Overview
TandaBuilder drives two separate audio outputs:
- Live Stream: Audio broadcast to the audience
- Pre-listen Stream: Audio for the DJ (monitoring)
These two outputs can come from a single device or from two different devices. That choice is what decides which hardware you need.
Two possible architectures
Both are fully supported. The second one is not a fallback: it is often the simplest and the cheapest.
Architecture A: a single interface
An interface that exposes two pairs of outputs, one of which can feed the headphone jack. One box to carry, one clock, one USB cable.
| Interface | Live | Pre-listen | Setting on the interface |
|---|---|---|---|
| Focusrite Scarlett 4i4 | 1-2 | 5-6 | none |
| SSL 2+ MkII | 1-2 | 3-4 | 3&4 button on headphones B |
| PreSonus Studio 68c | 1-2 | 3-4 | A/B button on the headphone output |
| Behringer UMC404HD | 1-2 | 3-4 | A/B button on the headphone output |
| MOTU M6 | 1-2 | 3-4 | 3-4 button on the second headphone jack |
| MOTU M4 | 3-4 | 1-2 | none, reversed setup |
| MOTU UltraLite mk5 | 1-2 | another pair | routing in CueMix |
| Audient iD14 MkII / iD24 | 1-2 | cue mix | assign the headphones to a cue mix in the iD app |
| ESI Gigaport eX | 3-4 | 1-2 | none, second headphone jack |
On the Studio 68c, never pick channels 5-6: those are the S/PDIF inputs and outputs, which reach no headphone jack. The Gigaport eX, for its part, only has unbalanced RCA outputs, which restricts it to short cables.
Architecture B: two devices
A stereo interface, even the simplest one, sends Live to the PA. Your Mac's headphone output handles pre-listening. Cheaper, lighter, and with no synchronisation problem: the two streams are different tracks, which TandaBuilder never mixes together.
| Interface | Live | Pre-listen | Setting on the interface |
|---|---|---|---|
| Focusrite Scarlett Solo | 1-2 | Mac headphone output | none |
| Focusrite Scarlett 2i2 | 1-2 | Mac headphone output | none |
| PreSonus Studio 24c | 1-2 | Mac headphone output | none |
| MOTU M2 | 1-2 | Mac headphone output | none |
These interfaces have only one pair of outputs, which their headphone jack carries. Plugging the headphones in there would play Live, not the pre-listen.
Will your hardware work? Two questions
No list will ever cover every piece of hardware. These two questions are enough to decide, including for an interface missing from the table.
- How many output channels does macOS show for your interface, in Audio MIDI Setup? Four or more open up architecture A. Two mean architecture B.
- Can the headphone jack be fed by a pair other than outputs 1-2? Look for an A/B or 3-4 button on the box, or the matching option in the manufacturer's software. Without that, the headphones reproduce Live.
TandaBuilder tests each pair of outputs itself and only lists those that are genuinely independent. Mirrored pairs, which some interfaces declare without wiring them, are ruled out automatically.
Your Mac's headphone output
It is made for this, and TandaBuilder treats it like any other output. Five precautions, the first of which is specific to Apple Silicon Macs.
- Plug the headphones in before launching TandaBuilder. On Apple Silicon Macs the headphone jack only exists as an audio device while a plug is inserted: unplugging it mid-evening makes the pre-listen output disappear.
- Set the macOS system output to the headphones, never to the interface feeding the room. A notification or a video opened by mistake goes to the system's default output: in the headphones only you hear it; on the interface, the whole room does.
- Check that setting again after plugging the interface in: macOS readily switches the default output to a device that has just appeared.
- No Bluetooth for pre-listening. The latency runs into tenths of a second and the link can drop without warning.
- Do not create a multi-output or aggregate device in Audio MIDI Setup: they send the same signal everywhere, which is the opposite of what you want.
Balanced outputs
To reach a milonga's mixing desk over a long cable, balanced outputs (TRS jack or XLR) matter more than the channel count: they reject the hum and interference picked up along the way. That is what rules out hi-fi converters with RCA outputs, and what justifies buying an interface even if you never use its inputs.
Configuration Guide
Focusrite Scarlett 4i4
Installation
- Download Focusrite Control 2 from the Focusrite website. The 4th generation no longer uses Focusrite Control.
- Install the software and restart your Mac
- Connect your Scarlett 4i4 interface via USB
TandaBuilder Configuration
- Open TandaBuilder
- Go to Preferences > Audio
- Select Scarlett 4i4, outputs 1-2, for Live
- Select Scarlett 4i4, channels 5-6 (headphones), for pre-listening
- Test the configuration with a track
Troubleshooting
Same sound on Live and Pre-listen
- Most common cause: the headphones are plugged into an interface that has only one pair of outputs. Plug them into your Mac's headphone output instead.
- On an interface with an A/B button (PreSonus Studio 68c, MOTU M6), check that the button is switched to outputs 3-4.
- Restart TandaBuilder
No sound on outputs
- Check that the interface is properly selected in macOS Preferences
- Restart the audio interface
- Check connection cables
Buying Tips
Specifications checked against the manufacturers' documentation on .
A tested setup missing from this page? Write to contact@tandabuilder.com.