I ment if a designer is convinced that he has find a way to improve the sound of his current design, he could choose the implement this designchange in all his new products and mark them as Series II or Mk 2 or .5 or .6 or .8.
He even could offer to his current clientele an update to the latest version.
I ment if a designer is convinced that he has find a way to improve the sound of his current design, he could choose the implement this designchange in all his new products and mark them as Series II or Mk 2 or .5 or .6 or .8.
He even could offer to his current clientele an update to the latest version.
I do believe that firms as Mark levinson, Threshold and PassLabs really are interested to bring their latest incarnations to clients that alraedy have invested heavily in their current designs. Call me naive.
There are couple issues you are juggling here. One, a designer can be convinced in many different ways. Easy one is self convincing, i.e. getting up one day and saying to himself, "Yup, I'm convinced that this design is better." Is that the kind of convincing you are talking about? Two, what kind of listening method does a designer use to figure out if the sound is improved or not?
Business 101, even if you have a good quality, start at lower version, then one by one, release the next up version so that your cash flow is extended. Or start at good quality but one by one, market other circuits as "better" along with some credible looking testimonies from so called users and extend the cash flow as far as you can.
As a kid, did you ever send away for Sea-Monkeys?😉
https://theawl.com/the-shocking-tru...-invented-sea-monkeys-9105de87d446#.6vu2xwvjp
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My kids raised Sea Monkeys for almost 6 months. They were pretty easy to keep alive as long as you feed them. Fish food worked fine when the provided food ran out. The biggest problem was changing their water to keep it clean. We would replace about 25% each week.
I´ve just bought an old Krell KSA-100 Mk2 and I'm currently reading a long thread started by Mark A. Gulbrandsen (arrived at page 135) about kloning this amp.
http://www.diyaudio.com/forums/solid-state/78129-krell-ksa-100mkii-clone.html
There was one before this that dealed with kloning a Krell KSA-50.
The kloningprocess mainly dealt with kloning the mainboard with the intput stage and the drivers on it. http://www.diyaudio.com/forums/attachment.php?attachmentid=598996&stc=1&d=1486976881
So I'm not implying 'only' but 'mainly'. The other items like the powersupply, chassis, cooling were of less importance and were discussed mainly to have them in a Group Buy or everbody for himself.
I deduce that this mainbooard, the layout of it, the kind of components selected is the central issue. Output transistors were discussed also if to use to original MJE 15003/15004 TO3's or the faster and having a better SOA: MJ(L)21194/3 or even another Sanken or Toshiba O.T.
I do understand that for a poweramplfier the PSU is important especially when you're designing an almost perdect voltagesource as the Krell, but I do find sustaining evidence that the mainboard (called it the frontend in this thread) is the most important item that contributes the most to sound of the amplifier.
http://www.diyaudio.com/forums/solid-state/78129-krell-ksa-100mkii-clone.html
There was one before this that dealed with kloning a Krell KSA-50.
The kloningprocess mainly dealt with kloning the mainboard with the intput stage and the drivers on it. http://www.diyaudio.com/forums/attachment.php?attachmentid=598996&stc=1&d=1486976881
So I'm not implying 'only' but 'mainly'. The other items like the powersupply, chassis, cooling were of less importance and were discussed mainly to have them in a Group Buy or everbody for himself.
I deduce that this mainbooard, the layout of it, the kind of components selected is the central issue. Output transistors were discussed also if to use to original MJE 15003/15004 TO3's or the faster and having a better SOA: MJ(L)21194/3 or even another Sanken or Toshiba O.T.
I do understand that for a poweramplfier the PSU is important especially when you're designing an almost perdect voltagesource as the Krell, but I do find sustaining evidence that the mainboard (called it the frontend in this thread) is the most important item that contributes the most to sound of the amplifier.
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IMHO, yes you do. And not just you. You seems to be a logical person so see the logic behind my statements.
Audio is not like food. What we perceive is (almost) 100% correlated with known Physics. You can be presented with a schematic (and a simulator) and WILL understand how it would sound provided that (a) You know the correlation between the numbers output by the simulator with perception (b) The models used by simulator have taken into account the properties of the real parts. It has not 100%, in which case you need to understand the consequences and the right engineering judgement.
So, (a) and (b), how much have you missed from any of the two? Part (b) is easy. You need to be intelligent and invest your time to study the subject. Part (a) OTOH, is very far from sufficient. What is the point saying that amp A is better than amp B if people cannot reliably tell them apart in a blind test??? (Think about this.) A long way to go for amp designers!
Your last post. Echoes your first hypothesis about the front-end importance.
We both understand that everything matters. So, where is the bottleneck? The bottleneck will logically be in the part where it is (a) difficult to design (b) expensive to design. Is the front-end expensive? No. Is it harder to design properly? I think not either. You only need a good impedance matching in input and output, the rest is about noise and power supply.
But the point I want to stress is within my previous statement. You can see everything in the simulation. No magic. Just simulate. For example, if you want to see the effect of a preamp, just simulate, it will be shown. You can always see (and hear) that there will be more distortion, there will be more noise. But the benefits are there too, sometimes.
The preamp can act as an effect box. It can add body or bloom, but when there's no issue with impedance matching (when the preamp is not there), it will only add more distortion and noise. Fortunately, the distortion and noise is so low that only a few people will reject it.
Perceived sound quality has many variables and aspects. You can improve in one, but miss the other aspects. You can happily sacrifice 5 degrees of phase margin for the sake of 0.005% THD, only if you understand the consequence of such decision. And if you do, then we have no problem with part (a) above, which is to understand the correlation between simulator's output and perceived sound quality.
In the DIYaudio threads were the Krell KSA-50 & 100 are cloned in my opinion.
The main issue here is the kloning of the Krell Audioboards not the Outputsection, the PSU or any other functional entity of the amp. The blueprint to clone is that board not another item. Again, a good amplifier is the sum of its parts but the thinking, the designing, the heart or the brain as you wish is the audio-board, that's what defines the character of the amp. Why would want to klone just this part it anyway as DIY?
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Of course. That means that ALL these parts have their impact on the final result.
Can you come up with any reason why this would be so, except 'this is what I think'?
Most people do understand that the output section is the one that determines most of the character because there is where the large voltages and currents are occurring which have a large impact on distortion spectrum, damping factor, transient response and so on. Also, the power supply has a lot of impact. In comparison, the input board is almost irrelevant.
Jan
When one considers that in almost all amplifier designs the output devices are straight across the power rails driven by the previous stages it seems self evident they would have the most bearing on the output
I have two amps in my possession (Levinson ML-2 & Conrad Johnson Premier Five) that were the debated in the eighties when one of the most brilliant designers Robert W. Carver tried to copy the by means of his transfer function duplication by a technique called 'null difference testing'. If the output of two 180 degrees out of phase speakers, one connected to the ML-2 or Premier Five and one connected to the Carver experimental amp and the signal and hence the sound nullifies, the amps have the exact same characteristics, sound the same. There were two audio periodicals that challenged Bob Carver to build a relatively chaep amp that could mimic the very expensive ones that were seen as references in that era. Audiocritic supplied the Levinson ML-2 and Stereophile the Premier Five.
In a blind AB test in both cases there was no significant result that people from listening panels could identify an amp positively.
Carver even stated that his M1.xt amplifiers had more power, generated far less heat etc... and cost only a fraction $ 400,00 instead of $ 6,000,00 for a pair of ML-2's or Premier Fives. So from your perspective, the perspective of logic reasoning, the discussion simply ends here, am I right?
It's a really tough subject and has been discussed many times. Broadly speaking there are two schools here: 1. the objective stand and 2. the subjective stand. The American 'Audio' magazine (doesn't exist anymore I believe) tended to emphasize schematics and measurements of equipment and belonged primarly to the first category. Stereophile and The Absolute Sound started both with subjective reviewing and emphasized the sound of the equipment. I still have TAS number 1 and I remember Harry Pearson was very impressed by the Phase Linear 700 from Bob Carver.
Another review I remember well was from my CJ Premier Fives by Bascom H. King of Audio (August 1986) where he concluded: "I wish I could quantify why the Premier Fives sound so good, but I can't. So I turn of my rational side and just enjoy the music"
I like to read reviews with great graphs and tables with numbers, I really do but when it comes to judge a design I trust my ears in in that sense I belong to the second school.
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"Most people do understand" that's a subjective way of reasoning. As said I'm not an technician but a knowledge engineer. Through deduction I reasoned that the most important part of an amplifier is it frontend board. Your remark that the inputboard is almost irrelevant can't be proofed either (I suspect many people will refute this), so why do you expect me to deliver "proof" of my hypothesis?
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