John Curl's Blowtorch preamplifier part III

[syn08]

If the notch filter and sig gen have self distortion that is low enough, it is
absolutely possible to see down around -160dB with the latest AP. I'm not
sure what they were using as a sig gen.

https://www.google.com/url?sa=t&rct...sheet-R1.pdf&usg=AOvVaw3z_OmpKDx_KE1cLH7UApqQ

Refer to page 13

TCD

I just mentioned above - the discussion was about power amplifiers (and in particular a CFA), not about op amps.

 

[Jakob2]

He probably knows what I'm driving at and is trying to divert 😉 No problem

That sounds like another car analogy, unintentional, I'm being brainwashed 🙂

HE, whose words you shall trust, says that HE hasn't got the foggiest idea, what you are driving at.

@Tournesol,

there is some truth in the old saying, "dogs have masters while cats have personnel" 🙂

 

[scottjoplin]

HE, whose words you shall trust, says that HE hasn't got the foggiest idea, what you are driving at.

No? Then can you answer the question below?

Well, you mentioned music and humans, thought you may know something we don't 😉 I'm presuming you are referring to the kind or psychoacoustics that goes beyond what we all share?

 

[TNT]

Ah, here I am forgiven.[/I]

If I may say so myself?

I’m not the only one who says things in a definitive way .[/I]

And therefore it is OK to commit what you seem to belive is a sin?

I would not comment* on the rest of your post on which we are in almost total disagreement.
Or agreement, if you re-read more carefully what I said.

* because it will not advance the subject of a millimeter.

The usual incoherent rant. What topic?.

//

 

[Tournesol]

The closest thing to being there is a dummy head recording ( you can make the ears copies of your own) over headphones.

Oh, I forgot this. Go figure: André Charlin was one of my close contacts in the 70th. We exchanged a lot about the pros and cons of the various stereo recording methods, multi tracks etc..
I was working in the R'n'R and pop music world, not classical apart few exceptions for the ORTF. Totally another spirit.
I think I still have one artificial head somewhere in my basement. Not sure.

I used-it, sometimes, for brass section, strings or chorales in studios. But found ORTF couple easier. It depends of the kind of result we want. Close miking is a better way, if you work on funk and ryth'n blues production and such.
Absolute truth do not exists in this matter.
(OMHO, of course)

 

[Tournesol]

The usual incoherent rant. What topic?.

Arf. Thanks for this surrealistic moment.
Happy Christmas TNT.
Take care of your wick with all those candles in the night.

 

[Joe Rasmussen]

Joe is off his meds again.

Nope, still on them! 😀

Hands up here anybody who is not?

 

[wrinkle]

When it comes to ****, I never thought of recommending a manure spreader instead of a fan . I have to admit, it's much more effective .

Here in the UK we have occasional problems with Gypsies/Travellors parking on any old piece of private property for a few months until the court order is signed, one farmer used the manure spreading technique nice and close to the caravans, it was worth the elf and safety fine as they went the same day...

 

[simon7000]

Here in the UK we have occasional problems with Gypsies/Travellors parking on any old piece of private property for a few months until the court order is signed, one farmer used the manure spreading technique nice and close to the caravans, it was worth the elf and safety fine as they went the same day...

Around here we can just have them towed away by a private company, that won't release them until they pay for the tow.

 

[scottjoplin]

Around here that would be called false imprisonment 🙂

 

[billshurv]

https://www.diyaudio.com/forums/equ...outer-foil-tester-capacitors.html#post6019252 This is a fun little project from Elvee for those with capacitor angst.

 

[dimitri]

Happy Holidays!

Here is my greeting card

 

[simon7000]

Around here that would be called false imprisonment 🙂

Just the vehicles not the people.

 

[billshurv]

Dmitri: What on earth does 'bold in colour, rich in detail, underpinned by a robust bass' mean? Sounds like a wine review?



Assume you had a hand in this so congrats on the award. Didn't even know this stuff was sold in the UK.

 

[wayne]

Here is my greeting card

Good to see Levinson back Dimitri. Congratulations!

 

[Mark Johnson]

Congratulations Dimitri!

 

[UniQ]

Congratulations and Merry Christmas DD.

 

[Tournesol]

Here is my greeting card

Congratulations, Dimitri. I'm sure it is a pearl.

 

[31697B]

No you cannot. There is no commercial ADC in the audio frequencies range on this planet that would provide -160dB THD+N, with or without a passive notch filter (that only helps with the dynamic range, not the distortion performance) and tricks like increasing the noise gain in the amplifier can only help so much. LIGO is using some -180dB in filtering the amplitude control of the laser. Talking about sources, Victor's fine oscillator is estimated between -140dB and -150dB distortions so no cigar for -160dB.

BTW, I have two of those Panasonic/Levear 7722A's and a Shibasoku AD725D + AG15C and the Shibasoku 2nd harmonic is not much better than -120dB. So unless you can come up with some solid data beyond "show me yours" photos, when it comes to measuring -160dB THD+N, I have to conclude you have no idea what you are talking about.

Meantime, you could consider an introductory lecture in ADC distortions definitions and types, and in particular about the effect of the ratio of sampling clock to the input frequency on the SFDR. Or ask about one of your 4 EEs working for you, I hope they have to knowledge and the guts to tell you the truth up front.

Another one of your straw man debates to and for yourself. Did I show you a plot of THD+N ? No I did not. I showed you FFT of harmonics. Conclude what ever you like about your own thoughts. The amplifier in question also showed numbers from FFT SIM test.

And, yes as i showed you and as you can read - I presume- the FFT plots. I can measure individual harmonics to -160dbv. Why are you ignoring what I told you on how I get source to <-160?
This is really distorted thinking.

Still boring me, Waly. Give up.


THx-RNMarsh

 

[31697B]

Here is my greeting card

Can you describe in a general way what the amplifier circuit topology is?


THx-RNMarsh