High gain Low noise preamp, amp system

[Qmavam]

Hi all,

I’m putting together either a parabolic or shotgun type, maybe try both.

I’m starting with an AOM-5024L capsule mic. I’m shooting for low noise.

This will be battery operated, I’ll use four 7.4V Lipo batteries, in some combination.

I have an HA Pro 2 headphone amplifier.

19.21US $ 28% OFF|HA PRO2 Professional Edition Ultra Low Noise Low Distortion Headphone Amplifier Finshed Board with AP Test|Amplifier| - AliExpress

I want to add a preamp between the mic and headphone amplifier.

I have the following

TS472

1.71US $ 5% OFF|TS472 Amplifier Module Low Noise Electret Microphone Audio Preamplifier Board With 2.0 V Bias Output PDA audio development board|Integrated Circuits| - AliExpress

SSM2167

2.58US $ |1PCS SSM2167 Microphone Preamplifier Board Low Noise COMP Compression Module DC 3V 5V|Replacement Parts & Accessories| - AliExpress

And I have a PCB for a INA217.

Ultra low noise low distortion balanced mic amplifier PCB ! | eBay

What I don’t know is, what would be the best combination for a low noise high gain system?

Got any ideas?

Mikek

 

[gyraf]

depends on what you actually need - these are different systems, two of them with some different processing built in..?

with electrect mic, your noise most usually is in the capsule head, not in later amplifier

 

[abbey road d enfer]

You posed the very same question on the micbuilders group, my answer will be the same.
Out of the three, only the INA217 really qualifies for low-noise, and you don't need 4 batteries, only two.
However, the overall noise performance will be dominated by the capsule.
The preamp has a balanced input, but the capsule is unbalanced. You'll need to take that into account.

 

[Qmavam]

depends on what you actually need - these are different systems, two of them with some different processing built in..?

with electrect mic, your noise most usually is in the capsule head, not in later amplifier

Yes, I know one chip has a high and lw pass filter and another has a compressor. I like the Filtering as I'm only interested in Voice.
I also like the Compressor (especially if it was fast attack) because I could hurt my ears if I have high gain and a motorcycle goes by.
So, I'm trying to gather info to figure out what I do need.
Mikek

 

[Qmavam]

You posed the very same question on the micbuilders group, my answer will be the same.
Out of the three, only the INA217 really qualifies for low-noise, and you don't need 4 batteries, only two.
However, the overall noise performance will be dominated by the capsule.
The preamp has a balanced input, but the capsule is unbalanced. You'll need to take that into account.

I do have a matching transformer, but, as I understand, that automatically reduces the mic output by a lot.
What type of reasonably priced mic would be better?
Mikek

 

[abbey road d enfer]

Well, as in any project, you should define precisely your needs. Not everybody needs a compressor in case of motorcycle, people who record night owls don't need that, so tell us what you want to record, in what environment, and what kind of performance you expect.

 

[Qmavam]

Well, as in any project, you should defin eprecisely your needs. Not everybody needs a compressor in case of motorcycle, people who record night owls don't need that, so tell us what you want to record, in what environment, and what kind of performance you expect.

Speech in the presents of traffic. yes the parabolic or shotgun mic should help eliminate some of that of axis sound. But, that attenuation is unknown by me. I just want to build something I can call very good, and then I can improve from there.
My little experience is the first amp with a gain of couple thousand, I could hear the clock across the room tick, but if my wife banged a pan in the kitchen it was not good for my ears. This probably has no relation to being outdoors, but it is my experience.

 

[abbey road d enfer]

Speech in the presents of traffic

At what distance?

 

[Qmavam]

30 to 150 yards

 

[Qmavam]

Let's say I go with the INA217, What is the best method to go from Unbalanced to Balanced? (AOM5024 mic) The mic cord to amp will be short, 12" to 15".

 

[Qmavam]

Here's what I'm proposing to build.
Any changes you might suggest?
Note, I have added a high pass between the mic and the preamp and both a high pass and low pass on the output of the preamp.
Only interested in 300 to 3300 Hz.
Edit to correct schematic. That may allow someone to post an opinion. Probably to confusing before.

 

[Qmavam]

I made a schematic, of the Aliexpress TS472 pcb, I hope it helps.
Qmavam

 

[Garagescience]

I’m curious what you get for results, as I want to build a parabolic as well. Building a small two channel low noise battery powered preamp is definitely on my “to do” list!