Creating PIP for microphone

Hardware
1

Hi there !

As I’m not an electronics guy, I just wanted to check a thing with you before potentially destroy everything.

I’ve made a Binaural device, it work great with a Yamaha pr7 but nothing on my Zynthian. I bought an amplifier, still nothing.

While looking for other stuff, what do I see ? Lot of device use PIP , they push voltage into the mics !

So. As I don’t find schematics about that, can you please confirm that :

Measuring 0v between tip and ground of my Zynthian V4 confirm that there is no PIP.

If I take 5 volts from USB, use one (or two for what it is) 2.2kohms resistor between 5v and left and right channel, plus two 10mf capacitor between Lmic and Lzynthian, and Rmic and Rzynthian then grounds to grounds (should I have to avoid USB ground to jack ground to avoid loop noises ?)… I have created a PIP adapter, from stereo mic to stereo input ?

Creating the right part of that, with a stereo jack output :

FIMBFBOIJHFDWEV
FIMBFBOIJHFDWEV270×225 10.8 KB

Thanks for reading :blush:

2

If you have headphones, you can test that file I’ve made for you.

And I’m upgrading the hardware, so it should be better soon.

My montage:

IMG_20250914_104304847
IMG_20250914_1043048471920×1920 288 KB

3

Very interesting matter, but i don’t get completely what PIP is. You mean some bias voltage for electret mics?

Doesn’t the V4 has a Hifiberry Dac+ Adc Pro in it? In the docs there is a physical jumper to close to provide bias voltage:

There’s also an additional ALSA setup to do afterwards.

But most likely I just missed the point.

4

No, you are good, it’s exactly that .

But the hifiberry is remade on the Zynthian. So it look like there is no PIP

5

Sorry, didn’t know that. I were just guessing, looking at the V4 building instructions.

But I will follow the threat, maybe I’ll learn something to finally get the 48V version.

6

Yes. I use a Hifiberry DAC/ADC with a piggy back amp on the zyncajon on one channel to power an internal electret microphone.

Works perfectly.

7

Just to clarify concepts:

V5 doesn’t support Phantom nor bias voltage (pip).

Regards

1 Like
8

So it is not this card is it ?

IMG_20250914_132513027
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9

So it doesn’t provide.

So making my own pip box in between look like the thing to do no ?

10

Good news, I’ve made some test and didn’t blown anything.

Using the USB as a power supply is not good. It work in mono but make a mmm noise in stereo.

Using a 3volts cell coin like cr2032 is doing a good job :+1:!

But.. splitting everything to audio input 1 and 2 make me able to create stereo input. While puting a stereo jack into a single input (1) doesn’t. I was thinking choosing the mode Balanced Mono TRS will work but it doesn’t.

11

Okay, for now, let’s pretend I know what I do :wink:

Here is the minimal circuit for stereo :

IMG_20250914_151534133
IMG_20250914_1515341331920×1920 149 KB

And the PIP box (yeah I know, it’s a plate, give me some time). I choose RCA because I have a lot RCA adapters. To mini jack, to big jack, mono, stereo, etc.

IMG_20250914_153253342
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IMG_20250914_152950244
IMG_20250914_1529502441920×1920 240 KB

So now, I’m able to connect my Binaural device to a with PIP or without PIP device.

IMG_20250914_145148020
IMG_20250914_1451480201920×2550 699 KB

2 Likes
12

I hope this doesn’t add to the quite understandable confusion about the card in Zynthian V4.x:

I believe that at some point during Zynthian V4.x production, Zynthian Labs changed from using a HiFiBerry DAC+ ADC Pro to using their own, Open Hardware, ZynADAC v1.0 board.

The Zynthian V5 eliminated the separate board and has the equivalent functionality on the Main Board.

Of course, @jofemodo , would be the authority on this.