I do both:
When DIY LM3886 EC-composite amp, low THD+N as possible is my goal. One kind of amp to litsen.
When DIY Pass' style amp, tube amp, SIT SED, the lowest THD+N is not my goal at all. Another kind of amps to litsen.
I am very happy with these two kinds of amps. They are fantastic to me.
When DIY LM3886 EC-composite amp, low THD+N as possible is my goal. One kind of amp to litsen.
When DIY Pass' style amp, tube amp, SIT SED, the lowest THD+N is not my goal at all. Another kind of amps to litsen.
I am very happy with these two kinds of amps. They are fantastic to me.
I value Nelson's simplistic approach to analog amplification. I think that's the true value right there: two gain stages, with the possibility of having the second gain stage working in theoretically best single-ended class a topology, a very short and direct signal path with no need for transformers or capacitors, and the possibility of having the first gain stage working as a differential input, allowing balanced signal transfer between source and amp. Can it get better than this?? He even explains ways to tune the distortion harmonic content, allowing people to get a suitable sound from the one and the same design.
... the distortion measurements then serve the purpose of learning what harmonic content and what distortion levels sound good to you. The measurements are merely a tool to tell you what's good for you as an individual.
I see many people falling through the cracks of becoming the slaves of the lowest possible THD + N....
I see many people falling through the cracks of becoming the slaves of the lowest possible THD + N....
^ You may want to check the published specs for the SIT-1, SIT-2, and SIT-4 at 1W into 8R.
For a a number of the First Watt amps, the distortion beyond 1W is beyond 0.5% THD.
Not that it's a bad thing... it just ... is.
Goes to show that it's different strokes for different folks (even the same designer).
For a a number of the First Watt amps, the distortion beyond 1W is beyond 0.5% THD.
Not that it's a bad thing... it just ... is.
Goes to show that it's different strokes for different folks (even the same designer).
Yeah, it just goes to show that a persistent search for the lowest possible THD&N simply doesn't work.... but learning what sounds good to you provides more possibilities when it comes to selecting an amp based on a solid and complete set of measurements. Subjectivism (what YOU like) can co-exist with the importance of a good spec sheet.
^ THIS.... a 1,000 times THIS!
I have a TON of fun making ridiculous attempts to learn if I can repeatedly discern A from B and if so, why?
Meh... who am I trying to kid. I just like building stuff.
Iamjf has a good point, it would be appreciated if you post db levels , % is illegible.
I am not talking about transistors output stages, I am talking about input stage.
Just read before typing.
very funny, you are talking about deemphasis. I am talking about the RIAA curve as it leaves the vinyl. You explained me nothing. You are completely incorrect.
I am not talking about transistors output stages, I am talking about input stage.
Just read before typing.
Seeking the lowest THD figures is a game or a pursuit for many. Looks great on paper, right?
Some of the most gawd awful sounding pieces I ever listened to were in the 0.000% and beyond THD department.
Some of them were popular threads or offerings on the DIYAUDIO forum.
It is a hobby so it is fun.
Don't forget your speakers can easily generate 3 to 5% distortion on a good day and a lot of speakers do not match their rooms or are placed in bad locations.
Some of the most gawd awful sounding pieces I ever listened to were in the 0.000% and beyond THD department.
Some of them were popular threads or offerings on the DIYAUDIO forum.
It is a hobby so it is fun.
Don't forget your speakers can easily generate 3 to 5% distortion on a good day and a lot of speakers do not match their rooms or are placed in bad locations.
Personal experience is everything, because one designer who spent all his life building amplifiers for a living has a personal experience doesn't mean that it is subjective then wrong.
Your logic can be reversed as it is written in my quote. It is the salesman who advocates higher power lower THD to sell you a 'better' amp. Which is totally unnecessary and is going to give you a poorer sound. When the customer has climbed the ladder of idiocy from 50, 100, 250, 500, 1500, 2500 watts and is totally abused, then the same salesman will offer a totally different approach with a 5% thd tube amp which sounds better than his 2500Watts class A.
This is something that intrigues me. Audio is a chain from source, amp and finally speaker, all summing THD.
If any chain link has high THD, all the chain will have high THD.
Speakers have THD around 0.5% (0.1 to 1% or more). So why insist in amp with 0.001% or even less?
We are fighting for 1/1000's in the amp while speakers are in the 1/10's.
"Why does the sun come up? Or are the stars just pin holes in the curtain of night, who knows? What I do know is that because you were born different, men will fear you........"
Juan Sánchez-Villalobos Ramírez
This has been explained many times. Speakers being mechanical systems don't tend to produce higher order harmonics, certainly not like an amplifier can do. Also, its still possible to hear amplifier distortion despite the distortion in typical speakers. Speakers may distort more at higher excursions, whereas amplifiers may have higher relative distortion at low power levels related always operating right around crossover in the output stage. And so on.
Moreover, some people use very low distortion ESL speakers. Even easier to hear amplifier distortion in that case.
It is fun to design or build many type of amplifier. Relative high distortion amplifier with H2 dominant or very low distortion at all audio frequency and all level before clipping.
Usually people who complaint about very low distortion amplifier are people who cannot design such thing or never use/build such thing.
Usually people who complaint about very low distortion amplifier are people who cannot design such thing or never use/build such thing.
I build amplifiers for a living too. They have extremely low THD. Now what?
Someone's opinion, even if it is an informed opinion, is by definition subjective.
Selling an amplifier because it's objectively as close to the mathematical definition of an amp, i.e., out = A * in, is a perfectly valid approach. You just happen to prefer an amp that adds a little something-something to the sound. That's your preference, which you are allowed to have.
An amp that has no distortion will not add anything to the signal. It will provide out = A*in.
Is this something you base on opinion or fact or are the two the same?
Tom
My 300B amp (0.2% THD) sounded fantastic on some music. Throw someting more complex at it and the something-something added by the THD doesn't sound so pleasing anymore.
I still prefer my solid state composite amp. 0.0001 % THD ... or better.
But THD alone doesn't provide the full picture. One must also look at IMD, slew rate, and other parameters.
Tom
I still prefer my solid state composite amp. 0.0001 % THD ... or better.
But THD alone doesn't provide the full picture. One must also look at IMD, slew rate, and other parameters.
Tom
Tom, you assume I like amps which add some THD to suit my taste, you assume that subjectivity is wrong,
I understand that to sell amps you need to provide the client with a certificate of some merit, thd is low, power is high= client buys.
Anyone can be fooled for some period of time before the illusion is gone that some THD pattern or high 2nd harmonics are Great!,
This is where subjectivity is important, otherwise you fall into the trap that you talk about : opinion.
The customer based on OPINION purchase the amp with more certifications, the one with A+, it doesn't add or subtract.
Subjectivity is not equal, especially when you try to reach to confirm an opinion.
Subjectivity is what ever you have as ears, taste, education and perseverance to criticize and ameliorate your ideas.
Instead of attacking everything that I say and quote as subjective and invalid, and its an opinion, just read and process.
I am not attacking or criticizing you , just listen to what I said about input stages, and what the JHL amps is and its purpose in obtaining low THD at all conditions on the audio band.
And why it sounds a lot better than all the other designs of the area.
You have a lot more intelligence and understanding of simulators and can easily simulate the conditions under which the JHL is protected at the input from gain errors and curved (like RIAA) gain. Why it is important to isolate with capacitor AC and DC parts of the amplifier.
And finally why there is no point of getting past 50 watts of power (arbitrary number) for audio as all the listening is done at around 1 to 30 watts in peaks.
I understand that to sell amps you need to provide the client with a certificate of some merit, thd is low, power is high= client buys.
Anyone can be fooled for some period of time before the illusion is gone that some THD pattern or high 2nd harmonics are Great!,
This is where subjectivity is important, otherwise you fall into the trap that you talk about : opinion.
The customer based on OPINION purchase the amp with more certifications, the one with A+, it doesn't add or subtract.
Subjectivity is not equal, especially when you try to reach to confirm an opinion.
Subjectivity is what ever you have as ears, taste, education and perseverance to criticize and ameliorate your ideas.
Instead of attacking everything that I say and quote as subjective and invalid, and its an opinion, just read and process.
I am not attacking or criticizing you , just listen to what I said about input stages, and what the JHL amps is and its purpose in obtaining low THD at all conditions on the audio band.
And why it sounds a lot better than all the other designs of the area.
You have a lot more intelligence and understanding of simulators and can easily simulate the conditions under which the JHL is protected at the input from gain errors and curved (like RIAA) gain. Why it is important to isolate with capacitor AC and DC parts of the amplifier.
And finally why there is no point of getting past 50 watts of power (arbitrary number) for audio as all the listening is done at around 1 to 30 watts in peaks.