audio source - Apple 3.5mm to usb dongle as dac - ...

Short answer: probably not in the way you’ve drawn it, and even if you get some audio, it’ll be fiddly and unreliable. Let’s unpack why and what would actually work.

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1. The big blocker: what the Apple dongles actually do

There are a few different “Apple 3.5mm ⇄ USB” style dongles in the world, and they don’t all behave the same.

a) Apple Lightning → 3.5 mm Headphone Jack Adapter

On an iPhone/iPad with Lightning, the official Apple Lightning-to-3.5 mm adapter does support microphone input when you plug in a TRRS headset or TRRS mic adapter. Apple’s own docs and third-party guides explicitly talk about using it with external mics. (RØDE Help)

So on iOS, this dongle can act as:

• DAC (digital → analog, for headphones), and
• ADC (analog mic → digital, from the TRRS mic pin)

b) Apple USB-C → 3.5 mm Headphone Jack Adapter

On Macs, this adapter generally appears as output-only. There’s an Apple Support Community thread where someone tried to use it as an audio input device in GarageBand, and macOS only exposed it as an output. (Apple Support Community)

So on a Mac (and often on other USB-C hosts):

• It’s a DAC only (headphone out).
• There’s no usable mic/ADC side presented to the OS.

If your “ADC end” is a Mac with the USB-C headphone adapter:
👉 Your chain cannot work, because the Mac never sees a mic input from that dongle at all.

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2. The TRRS splitters / cable: wiring weirdness

Your proposed chain:

audio source
→ Apple 3.5 mm ↔ USB dongle as DAC
→ headphone end of TRRS–to–headphone+mic splitter
→ TRRS audio cable
→ mic end of TRRS–to–headphone+mic splitter
→ Apple 3.5 mm ↔ USB dongle as ADC
→ recording

Conceptually, you’re trying to do:

• Headphone out of device A
  → get onto the mic pin of device B’s TRRS input
  → device B records it as microphone audio.

That idea is fine. People do something similar with adapters like the RØDE SC4/TRS→TRRS mic adapter into a phone’s TRRS jack. (RØDE Microphones)

But your exact wiring has a few traps:

1. TRS vs TRRS mismatch
   Those “headphone & mic” Y-splitters usually break one TRRS jack into:

   • 3-pole TRS headphone jack (L/R/GND)
   • 3-pole TRS mic jack (mic/GND, sometimes with bias)

   Plugging a TRRS cable into a TRS jack sort of “works”, but the extra ring gets either ignored or shorted with ground depending on how the contacts land. (Wikipedia)

   • You might lose one channel,
   • Or short parts of the signal,
   • Or get weird mono/phase issues.

2. You’re relying on the splitter wiring to cross-route correctly
   For this to behave as you intend, the splitter on the “record” end has to:

   • Take what arrives on the TRRS cable’s headphone pins
   • Then somehow spit that out on the mic TRS jack,
   • And then the Apple dongle has to treat that as the mic line.

   Most cheap Y-splitters are not designed to be used “backwards” like that, and the mapping may not line up the way you think.

3. Level and impedance mismatch
   You’re feeding a headphone/line-level output into a tiny electret mic input:

   • Mic inputs expect very low level (millivolts) plus DC bias.
   • Headphone outputs are much hotter (hundreds of millivolts/volts).

   It won’t usually damage anything, but it’s extremely easy to clip/distort unless you keep the source volume very low.

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3. When could something like this work?

It can work in a more controlled form if:

1. Your recording device is an iPhone/iPad using an official Lightning → 3.5 mm adapter, and iOS is actually using the TRRS mic input. (RØDE Help)
2. You use the correct TRS→TRRS mic adapter on the recording side (e.g. a RØDE SC4 or similar), not a random headphone/mic splitter. (B&H Photo Video)
3. You run simple cabling:
   • Source device’s headphone out (or Apple DAC dongle)
   • → 3.5 mm TRS cable
   • → TRS-to-TRRS mic adapter (SC4-type)
   • → Lightning/USB-C headphone adapter
   • → recording device.

That’s the common recipe used for:

• Sending mixer/recorder output into a phone for livestreams,
• Recording camera audio into a phone, etc.

Your proposed “two splitters + TRRS cable + two Apple dongles” is just an over-complicated, less predictable version of that.

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4. So, will your exact chain work?

Realistically:

• If the ADC side is a Mac using the Apple USB-C → 3.5 mm headphone jack adapter:
  ➜ No. The dongle doesn’t expose any input device to macOS; it’s output-only. (Apple Support Community)

• If both sides are iPhones/iPads with Lightning 3.5 mm adapters, and you wire everything just right and keep levels low:

  • You might get audio through, but:
    • The splitter + TRRS cable wiring is fragile and easy to get wrong.
    • Expect mono only, odd levels, and a lot of trial-and-error.

So, I’d personally treat the answer as:

“Not reliably, and not in a way I’d recommend.”

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5. What I’d do instead

Depending on what gear you actually have / want to connect:

Option A – Simple “headphone out → phone mic in”

For sending audio from any device with a headphone out into a phone/tablet:

1. Source device:
   • Built-in headphone jack or Apple DAC dongle for output.
2. Cable:
   • Plain 3.5 mm TRS (stereo) cable.
3. Recording side:
   • TRS-to-TRRS mic adapter (RØDE SC4-type). (RØDE Microphones)
   • Then into the phone’s Lightning/USB-C headphone adapter.

That’s it. No Y-splitters needed.

Option B – Use a small USB audio interface

If you’re going computer ↔ computer/phone and want something cleaner:

• Get a cheap USB audio interface (even the little USB “sound card” dongles that have separate mic and headphone jacks).
• Treat it like this:
  • Source device → USB DAC/headphone out → 3.5 mm/TRS cable → USB interface line/mic in → Recording device.

Far simpler, predictable, and you get proper level controls.

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If you tell me which exact Apple dongles and which devices are on each end (Mac, iPhone, iPad, etc.), I can sketch the minimum-cable version that will actually work for your setup.