Author Topic: solid state amps - always on or turn off when done listening?  (Read 831 times)

Offline Nick B

  • Global Moderator
  • *****
  • Posts: 3645
Re: solid state amps - always on or turn off when done listening?
« Reply #30 on: October 12, 2022, 02:12:24 PM »
Been quite busy lately, so if I have not posted. My replies might also be intermittent.

Nick perceiving a sonic difference in the stereo after the amp is on 24 hours may not
be unusual in a good system. One of the weaknesses when designing a component/system
is to cause masking. Nick has a good system, thus minimal masking.

Time for warm up, part values changing do occur over time. My system takes a minimum of
3 hours and preferred 4 hours. As such, another may actually take 6 hours, 10 hours,
depending upon the mass needed to be warmed.

Masking is the "ability" to "remove" inner detail, change harmonic structure etc. This
occurs with either full, or lean individual components, and passive parts with temperature
change. As such, masking will affect the ability to perceive sonic differences.

Temperature and humidity can affect musical playback perception due to air mass change,
thus the energy required to vibrate the air mass. This is Not a linear function.

Bling testing is difficult to perform correctly. Typical audio blind testing always skews towards
no sonic difference.
Does blind testing equate to typical listening. I have yet to see an answer.
If we have a group, statistically half are in a bass increasing mode
and half in a bass decreasing mode, how does one obtain a 95% confidence result?

Lastly, how perceptive is the "ear" (complete listening system)? In the lab, which I have at home now,
I have found a correlation of adjustments whose results essentially match.

1. Changing a resistor value by 1 part in a million is clearly perceived as a tonal balance change/
     frequency response change. That equates to at least -120db down from the fundamental. A
     specification of +/- 0,1db is in the range of -54db variation. If just -0,1db, that is only -60db.
     As one can see, that specification means virtually nothing when compared to -120db. Not
     surprised at all that sonic differences are perceived.

2. Changing 3/16th inch of one turn on a 600 watt 10mh iron core crossover inductor is clearly perceived.
     Every time an inductor is used, some sort of distortion of the signal occurs. Even in a simple circuit as
     shown below. Some effects also occur due to dc resistance of the wire. So we usually have one term   
     being frequency sensitive and another term not frequency sensitive.

3. I am now using 10 parallel 18 gauge 6 foot wires in one speaker leg and 11 wires in the other leg.
     Altering either leg by one additional or one less wire is clearly perceived.

4. Exchanging just one speaker leg wire from 3n (99.9% pure) to 6n (99.9999) is clearly perceived.

5. Using a 0,5mm pen marking, such a small rotation of a speaker is clearly perceived.

6. In the upgraded dac, two 6" wires are used from the board to the filter cap. Changing it from 3n to 6n
     is perceived.

Notice these are Not subjective preferences but sonic differences noted.

As one can see, each of these points is an extremely minute variation that supports
the other minute variations noted.

Granted, this is arrived at in a laboratory. However, in the real world at least a partial
realization occurs as Nick and others have observed.

Cheers

steve

Hi Steve,

Busy is good! As always, interesting comments from you including masking. I donít know what the normal operating temperature is of Van Alstine solid state gear or if thereís a normal for solid state amps in general. At the 5-6 hour mark, thereís a definite improvement and at 24 hours, itís like hearing a better amp. I really havenít tested at the 10 hour mark, or 15 hours etc. Itís irrelevant to me now and my amp is on 24/7 nowadays.

Now, the area of perceived vs real differences is interesting to me as well. Iíd say perceived differences might be better bass, more air etc. What Iím hearing is additional informationÖ.instruments and individual voices in a chorus for example. Are those perceived differencesÖno theyíre not. Theyíre additional information. For example, if I can hear test tones at 14 kHz and another individual can only hear until 10 kHz, thatís a real difference and not a perceived one. To argue to the contrary would render hearing tests a bit useless.

Hal also mentioned humidity affecting hearing perception and Iíll take your word on that as I donít know. The humidity level in so. Utah is low and stable. It would be interesting to see if I can hear the minute differences you described when making what I think are very small changes in your system. I donít know if I could and Iím not trained or experienced in that either. Iím just an audio enthusiast whoís been in the hobby for 35+ years whoís spent too much 💰 over the years but keeps learning more each month.
Van Alstine SET 120 Control Amp
Supratek Chardonnay preamp
Fritz Carrera 7 BE speakers
Border Patrol SEi dac
iFi Zen Stream & Mojo Audio lps
Wywires Silver cables & Audio Envy power cords
Roon, Tidal, Qobuz
PI Audio UberBUSS

Offline steve

  • Audiologist
  • *
  • Posts: 1083
Re: solid state amps - always on or turn off when done listening?
« Reply #31 on: October 13, 2022, 03:11:34 PM »
Been quite busy lately, so if I have not posted. My replies might also be intermittent.

Nick perceiving a sonic difference in the stereo after the amp is on 24 hours may not
be unusual in a good system. One of the weaknesses when designing a component/system
is to cause masking. Nick has a good system, thus minimal masking.

Time for warm up, part values changing do occur over time. My system takes a minimum of
3 hours and preferred 4 hours. As such, another may actually take 6 hours, 10 hours,
depending upon the mass needed to be warmed.

Masking is the "ability" to "remove" inner detail, change harmonic structure etc. This
occurs with either full, or lean individual components, and passive parts with temperature
change. As such, masking will affect the ability to perceive sonic differences.

Temperature and humidity can affect musical playback perception due to air mass change,
thus the energy required to vibrate the air mass. This is Not a linear function.

Bling testing is difficult to perform correctly. Typical audio blind testing always skews towards
no sonic difference.
Does blind testing equate to typical listening. I have yet to see an answer.
If we have a group, statistically half are in a bass increasing mode
and half in a bass decreasing mode, how does one obtain a 95% confidence result?

Lastly, how perceptive is the "ear" (complete listening system)? In the lab, which I have at home now,
I have found a correlation of adjustments whose results essentially match.

1. Changing a resistor value by 1 part in a million is clearly perceived as a tonal balance change/
     frequency response change. That equates to at least -120db down from the fundamental. A
     specification of +/- 0,1db is in the range of -54db variation. If just -0,1db, that is only -60db.
     As one can see, that specification means virtually nothing when compared to -120db. Not
     surprised at all that sonic differences are perceived.

2. Changing 3/16th inch of one turn on a 600 watt 10mh iron core crossover inductor is clearly perceived.
     Every time an inductor is used, some sort of distortion of the signal occurs. Even in a simple circuit as
     shown below. Some effects also occur due to dc resistance of the wire. So we usually have one term   
     being frequency sensitive and another term not frequency sensitive.

3. I am now using 10 parallel 18 gauge 6 foot wires in one speaker leg and 11 wires in the other leg.
     Altering either leg by one additional or one less wire is clearly perceived.

4. Exchanging just one speaker leg wire from 3n (99.9% pure) to 6n (99.9999) is clearly perceived.

5. Using a 0,5mm pen marking, such a small rotation of a speaker is clearly perceived.

6. In the upgraded dac, two 6" wires are used from the board to the filter cap. Changing it from 3n to 6n
     is perceived.

Notice these are Not subjective preferences but sonic differences noted.

As one can see, each of these points is an extremely minute variation that supports
the other minute variations noted.

Granted, this is arrived at in a laboratory. However, in the real world at least a partial
realization occurs as Nick and others have observed.

Cheers

steve

Hi Steve,

Busy is good! As always, interesting comments from you including masking. I donít know what the normal operating temperature is of Van Alstine solid state gear or if thereís a normal for solid state amps in general. At the 5-6 hour mark, thereís a definite improvement and at 24 hours, itís like hearing a better amp. I really havenít tested at the 10 hour mark, or 15 hours etc. Itís irrelevant to me now and my amp is on 24/7 nowadays.

Now, the area of perceived vs real differences is interesting to me as well. Iíd say perceived differences might be better bass, more air etc. What Iím hearing is additional informationÖ.instruments and individual voices in a chorus for example. Are those perceived differencesÖno theyíre not. Theyíre additional information. For example, if I can hear test tones at 14 kHz and another individual can only hear until 10 kHz, thatís a real difference and not a perceived one. To argue to the contrary would render hearing tests a bit useless.

Hal also mentioned humidity affecting hearing perception and Iíll take your word on that as I donít know. The humidity level in so. Utah is low and stable. It would be interesting to see if I can hear the minute differences you described when making what I think are very small changes in your system. I donít know if I could and Iím not trained or experienced in that either. Iím just an audio enthusiast whoís been in the hobby for 35+ years whoís spent too much 💰 over the years but keeps learning more each month.

Understandable Nick, I don't know of anyone who has tested every 3, 5 10 hours over a 24 hour period for sonic differences. It was just a thought for anyone who wanted to experiment on their own.

I must apologize for the term perceived sonic differences. I meant a real sonic difference, not trickery of our minds.
In my experiments over the decades in the lab, when I mentioned changing a resistor by 1 part in a million or other changes in my previous post, that sonic change is real, our hearing mechanism is actually that sensitive, to -120db tonal balance change, frequency response change.

cheers

steve
« Last Edit: October 13, 2022, 03:16:39 PM by steve »
Steve Sammet (Owner, Designer, Electron Eng, SAS Audio Labs, Ret)
SAS "V" 39pf/m 6N copper ICs,
SAS Test Phono Stage
Accutex 320 iii STR Mov Iron Cart
SAS 11A Perfect Tube Preamp
SAS 25 W Reference Triode/UL Monoblocks
2 way Floor standing Test Speakers

Offline rollo

  • Industry Participant
  • *
  • Posts: 6847
  • Rollo Audio - Home demo the only way to know
Re: solid state amps - always on or turn off when done listening?
« Reply #32 on: November 17, 2022, 12:31:03 PM »
  Agree Steve. Voicing is a wonderful thing.


charles
contact me  at rollo14@verizon.net or visit us on Facebook
Lamm Industries - Aqua Acoustic, Formula & La Scala DAC- INNUOS  - Rethm - Kuzma - QLN - Audio Hungary Qualiton - Fritz speakers -Gigawatt -Vinnie Rossi,TWL, Swiss Cables, Merason DAC.

Offline doug s.

  • Obsessively Audiophilic
  • ****
  • Posts: 706
Re: solid state amps - always on or turn off when done listening?
« Reply #33 on: November 26, 2022, 03:14:36 PM »
...Bling testing is difficult to perform correctly. Typical audio blind testing always skews towards
no sonic difference...

of course bling testing must be performed sighted!  everyone knows the coolest, most expensive looking component will perform the best! :mrgreen:

sorry, i couldn't resist.

doug s.