If you can hear a difference, it has to be measurable. As is the case for many things in audio, were just not there yet.

[17629v2]

There are such tube amps that I didn't like for just the reason Dennis mentioned, though ARC and others have a reputation for accuracy.

 

And then there are the Pass SIT amps, where Nelson says they use those transistors because they sound more like tubes. I haven't heard these, though I have heard Pass amps sounding what I would describe as gorgeous but not inaccurate. Of course that's a subjective impression.

 

He's the only one who can make a mosfit sound like it has the clarity of a bipolar transistor. No idea how he does it, but I haven't heard any other amp that sounds like his. I never had an SIT, but I had the Aleph 0's which had 2 gain stages, and the 3 & 5 that had 3 gain stages, and there was a pretty big difference between the 2 designs.

[witchdoctor]

I have written of this before, but you might well have never seen it.

 

I once thought that gear showing these large 3D images vs smaller less 3D or 2D presentations of other gear meant the 3D gear was better. It would show these characteristics across most or all systems and those that weren't 3D were not as good somehow. Such gear seemed more real, transparent and direct to the source if it painted large, deep spacious realistic musical soundstages.

 

I changed my mind after performing an experiment for other reasons. I took a good VTL triode amp which had these qualities in abundance, loaded the output with an appropriate value of power resistors, tapped that in a way that meant the whole affair was unity gain. 1 volt input and out comes 1 volt output from the triode amp. Made some interconnects and fed it on into a nice sounding Spectral amp that lacked all of these wonderful qualities. The Spectral fed my Quad ESL63 speakers.

 

The result was not anything I expected. I heard all of the wonderful qualities of the triode amp undiminished. So my supposition that solid state couldn't do such a thing was clearly wrong. There it was for all to hear. I then reversed position of the two amps. Spectral feeding VTL connected to Quads. My thinking was if the Spectral was lacking in these qualities it would diminish or completely eliminate them if between the source and the VTL. Instead nothing was effected. You could insert or remove the Spectral and hear nothing change. No difference. The Spectral was as clean as a piece of interconnect.

 

The only reasonable conclusion is these other qualities were colorations of the triode amp added to the source signal. Not all ss amps are as transparent as the Spectral. Some came close most didn't. Some would transmit maybe 2/3rds of the triode quality and add other colorations on top or have colorations that somewhat limited the effect. Still nothing I heard doing this with several different amps did anything to argue against the idea the beautiful wonderful sound of the triode amp is an additive set of colorations. This is not due to superior fidelity. It was and is quite compelling and most would prefer it I think.

 

I once thought that gear showing these large 3D images vs smaller less 3D or 2D presentations of other gear meant the 3D gear was better.

 

It is better if you use 10 speakers, with two you need to have mad skill, a huge budget and be a member of the LF. All amps have colorations, the issue is which colorations you prefer. Active speakers help reduce these colorations IMO.

[esldude]

If you'll read in each example I gave, I made it clear that the imaging qualities on each of the 3 products I mention were consistent with changes in gear. Now, when I read through your responses, its clear that you are giving me your best guess as to what you think accounts for the imaging qualities I mention. That's fine. There's nothing wrong you attempting to explain what's happening. But I see nothing conclusive. My best guess would be that the relationship between all the components is too complex for simple answers. I'm sure output impedance factors in somehow, but not enough to be the single cause.

 

To understand my main point, look at the problem in reverse. Assuming a fairly normal room with no major sonic issues, if I gave you the specs for a CD player, amp, preamp and speakers, can you tell me imaging properties of the system? I can't, and I don't know anyone who can, and that includes the designers themselves.

 

You know my position on this type of thing. If you can hear a difference, it has to be measurable. As is the case for many things in audio, were just not there yet.

 

Its more than a guess. It isn't precise to the nearest 1 or 2% in each dimension.

 

I know Carver's amp challenge was mentioned. Guess what the first thing he did was when trying to emulate the tube amp? Put the proper resistance in the output. It was important to the sound you heard that gives tube amps their character. The very fact he accomplished what he did indicates it isn't beyond measure or knowledge. It may have been messy, but using conventional measures he got them to sound identical. Puts lie to the idea "we're just not there yet". At a minimum he could see what changes from linearity produced results of a target amp that did have all of this stuff. It also wasn't just a case of A/B comparison being a bad approach. He nulled the things together at better than -70 db. That also puts lie to the idea it wasn't really close to the same.

 

The designer of LAMM gear has specific things he wants his gear to do. He uses tubes and has used some FETs in more affordable models. He wants distortion to be the same at any frequency and given power level, but to smoothly increase with levels. The levels at peaks get into an audible range. This is a coloration, but one he judged was optimal for a preferred sound he wants which includes the big spacious image.

 

Now I am not sure why the big focus on imaging (especially in a thread about cable directionality). The truth is transparent gear all images the same. There is such gear. Those that give something bigger, something else are not more accurate. It may be more preferred and that is fine. Looking for some measure we can't do or at some limits we can't achieve is not where that comes from. You would be looking for what isn't there in my opinion. It is already in the characteristics we know about. Bob Carver made that clear.

[sandyk]

The truth is transparent gear all images the same. There is such gear. Those that give something bigger, something else are not more accurate. It may be more preferred and that is fine. Looking for some measure we can't do or at some limits we can't achieve is not where that comes from. You would be looking for what isn't there in my opinion. It is already in the characteristics we know about. Bob Carver made that clear.

 

What an unmitigated load of codswallop !

[Sal1950]

Now I am not sure why the big focus on imaging (especially in a thread about cable directionality).

Maybe you should give the files a second listen? I did and now that I know I can clearly hear the musicians standing backwards on the reversed polarity files!

[Sal1950]

What an unmitigated load of codswallop !

This from the lord of imaginary delusion. LOL

[sandyk]

Maybe you should give the files a second listen? I did and now that I know I can clearly hear the musicians standing backwards on the reversed polarity files!

 

Try listening again when you are sober and drug free !

[Sal1950]

This from the lord of imaginary delusion. LOL

 

Try listening again when you are sober and drug free !

Come on Alex, you mean you cant' hear their farts with much greater detail? Maybe your using your SATA cables reversed?

[Sal1950]

Come on Alex, you mean you cant' hear their farts with much greater detail?

They're blowing you kisses.

[17629v2]

What an unmitigated load of codswallop !

 

I don't want to start an argument with you, but I have to agree. You bring up the transparency comment constantly. And every time you do I ask the same question. How do you go about deciding if any one component is more transparent than the other? I never once got a straight answer out of you.

 

"It is already in the characteristics we know about. Bob Carver made that clear."

 

I have nothing against Carver, but after owning and listening to some of his amps, I don't see how he could have made such a claim. His amps were OK, but he's no Charles Hanson or Nelson Pass. And there's no way you would mistake one of Carvers amps for a tube amp. Before you argue with me, consider this. Every solid state designer dreams of making their gear sound like tubes. If he was really able to pull that off, the industry would be very different than what we see today. For starters, most of us would have Carver amps in our systems.

 

Its just my personal subjective opinion, but here's a list if SS manufacturers that I feel, do the best job of making SS sound like tubes. Pass, YBA, Pathos, Sugden, Mac, CJ, BAT, Plinius, Hovland

 

Before I forget, you asked me why I went OT.

 

"Now I am not sure why the big focus on imaging (especially in a thread about cable directionality). The truth is transparent gear all images the same. There is such gear."

 

I was responding to this comment that you made.

 

"However, secondly, stereo's limitations mean it will never give immersive 3d sound. It can't. Various colorations can sort of fool you, but it isn't in the capability of stereo to really accomplish that. You do need more channels. "

 

I thought it was fair to respond to a comment you made in your own thread.