That's the only issue I can see/hear with Cdom. Otherwise it is the best weapon of any available techniques.
If you are disturbed by the Miller compensation cap Nigel, don't forget the 30 pF varactor hiding in the ZTX753 - it probably adds to niceness too. Anyway, I thought you were satisfied with your NAP250's SQ. Is that satisfied but still curious?
BTW. Whilst this is a jump to say the next bit it is worth saying.
If a pipe organ has the pipes below 40Hz it is almost impossible to hear them when in the Organists chair. However not playing these pipes spoils the sound. Less depth, less midband depth, less sweet, and far less volume. Play these pipes slightly out off time to loss all of that. The volume is the weirdes bit as that's how the volume builds or often doesn't. In a way an amplifier might do things like this.
If a pipe organ has the pipes below 40Hz it is almost impossible to hear them when in the Organists chair. However not playing these pipes spoils the sound. Less depth, less midband depth, less sweet, and far less volume. Play these pipes slightly out off time to loss all of that. The volume is the weirdes bit as that's how the volume builds or often doesn't. In a way an amplifier might do things like this.
Magic or Science
I think it might help if we had a professor with a strong knowledge of acoustics on this forum. They might be able to take some of the "magic" out of the equation. It might also help if they had a good interest in music and hi-fi. Can any of us put out feelers?
I think it might help if we had a professor with a strong knowledge of acoustics on this forum. They might be able to take some of the "magic" out of the equation. It might also help if they had a good interest in music and hi-fi. Can any of us put out feelers?
It's a great bargain. I have one. Simple legit hack and it becomes a 100MHz scope with a lot of extra fruit.
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I was referring to the pic included in Bigun's contribution #3. We clearly see four 10 MHz BDY56's in this NAP110.
Totally agreed!
Best regards!
Music is the magic that gets left out. I know a few PHD's who mostly are confident what they know is the " right stuff ". Seldom is it more than common sense. I always remember a friend saying E=MC^2 almost has 10^17 in it. What more is there to know.
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I don't think it's that simple. Cdom doesn't just load the LTP - as others have pointed out, non-linear capacitance of the VAS device will have an impact and in the NAP 140/160 this is much higher than other amplifiers I've built. I've found Cdom to have a strong influence on the sound signature. fyi - other 'weapons' you should include that are available to help stability include power-rail decoupling, pcb-layout, bas-stoppers, output-inductors....
there are professors who will say that properly engineered amplifiers all sound the same.
It's amazing how our opinions can be different, with large areas of overlap at times, but still different.
A couple of thoughts:
a) If we insist on making a clone of the NAP 140/160 then in the strictest sense this means using NOS parts, identical layout, chassis, wiring etc. etc. But to what end - it's way easier and cheaper to go out and buy an original Naim amplifier, they're not that rare. As soon as you deviate from an exact clone there will be folk who insist it's not good enough, either because the parts are not the same, pcb layout is different, the quality of mains in the wall-socket is different, speakers are not from that era etc. etc. And you don't learn much, it isn't sufficiently challenging for me. As a result, I've never built clones.
b) You'll notice my projects are 'inspired by' or 'based on' and I use modern pcb layout and components where it suits me. The fun is getting inside the head of the original designer, which we've tried hard to do on this thread. And learning about a new amplifier topology (I use Spice to help with this process). It's also an opportunity to try and understand what elements (topology, parts) are important for achieving the 'sound'. We can't ask JV but I don't think many designers necessarily understood all the key elements at the time of the design and filled in some of the gaps later, perhaps embellishing along the way, or even confusing things as ideas change over time or to protect IP or to create an aura of mystery around the brand. So there is a danger of over-analyzing and drawing the wrong conclusions from thinking you know what JV was about and what he wasn't.
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🙄 A vague statement from these profs at best. What does "properly engineered" mean? What does "all sound the same" mean? I suppose if you are an old enough professor everything will sound the same.
All I know is that the top few amps in the world (by price and reputation) that I have heard do not sound the same to me. So either the statement isn't true or none of those top amps are properly engineered or I have erratic hearing.
Really, it is a nonsense remark because it is basically saying if everything sounds the same it will sound the same. Give that person tenure. 😀
Please do tell us what JV was trying to achieve.
Please also tell us why Bigun's tgm10 fails to achieve JV's objective.
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Sure it does a few things. Why it has a bad rap is because it adds extra load. For other things it does good things. How big a load is too big? You need to define a threshold like Nigel when he said that higher than 39p could be too high (for a given cct).
For me, I dont really care with threzhold with Cdom because I can always get away with much smaller or even nothing at all.
Sure they are ones of them. Each of them has tricks to use it. But they present different problems as they solve different problems. The output inductor for example, just like zobel, works more with external than internal like Cdom.
I said i guess JV knew what i know. I will find out once i studied his ccts, but with the available proofs/info im quite sure he did.
I dare to say this: if his design is not like i thought it is, then it is impossible his design achieve such "popularity". And i need to learn more.
If my prediction is correct im going to say this: i dont believe most people, including Naim owners know the real charateristics of Naim amps. Change the power supply, the cap type, the preamp, or better do it blind, they wouldnt know which one is Naim at all.
Why i said that? Sound has different facets. If we change one variable, the sound will change. But do we know which variable affecting which? This one specific variable im talking about is hard to digest by ears. You need to live with it for sometime and you will gain the perception of how musical it is, how harmonious, etc. And how not fatiguing, unless your ears are very sensitive to distortions as found in most class-A and tube amps (which most people find is not disturbing at all).
No. I have never underestimated veterans who dont know what we know today. For me, what they know often is more important than what self wrote in his book (Using him as analogy). Different sets of knowledge, that is.
I strongly believe Nigel was right when he said that theres nothing a (real) commercial designers can learn from internet forums like this. How can i know that? By studying their works i know what they know that have never been discussed on the net.
So yes, i believe that there are secrets that each designer wont just expose easily. Its a competition afterall. And i believe that if you ask JV (if he were member of this forum) he wont give you the answer. But keeping the secret for himself is also impossible because he didnt work alone producing his amps. He needs to work with his employees. But the fact that some audio secrets (not just this one) have never been explained at least explicitly, tells me that people do hold secrets in audio.
I dont know exactly what JV was trying to achieve. I have never studied his amplifiers. All great amplifiers (unfortunately not everyone has the ears to differentiate the great from the good, if it is not subjective at all) have this characteristic (sorry not all, only those with negative feedback) and TGM10 doesnt have it. Im not going to disclose my own secrets but you can always connect the dots when you see it mentioned (Such as why it must relate to nfb).
No it doesnt have to be like that. Actually, what will you learn by copying like that??
Yes. It is possible like that. You must outperform him in order for that not to happen. The sound is a product of several variables or call it secrets. You can possibly unleased the main secrets and outperform him in the rest. For example, if you know better than him regarding power supply sound, you can easily make a better power supply! And your clone will sound better!
Theres trick with pcb layout too. But imo if you make the whole pcb small, this will be achieved automatically.
I believe youre wrong. It could be more challenging than you think. Here is a why (clue):
Measurement tools will show you results, simulation tools will show you the process (to achieve the results). And wise men said: you can focus on the process and result wont betray you.
Rigol Scopes (Slightly off-topic)
I use a Rigol DS1052E at home and for work debugging DSP and audio. Good 50 MHz, dual channel scope. Find it great for recording waveforms to USB stick for documentation purposes. Easy to use.
Recommend you check out if you can purchase from a local supplier who can support warranty and repair (In Melb OZ it's Emona).
What sort of bench drill did you buy? Is it suitable for drilling heat sinks and PCBs as well😕?
I use a Rigol DS1052E at home and for work debugging DSP and audio. Good 50 MHz, dual channel scope. Find it great for recording waveforms to USB stick for documentation purposes. Easy to use.
Recommend you check out if you can purchase from a local supplier who can support warranty and repair (In Melb OZ it's Emona).
What sort of bench drill did you buy? Is it suitable for drilling heat sinks and PCBs as well😕?
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