Analog amplifier with best THD+N, i.e. minimum and without any color (what goes in must come out)

[muzzammil236]

Hi all,

Can anyone tell me for the best analog amplifier with gain between 120-160db and with best THD+N values. It must be clean and without any color (what goes in must come out). Actually, I need to connect it with plants, and need it to be without any interferance and without change in anything, i.e. what is there must be captured without noise and without any clipping of frequencies. Kindly guide and suggest with logic. Thanks.

 

[DVDdoug]

Can anyone tell me for the best analog amplifier with gain between 120-160db

That's "difficult". You can find microphone preamps with 60dB of gain and power amps are usually in the range of 30dB. If you put both together you'll still be short of your goal.

and with best THD+N values.

I don't know what's "best" but you'll be amplifying any existing noise, and there are "theoretical" limits because of thermal noise that always exists. More gain = more noise amplification.

It must be clean and without any color (what goes in must come out).

Most amplifiers are better than human hearing as long as they are not driven into clipping, except for sometimes noise. I assume the plant is generating the sound/signals and a human is listening?

without interferance and without change in anything, i.e. what is there must be captured

A plant IS going to pick-up interference unless you put it in an electromagnetically-shielded container. Have you ever touched the input of an amplifier and heard a "buzz"? That's your body picking-up radiated signals from the 50/60Hz AC power in your house.

without noise

And there is always SOME noise in ANY electronics. (It's not always audible, but with a lot of gain it will be audible.)

and without any clipping of frequencies.

Most audio amplifiers have no trouble covering the audio frequency range. i.e. They have flat frequency response over the audio range. ("Clipping" is "overload distortion, like if you try to get 150 Watts out of a 100W amplifier.)

 

[sarumbear]

Hi all,

Can anyone tell me for the best analog amplifier with gain between 120-160db and with best THD+N values. It must be clean and without any color (what goes in must come out). Actually, I need to connect it with plants, and need it to be without any interferance and without change in anything, i.e. what is there must be captured without noise and without any clipping of frequencies. Kindly guide and suggest with logic. Thanks.

Maybe you check the meaning of dB? 160dB is 100,000,000 times amplification. For 1V out you need 10 nano Volt input and for that to happen you need almost super conductor level cooling.

PS. What do you mean by “connect it with plants.”

 

[jae]

Amplifier SINAD list ASR + 3rd parties

List Name,THD+N (5W, 4 ohms),SINAD (dB) (5W, 4 ohms),Power (W) (1% THD+N, 4 ohms),Price (USD),Source Topping LA90 (stereo, bypass, low gain),0.00009%,121,90,800,<a href="https://www.l7audiolab.com/f/topping-la90/">L7 Audio Lab</a>,Suggestions, corrections and more info here: Topping LA90 Discre...

docs.google.com

 

[muzzammil236]

Yes, thanks. Yes, I will shield them from electromagnetic interference. It means I must lower my expectation between 40-70 dB of gain, in order to get less audible noise after amplification. I do have Focusrite ISA one amplifier connected with Scarlett 2i2 3rd Gen. Cumulatively, do they have a good THD+N or I must look for more precise and quieter ones?

 

[muzzammil236]

Maybe you check the meaning of dB? 160dB is 100,000,000 times amplification. For 1V out you need 10 nano Volt input and for that to happen you need almost super conductor level cooling.

PS. What do you mean by “connect it with plants.”

I need to listen to plants and their tissues and cells.

 

[muzzammil236]

Maybe you check the meaning of dB? 160dB is 100,000,000 times amplification. For 1V out you need 10 nano Volt input and for that to happen you need almost super conductor level cooling.

PS. What do you mean by “connect it with plants.”

Yes, you are right. I need to lower amplification between 40-70 dB.

 

[SIY]

Yes, thanks. Yes, I will shield them from electromagnetic interference. It means I must lower my expectation between 40-70 dB of gain, in order to get less audible noise after amplification. I do have Focusrite ISA one amplifier connected with Scarlett 2i2 3rd Gen. Cumulatively, do they have a good THD+N or I must look for more precise and quieter ones?

If you say specifically what you're trying to accomplish, you'll get better suggestions.

 

[muzzammil236]

If you say specifically what you're trying to accomplish, you'll get better suggestions.

I need to listen to plants and their tissues and cells. I need to have data acquisitions for their frequencies over the time period.

 

[muzzammil236]

Amplifier SINAD list ASR + 3rd parties

List Name,THD+N (5W, 4 ohms),SINAD (dB) (5W, 4 ohms),Power (W) (1% THD+N, 4 ohms),Price (USD),Source Topping LA90 (stereo, bypass, low gain),0.00009%,121,90,800,<a href="https://www.l7audiolab.com/f/topping-la90/">L7 Audio Lab</a>,Suggestions, corrections and more info here: Topping LA90 Discre...

docs.google.com

Very helpful, thanks!!

 

[jae]

Very helpful, thanks!!

Purifi or Hypex are the best buys

 

[jae]

Are you only interested in the "human-audible" / lower bandwidth of plant bioacoustics? What about the ultrasonic emissions?

 

[pjug]

Do you have the microphone/preamp end worked out? I'd think if you've figured out how to get a clean low level signal, data acquisition is just a matter of capturing the analog with a good A/D converter like the E1DA Cosmos ADC.

 

[SIY]

I need to listen to plants and their tissues and cells. I need to have data acquisitions for their frequencies over the time period.

Can you explain what you mean by "listen to plants and their tissues and cells"? Is this something like photoacoustic effects where you hit them with chopped light beams? Or are you hypothesizing that they emit sound spontaneously?

 

[pma]

Purifi or Hypex are the best buys

This seems to be one of the so many crazy threads here. But he definitely does not need a power amplifier, in case he is serious, he needs low level signal amplifier and a good sensor.

There are many areas where you need special designs of amplifiers. About 20 years ago I was asked to develop a low level signal amplifier with >1000 Mohm input impedance and capacitive sensor to detect tiny electric discharges near high voltage overhead power lines. I think one would not suggest Purifi to make the job .

 

[muzzammil236]

Are you only interested in the "human-audible" / lower bandwidth of plant bioacoustics? What about the ultrasonic emissions?

I am also interested in ultrasonics.

 

[muzzammil236]

Can you explain what you mean by "listen to plants and their tissues and cells"? Is this something like photoacoustic effects where you hit them with chopped light beams? Or are you hypothesizing that they emit sound spontaneously?

Due to the presence of molecules, they have their own spectrum of frequencies, it is not only limited to photoacoustic effects, it is also about their own symphony and response against what is around them.

 

[muzzammil236]

This seems to be one of the so many crazy threads here. But he definitely does not need a power amplifier, in case he is serious, he needs low level signal amplifier and a good sensor.

There are many areas where you need special designs of amplifiers. About 20 years ago I was asked to develop a low level signal amplifier with >1000 Mohm input impedance and capacitive sensor to detect tiny electric discharges near high voltage overhead power lines. I think one would not suggest Purifi to make the job .

wao ...

 

[SIY]

Due to the presence of molecules, they have their own spectrum of frequencies, it is not only limited to photoacoustic effects, it is also about their own symphony and response against what is around them.

Well, molecular vibrations are in the infrared range, so you should be looking at something like a TGS or MCT detector system, not a microphone.

 

[JayGilb]

No consumer available microphone preamplifier has the specifications you want and one would have to build a sound proof enclosure around the plants to stop outside noise from interfering in the recording/data acquisition you desire.

Texas Instruments makes several instrumentation amplifiers ics that might be applicable. The TI INA849 might be a good choice in constructing a custom amplifier for your experiments.