| Gabevee |
Any thoughts, theories, opinions?
For those who don't know what I mean, it is a phenomenon that occurs when listening to our systems at night, from about 11:00 PM to 5:00 or 6:00 AM, where everything seems to sound much better and wider and deeper, etc.
Gabe |
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| mrothacher |
I've always felt it was primarily the result of these effects:
1. Far less power line noise at these hours
2. Far less ambient noise at these hours.
3. Our auditory acuity peaks at night, and arguably more so in the critical midrange.
Mike |
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| Da5id4Vz |
Its probably worth considering the effects of cooler and denser air.
Physiologically, the effect of the mornings caffeine may also be at a minimum. |
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| mrothacher |
Ah yes. The "Starbuck's Effect."
How about the effect of the Moon's gravity on speaker cones? |
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| Sch3mat1c |
Man, I notice this too. It's weird isn't it?
Like...I'm listening right now and it doesn't sound all that great. But last night it sounded good, wtf?...
Maybe it could be the sleepiness acting like alcohol...people always say it comes alive with a shot or two of Bourbon or what-have-you :)
Tim |
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| Da5id4Vz |
Steve Deckert's article is interesting, but I have to wonder about the microphonics caused by the tube amp on top of the subwoofer.
I am also starting to wonder about the length of widow for the sweat spot for the effect.
I don’t know about the rest of you, but after about 3 hours of serious listening, regardless of the quality of the source material.
my hearings pretty shot. |
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| Gabevee |
Yes, I also read Steve's article a few years back (if you notice, he posted my reply to him about it ;) ).
I just wanted to see what the opinions were here about it.
Gabe |
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| fdegrove |
Hi,
It will be a different experience depending on where you live but...yes, AC quality is a major factor.
I feel tubes are less prone to this kind of disturbance thanks to choke filtered supplies and...bear with me...stiff PSU designs with very high PSRR.
If you want look at the PSU I designed for a preamp, it provides very high isolation from the mains and sounds all the better for it.
Mind you, that was not the only target.
When I see the often poor, meagre PSU offered by some members here I often think: they'll never hear their circuits' potential at its best and they have no clue about PSU isolation from the mains...
On some occasions batteries are close to the ideal but a well designed PSU should come close.
Nonetheless, I still enjoy better sound way passed midnight...nothing's ever perfect?
Cheers,;) |
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| Sch3mat1c |
'Nother one of those ironies...people push tube rect's yet say PSUs need good regulation... oh well :rolleyes:
Tim |
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| mrfeedback |
My whole system hangs off a mains isolation transformer, and not in use audio and video items are unplugged.
Items like microwave oven and TV's and my washing machine containing SMPS are turned off at the wall when not in use.
I find that these loads on the mains can cause audible degradation despite the isolation transformer, but the ISO TX does give very great benefit in terms of smoothness and cleanliness in the sound of my hifi, and the day/night difference is very much reduced if not eliminated.
Eric. |
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| Brett |
| quote: | Originally posted by mrothacher
I've always felt it was primarily the result of these effects:
1. Far less power line noise at these hours
2. Far less ambient noise at these hours.
3. Our auditory acuity peaks at night, and arguably more so in the critical midrange. |
Agreed, although #1 can and should be addressed by correct PSU design. Frank is correct in his post below that a high PSRR is A Good Thing.
Tim said,| quote: | | 'Nother one of those ironies...people push tube rect's yet say PSUs need good regulation |
I'd rather not have all the wideband hash that SS rectifiers generate. Snubbing and filtering seldom works anywhere near as well as not generating the problem in the first place, esp with SE circuits where the rectifier duty cycle will vary with load. Then there are a number of dampers with quite low series resistances (very cheap too), and of course a differential PP circuit is much closer to a constant draw, so the rectifier resistance is much less of an issue IMO/IME. Finally using a decent <i>regulator</i> properly implemented makes the diode resistance moot. I have CCS's as the first stage in my shuntregs with impedances (depending on which one) of 100k -> Gig ohms.
It'll be interesting to try the Cree HV Schottky's later and get Paul to measure them in circuit.
It all depends how and what you're trying to do. If you want to build an amp for $100 from junkbox parts, then there will inherently be compromises that could be aleiviated for a little more outlay, even if that simply means another choke and cap, that you don't already own, for another LC stage. Both approaches have equal merit, just depends on the results you're seeking.
Cheers |
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| Aiace |
Since 11pm your blood is rich of cortisolo, so you can hear light better.
Hi, Aiace |
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| Morse |
Interesting topic guys;
I agree that line noise is a big problem that helps explain the 'wee hours' phenomenon - which is one reason that I put together a JR Isofilter for my CD source.
Okay, let's go all the way then to cut out line noise - a battery supply on the amp. Anyone here tried it and if so, what are the ups and downs? I've thought about getting about a dozen of those rechargeable 12V gel cells together and using it for a headphone amp. Good or bad idea? And, with only about 144V to play with, what valve would you recommend for a headphone amp - pref something cheap (er, uh that's affordable...)!
Suggestions?
Thanks and all the best,
Morse |
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| Sch3mat1c |
I highly doubt it's line noise; I have my comptuer running basically any time I'm awake, and my amps being plugged into the same strip as the computer, surely experience quite a bit of line noise.
Earlier today (or yesterday I should say) the radio didn't sound all that great at all, but now it's listenable, and the computer's been on all the same. :scratch:
Think I'll try listening during the day with the computer off to complete the proof..
Tim |
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| dhaen |
| quote: | Originally posted by Sch3mat1c
snip...
Earlier today (or yesterday I should say) the radio didn't sound all that great at all, but now it's listenable, and the computer's been on all the same. :scratch:
snip...
Tim |
Tim,
If your radio is anything like ours over here, the quality is variable by the hour. It depends who puts what presets into the Optimod (generic), who sets the studio out levels, and which lines are selected.
I am currently listening to a station called BBC Radio 2 (for old fogies) on FM, and the announcers voice has clearly audible compression artifacts bordering on distortion.
The BBC used to be the pinacle of standards and quality....
Things 'aint like they used to be:(
Cheers, |
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| Bas Horneman |
| quote: | | My whole system hangs off a mains isolation transformer |
I've been thinking about oneday getting one of those wound with electrostatic screen....what would be a rough guide to the current such a thing should deliver?
Cheers,
Bas |
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| dhaen |
Bas,
Go for as big as you can afford. Maybe 500 to 1000 VA.
The larger you go, the better the load regulation becomes.
If you're having it wound, I'd recommend adding some taps for + & - 5% to optimise your mean mains voltage.
Including such a transformer with an ES will reduce the mush from "outside", but mush produced "inside" will spread more, due to the increased power source impedance.
Cheers, |
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| Bas Horneman |
Hi John,
| quote: | | but mush produced "inside" will spread more, due to the increased power source impedance. |
So seperate isolation transformers for each component is preferable?
Regards,
Bas |
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| Bas Horneman |
| quote: | | I'd recommend adding some taps for + & - 5% to optimise your mean mains voltage. |
Brilliant idea! |
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| dhaen |
| quote: | | So seperate isolation transformers for each component is preferable? |
Bas,
Possibly.... It's a grey area.
Let's wait for some other opinions;)
Cheers, |
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| Brett |
| quote: | Originally posted by Bas Horneman
So seperate isolation transformers for each component is preferable? |
That would probably be the ideal, with each well sized for the device it's powering. But I'd just try one for your digital stuff, and one for analogue, as big as you can get or afford. A great place for iso transformers is a metal recycler, where large units can be picked up cheap. If I had a basement where I could put them, I'd have no problem having a multi-kVA trans for each component, because the ones I've sourced from recyclers in the past have been very modest in outlay, but physically large and ugly industrial items. I also bought a 2.4kVA toroid off ebay that was surplus from a manufacturer of medical gear. It came with multiple 240V secondaries, dual primaries and an ES sheild for about $US20. He'd thrown others away before this because he couldn't sell them!. Hunt around, you might be able to find something cheap.
Years back we measured some large EI core iso trans for frequency response (noise) on a specan because of a noise problem we couldn't quite get rid of in an industrial area with VERY dirty mains, and the ones we bought dropped off quite steeply above 1kHz or so. |
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| EC8010 |
I've noticed things sound better at night, too. But I don't think it's RF noise, or even really audio. Up until 23.00, the mains voltage jumps around all over the place, but after midnight, it's far more stable. Thus, all our AC heaters are constantly having their temperature changed slightly and do not reach a stable equilibrium, similarly for unstabilized HTs.
An isolation transformer with E/S would be a very good start for getting rid of the RF hash. They're not expensive, so a 500VA or even 2kVA wouldn't be ridiculous. Because the mains often has a DC component (which saturates cores easily), a bigger transformer would be better. Unless, you have one specially made, and ask for a gapped core to prevent saturation due to DC.
However, an isolation transformer won't do anything that a properly designed mains transformer in the equipment should do. It's penny-pinching that hardly any modern kit has an E/S screen on its mains transformer. |
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| Bas Horneman |
| quote: | | It's penny-pinching that hardly any modern kit has an E/S screen on its mains transformer. |
Luckily DIY'ers don't have such a problem...All my transformers torroïdal or EI have such a screen :nod:
| quote: | | However, an isolation transformer won't do anything that a properly designed mains transformer in the equipment should do |
Wouldn't they give you an extra 40dB reduction in capacitive coupling of noise?
That said spec's aren't everything. I'll just wait till I strike the jackpot with some or other lottery before I kit out my house with Isolation transformers all round. Then again I might just get a moderate one and see what it does..There is no substitute for experience.
Regards,
Bas |
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| Morse |
Hi Tim;
>>>...I highly doubt it's line noise...<<<
No offence intended, but the difference between better line isolation on my CD player was "night and day", literally. And it's not like I had a big investment one way or the other (thus no psychological imperative that "I paid a gazillion $$ on this thing so it BETTER work") - the first isofilter I tossed together was just a pair of RS 25.2VCT trafos and some AC rated caps - all of which were on a breadboard and all of which were 'recyclable'.
In that same vein, the addition of a 90 cent "X2" 250VAC rated, UL Listed AC mains filtering cap to the mains in of my 2A3 yielded an instant improvement in the sound. Again, if it's not line AC noise, I'm darned if I know why.
Hi Bas;
>>>...I'll just wait till I strike the jackpot with some or other lottery before I kit out my house with Isolation transformers all round. Then again I might just get a moderate one and see what it does...<<<
I'd love to read the results of that experiment! Just wish I could afford to try it over here!!
All the best,
Morse |
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| Bas Horneman |
Hi Morse,
I'll keep you posted once it happens.:cool:
Regards,
Bas |
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| Gabevee |
mrothacher says:
| quote: |
I've always felt it was primarily the result of these effects:
1. Far less power line noise at these hours
2. Far less ambient noise at these hours.
3. Our auditory acuity peaks at night, and arguably more so in the critical midrange.
|
#1... OK. I agree to an extent. I once plugged my TV into a computer grade line filter. Picture seemed better. But... with capacitance in the power transformer (TVs nowadays use direct connected AC, no step down/up transformer), and 1.5H and up choke, and 20-100µF capacitance.... it is difficult for 60 or 120 Hz to get through, let alone the kilo to megahertz frequencies. I would argue that one. But it is possible.
#2... I agree moreso. During the day there is much disturbance in the force... uh... much noise around from cars and planes (I live about 5 miles from a private airport) and birds and neighbors. At night it is much quieter. Has the "feel" in the ears like being up in the mountains (Blue Ridge/Appalachains to be exact. Not too high up, just very quiet). Very quiet.
#3... very interesting. I did not know this.
Thanks for the input so far folks!
Gabe |
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| fdegrove |
Hi,
| quote: | | However, an isolation transformer won't do anything that a properly designed mains transformer in the equipment should do. It's penny-pinching that hardly any modern kit has an E/S screen on its mains transformer |
This is oh so true....it seems that a lot of manufacturers try to save money by cutting corners in the wrong places.
For us. DIY or on demand maunfacturers;) , knowing how to specify a good transformer or having a good xformer manufacturer who actually knows his stuff can be crucial to the endresult.
For my own projects I always have them custom made and I've never regretted this approach one minute.
Benefits are:
-absulotely dead quiet.
-no excessive heat.
-good regulation.
-good isolation from the mains.
There is more to a good PSU than just that but it's a darn good place to start.
Cheers,;)
P.S. Fellow member Nania started a thread on powerxformers for audio about a month ago, have a look if you like. |
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| Da5id4Vz |
Ive seen it stated here that our audio acuity becomes better at night. Is the assertion that this is because it is night, or because we are subject to less noise allowing the acuity to grow.
Would 20 minutes in an NC-10 anechoic chamber have the same effect on our hearing?
If this is the case it would argue well for listening environments with greater outside noise isolation. NC-10 would be a bit too extreme. It would also argue well for preconditioning ourselves before critical listening. |
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| Kuei Yang Wang |
Koinichiwa,
| quote: | Originally posted by Gabevee
Any thoughts, theories, opinions?
For those who don't know what I mean, it is a phenomenon that occurs when listening to our systems at night, from about 11:00 PM to 5:00 or 6:00 AM, where everything seems to sound much better and wider and deeper, etc.
|
It is simple.
Ever since I started to use circuits that keep DC out of my Mains Transformers and PSU circuits that really isolate from mains born noise, I have found the sound of the system to be VERY consistent. There may still be a slight variation with time of day, but in general, my magic hours have increased to about 24 out of 24 Hours....
Sayonara |
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| mrothacher |
Ambient noise is definitely a fairly big deal. I think the average noise level in a typical home is 40-50 dB during the day and 10dB or so lower at night, so some of those spacial cues, overtones, and other "bloomy stuff" may seem 10dB louder at night.
As far as acuity at night goes, I read about this effect sometime ago and I'll try to dig up a reference. It seems that humans have very poor night vision (especially when compared to animals that might want to eat humans) and it is thought that our sense of hearing may pick up some of the slack at night to warn us of approaching predators, crying babies and the like.
Sense deprivation is another trick of the mind. Try wearing ear plugs for an hour or so, then take them out and listen to music the result may surprise you. Depriving yourself of the sense for a little while can give you the (psychological?) impression that you have "Super Ears" I'm not sure if the the effect is purely psychological or physiological. I'll try running an audiogram on myself sometime and see if there's anything to it.
I also agree with the comment about power line noise vs. powerline stability.
I think powerline stability is much better after business hours and better still in the wee hours. I have a Kil-A-Watt (mentioned by Nelson Pass in another forum here) power meter plugged into an outlet in my listening room at all times and my powerline swings by tens of volts throughout the day. So, powerline stability probably has a bigger impact than the noise contribution.
Beer is also pretty good. ;) |
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| Da5id4Vz |
I believe that there is a physiological effect attached to acuity. My understanding is that there are muscles associated with the bone structure of the middle ear that effect energy transfers to the cochlea form the basilar membrane.
There should be both sensory and chemical cues that affect these muscles. Loud noises would obviously be a cue to decrease transfer and protect the cochlea. Caffeine has long been associated with tinnitus. |
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| slowmotion |
| I usually fall asleep when listening late at nigth ;) |
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| Helix |
I love midnight bloom, a wee drink in the small hours too!
But it is true that you even get it on rubbish little garage radios, I often been working late at night and franticly trying to write down that song name I just heard, get it later in the week and it just doesn't seem the same. |
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| SY |
I don't see much difference in power line noise and stability between night and day chez moi, but I live in a bedroom community; the biggest local industry is probably NHT. The IS a big difference in ambient noise (2 year old Jimi asleep is much quieter than 2 year old Jimi awake), and a big difference in my hypothalamic response. Serotonin levels can affect subjective experience.
Either that or it's the random phase noise from photons in the daytime hitting my speakers and cables, screwing up subtle timing cues in the music. Or something. The bong hits can't have anything to do with it. |
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| pedroskova |
When does music sound its best?
After a long road trip in a cheap car.
Eight hours: very good.
Twelve hours: most excellent.
Sixteen hours: best system on the planet. |
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| Morse |
Konnichiwa Kuei Yang Wang
>>>...Ever since I started to use circuits that keep DC out of my Mains Transformers and PSU circuits...<<<
Could you suggest a schematic for a DC blocker that has proven to be effective? I'd like to try building something like that here.
Doumo arigatou gozaimasu for any assistance.
Morse |
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| fdegrove |
Hi,
| quote: | | Ever since I started to use circuits that keep DC out of my Mains Transformers and PSU circuits that really isolate from mains born noise, I have found the sound of the system to be VERY consistent. There may still be a slight variation with time of day, but in general, my magic hours have increased to about 24 out of 24 Hours.... |
Indeed that does make a huge difference.
Some ways I know of to go about it:
- An expensive airgapped xformer
- An electrostatic screen + using CT windings on the secundary side.
- Keeping high current windings on separate xformers.(heaters for instance)
- Using series regs + high capacitance behind them, chokes help too.
-The other way + some of the above:****
****Use at your own risk, I haven't actually tried this...I think it was TL who proposed it first so I welcome his comments.
At first glance it should be fine but beware of safety measures and use it at your own risk.
Cheers, ;) |
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| Gabevee |
How does one keep DC out of the power transformer? Unless you use capacitors in some kind of bridge between the winding points and the rectifier, there will be DC flowing through the secondary.:scratch:
How does the above circuit work? Is it a direct coupled circuit to use AC straight from the wall? Otherwise.. there would be no DC through it at all... from what I could tell first glance.
Gabe |
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| dhaen |
And, of course there's this one:
http://www.diyaudio.com/forums/show...rcuit#post16083
Gabe,
It is indeed intended to fit in series with the AC supply from the wall outlet, though I must reiterate Frank's comment on safety. There is potential for danger, if not engineered properly.
In the event of DC being superimposed on the AC mains, the diode bridges allow up to about 1.8v to be developed across each capacitor network.
IMO There is no point to having a network in each mains wire leg. If more DC offset needs to be catered for, simply put more bridges in series. After all, it's the caps that are a bind - big values, high current.
My above comment only applies to fdegrove's circuit. Mlloyd1's circuit depends on an electrolytic cap's tolerance to small amounts of reverse voltage.
The effectiveness of such circuits will depend on the type of transformer. Some, such as toroids are more susceptible to DC than others.
Cheers, |
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| Morse |
Hi Frank, Peter, Gabe, and John;
Thanks! I'll take a good look at each of those circuits later after I catch up on my sleep (it's about 3am here as I type away).
It's been a long day here since my 270DX showed up and I performed major surgery on my little 6BM8. The patient survived and is going through it's paces as I bang away at the keyboard. Sam Cooke sounds just fine!
So far (after about 4 hours of continuous operation) it looks like I bought myself 9 degrees C on the cooling issue (51C/46C depending on the part of the trafo you measure - hottest near the valves) as well as some extra 'oomph'. I upped the 820r dropper ('twixt the 100uF filter caps) to a 1k2r 25W dropper and as expected the B+ climbed to just over 260V. Sonically, the effect is a greater sense of dynamics as well as a little smoother overall sound (biggest diff at this B+ is that the triode input stage is drawing a bit more current). Overall I like the changes, though it would've been nice if it'd run cooler than this (*sigh* - I probably should've splurged and got the 270FX instead).
John, I'll answer your email after I get some sleep. I just checked my email (I've been drilling, cutting, soldering, occasionally cursing, and in general working like a maniac all day on my 6BM8/ECL82). ‚Ç‚¤‚à ‚·‚Ý‚Ü‚¹‚ñ for the delay!
Thanks again everyone!
All the best,
Morse |
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| alk |
Hi,
Could somebody explain to me why my amp sounds excellent at 4:00 a.m. and just ok in the daytime?
Puzzled....anyway i'm lucky here for i go to bed when most are beginning to wake up.:cool:
Now that i know how my amp behaves i wait until 2a.m. to begin my listenings....i am spoiled....it makes a REAL difference!
What i want to know if this is a subjective impression or not. Has anybody noticed? |
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| SY |
Well, it's something not so easy to subject to a valid analysis. There will only be unsupported speculation- that may be fun to some in and of itself, but can't answer your question.
So the empirical solution is to listen at 4 a.m. and enjoy. |
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| Sch3mat1c |
Your brain too tired to bother critiqueing it maybe? :D
Tim |
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| serengetiplains |
| Unless a person's physiology listens differently in the wee hours or some factor like temperature or humidity is causing a change, it seems to me the variable factor causing the change is the quality of your mains electricity. Mains quality has not been well addressed, IME, by the audio community. I've heard substantial differences in my system using various forms and combinations of passive (usually transformer based) and active mains regulation. That difference is perhaps of equal or similar magnitude to the difference you are hearing. |
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| analog_sa |
| quote: | | sounds excellent at 4:00 a.m |
Isn't it obvious? Low mains pollution, low level of structural and air-borne vibrations. Possibly higher level of alchohol in the blood... |
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| fdegrove |
Hi,
All of the above plus the fact that the ambient noise is much, much lower....
IMO a lot of people would report the same if only they'd bother to try it for themselves some time.
Cheers, ;) |
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| alk |
Thanks for the insights, well i have just read an interesting article which may be a bit esoteric but explains my late night experiences. Here's the link in case anyone is interested:
http://www.decware.com/newsite/mainmenu.htm
| quote: | | Possibly higher level of alchohol in the blood... |
Sharp senses... not really alcohol...try another:D |
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| alk |
| Well i can't get the direct link to the article. It's in the audiophile articles section, named " the magical hour";) |
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| dhaen |
:cop: I have merged these 2 similar threads.
They seem to deal with the same perceptions. Hope it's useful. ;) |
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| analog_sa |
| quote: | | Sharp senses... not really alcohol...try another |
I would if it were not for that uniformed guy above :) |
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| alk |
LOL:D
they're everywhere |
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| serengetiplains |
| What are the sources of mains noise? Doesn't every electrical component drawing electricity from the mains contribute some form of noise---and not only every component drawing electricity in my house/apartment, but every component drawing electricity from the sub-transformer feeding my house/apartment and all my neighbours' houses/apartments? And why stop at the subtransformer? |
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| Layberinthius |
Firstly everything contributes noise to your power distribution.
Even the actual wiring of your house /and/ the miles and miles of interconnected super-powered Antenna system which we call a "Power grid".
From a simple resistive load like a street light to your Computer or Fridge or Hot-water system...
I personally have been listening to audio for the past 3 years after 12 AM and apart from the very large drop off in ambient noise I think tiredness plays an extremely important part in making things sound 'better', I believe when you are tired you become emotionally enravelled in the music and because you /know/ everyone else is asleep you can feel completely alone with the music!!
I've been doing this for 3 years and just recently I've managed to schedule my sleeping pattern so I go to sleep at 6PM so I can wake up at 1AM in the morning, however, now that I get a full nights sleep something strange happens, I am no longer tired therefore I am no longer interested in the music!
Conclusion:
The music maybe the most perfect representation of the original performance in the world but it is all based upon EMOTIONS.
Yes I believe also that Line noise plays a good deal in sound quality, thats why I have re-designed my KT88 amp's PSU with E core trafos and heavy capacitance through the usual choke arrangement.
I wouldn't be surprised one bit that DC Battery-fed Filaments are much more stable than AC line fed filaments simply because of unregulation of the AC mains, however, I believe the 50hz 'radio-wave' operation of a filament plays a very large part in keeping it at optimatum.
Has anyone done reports on filament operation at AC and DC and does it affect way the tube works? Is there more saturation?
Would it be beneficial to run the entire amplifier and source devices off remote-controlled Generator power? Generators are becoming incredibly cheap nowdays, so why not?, As long as acoustical isolation is taken care of...? |
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