Do you use SAM?

[Pim]

on with 0% in the past, off since yesterday. After some system tuning on the digital frontend (Mutec Ref10) I noticed that I can get better resolution and transparency without it. Speakers are Giya G2.

Hi Vivialet, your perception is exactly right.
The more 'In Phase' your digital frontend signal (the signals bits&bites) gets the more you won't need (or do reject) SAM in your system.
SAM is a disimprovement for an audiophile listener who has tuned his system to the point where subtle changes in the (digital) chain can cause immense deterioration.

Transparency is a consequence when one can reduce jitter and improves 'In Phase Signal Integrity' in his audio chain. If you then add something like SAM that corrupts this integrity it's a must you loose transparency again.

SAM gives a 'virtual transparency' to an audio system as it 'cuts' off the tinyest of the signals due to phase shifts it produces (it swirls the phase of this tiny signals so your brain can't locate them together again. The swirled informations just add to background of your music then).

This 'virtual transparency' you can hear in form of better locatability of instruments and voices...more air (the void) all around the instruments...at least so it seems.
But that's an illusion...because better locatability in this case comes from cutting of the 'space' (tiny informations) around instruments and voices. It cuts off the tiny information of the recording room (only the big bulk of it stays and you have better perception of this)  and adds void to the scene hence the 'virtual transparency' you perceive. Your brain has less to work hence can better locate the origins of sounds.

If your system hasn't achieved a certain level of accuracy for the signal (signal phase integrity) yet you might gain more than you loose by using SAM.
But at a certain level of transparency you won't let go at this fascination of listening into the details and emotions of your music you never heard in such clarity.

I hope I could contribute to the fuzzy of space & time

gui


*  it's no arrogance intended here

I'm a bit lost by what it is you mean here Gui but if you mean that SAM alters the digital signal and that some how corrupts the integrity of the original I think you're forgetting that during mastering exactly the same thing happens over and over again. SAM is just one digital alteration of the signal in a long line of them from recording to DAC. I believe that when someone doesn't 'like' what SAM does, it's more how the room reacts to the extended bass than the alteration of the digital signal.
I for one have SAM on 100% because it gives deeper bass from my small-ish speakers. It's therefore much more enjoyable. I've never heard any negative effect from SAM that leads me to think that the signal is distorted in any way.

[yabaVR]

I'm a bit lost by what it is you mean here Gui but if you mean that SAM alters the digital signal and that some how corrupts the integrity of the original I think you're forgetting that during mastering exactly the same thing happens over and over again. SAM is just one digital alteration of the signal in a long line of them from recording to DAC. I believe that when someone doesn't 'like' what SAM does, it's more how the room reacts to the extended bass than the alteration of the digital signal.
I for one have SAM on 100% because it gives deeper bass from my small-ish speakers. It's therefore much more enjoyable. I've never heard any negative effect from SAM that leads me to think that the signal is distorted in any way.

Hi Pim,
It's nothing to do with the room reacting to SAM. The effect SAM has to the signal is even present at SAM 0%.
And you're right. There is good and bad mastering and the better does less processing to a signal be it a voice or an instrument. Have you ever compared a 'no mastering recording' to the same that is then being mastered?
I've two of this from a Patricia Barber recording (don't have the album name at the moment). Despite the fact that I can't know what they really did to the signal the 'unmastered' version sounds so much more 'live' and natural with more details that I for sure won't choose the mastered version to listen to.
There is a new record on sale that features Anne Bisson
https://www.sieveking-sound.de/anne-biss...nie-s.html
This record was recorded live w/o mastering as far as I know. I've listened to the LP and it sounds so natural...mindblowing. I hope they release a 24bit version also.


It's a difficult thing to describe a fact that you have to hear before you get familiar with it and then can hear every time it comes your way. As Vivialet proofs I'm not the only one hearing this but it's very depending on the transparency of the whole audio chain if you want to get aware of it.

One more...I'm not speaking of a distortion of a signal that you can hear but of the lack of musical information that SAM blocks by phase shifts leading to less transparency.

gui

[Vivialet]

Out of curiosity, @Vivialet:

• have you observed a major difference with 2 stacked MC-+ USB compared to one when synced with the Ref-10 ?
  
• are your two MC-3+ USB using the stock SPSU or did you transform them ? In this case, what LPSU are you using ?
  

the second MC-3 brings again more stability and less glare. A major difference ? No...and of course yes
I'm using the stock SPSU, but thinking about an upgrade.

SAM is also having some benefits of course, together with a room correction it gives a very flat bass response in my room. More bass is one way to mask HF problems from a mediocre digital source. With all that Mutec gear these problems do not exist anymore, so I don't need that extra bass anymore. There is no measurable frequency response change with the Mutecs, but still I had to rebalance my sound with a new measurement. And with switching SAM off...

[no32]

Few days ago I tried the SAM again. And as before I’m better off without it, I I loved it with my Wilson’s but with my YG it’s bad.
when I compare between the Sam graph with my speaker measurements , the SAM can’t repair it

[Confused]

The recent posts in this thread remind me of the 'Gui test'. So no need to worry about jitter or Phase Signal Integrity if you don't want to, it is very easy to try this yourself, and indeed hear for yourself. The 'Gui test' is as follows:

Test:
To experience for yourself what I'm hearing listen to a recording with no bass but high frequencies (single instrument, woman's voice) and many of room information (best is live recordings). Listen - switch off SAM on RC - listen again. Then you know if SAM alters something in your music...may sound better or worse...your comments.

https://devialetchat.com/showthread.php?tid=3714

[thumb5]

The gui test might (or might not) demonstrate that there's an audible difference between SAM on and SAM off for a given listener with a given system, but in any case it tells nothing about the cause of any difference (e.g. jitter, phase, ...).

[alphafox]

I've been fortunate enough to have Devialet perform the SAMage of my vintage Cabasse Galion IV, at their headquarter, rue Réaumur in Paris. It is amazing how much precise bass a 21st century amp can drive from 35-year old speakers!

[SwissBear]

Just to elaborate about my own findings in relation to SAM and without any attempt to contradict anyone, I have observed that SAM was :

• negatively affecting the acoustic phase as mentioned above
  
• significantly increasing the level of bass, which was not necessary desirable. To illustrate this last effect, here is a measurement made at the listening position with SAM (Red) and without SAM (blue). Please note that both curves are identical above 150 Hz, which was expected.
  

[img][/img]

Having said that, I also observed that SAM was significantly improving the cleanliness of the bass of my speakers (B&W 802D3). These clean basses were also contributing to much enhanced transients brought to the system by the Ref-10.

So on my system, I made the necessary corrections in amplitude and in phase (frequency and time domains) in order to correct for the adverse effects mentioned above, and continue enjoying the very positive effects brought by SAM in conjunction with the Ref-10 on the coherence of the sound stage and the superb transients.

After correction, both amplitude and phase are good, and the adverse effects of SAM have been eliminated. There is no masking of HF by SAM enhanced bass.
[img][/img]

[Pim]

The recent posts in this thread remind me of the 'Gui test'.  So no need to worry about jitter or Phase Signal Integrity if you don't want to, it is very easy to try this yourself, and indeed hear for yourself.  The 'Gui test' is as follows:

Test:
To experience for yourself what I'm hearing listen to a recording with no bass but high frequencies (single instrument, woman's voice) and many of room information (best is live recordings). Listen - switch off SAM on RC - listen again. Then you know if SAM alters something in your music...may sound better or worse...your comments.

https://devialetchat.com/showthread.php?tid=3714

I'm going home today for a week without the missus so I'll have plenty of opportunity to give that one a try.

[Pim]

The recent posts in this thread remind me of the 'Gui test'.  So no need to worry about jitter or Phase Signal Integrity if you don't want to, it is very easy to try this yourself, and indeed hear for yourself.  The 'Gui test' is as follows:

Test:
To experience for yourself what I'm hearing listen to a recording with no bass but high frequencies (single instrument, woman's voice) and many of room information (best is live recordings). Listen - switch off SAM on RC - listen again. Then you know if SAM alters something in your music...may sound better or worse...your comments.

https://devialetchat.com/showthread.php?tid=3714

I'm going home today for a week without the missus so I'll have plenty of opportunity to give that one a try.

OK, it took a bit longer to get home (bloody work getting in the way of having fun) but I've finally done the 'Gui test'. First last night on a cold system. I played 'Love' by Anouk from the 'The Lost Tracks' album. It's just her and a piano with sometimes just her or sometimes just the piano so it gives a chance to concentrate on the voice and the piano separately as well as together.

I put the song on repeat. SAM off and listened for a while over and over. After a while I started switching SAM on and off (0%) song after song and couldn't hear a difference. 

I just want to mention here how hard it can be; the song starts with just Anouk singing and there's much more spacial information to hear at the start than throughout the song. So if you don't keep that into account it's easy to fool yourself every time you start the song into thinking that it sounds better than before.

So I tried a different approach; I turned SAM on and off during listening. Still nothing. So I left the system on for the night and went to bed.

It's now morning and I tried again. At first I thought that it sounded a tad fuller when SAM was on but after trying on / off blind* for a while it was clear to me that there was no discernible difference between the two.

I also tried with 'It's so Hard' (2 meter session) from the same album. An acoustic very simple honest recording. Again I couldn't tell the difference.

So back to SAM at 100% and a little bump in the 250Hz region on Roon and the music sings again. It's fuller, more enjoyable and the spacial information stays as is. 

This has been an interesting exercise. It's clear to me that with my speakers SAM doesn't fix anything in the phase / timing domain. Maybe that is because Dynaudio has this covered. Maybe it is because I have spent considerable time setting up my speakers. Due to the smallish living room they're in, I had to set them up on top of my CD cabinets. So they're above my head. I made some blocks to lean them forward to line them up properly with my seating position. They don't point straight at me but a little down (probably towards my shoulders). This gives the most natural sound. SAM does give me that extra bit of bass extension and with these small speakers that's a bonus. The extra bump in the 250 Hz region I gave it in Roon again makes the system sound that little bit more enjoyable. 
Both setup and 250Hz bump are things I learned from reading Jim Smith's 'Get Better Sound'. I've read that book through and through and love where it's taken me. Not everyone would agree with Jim about what he's trying to achieve. He's not after the ultimate linearity. He's after the most emotionally fulfilling sound. To him, that's in the tone first and foremost and then in the spacial cues. I'm up with that.

* Being home with the dog alone it's hard to change SAM on/off without knowing you're doing it but I used the approach of just twisting the remote button left and right whilst concentrating on the music. After doing this for a while you forget what your left hand is doing and you just listen. It's the closest to a blind test I could do without re-configuring the whole system to have a SAM on/off button on the remote.