Bas Horneman said:
It shoud not be forgotten the chochlea is an active distributed amplifier (and non linear to boot). In fact IM pickup measurement is a novel diagnostic technique for evaluating hearing functionality.
It has been shown (will look for the reference if someone is interested) IM is higher at low listening levels (because of the larger biomechanical gain) and decreases at higher signal level.
This goes a long way to explain why we use to get a far better experience cranking up the power.
Rodolfo
PS Great thread! I'v not yet gone through it all at this time.
baggystevo82 said:
True, but this case (Fletcher - Munson profile) is about frequency response, why bass is not appreciated at low levels.
What I was refering above is about transduction nonlinearity, which improves with higher levels of excitation.
Rodolfo
Not to dispute exactly what anyone is talking about, Fletcher Munson curves are dismissed too readily, too often. The bulk of musical energy is between 300 and 1000 Hz. LOOK at those curve thoughfully... those are not 1 or 3, those 10 dB lines on the graph.
I still do not understand, nor wish to hear anyone's explanations for; why loudness controls and tone controls have disappeared from so-called "high end" audio.
arghhhh........
I still do not understand, nor wish to hear anyone's explanations for; why loudness controls and tone controls have disappeared from so-called "high end" audio.
arghhhh........
Fletcher-Munson (or Robinson-Dadson) means you should listen to reproduced audio at the right level. Looking in another direction, this means that you have a better chance of reproducing string quartets correctly than you have of a Mahler orchestra or a Led Zeppelin concert.
Hmm, would be nice too if instead of it just being an "on / off" kind of switch thing, that it continuously varied (as appropriate) so that once the right volumes were reached that the curves were automatically no longer enhanced.fdegrove said:Hi,
Would be cute to have some sort of volume controlled loudness control.....
Cheers, 😉
Naturally there would be no sonically deleterious effects from this circuit either.
Sorry, I'm probably dreaming again! 😛
loudness control compensation
"There is nothing new under the sun." -Ecclesiastes
"There is only one proper volume level for any given recording." -Peter Walker
"There is nothing new under the sun." -Ecclesiastes
"There is only one proper volume level for any given recording." -Peter Walker
There was some discussion earlier regarding the inherent noise limits of tubes. The png below is a residual noise sweep of my current bench toy, an LED biased 6C45 driving a 7K ohm SE OPT. It's safe to say the amplification device isn't the limiting noise factor. Down low it's PS and lack of shielding, across the meat of the band it's the 24-bit DAC. 0 dB with most headphones is very loud and clipping occurs 6 dB higher still. Just saying....
Attachments
fdegrove said:Hi,
Would be cute to have some sort of volume controlled loudness control.....
Cheers, 😉
Hang on....I seem to remember this was one once a standard feature on some mid 70's SS hi fi amps....a 4 ganged vol control audio log/ and anti law log.. (or whatever)..I believe Sanyo and some other Jap units had this as standard.
Another reason to the loudness control has vanished is that boom-box alignment philosophy seems the norm and LS driver units are far more compliant than the older kellogs types.
All in all the subject of tastes has put the Flet Munsen curves a bit pear- shaped in the wrong end....but the mass public has swallowed the boom box quality to hearts content. Me No. A good proper relaxed mid range in most made systems is lacking with a horrid sizzling sounding HF unit..
richj
Hold on, chaps! I wasn't suggesting we use loudness controls - far from it. I was merely pointing out that we should listen at the correct level.
EC8010 said:
May be it is not that terrible after all. There are two natural sound levels we normally use. The right one, where frequency response matches reasonably well with reality, and then the socialy compatible level.
At this level we give up fidelity in all respects and just grab a program mutilated remains while doing something else like working or reading or whatever.
Our brain fills the holes and manages to elicit the emotional responses anyway.
Rodolfo
EC8010 said:
People, including yourself, may be interested in Mr. Bench's clever implementation of a "loudness control".
inductor-based attenuator with frequency control
More ramblings
Having worked through all posts, some reflections.
Good old vacuum tubes.
I am old enough to have lived the electronics revolution the other way round. My first serious attempt as a teenager to build audio amplifiers ended in a 6BQ5 push pull flooding my room with all of an incredible, earth shaking 10 W through a great 12" PHILIPS double cone speaker in an open back cedar enclosure I'd built. For years it was magic sound - vinyl based - going through the Classics, to early 70's rock (Moody Blues comes to mind!) and so on.
Then it happened, I could at last build and test a truly DC coupled half bridge complementary symetry differential input discrete transistor amplifier a la OpAmp of about the same power. The difference was so overwhelming I could not belive. The level of perfection , frequency flatness and detail.
I dropped tubes altoghether at that time to never look back again. In retrospect, probably what was surprising for me was much more the **difference** with the previous experience rather than an actual improvement in reproduction. That is, it probably didn't sound so much better but it did sound different and that was enough to be led to belive it was better.
May be this is going on today again but the other way round.
Rodolfo
Coming next, measurement vs. auditioning
Having worked through all posts, some reflections.
Good old vacuum tubes.
I am old enough to have lived the electronics revolution the other way round. My first serious attempt as a teenager to build audio amplifiers ended in a 6BQ5 push pull flooding my room with all of an incredible, earth shaking 10 W through a great 12" PHILIPS double cone speaker in an open back cedar enclosure I'd built. For years it was magic sound - vinyl based - going through the Classics, to early 70's rock (Moody Blues comes to mind!) and so on.
Then it happened, I could at last build and test a truly DC coupled half bridge complementary symetry differential input discrete transistor amplifier a la OpAmp of about the same power. The difference was so overwhelming I could not belive. The level of perfection , frequency flatness and detail.
I dropped tubes altoghether at that time to never look back again. In retrospect, probably what was surprising for me was much more the **difference** with the previous experience rather than an actual improvement in reproduction. That is, it probably didn't sound so much better but it did sound different and that was enough to be led to belive it was better.
May be this is going on today again but the other way round.
Rodolfo
Coming next, measurement vs. auditioning
Some of us have made the complete circle. First amp, a 6V6 P-P (1967) mono playing The Days of Future Passed on vinyl. Then twin Stromberg Carlson's with 4 X 6L6 each (1969). I caught the SS revolution, built every one of the Tiger series amps (late 60's - early 70's) that were published in Popular Electronics. I even had a Crown DC 300, considered by some to be the ultimate in its day. I continued to build amps and other electronics, but settled on commercial stereo equipment.
I was happy with my Phase Linear 4000 and Carver M400 setup until someone gave me an old Scott Laborotory Reference Amplifier. 4 X Mullard EL34. I fixed it and the Phase Linear - Carver setup hasn't seen power since. I have built many amps since then, both tube and SS. My setup now has 3 tube amps and one SS amp. Now The Days of Future Passed on audio DVD plays through my 845SE. I wouldn't want it any other way. Second choice, The Days of Future Passed on vinyl, only because I haven't built a decent phono stage yet.
I was happy with my Phase Linear 4000 and Carver M400 setup until someone gave me an old Scott Laborotory Reference Amplifier. 4 X Mullard EL34. I fixed it and the Phase Linear - Carver setup hasn't seen power since. I have built many amps since then, both tube and SS. My setup now has 3 tube amps and one SS amp. Now The Days of Future Passed on audio DVD plays through my 845SE. I wouldn't want it any other way. Second choice, The Days of Future Passed on vinyl, only because I haven't built a decent phono stage yet.
Hee hee. It's good hearing these stories. 🙂
For me, I started out listening to Johnny Cash records when I was 5 on my parents' suitcase HMV 3-in-one. It was tubed of course 😀
Later on like most teenagers, I needed a hi-fi setup of my own. So I aquired a ghetto-blaster-esque portable, and then later built my own pair of 2-way loudspeakers (total cost $35) to run from it, seperately. Then got the turntable (this portable had a built-in phono preamp!). And the aquisition of 'seperates' slowly began.
Being technically minded, I tried to do the dutiful thing and buy by the specs. Though I was guided by reviews in local music journals too after finding that I could hear some of the sonics they were talking of, for each unit. However I used to laugh at the mention of auiophools who liked tubed gear? "What about all that distortion. And must be slow?? -- those slew rates!" etc.
The big break came getting a casual job at my local high-end salon. There I heard a pair of Luxman XE300B's. Wow, what a way to be introduced to tubes! (And this was in 1985 -- waay before almost anyone had heard of the 300B)
After bulding another proper set of speakers (Dynaudio's, this time); I eventually got around to getting a pair of class-A, local-made monoblocks from the 60's based on the Mullard-20 circuit, and started tinkering around myself.
...It would now appear that I'm here!
It certainly sounds like it might be directly relevent to this thread. (But might just be marketing 'spin' too).
For me, I started out listening to Johnny Cash records when I was 5 on my parents' suitcase HMV 3-in-one. It was tubed of course 😀
Later on like most teenagers, I needed a hi-fi setup of my own. So I aquired a ghetto-blaster-esque portable, and then later built my own pair of 2-way loudspeakers (total cost $35) to run from it, seperately. Then got the turntable (this portable had a built-in phono preamp!). And the aquisition of 'seperates' slowly began.
Being technically minded, I tried to do the dutiful thing and buy by the specs. Though I was guided by reviews in local music journals too after finding that I could hear some of the sonics they were talking of, for each unit. However I used to laugh at the mention of auiophools who liked tubed gear? "What about all that distortion. And must be slow?? -- those slew rates!" etc.
The big break came getting a casual job at my local high-end salon. There I heard a pair of Luxman XE300B's. Wow, what a way to be introduced to tubes! (And this was in 1985 -- waay before almost anyone had heard of the 300B)
After bulding another proper set of speakers (Dynaudio's, this time); I eventually got around to getting a pair of class-A, local-made monoblocks from the 60's based on the Mullard-20 circuit, and started tinkering around myself.
...It would now appear that I'm here!
On that note; I remember Carver developed what he called a "transfer function" whereby he (claimed) to be able to tune his (or anyone's) amps to souind like any other. But I've not seen much in the literature about not only how he's supposed to do this, (only that it doesn't actually work quite exactly like he claims), but what a/the "transfer function" really/actually is?tubelab.com said:
It certainly sounds like it might be directly relevent to this thread. (But might just be marketing 'spin' too).
Careers are always interesting....working on the Short wave was the cherry on the icing... first weaned on ex service R1154, 807's, 6146's, & KT55 marine and stayed with 807's for audio since 1964 and present. Naturally timewise my collection has expanded.
The Merchant Navy was then dreadfully slow to change and we often had to take and deliver cartons/stillages of spare tubes/valves amongst other items around the remnants of the old Empire. The quantity was enormous and so was the travel.
A hint of the period I and others went through is to brouse at a 1958 Wireless World magazine (or others of that era) and the amount of surplus post war gear around was simply enormous. There was no excuse to get bored or not to learn as so many people nowdays lack incentives to hobby. The KT88 was priced around 1 Guinea (or 21 UK Shillings) and the good wage at that time was about £20 a week so it wasn't cheap then. Most other tubes were a pittance of that.
The red spot transistor and OC series were new born pups and somewhat unreliable.
Look what inflation has done!
richj
The Merchant Navy was then dreadfully slow to change and we often had to take and deliver cartons/stillages of spare tubes/valves amongst other items around the remnants of the old Empire. The quantity was enormous and so was the travel.
A hint of the period I and others went through is to brouse at a 1958 Wireless World magazine (or others of that era) and the amount of surplus post war gear around was simply enormous. There was no excuse to get bored or not to learn as so many people nowdays lack incentives to hobby. The KT88 was priced around 1 Guinea (or 21 UK Shillings) and the good wage at that time was about £20 a week so it wasn't cheap then. Most other tubes were a pittance of that.
The red spot transistor and OC series were new born pups and somewhat unreliable.
Look what inflation has done!
richj
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