Asynchronous I2S FIFO project, an ultimate weapon to fight the jitter

[A123]

Originally Posted by Gabster 2000

I have a transportPI that I swapped with HdmiPI as I did not want the unneeded extra circuitry so I was able to take a nice photo L1 is on the back close to the input voltage

Thank you for taking the time to take a photo.

I always wondered where the "L1" was located...

I will not start this process until a ReclockPi is in hand when I have to purchase my 2nd TransportPi.

My 1st TransportPi will be left un-modded.

[holco]

Look at b and d.


If you want to use an independent DC power supply for TransportPi, you will need:
a. Solder the supplied DC terminal connector to the position of J3.
b. Remove FB L1 at bottom side of PCB if you don’t want this power supply connected to GPIO anymore.
c. Feed good 5V linear/ultra capacitor voltage rail or 3.3V LifePO4/ultra capacitor rail to J3.
d. If 3.3V pure LifePO4 or ultra capacitor voltage is used, it’s highly recommended to bypass the on-board low
noise LDO by soldering jumper wires between IN and OUT as described above

Originally Posted by A123

Thanks for the heads up. I noticed this step in the manual but I could never locate "L1" on the PCB Layout (top) within the manual. I have not physically looked under the TransportPi yet (bottom).

Is "L1" basically that small board in the middle of the TransportPi with the labels "3.3V REG" and "LOW NOISE"?

If so, do I just solder a wire to "IN" on one end and "OUT" on the other end?

EDIT: I noticed in your photo the wiring on the TransportPi. Is this the step to remove "L1"?



Manual

[Markw4]

Originally Posted by Gabster 2000

* But still should I let City ground connect to the hats negative poles?

I would suggest to make it optional. IME it can help, hurt, or make no difference. Have to try it under the conditions where the equipment will be used to see.

[A123]

Originally Posted by holco

Look at b and d.

b. Remove FB L1 at bottom side of PCB if you don’t want this power supply connected to GPIO anymore.

d. If 3.3V pure LifePO4 or ultra capacitor voltage is used, it’s highly recommended to bypass the on-board low
noise LDO by soldering jumper wires between IN and OUT as described above

d. seems pretty straightforward. just need to solder a single jumper wire on two ends.

b. unsure how to remove. can I just pull out the metal piece off of L1? do I need to de-solder?

Note: I cannot proceed ATM because I need to purchase a second TransportPi. My current TransportPi is in production un-modified, so I don't want to touch since STABLE. But this will really be beneficial once I get the second TransportPi.

[holco]

L1 must of course be desoldered.

Originally Posted by holco

Supporting picture,

Best regards,

Mario

Originally Posted by A123

d. seems pretty straightforward. just need to solder a single jumper wire on two ends.

b. unsure how to remove. can I just pull out the metal piece off of L1? do I need to de-solder?

Note: I cannot proceed ATM because I need to purchase a second TransportPi. My current TransportPi is in production un-modified, so I don't want to touch since STABLE. But this will really be beneficial once I get the second TransportPi.

[A123]

Originally Posted by holco

L1 must of course be desoldered.

Cheers for the confirmation.


I likely will not be able to attempt this feat until the Summer, so it's great to know the proper step in advance.

[holco]

Not comparable to how it sounds in real live, but it gives an idea

Recorded with a Tascam DR-40 (48kHz)

Raspian (Ian Canada) streamer
Audio-GD R8 (2021) DAC
Audio-GD Master 1 Vacuum XLR preamplifier
Mordaunt Short Performance 6 Limited Edition loudspeakers (converted to full active with 6x NCore poweramp's (Two Hypex FusionAmp's FA253)


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