When querying ChatGPT on the viability of connecting an USB splitter cable from a DC-DC 12V-5V converter to supply a Raspberry Pi ZERO 2W and SuperSID preamp, ChatGPT gave this response:
❌ The key problem: a USB splitter ≠ power distributor
Despite the marketing wording (“charging and data”), these cables are not power splitters.
They are intended mainly to:
- duplicate a host USB port
- for low-power peripherals
- where total current stays small
Typical specs show ≈1.5 A total shared current across both outputs.
That means:
👉 The two outputs are simply wired in parallel.
There is:
- ❌ no current limiting
- ❌ no power negotiation
- ❌ no isolation between devices
⚠️ Why this is risky in your case
1. Raspberry Pi Zero 2 W current demand
Typical consumption:
| State | Current |
| Idle | 150–250 mA |
| Wi-Fi active | 300–450 mA |
| USB activity + CPU | 600–800 mA peaks |
The Pi is very sensitive to voltage drop.
2. USB audio preamp behaviour
Many USB audio devices:
- draw pulsed current
- inject switching noise
- may momentarily exceed rated current at startup
This causes:
✅ voltage dips
✅ ground noise
✅ USB brownouts
Result on Pi:
- random resets
- SD-card corruption
- audio glitches
- RF noise entering your receiver chain
3. Shared wiring = shared noise path
A passive Y-cable directly connects:
Pi ground ⇄ Audio preamp ground
For radio / VLF / SDR work this is especially undesirable.
You effectively create a noise injection loop.
🚨 The deeper USB rule
USB architecture assumes:
One host → multiple devices via a HUB
A splitter cable is not a hub.
Experienced USB hardware discussions repeatedly conclude:
“What you want is a powered USB hub.” (community consensus)
✅ Correct (and safe) solution
⭐ Best solution
Use a powered USB hub instead.
12V
│
DC-DC 5V (≥3A)
│
Powered USB Hub
├── Pi Zero 2W
└── Audio preamp
Advantages:
- regulated 5 V per port
- current sharing handled properly
- reduced voltage sag
- electrical isolation between ports
- far lower noise coupling
✅ Even better for radio work (recommended)
Since you already have a DC-DC converter:
Option A (cleanest):
- Power Pi directly from 5 V GPIO pins
- Power audio preamp from separate USB output
Option B
Use two independent 5 V outputs from the converter module.
This greatly reduces conducted noise into your receiver.
✅ Rule of thumb
| Device | OK with Y-splitter? |
| Keyboard + mouse | ✅ |
| USB fan + LED | ✅ |
| Phone charging | ⚠️ |
| Raspberry Pi | ❌ |
| SDR / audio electronics | ❌❌ |
✅ Final verdict
Can it work?
➡️ Possibly, briefly.
Is it electrically correct or reliable?
➡️ No.
Recommended?
➡️ Avoid for Pi + instrumentation systems.
However, Bill gave this response, in contrast to the ChatGPT assessment above:
I’ve been using a splitter cable on my setup for just under two years now without any problem.
The output of the buck converter that I am using has a USB connector and the splitter cable is connected to that.
The output of the converter is rated at 5 volts 3 amps.
_._,_._,_