Here are the results of the more conventional feedback. Gain is about 1 V2 to output. Not fantastic really. I have a better use of the PSU which still will let you down. I wish I had used noise averaging, I forgot. Remember my final amp is better on all counts and used two valves.
Thought I couldn't talk about the RH34/88 amp types without showing my results. 560R for EL34, here it is shunted to give 400 R .
It seems that you aren't familiar with the goings on internet audio forums. One poster who has displayed through his posts, his lack of familiarity on the subject, start "talking" as if he knows what he is talking about, should be tamped down. Since this isn't the face-to-face interaction, the method of tamping down will differ from that of face-to-face. Otherwise they keep on going with their ignorance and before you know it, the site gets filled with misinformation. I've seen those sites and they are ugly. Also, they become useless for those seeking useful info on audio.
Some guys take tech talk with emotion and the result is such, unfortunately.
Just i wonder about the most and most frequent position of more and more people about so calling "science".
It seems that more and more people have lost the most elementary bases : Doubt and skepticism, the spirit of curiosity, observations and attempts to find good explanations... ad solutions. And modesty.
They consider our poor partial knowledge we have at this time of the physical laws as a dogma ?
I feel sometimes that we are back to the times of the Inquisition .
And, what when it is not about science, but only technology ... like electronic for Hifi... So strange...
It seems that more and more people have lost the most elementary bases : Doubt and skepticism, the spirit of curiosity, observations and attempts to find good explanations... ad solutions. And modesty.
They consider our poor partial knowledge we have at this time of the physical laws as a dogma ?
I feel sometimes that we are back to the times of the Inquisition .
And, what when it is not about science, but only technology ... like electronic for Hifi... So strange...
It won't be so strange after this video. https://www.youtube.com/watch?v=BYTlN6wjcvQ
Tracy Chapman
For more extensive evaluations the source material could be more varied, the tests longer. One departed engineer who steadfastly refused to participate in DBT was told he could do it his way, take as long as he wanted, select his program material --- but just had to adhere to the no-peeking protocols. He still refused to go near any of it.
But for all the testing that has been done to date at Harman of which I'm aware, there has been very little nonlinear distortion focus, and very little work on anything other than loudspeakers, and their interaction with rooms. And of course the correlation with anechoic measurements.
There have been some interesting studies on the effects of sighted listening, which tests almost inevitably favor the more imposing and attractive speakers. A funny side-effect result that audio writers almost always get wrong is that listeners drawn from Harman staff naturally favor Harman products, which is almost always untrue --- particularly if they are smaller speakers, they tend to be rated much lower when they can be seen. There is if anything the opposite of in-house brand loyalty.
And even the people designing and running the tests are not immune to bias. I recall when a manufacturer of a desktop speaker that used a planar magnetic driver had Olive anticipating that it would do well in DBT, having auditioned it informally in a sighted demo before. EDIT It didn't do that well in DBT.
Of course there has been plenty of science on audibility of nonlinear distortion and other psychoacoustical phenomena done elsewhere. For some historical background listen to James Johnston's Heyser lecture from a few years back.
It was explained to me once why the Tracy Chapman excerpt for DBT was deemed suitable, and I think it was mostly due to the distribution of spectral content. That is in keeping with the notion that linear distortions, i.e. frequency responses departing from flatness, are the most important variables for loudspeaker evaluation, once you manage level matching.
For more extensive evaluations the source material could be more varied, the tests longer. One departed engineer who steadfastly refused to participate in DBT was told he could do it his way, take as long as he wanted, select his program material --- but just had to adhere to the no-peeking protocols. He still refused to go near any of it.
But for all the testing that has been done to date at Harman of which I'm aware, there has been very little nonlinear distortion focus, and very little work on anything other than loudspeakers, and their interaction with rooms. And of course the correlation with anechoic measurements.
There have been some interesting studies on the effects of sighted listening, which tests almost inevitably favor the more imposing and attractive speakers. A funny side-effect result that audio writers almost always get wrong is that listeners drawn from Harman staff naturally favor Harman products, which is almost always untrue --- particularly if they are smaller speakers, they tend to be rated much lower when they can be seen. There is if anything the opposite of in-house brand loyalty.
And even the people designing and running the tests are not immune to bias. I recall when a manufacturer of a desktop speaker that used a planar magnetic driver had Olive anticipating that it would do well in DBT, having auditioned it informally in a sighted demo before. EDIT It didn't do that well in DBT.
Of course there has been plenty of science on audibility of nonlinear distortion and other psychoacoustical phenomena done elsewhere. For some historical background listen to James Johnston's Heyser lecture from a few years back.
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I was actually referring ESPECIALLY to show demos. I used to visit some with a copy of Bluem Man group first audio CD, which is exceptionally dynamic throughout, and even has a point in numer 8 track which will give a wake up call to the biggest Krell behemoth around. It's ridiculous watching the salesmen's faces when that bit comes along and shows up their 5W SET amps and speakers to be wildly mismatched and sound ridiculozusly weak. This has spolit many a deal for funny money systems.
Decently made regular solid state power amps rated at 100W or so really come into their own in such cases, and wipe the floor with tube toys under regular listening conditions, not at ball breaking loudness evels. And if paired with relatively efficient speakers, say 92+ dB/1W/1m they can sound actually impressive.
One thing I have learnt being here is don't take anything too seriously, but do give it serious thought. Even if I don't think someone is right I read what they say and see where they are coming from. Often even though they say something that won't change how I do things it is logged as interesting and valid.
Where is Mr Wayne? That would complete our clan. Mr Wayne or 1000 watts into 1R minimum Wayne. Frank also, Happy New Year and Mr Waveborn.
https://www.youtube.com/watch?v=hnTmBjk-M0c
Where is Mr Wayne? That would complete our clan. Mr Wayne or 1000 watts into 1R minimum Wayne. Frank also, Happy New Year and Mr Waveborn.
https://www.youtube.com/watch?v=hnTmBjk-M0c
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Wayne has left us quite some time ago, I suspect not of his volition.
Frank has gone into hiding so to speak and does his own thing on his own, since he's satisfied with the results he achieves. We correspond off the forum.
History shows that Derrida's initiative failed and he eventually voluntarily left, his tail dangling between his legs.
Send my regards to Frank. I hope Mr Arnyk persists with us. I think he is mostly right about what he says. He probably is a bit angry with us because we like converstaion and allow a bit of liecence. I very often say things here I wouldn't say in day to day life. It is to get reactions and sometimes learn something. That is " right " taken as a whole. I have my own tastes and they seem to be to be my life's quest. I am not exactly like the herd. As you say Degan " Nige takes parts out until it stops working ". I also said once " I don't believe anything anyone says totally, not least if I said it ".
I would love a discussion on UL feedback when tubes. Seems to me it's triode connected with AC feedback pulling it back to pentode. I know the standard arguments. One that I was told a no-no is to put forward biased 1n4007 in the UL tap to g2. A Russian guy is convinced it works. He thinks speaker back EMF the reason. The EL 84 run at 315 V shouldn't find a cunning way to exceed 550V. I found UL without loop feedback really is a special thing. It would be interesting to know the real Rp of EL34/84 in pentode, triode and UL ( 43% seems ideal even for EL84 ).
My friend Janine has blown up her Krell and is using a Leak 20 ( EL 84 UL ). She prefers it. Somehow that isn't a surprise to me. Janine has perfect pitch and worked as a sound engineer at the BBC. I have some new high grade 84's she might have. One thing I will show her is a 100 R resistor to g2 when either triode or UL. Some will prefer triode for complex reasons. The simplest being better damping factor. The other being ringing is less likely. EL84 at 43% UL and 20 db feedback will have 0.07% distortion.
My interest in tubes/valves only started 5 years ago, we did do them at college. I never really wanted to know about them. My brother left me some half finished projects. I think I was a duck to water. I don't like them much in themselves. I like how the engineering goes. My larger surprise is how easy it is to get reliable results. If you do what lets say what Mullard say best it works. Some people put LED's in the cathode of a signal valve. Why would they do that. A resistor is better. The resistor will micro adjust the working point and keep that tube/valve working for many years with no real change in distortion if not asking too much current. Then use an LED and see what you get if an older tube.
I would love a discussion on UL feedback when tubes. Seems to me it's triode connected with AC feedback pulling it back to pentode. I know the standard arguments. One that I was told a no-no is to put forward biased 1n4007 in the UL tap to g2. A Russian guy is convinced it works. He thinks speaker back EMF the reason. The EL 84 run at 315 V shouldn't find a cunning way to exceed 550V. I found UL without loop feedback really is a special thing. It would be interesting to know the real Rp of EL34/84 in pentode, triode and UL ( 43% seems ideal even for EL84 ).
My friend Janine has blown up her Krell and is using a Leak 20 ( EL 84 UL ). She prefers it. Somehow that isn't a surprise to me. Janine has perfect pitch and worked as a sound engineer at the BBC. I have some new high grade 84's she might have. One thing I will show her is a 100 R resistor to g2 when either triode or UL. Some will prefer triode for complex reasons. The simplest being better damping factor. The other being ringing is less likely. EL84 at 43% UL and 20 db feedback will have 0.07% distortion.
My interest in tubes/valves only started 5 years ago, we did do them at college. I never really wanted to know about them. My brother left me some half finished projects. I think I was a duck to water. I don't like them much in themselves. I like how the engineering goes. My larger surprise is how easy it is to get reliable results. If you do what lets say what Mullard say best it works. Some people put LED's in the cathode of a signal valve. Why would they do that. A resistor is better. The resistor will micro adjust the working point and keep that tube/valve working for many years with no real change in distortion if not asking too much current. Then use an LED and see what you get if an older tube.
You know even aethists could have a conception of original sin just as the big bang is now a comfortable subject. Original sin is talking. We force others however reluctant to see the picture we paint. I believe " don't think of elephants " is suggested to show that. You can't.
When we write we stop any chance of a raised eye. That's when it gets interesting. Alas the worlds problems come when unwise talking is not allowed. I was brought up in and around Oxford. I thought it was the whole world. I had a shock. One thing I am very OK with is high flug ideas. You get imune in time. The really great brains in Oxford seem very humble people. Seems is the word. They have a mental gearbox they use. If somone offers an interesting converstion suddenly they are running at that speed. More interesting is how they drift back to street speed in seconds. None avoid having the weirdness true intellect brings. Many make it most attractive.
When we write we stop any chance of a raised eye. That's when it gets interesting. Alas the worlds problems come when unwise talking is not allowed. I was brought up in and around Oxford. I thought it was the whole world. I had a shock. One thing I am very OK with is high flug ideas. You get imune in time. The really great brains in Oxford seem very humble people. Seems is the word. They have a mental gearbox they use. If somone offers an interesting converstion suddenly they are running at that speed. More interesting is how they drift back to street speed in seconds. None avoid having the weirdness true intellect brings. Many make it most attractive.
Even I don't understand my posts, so why should anyone. My point is to see a bigger picture. Don't forget the hi fi is a snapshot at best. Time and place is distortion number one. The point I am trying to make is the ideal hi fi will be about 1% THD from microphone to ear. Better still it would be 0.1%. As it can not be that, it should have harmonics that fall exponetially or on a linear slope ( no idea which is best, instinct says exponential ). That would not be impossible to work out. 1% THD might have the third harmonic at - 56 dB. This to me implies a 56 dB dynamic range as I doubt the 2nd Harmonic at perhaps -42 dB is a reduction in range. I suspect >90% of expensive hi fi's don't get close. They usually have raised 3 rd and 5 th, or suppressed second. Now the big deal. suppressed second is a mistake and is a distortion. Many amps have that. Naim has a ciricuit to make it better balanced. Alas Naim is far from being the best it could be. It is only silly things wrong with it. One is that TID wasn't discussed in 1976. Naim almost certainly has TID if the NAP140/160. That is if pushed hard enough the crossover distortion happens up the wave like when a LM324 op amp. If one increased the long tail pair current to 5 mA and either degenerated the pair ( 39 R x 2 ) or added 10 R to the VAS emitter it should cure this. I favour the VAS emitter as it makes TID even less likely due to input impedance being raised. The degenertion will only be to maintain Nyquiste requirements. The I to V function of a VAS seems poorly understood. If a DAC it would be well understood ( oh yeah ).
Thanks Dan. Great to hear from you.
I will try. It's is honesty very often. I discovered how weird I am when not in Oxford. In Oxford I am hardly noticable. They made me worse I am sure. At Oxford University Press one can live a whole life without ever saying hello to anyone. Some we suspect don't go home at night. The boss of one section is the woman of my dreams. She seems totally normal. That's why she is always the one on TV. It can happen. I know her well and can say she puts on a good act. She is a brain on wonderful legs. She is not the slimest of ladies, mores the better.
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