Yes and the new dematerialized invaders (let's call it the goods vendors) swaped the last one : we can see Christmas trees in front of our Cathredal here like I saw in Paris in front of Notre Dame one week ago !
So good Solstice light fest to you, should be great to be in place like Valsaintes Abbaye, Veselay church or Stonehenge.
The datasheets I have state that BD 139/140 go as high up as 170 MHz.
Problem is what is the overal result? Of all the things people get hung up on this one seems worth knowing. It suddenly struck me that the FET's I usually use do not have this problem. They possibly are as fast as the fastest bipolars or better. They need no driver. The very low distortion from a very unpromising initial 0.8% distortion must indicate they are a very different animal. They will hold this very low disortion right up to 50 kHz and more. Although very high feedback is required they sound nothing like bipolar amps of that sort. Those usually sound bland and paper thin at best. FET amps sound not unlike good valve designs. I strongly doubt if is anything to do with them having a gate rather than a base. A MOS FET is an enhancement pentode at best. The P type has no valve similartiy. If 6 devices used together Ron is reasonable. Exicon do voltage matched sets which means no special setting up. Even if you don't bother they work OK for hi fi use. Exicon supply the matched sets for big PA amps where it is important. Many of these didn't have them in the past. The Exicon set is an upgrade. HH 1200 comes to mind. It is a Hitachi clone with MPSA92/42 in the op amp bit. So good the BBC used it as a general purpose amp I am told.
The most excellent output stage I ever built was BD139/140 2SC5200/2SA1943 ( guessing the numbers , 30 MHz ) . It had very nearly zero distortion without loop feedback at 0.7A standing currrent. It was used with OPA604,it is stable and similar with or without feedback to the dumpers or a mixture. The NE5534 is not very nice like this. Progressing this to a standard amp I could not get the MOSFET's to equal it. 0.7 A is not where they want to be. Mostly I could not beat the 50 kHz distortion. Usually FET's are fine. I then returned the FET's to the VAS Cdom ( split ). It was a dream solution. Doing the same to the Complimentary feedback pair did nothing either way. I did not do the obvious. I did not take Cdom to the FET's directly. That looks to me to be an OK thing to do. I would think the bipolar a different story,
Dejan. Will your simulator say the Ft of a homebrew Darlington ? As you know simulators are not part of my life. I would say there was very little to choose between the two output stages when they measured about the same. The sound is neither sweet nor bright. As I have had runaway Cfbp stages I would prefer the FET's.
Cfbp as a home made LDO regulator seems very good. I built one recently in the style of H C Lin. The DC offset exacly what I wanted. I think it outperformed a LM317. As usual I can never make a foldback current limiter as good as the professionals so did not push on. I have very big doubts foldback limiters on amps work. The simple one in a Quad 303 is no worse.
Ben Duncan says why FET's do not upset the VAS with very high Cg ( 1 nF ) . I always thought that the signal levels do not demand much current. FET amps do not sound dull. The answer was rather obvious. The capacitance is bootstrapped by how it moves both gate and source together. The current needed is very small. The other losses count more, e.g. Cgd. I was being a bit stupid. I have measured full power 100 kHz without any problem ( do you dare do the same). That should have said think again. That's the trouble , people say things and it becomes the accepted wisdom. " Don't use FET's as the Cg is too high to drive. Talk about an Elephant in the room. There is a heard of them in hi fi folklaw. I would suggest 90% of hi fi is folklaw. people forget the music is not hi fi. It is mass market mid fi. All this splitting the atom is for nothing really. Most people to me have hi fi's no better than they had 30 years ago. Different, perhaps. If I was to say one thing to back up my story it is open baffle speakers are hi fi and boxes at any price are mid fi. KEF LS 50 is the best I have heard of mid fi as it is pocket money excellence. Hate their looks. Box speakers are about living with wives or thinking your home impresses people. I keep mine clean and that's the limit. People say " your speakers are very large, I couldn't have those " I say " that's because I like music".
It will show the values, yes. The version I use is the professional version, and it has RF as well.
Agreed on nonsense being peddlied as wisdom. You saw that TI app note on power supplies - I should mention that what they say is good is EXACTLY what I have been using since around 1975. Some of it taken from the Otala/Lohstroh amp, the rest from that German made beauty LAS. Together, they add up to TI's work. All knowledge pre 1980.
Look back at any of the schematics I sent you over the years and you'll find the RC components right next to the output section, getting rid of residual inductance. That is one beauty of a trick, I have advised it to several people as an afterthought, and all to the one reported easily audible inmprovements. Most had standard gear, where such considerations are almost never present.
Happy Christmas all
I am too lazy to write this again. Poking some in the ribs here.
http://www.diyaudio.com/forums/anal...so-good-my-entry-level-phono.html#post4163085
I am too lazy to write this again. Poking some in the ribs here.
http://www.diyaudio.com/forums/anal...so-good-my-entry-level-phono.html#post4163085
And to you Nigel . I have a dedicated room for the Stereo and an other for the work shop. Given my wife has a dedicated room for her hobbies we are all good as they say. My little project up at the present is a power supply for my old dac . Start with the 317 /337 to establish a base line sound and then move forward with the regulation. I am interested in seeing how the old audio alchemy 1.0 one bit responds and sounds to separate digital power and uping the voltage on the chips from 8 +/- to 12 volts +/- .
Just came across this thread....many years ago as a university student i made some money assisting a "psycho-acoustics" group with some technical details and some more.
For brevity: the "steady state" sound of e.g. a cello is not called distorted even if the second harmonic is +10 dB above the fundamental and the third even + 15 dB. Insofar, it could not surprise that neither trained musicians nor orchestra conductors could tell an - per thd- quasi undistorted reproduction of such a recorded sound from a heavily distorted - tdh 5 to 20%- provided the spectrum of the added harmonics matched the spectrum of the real musical instrument. The added distortion was attributed to the personal manner , preference, etc. of the musician playing the cello. But not to the distortion of the recording, amp, speaker. This lead to the eventually only interesting question , informally, what must happen that one does no longer recognize a cello as a cello? The answer is, more than 20 years later, not there . neither in terms of consistency nor of completeness. But one is sure, the thd is NOT the big factor. Nor is "noise". It has possibly more to do with "timing" .
Apparently the "brain" of mammals is an extremely powerful audio processor. The processing strengthens the significant and weakens the irrelevant. But one can only speculate ad nauseam how the audio processor tells significant from irrelevant. I met a renowned violinist found him listening obviously enchanted to an original Caruso recording. While i heard all the crackling noise, the resonances, distortion, he heard only the divine voice, the rest was insignificant to him.
In a technical respect I think a big step forward is a methodical. Turn to systems theory.
Amplifier and speaker is not two objects, it is one system ( a system is a quite different type of object). Next is the one system amp speaker listening room.
For brevity: the "steady state" sound of e.g. a cello is not called distorted even if the second harmonic is +10 dB above the fundamental and the third even + 15 dB. Insofar, it could not surprise that neither trained musicians nor orchestra conductors could tell an - per thd- quasi undistorted reproduction of such a recorded sound from a heavily distorted - tdh 5 to 20%- provided the spectrum of the added harmonics matched the spectrum of the real musical instrument. The added distortion was attributed to the personal manner , preference, etc. of the musician playing the cello. But not to the distortion of the recording, amp, speaker. This lead to the eventually only interesting question , informally, what must happen that one does no longer recognize a cello as a cello? The answer is, more than 20 years later, not there . neither in terms of consistency nor of completeness. But one is sure, the thd is NOT the big factor. Nor is "noise". It has possibly more to do with "timing" .
Apparently the "brain" of mammals is an extremely powerful audio processor. The processing strengthens the significant and weakens the irrelevant. But one can only speculate ad nauseam how the audio processor tells significant from irrelevant. I met a renowned violinist found him listening obviously enchanted to an original Caruso recording. While i heard all the crackling noise, the resonances, distortion, he heard only the divine voice, the rest was insignificant to him.
In a technical respect I think a big step forward is a methodical. Turn to systems theory.
Amplifier and speaker is not two objects, it is one system ( a system is a quite different type of object). Next is the one system amp speaker listening room.
I agree, Hahfran, the brain is a magnificient multi core processor running at a few hunfdred teraherz, and the way it works puts to shame many of our feeble attempts.
The encouraging part is that some do get it right, proving it can be done.
Being a student of the systems theory myself since my student days (early 70ies), it has taken me around 35 years to arrive at a true SYSTEM, where the electronics, the speakers, the room and I are one. With just one difference, I actually use two stereo amps. i.e. I am biamping.
The "psucho-acoustics" you refer to, while in general terms is similar for most of us, in personal terms varies with one's tastes and one's hearing habits. When I like a musical piece, I can easily overlook the small wrinkles and odd sounds which should not be there for the benefit of the whole; for example, the squeaking of the kick drum pedal in the "Sky Pilot" song by the Animals, circa 1968. The Ascoustics were not good, but the song is wonderful, so it doesn't really bother me. In short, I prefer to listen to the music rather than the technology.
I have also encountered the effect you speak of, when a professional musician simply filters out the disturbances and anomalies to listen to the essence of the musical piece as he understands it.
The encouraging part is that some do get it right, proving it can be done.
Being a student of the systems theory myself since my student days (early 70ies), it has taken me around 35 years to arrive at a true SYSTEM, where the electronics, the speakers, the room and I are one. With just one difference, I actually use two stereo amps. i.e. I am biamping.
The "psucho-acoustics" you refer to, while in general terms is similar for most of us, in personal terms varies with one's tastes and one's hearing habits. When I like a musical piece, I can easily overlook the small wrinkles and odd sounds which should not be there for the benefit of the whole; for example, the squeaking of the kick drum pedal in the "Sky Pilot" song by the Animals, circa 1968. The Ascoustics were not good, but the song is wonderful, so it doesn't really bother me. In short, I prefer to listen to the music rather than the technology.
I have also encountered the effect you speak of, when a professional musician simply filters out the disturbances and anomalies to listen to the essence of the musical piece as he understands it.
The Caruso recording is a very good example of how the "best" sound is extracted via an audio system and the brain's DSP processor - and IME the key is reducing the impact of low level, disturbing distortion artifacts. The latter are apparently much harder for the brain to process and filter out, perhaps because they are less "predictable" ... I listen to that Caruso recording on an "ordinary" system and the recording defects are overwhelming, they overpower my ability to "tune" into the musical content - it's a disaster. Yet, put that very same recording on a setup in a very high state of tune - and the subjective experience is transformed - the voice emerges, huge in its power and richness, and all the surface noise, etc, "disappears" from my focus - it "doesn't matter". In easily measurable terms very little has changed, but the presentation has been altered enough by eliminating the extra distortion injected from the playback chain - and my hearing can "reach through" the recording issues ... and the original musical event rises up, and now completely dominates the soundscape, subjectively.
I've done this many, many times - running the system at close to maximum volume, with amazing impact from these "ancient" recordings ... it's been a real pleasure to achieve this playback quality, because of what one can experience from any recording one chooses to put on.
I've done this many, many times - running the system at close to maximum volume, with amazing impact from these "ancient" recordings ... it's been a real pleasure to achieve this playback quality, because of what one can experience from any recording one chooses to put on.
Agreed, Frank. I did that with a wonderful recording from the early 60ies, in mono, of Harry Belafonte singing in an acoustically great church, accompanied by an "orchestra" of 64 male and female voices, religious music only. Just turn it up to realistic levels and all your troubles fade out and you're left with an excellent recording of emotionally engaging music. It takes you away somewhere else.
A joy to listent to, truly. And you never really notice it's in mono.
A joy to listent to, truly. And you never really notice it's in mono.
There is no objective world "out there". The "objective " issues noise, distortion etc. have been demonstrated in numerous psychological experiments to have a more culturally tainted impression. Some ethnicities appeared as almost noise-immune but highly timing-sensitive, for example. Others are turned down by any noise but don't give anything on timing. The problem is, the totality of "apparatus" , from sound field recording to sound field reproduction, must be considered as objective, that is, measurable.
But this appears as impossible. Sound recording engineers have personal likes and dislikes as well in terms of microphone positioning. Some use just 2 microphones, others place a mic for every instrument. The result is the very same performance sounds entirely different.
Certainly, the playback volume has a huge impact on the auditive impression. That is perhaps the only excuse for thd at max power measurements.
But this appears as impossible. Sound recording engineers have personal likes and dislikes as well in terms of microphone positioning. Some use just 2 microphones, others place a mic for every instrument. The result is the very same performance sounds entirely different.
Certainly, the playback volume has a huge impact on the auditive impression. That is perhaps the only excuse for thd at max power measurements.
We have three major concert halls in Oxford and many other good ones. The Town hall my unfavourite. I use to work as recording engineer there. Over many years I learned to hear through it. My recordings sounded better than the building. Easy to explain and not worth the effort. I conclude the Sheldonian to be the ideal Beethoven venue. I have never heard hi fi able to do that. There is a magic about Beethoven that sometimes 78's captured. Doubtless as the options were limited. My own hi fi can get close. The Disney Fantasia hints at it.
Last night Colleen wanted a Beatles evening, she had worked a shift! The system will run 10/10 as the DL 110 is 1.6 mV and the amp 2 mV. 10/10 it was. Colleen said she had been to a David Bowie concert and had never heard him sound so unforced ( It was slipped in whilst I looked for more Beatles ). Without any help from me she is getting there, she has her own version of hi fi speak. She loves the Denon DL110. As I said I don't dare use my Lyra and it wouldn't suit anyway. That way Collleen on her well deserved second bottle of Champagne and then Aussie Reisling can change records without me cringing.
Why we don't hear some distortions ? My opinion is we hear them in good concert halls. My system is for classical music and without doubt tilts that way. It plays rock very well and Acid House which makes it best of all worlds. My experimental OB speaker did it better. Mostly because it was faster. I must finish them. My main speakers have less distortion than some amplifers. The OB's more. The OB mostly shows polar distortion as one that I can hear.
Colleen bought me some Sennheisser HD219 closed back phones. They had a remarkably short run in time . No extended HF for 15 minutes!. They would never be my choice ( and I am wrong ). The bonkers thing is they are exactly right. I have no idea what they cost but would say $100 would be fair. The daft thing is they turn my basic Nokia phone into a real performer. Even the ear damage warning is about right! I do have some Stax that don't float my boat.
Last night Colleen wanted a Beatles evening, she had worked a shift! The system will run 10/10 as the DL 110 is 1.6 mV and the amp 2 mV. 10/10 it was. Colleen said she had been to a David Bowie concert and had never heard him sound so unforced ( It was slipped in whilst I looked for more Beatles ). Without any help from me she is getting there, she has her own version of hi fi speak. She loves the Denon DL110. As I said I don't dare use my Lyra and it wouldn't suit anyway. That way Collleen on her well deserved second bottle of Champagne and then Aussie Reisling can change records without me cringing.
Why we don't hear some distortions ? My opinion is we hear them in good concert halls. My system is for classical music and without doubt tilts that way. It plays rock very well and Acid House which makes it best of all worlds. My experimental OB speaker did it better. Mostly because it was faster. I must finish them. My main speakers have less distortion than some amplifers. The OB's more. The OB mostly shows polar distortion as one that I can hear.
Colleen bought me some Sennheisser HD219 closed back phones. They had a remarkably short run in time . No extended HF for 15 minutes!. They would never be my choice ( and I am wrong ). The bonkers thing is they are exactly right. I have no idea what they cost but would say $100 would be fair. The daft thing is they turn my basic Nokia phone into a real performer. Even the ear damage warning is about right! I do have some Stax that don't float my boat.
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@Hahfran, in all truth, I am beyond that kind of argument. I don't know whether objective even exists, however I do know what sounds good and "right" to me. I know it due to two factors: 1) my experience with live music, even if in some cases the acoustics of the place was terrible, and 2) my own feelings. Simply put, if I listen to something, it either sounds "right", meaning that it allows me to dive into the music and forget everything else, or it doesn't. If it doesn't, I don't comment on it because I know how sensitive people can be regarding their own hearing and their systems, so I can't very well say: "Your system is very poor because your hearing is very poor". No need to insult anyone.
I just stick to my own system, which I believe is much better than it was paid for, although I have invested a lot of time and some good money in maintaining it to keep it in full shape and let it do its job. The closest I can come to describing my taste would be to say I prefer an unbiased, undistorted and uncompressed studio monitoring sound. If the recording is good, I should hear it, if it's bad, I should also hear that and then decide is the music important enough to me to keep it anyway. The key here is my DECISION based on my system capabilities, which obviously assumes that even if faults can be found, the quality of music will outweight the down side.
I do not claim this is any great wisdom, much less a universal truth carved in stone, that's simply my way of doing it. It works for me. It may also work for others (for example, I have a strong suspicion Frank and I would need like 10 seconds to agree over most issues, while say Nigel and I have no issues), but not necessarily so. A good friend, with a good hearing, who owns a pair of Elac speakers, was disappointed in my speakers; I on the other hand found his speakers to be too bright, I think it goes like +3...5 dB in the 2...10 kHz range, a fairly common event with many otherwise very good German made speakers.
Ultimately, let's not lose sight of the real goal of our beloced hobby, which is to please US. That's all that matters, who do I care what somenody else thinks about my system or I of his, both are here to please US.
I just stick to my own system, which I believe is much better than it was paid for, although I have invested a lot of time and some good money in maintaining it to keep it in full shape and let it do its job. The closest I can come to describing my taste would be to say I prefer an unbiased, undistorted and uncompressed studio monitoring sound. If the recording is good, I should hear it, if it's bad, I should also hear that and then decide is the music important enough to me to keep it anyway. The key here is my DECISION based on my system capabilities, which obviously assumes that even if faults can be found, the quality of music will outweight the down side.
I do not claim this is any great wisdom, much less a universal truth carved in stone, that's simply my way of doing it. It works for me. It may also work for others (for example, I have a strong suspicion Frank and I would need like 10 seconds to agree over most issues, while say Nigel and I have no issues), but not necessarily so. A good friend, with a good hearing, who owns a pair of Elac speakers, was disappointed in my speakers; I on the other hand found his speakers to be too bright, I think it goes like +3...5 dB in the 2...10 kHz range, a fairly common event with many otherwise very good German made speakers.
Ultimately, let's not lose sight of the real goal of our beloced hobby, which is to please US. That's all that matters, who do I care what somenody else thinks about my system or I of his, both are here to please US.
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Nige, through a series of events beyond my control, all my audio life I have been blessed with Sennheiser phones, rebadged as "Uher" on the first sample. While developing my headphone amps, I bought Koss, Grado and Sony cans as well. Suffice it to say that today I still wear Sennheiser can, in my version HD 598 (locally cost around €280 or so).
Most Sennheisers lack conviction with very deep bass, but they do ambience much better than most, and never ever misbehave. And unlike a lot of other cans, they do not fake the top end, they don't have to because they really have it.
So, just sit back, enjoy the music and smile.
Most Sennheisers lack conviction with very deep bass, but they do ambience much better than most, and never ever misbehave. And unlike a lot of other cans, they do not fake the top end, they don't have to because they really have it.
So, just sit back, enjoy the music and smile.
Something about the system. After some lean years I was left with things I would not sell or thought I would have to give away. Linn LP12 Ekos Lyra Helikon ( or Ortofon M25 calibration ). Quad 33/303/FM3 and Magneplanar SMGa. This would be like an arranged marriage and not a love match. The Quad was in my kitchen with Mission 760 speakers. It was like using a Bentley as a shopping car. The LP12 unloved and lived in the loft for > 10 years. The Lyra was from my Garrard 401.
For many years I gave advice to people. Many Oxford people get their hi fi very badly wrong. A friend buys a new one and they learn they need something better. This is where life becomes difficult as these people are not turned on by what others have. What I did was work out where the weaknesses were and cure them. This would never be ideal. I would work better. The worse thing is these people often are music experts.
What I did here is the same for myself as them. That is surprisingly hard. The strange thing is the system has great strengths ( very great ). As an attempt to be a professional I have won far more than I hoped for. I simply looked for problems mathamatically and never allow them to happen. The Quad is a binary device. It works or it doesn't. Usually the latter. The Quad 57's are a tougher load than the SMGa so it always was possible. The 33 in some ways it like a less advanced transitor radio.
The 33 is a dreadful thing. The Denon will not show that. Did anyone every use the S1 board to build an ideal PU stage? I am tempted as it is spare and why not.
There was a young lad I knew who had a Morris Marina car that looked standard. The Marina a big joke. This lad was the local car expert. This car would eat BMW's for breakfast. He mostly had it to be invisible to the Police. My idea is to take a spare 303 or clone and beef it up in his style. I do build my own things. For some reason I like to use the Quad. I think mostly as it is an antihero .
For many years I gave advice to people. Many Oxford people get their hi fi very badly wrong. A friend buys a new one and they learn they need something better. This is where life becomes difficult as these people are not turned on by what others have. What I did was work out where the weaknesses were and cure them. This would never be ideal. I would work better. The worse thing is these people often are music experts.
What I did here is the same for myself as them. That is surprisingly hard. The strange thing is the system has great strengths ( very great ). As an attempt to be a professional I have won far more than I hoped for. I simply looked for problems mathamatically and never allow them to happen. The Quad is a binary device. It works or it doesn't. Usually the latter. The Quad 57's are a tougher load than the SMGa so it always was possible. The 33 in some ways it like a less advanced transitor radio.
The 33 is a dreadful thing. The Denon will not show that. Did anyone every use the S1 board to build an ideal PU stage? I am tempted as it is spare and why not.
There was a young lad I knew who had a Morris Marina car that looked standard. The Marina a big joke. This lad was the local car expert. This car would eat BMW's for breakfast. He mostly had it to be invisible to the Police. My idea is to take a spare 303 or clone and beef it up in his style. I do build my own things. For some reason I like to use the Quad. I think mostly as it is an antihero .
Another "psycho-acoustic" experiment I participated: a musician was recorded playing a violin solo, and another musician a saxophone solo, first in an assumedly acoustically perfect studio, and next, outside, in a noisy market place, the latter in Perugia, Italy.
The recordings were played to a group of about 20 students of psychology they were asked to rate such as "touching " "impressive" "interesting" "mediocre" etc. without any rationale, or substantiation. First impression, so to speak. The majority rated the recordings taken at the market place as "touching" "impressive" while the studio takes ranged from impressive to interesting to mediocre. Recordings taken outside tend to sound dull because the environment is anechoic. Possibly the said brain audio processor takes it as a challenge to sync with the music and suppress the noise. Imaging methods of brain activities may demonstrate how that could be so. One might assume the brain runs a maximum activity when into solving a difficult abstract problem. Not so. Actually, the brains of 2 musicians playing a fully improvisated tune - out of nowhere- run at full force all areas maximally activated. One has eventually to acknowledge humans are first of all social animals , and just not individualists.
The recordings were played to a group of about 20 students of psychology they were asked to rate such as "touching " "impressive" "interesting" "mediocre" etc. without any rationale, or substantiation. First impression, so to speak. The majority rated the recordings taken at the market place as "touching" "impressive" while the studio takes ranged from impressive to interesting to mediocre. Recordings taken outside tend to sound dull because the environment is anechoic. Possibly the said brain audio processor takes it as a challenge to sync with the music and suppress the noise. Imaging methods of brain activities may demonstrate how that could be so. One might assume the brain runs a maximum activity when into solving a difficult abstract problem. Not so. Actually, the brains of 2 musicians playing a fully improvisated tune - out of nowhere- run at full force all areas maximally activated. One has eventually to acknowledge humans are first of all social animals , and just not individualists.
The other day I said I might like to tweek the DL 110 into the Quad 33 / 303 . I have it so 8 out of 10 will clip the amp on typical stuff now. It took ages to figure it out and ten minutes to do. Dejan. Enya sounds great now.
If you want to read more the link below. No one at Quad showed this interest. I wish I had worked there. I got on very well with them. It was my natural home. I even had my meals there. Geoff Popple was great. Also Ray Churchouse. Never met Mr Walker although saw him many times at shows. His son was very nice when I spoke to him. Mr McDowell ( ? ) also.
http://www.diyaudio.com/forums/anal...so-good-my-entry-level-phono.html#post4164314
If you want to read more the link below. No one at Quad showed this interest. I wish I had worked there. I got on very well with them. It was my natural home. I even had my meals there. Geoff Popple was great. Also Ray Churchouse. Never met Mr Walker although saw him many times at shows. His son was very nice when I spoke to him. Mr McDowell ( ? ) also.
http://www.diyaudio.com/forums/anal...so-good-my-entry-level-phono.html#post4164314
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