Yamaha A-S801 Boost or Roll-Off?

[lovinthehd]

Thanks. I'm going to order the Umik-1. Is this the legit site (best way to order)?

https://www.minidsp.com/products/acoustic-measurement/umik-1

I've bought directly from miniDSP, but believe you can even use Amazon these days....or you can even buy from Cross-Spectrum with more detailed/increased range calibration files. http://cross-spectrum.com/measurement/calibrated_umm6.html. Personally I've got the Dayton Omnimic V2 kit.

 

[KEW]

I've bought directly from miniDSP, but believe you can even use Amazon these days....or you can even buy from Cross-Spectrum with more detailed/increased range calibration files. http://cross-spectrum.com/measurement/calibrated_umm6.html. Personally I've got the Dayton Omnimic V2 kit.

I also have the Omnimic, but would not recommend it. It is inaccurate above 10kHz!

 

[lovinthehd]

I also have the Omnimic, but would not recommend it. It is inaccurate above 10kHz!

Source?

 

[KEW]

Source?

Dennis Murphy:

After getting your pm, I reread your post here and saw that I hadn't glommed on to the fact that you were using the Parts Express Omni Mic. I just thought it was some kind of omni-directional mic. That explains your measurements. As I mentioned to you in my pm, the PE Omni Mic is severely rolled off at the top end despite the calibration file you get. I wish they could fix that, because it's a very nice piece of hardware and software. I use it for THD measurements, which don't extend above 10 kHz. But it's not very useful as a design tool.

https://forums.audioholics.com/forums/threads/klipsch-rp-160m-vs-phil-bmr.110633/#post-1236241

 

[lovinthehd]

Dennis Murphy:

https://forums.audioholics.com/forums/threads/klipsch-rp-160m-vs-phil-bmr.110633/#post-1236241

I kind of remember reading that now that you mention it, wondered how it was determined, if it's specifically his unit. Wonder if I can find further on this.... @Dennis Murphy ?

 

[gene]

So I've been wondering about this ever since I got this unit a while back. What is it in the signal path that creates such a noticeable difference between having the Pure Direct ON vs OFF (even with all the tone controls set to flat)? I'm using FLAC files fed to the built-in USB connection and internal DAC.

I've always felt that the highs are either somewhat boosted in pure direct or slightly rolled off in the normal mode? Which one is it? Are they somehow "juicing" one or the other? If not, what is the impeding factor in the path with the tone controls (set to flat)? What parts are in the OFF path that might be causing this clear difference? Has anyone looked at the schematic?

I reviewed and own this unit and don't recall it being anything but flat in regular or pure direct mode:
https://www.audioholics.com/amplifier-reviews/yamaha-a-s801-amplifier-review

 

[<eargiant]

I reviewed and own this unit and don't recall it being anything but flat in regular or pure direct mode:
https://www.audioholics.com/amplifier-reviews/yamaha-a-s801-amplifier-review

Does that rule out the possibility of additional gain as PENG mentioned or DSP as ACDTG mentioned or something else that would create an audible difference between the two settings (especially at higher volumes)? Are we sure there should be no detectable sound difference between the two settings on this unit?

EDIT: I did some crude SPL measurements using the Audio Technica Installed Sound Support App using test tones and pink noise and I was not able to measure a meaningful difference in the sound levels between the two settings so it doesn't seem like it's a gain thing. Maybe it's just that it sounds clearer to us so we're perceiving a "crisper" more detailed sound which can either be a good or bad thing depending on the recording and volume.

I have this amp on my Polk SDA SRS2 (4ohm version) which have the original SL-2000 tweeters which are peaky and sharp in some rooms (I will be updating them with the RDO-194 which are supposed to be much better). Maybe that's part of the problem. The direct setting seems to really take them over the top on some recordings at higher volumes which is how I noticed the difference in the first place.

Hopefully that Direct switch is not like Volkswagen's "clean diesel" was a few years ago .

 

[AcuDefTechGuy]

Does that rule out the possibility of additional gain as PENG mentioned or DSP as ACDTG mentioned or something else that would create an audible difference between the two settings..

I think technically, anything other than DIRECT or PURE DIRECT might be considered "DSP", including "STEREO".

Even if the volume level were identical, some STEREO modes may sound differently than DIRECT (even if only slightly different).

I've compared STEREO vs DIRECT on my Denon components. Without the Audyssey Dynamic EQ, the difference isn't enough for me to debate. But every case is different. Every room is different. Every speaker and system is different.

 

[Pogre]

I think technically, anything other than DIRECT or PURE DIRECT might be considered "DSP", including "STEREO".

Even if the volume level were identical, some STEREO modes may sound differently than DIRECT (even if only slightly different).

I've compared STEREO vs DIRECT on my Denon components. Without the Audyssey Dynamic EQ, the difference isn't enough for me to debate. But every case is different. Every room is different. Every speaker and system is different.

I just very recently did that. I measured and listened for the difference between direct, pure direct and stereo. There may be some differences, but I could neither measure nor hear anything that had any profound impact between the 3.

 

[AcuDefTechGuy]

I just very recently did that. I measured and listened for the difference between direct, pure direct and stereo. There may be some differences, but I could neither measure nor hear anything that had any profound impact between the 3.

Of course, we are talking about Marantz/Denon components here. We can't speak for other components.

 

[Pogre]

Of course, we are talking about Marantz/Denon components here. We can't speak for other components.

Yes. I should have added that as well. I love my Marantz and before that I've always had a Denon.

 

[AcuDefTechGuy]

Yes. I should have added that as well. I love my Marantz and before that I've always had a Denon.

I could switch between Marantz and Denon without any reservation or hesitation whatsoever.

Same thing with the McIntosh MX122 Pre-Pro since it has Audyssey XT32 Dynamic EQ. Shoot, it's practically a bargain at only $7,000. Heck, my Denon AVP-A1HDCI was $7,500.

 

[PENG]

Does that rule out the possibility of additional gain as PENG mentioned or DSP as ACDTG mentioned or something else that would create an audible difference between the two settings (especially at higher volumes)? Are we sure there should be no detectable sound difference between the two settings on this unit?

EDIT: I did some crude SPL measurements using the Audio Technica Installed Sound Support App using test tones and pink noise and I was not able to measure a meaningful difference in the sound levels between the two settings so it doesn't seem like it's a gain thing. Maybe it's just that it sounds clearer to us so we're perceiving a "crisper" more detailed sound which can either be a good or bad thing depending on the recording and volume.

I have this amp on my Polk SDA SRS2 (4ohm version) which have the original SL-2000 tweeters which are peaky and sharp in some rooms (I will be updating them with the RDO-194 which are supposed to be much better). Maybe that's part of the problem. The direct setting seems to really take them over the top on some recordings at higher volumes which is how I noticed the difference in the first place.

Hopefully that Direct switch is not like Volkswagen's "clean diesel" was a few years ago .

Or can you turn it up a little to make sure in stereo it definitely sounds louder and ask you wife again which one sounds "clearer" to her?

Regarding the potential gain difference between pure direct on/off, it depends on the design. For example, my Marantz SC-7 has the "flat amp" switch that is a variation of the modern day "pure direct", sort of anyway, and it would change the gain though in this case with the tone control stage the gain is higher.

 

[gene]

Does that rule out the possibility of additional gain as PENG mentioned or DSP as ACDTG mentioned or something else that would create an audible difference between the two settings (especially at higher volumes)? Are we sure there should be no detectable sound difference between the two settings on this unit?

EDIT: I did some crude SPL measurements using the Audio Technica Installed Sound Support App using test tones and pink noise and I was not able to measure a meaningful difference in the sound levels between the two settings so it doesn't seem like it's a gain thing. Maybe it's just that it sounds clearer to us so we're perceiving a "crisper" more detailed sound which can either be a good or bad thing depending on the recording and volume.

I have this amp on my Polk SDA SRS2 (4ohm version) which have the original SL-2000 tweeters which are peaky and sharp in some rooms (I will be updating them with the RDO-194 which are supposed to be much better). Maybe that's part of the problem. The direct setting seems to really take them over the top on some recordings at higher volumes which is how I noticed the difference in the first place.

Hopefully that Direct switch is not like Volkswagen's "clean diesel" was a few years ago .

Have someone else switch between direct on/off while you don't know which is which to see if the audible differences remain or disappear.

Also, make sure all of the tone controls, including the loudness contour are set flat.

 

[<eargiant]

Have someone else switch between direct on/off while you don't know which is which to see if the audible differences remain or disappear.

Also, make sure all of the tone controls, including the loudness contour are set flat.

Yes, I was sure to have the tone controls set to flat and the variable loudness off.

As previously mentioned I had my wife listen and she got them all right. I just got done doing it again with my daughter and she also got them all right. When we started I told her I was going to flip a switch while the song was playing and wanted to know if there was a difference. Like my wife, she immediately said the difference was "obvious" and when I asked her what the difference was she said it was "clearer".

We then switched roles. I had her do the same for me after I told her that the little yellow light indicated the one she thought was clearer. I left the room and told her to switch it back and forth a few times with the volume down so that I would not know what my first trial was set to. I came back in and also got them all correct.

My daughter and I used the same track that I had played for my wife a couple of days ago. I figured I'd keep it consistent. The SPL was moderate/casual listening level.

The song was "Fragile" on the CD Sting - Fields of Gold: The Best of Sting 1984-1994. I had ripped it into FLAC using Exact Audio Copy and was playing it using Roon through a Macbook Pro directly into the USB of the Yamaha.

 

[<eargiant]

So I did some more listening last night with several different recordings. This time I was focusing on the mid-range and paying close attention to vocals. It's uncanny, you can clearly hear a difference on 9 out of 10 tracks.

This time I used many of the tracks I use when auditioning/comparing the mid-range on speakers. It's like a slight haze is lifted in Direct Mode, almost as if there is less reverb and more clarity. The more I listen the less I think it's a volume difference or even a frequency difference. It simply sounds less veiled, not to the point that it's going to smack you in the face, but it's undeniably there.

When I get the Umik-1 and REW what is the best method to try and capture the difference since it doesn't appear to be SPL or frequency variations?

Will a budget mic like this and REW be sensitive enough to capture the difference between the veiled/more muffled sound vs the clearer/cleaner sound in Direct mode?

 

[PENG]

So I did some more listening last night with several different recordings. This time I was focusing on the mid-range and paying close attention to vocals. It's uncanny, you can clearly hear a difference on 9 out of 10 tracks.

This time I used many of the tracks I use when auditioning/comparing the mid-range on speakers. It's like a slight haze is lifted in Direct Mode, almost as if there is less reverb and more clarity. The more I listen the less I think it's a volume difference or even a frequency difference. It simply sounds less veiled, not to the point that it's going to smack you in the face, but it's undeniably there.

When I get the Umik-1 and REW what is the best method to try and capture the difference since it doesn't appear to be SPL or frequency variations?

Will a budget mic like this and REW be sensitive enough to capture the difference between the veiled/more muffled sound vs the clearer/cleaner sound in Direct mode?

It may be able to capture small differences such as 1 dB reliably, but if the difference is 0.1 or even 0.5 dB then I don't think you can 100% conclude there is a level difference. Again, the easiest way is to use a good digital meter to measure the output voltage. 40 mV difference would indicate about 1 dB difference in spl. It sounds like there is a level difference of may be 0.1 to 0.5 dB, louder in direct mode for whatever reason.

Just curious, have you tried the same comparison using a headphone? You can still do it blind obviously, and more easily.

 

[PENG]

I was finally curious enough to start power googling this morning for relevant info and so far found the following:

- The A-S801 does use some sort of buffer amp for tone control.

- Could not find any reviews with measurements except for Gene's that I read long time ago and read it again after seeing your post, and he didn't mention anything about direct vs tone control that is relevant to your findings.

- Did find one, with measurements, for the A-S3000, and that one showed a slight level change with tone control on.

By the way, if I remember right, for a good ABX between electronics, it is important to level matched to 0.5 dB. A quick search found the article linked below:

http://www.bostonaudiosociety.org/bas_speaker/abx_testing.htm

In the 2nd paragraph under the "Listening" heading, it says:

"Meyer handed out a sheet photocopied from the ABX manual which showed typical level-matching required for reliable detection of differences between sources with 1/3 octave frequency-response aberrations. When the aberrations span a wider spectrum, level-matching becomes increasingly critical, dropping to less than 1/3 of a dB especially in the ear-sensitive 2-5kHz region. Acuity (ability to hear difference) also depends sometimes on how close to the threshold of hearing the level of the frequency is. At threshold, a small increase in level will make the sound audible and enable the listener reliably to distinguish A and B when different."

I am not ruling out the difference you found is not due to something other than level difference, but I sure hope it is not due to audible distortions or change in FR or other critical criteria that could degrade sound quality. I am somewhat confident that Yamaha should know better not to degrade SQ just because someone needs tone control for whatever reasons.

 

[<eargiant]

It may be able to capture small differences such as 1 dB reliably, but if the difference is 0.1 or even 0.5 dB then I don't think you can 100% conclude there is a level difference. Again, the easiest way is to use a good digital meter to measure the output voltage. 40 mV difference would indicate about 1 dB difference in spl. It sounds like there is a level difference of may be 0.1 to 0.5 dB, louder in direct mode for whatever reason.

In that case It'll have to wait until the next time I drive down to my techs place, I may bring the Yamaha along. I don't really want to spend the money on a quality DMM.

Just curious, have you tried the same comparison using a headphone? You can still do it blind obviously, and more easily.

Yes, I have tried it with headphones.

I was finally curious enough to start power googling this morning for relevant info and so far found the following:

- The A-S801 does use some sort of buffer amp for tone control.

- Could not find any reviews with measurements except for Gene's that I read long time ago and read it again after seeing your post, and he didn't mention anything about direct vs tone control that is relevant to your findings.

- Did find one, with measurements, for the A-S3000, and that one showed a slight level change with tone control on.

By the way, if I remember right, for a good ABX between electronics, it is important to level matched to 0.5 dB. A quick search found the article linked below:

http://www.bostonaudiosociety.org/bas_speaker/abx_testing.htm

In the 2nd paragraph under the "Listening" heading, it says:

"Meyer handed out a sheet photocopied from the ABX manual which showed typical level-matching required for reliable detection of differences between sources with 1/3 octave frequency-response aberrations. When the aberrations span a wider spectrum, level-matching becomes increasingly critical, dropping to less than 1/3 of a dB especially in the ear-sensitive 2-5kHz region. Acuity (ability to hear difference) also depends sometimes on how close to the threshold of hearing the level of the frequency is. At threshold, a small increase in level will make the sound audible and enable the listener reliably to distinguish A and B when different."

I am not ruling out the difference you found is not due to something other than level difference, but I sure hope it is not due to audible distortions or change in FR or other critical criteria that could degrade sound quality. I am somewhat confident that Yamaha should know better not to degrade SQ just because someone needs tone control for whatever reasons.

Thanks for trying to do research on this. It's really had me wondering. This is getting interesting.

Probably unrelated but can anyone tell me why this DSP chip is on the DAC board? Do all DACs require a chip like this?

 

[KEW]

Wow! For a lot of people who would buy an integrated, that represents a sacrilege of the highest degree!