ts472 microphone preamplifier module

Thread Starter

stuartiannaylor

Joined Aug 18, 2020
9

peterdeco

Joined Oct 8, 2019
251
I use the attached circuit to get about 40mV from an electret mic. I believe I got a voltage gain of 8 when I powered it with 3V and not 5V. It was a couple of years ago.
 

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Audioguru again

Joined Oct 21, 2019
2,090
The owner's manual of the mic preamp module should show you how to connect it and adjust it as shown in the IC datasheet. Without an owners manual then you do not know where in the module to connect which to what.
 
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SamR

Joined Mar 19, 2019
2,812
Looks pretty self-explanatory to me from the backside marking. At least HOW to connect the electret. The module itself will require some googling for some of the functions other than the obvious jumper pads on the front for the gain. Have you put a jumper across any of the gain pads? Probably won't work without one.

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SamR

Joined Mar 19, 2019
2,812
Wire shielding or mike case ground since the electret element only has 2 connections. Dunno what Vx is unless it may have to do with Voice-Activated (VOX)? Standby and Vbias should be covered on the chip PDF. Have you read it?
 

sghioto

Joined Dec 31, 2017
1,562
its what vx and standby with what seems +/- with a middle common?
Standby is the middle pad. Short that to the + pad for device on. Not sure what Vs is either.
Electret mics are polarized. The negative side of the element is normally soldered to the case. This pin connects to IN- the other to IN+
SG
 

Thread Starter

stuartiannaylor

Joined Aug 18, 2020
9
Thnx for the standby so tomoz will give things a go and report back.

PS I got this because of the amazing RK3308 RockPiS that is slightly less amazing as the 8 channel ADC is noisy and doesn't seem to like single end with - to gnd.

So fingers crossed.

Vx seems to go through one resistor and join the bias track. Maybe the gain select output?

Thanks all for commenting as just did an aliexpress and then was like oh blimely there is absolute zero about this module!!!
It was going to go into projects for infinite later box.
 

Thread Starter

stuartiannaylor

Joined Aug 18, 2020
9
Yeah guys, success.

Well sort of as my RK3308 ADC is still noisey as hell but the preamp works.

Short +Standby & Bias leave Vx open.
Still clueless about Vx but in operation effectively a mute
 
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