Where do you buy the boxes? DK wants €70 or so for an empty one from Pomona. 😱
Shocking. I need to build some RF filters.
BTW I delivered this week a 0.6 Kg parcel from our Saar state to Limoges, France,
traceable, to DHL (only abt. €17.50) and the lady said I was lucky that this worked at all.
Many packets, esp. to Asia would currently simply come back to .de .
Some countries would reject them.
And the prices were currently higher than normal.
Gerhard
Shocking. I need to build some RF filters.
BTW I delivered this week a 0.6 Kg parcel from our Saar state to Limoges, France,
traceable, to DHL (only abt. €17.50) and the lady said I was lucky that this worked at all.
Many packets, esp. to Asia would currently simply come back to .de .
Some countries would reject them.
And the prices were currently higher than normal.
Gerhard
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As long you mask out the noise with a passive notch... for sure you will never ever see any noise bell around the fundamental! 😀
See RME ADI-2 Pro Fs R manual 😀 using a AP555B analog generator & ADC ..
Just my 2 cents
Hp
I know about the bell. I am using passive notches for to get lower as possible distortions at the measurement tool side, not for mask the bell.
If you are sure that the TL072 contribute significant noise, you can change it to another opamp. Then show us the difference please. Too many words. Where is the job?
Vic.
1. It is your product.
2. As soon I have a new LDO on my desk with 2 x OPA1656.
3. I do not have any OPA1656, nor would solder my existing any more!
4. I would measure as soon as possible
5. And provide to the corona world the results 😀
Hp
Yes, and I previously wrote: "Probably you won't see the difference, if the TL072 will be changed." Maybe I am wrong in my experience in the past. Please show me that. Otherwise someone periodically write about the "noisy" TL072. The TL072 works in the AGC, not in the main signal phase. The contribution of the AGC is very small. Every cent counts in this concept.
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There are always people who don't understand the structure of the oscillator. The TL has nothing to do with the sine signal. It is only necessary for the AGC DC voltage.
Now that you mention the OPA1656:
I happen to have its data sheet open in another window.
Is it unity gain stable?
Normally that is listed under key features, but the word "stable"
is so carefully avoided in the entire data sheet that it makes me nervous.
From the gain/phase plot it should be possible.
I just had a THS4022 ( > -9 or +10) that was completely stable
at +3.15 while the other half oscillated at 160 MHz with G= +11,
even when heavily overcompensated. Weird.
And that while giving an excellent phase margin in simulation.
cheers,
Gerhard
I imagine you're seeking CMOS bias currents, but this particular opamp is rated to only 16V rather than 30V. 😉
The Vos on the TLC271 is pretty high (10mV). This is a function where precision DC would be important. Voffset and tempco would be the important parameters to get amplitude stability. Something more like this: OPA2182 https://www.ti.com/product/OPA2182 however the 10X(?) difference in price may give no measurable improvement in performance.
Would it be possible to show the full screen? It is always good for confirmation to see all levels/scales/settings etc.
And why making a picture instead of showing the QA screen? Pictures are sooo 20th century ;-)
Jan
And why making a picture instead of showing the QA screen? Pictures are sooo 20th century ;-)
Jan
Where did you get these data, please? I can see only THD+N graph in the data sheet.
The noise is the dominant at low levels, but the distortion typically becomes lower at lower signal levels.
Vic.
It is the problem of all these THD+N measurements. Why manufacturers continue to include the N beats me.
THD+N, an industry standard ?
This is what Bob Bauman (co-founder / chief hardware engineer at Lynx StudioTechnology, Inc.) told me once:
" .... the Ap does not measure THD alone. We have chosen to use the THD+N value (measured on the Ap) in our specifications because it’s an industry standard that allows customers to easily compare to other products and it is an excellent gauge of overall audio quality."
Cheers,
E.
(BTW, I disagree with above statement)
This is what Bob Bauman (co-founder / chief hardware engineer at Lynx StudioTechnology, Inc.) told me once:
" .... the Ap does not measure THD alone. We have chosen to use the THD+N value (measured on the Ap) in our specifications because it’s an industry standard that allows customers to easily compare to other products and it is an excellent gauge of overall audio quality."
Cheers,
E.
(BTW, I disagree with above statement)