Why Test Cuts Are the Only Way to A/B Properly
In the world of lathe cutting, A/B comparisons are essential for understanding how your audio is translating from digital to disc. But how you A/B makes all the difference. One of the most common problems we help people with — especially users of the Vinyl Recorder T560 — is identifying why real-time comparisons while cutting are misleading and ultimately a bad habit to fall into.
The Vinyl Recorder T560’s stock configuration includes a feature for live A/B switching — letting you flip between the original digital source and the playback from the disc while the record is being cut. On paper, this sounds great: you can hear how things are translating in real time and make adjustments on the fly.
But from a mastering perspective, this setup is not just ineffective — it’s misleading.
Problem 1: Room Noise Skews Perception
Cutting vinyl is a physical process. The lathe is running, the cutterhead can be loud, the swarf vacuum is pulling. Even in a treated room, you're listening through a cloud of mechanical noise. This masks crucial frequency content — especially in the highs — and tricks your ears into misjudging tonal balance, sibilance, stereo width, and transient detail. You’re not making informed choices; you’re reacting to interference.
Problem 2: Groove Playback is Delayed
In systems like the T560, the playback stylus is physically positioned several grooves behind the cutterhead For some good info on this and over cutting, check the latest Phonolab video HERE). This means the audio you're hearing is delayed by several seconds. So when you switch between the live source and the disc playback, you're not comparing the same musical phrase — you're comparing mismatched moments. That makes direct, meaningful comparisons almost impossible.
Why Test Cuts Are the Only Way to Do It Right
If you want to improve your cutting and make confident, accurate mastering decisions, test cuts followed by critical playback are the only way to do it properly. Here's why:
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Quiet Environment
Once the cut is done, record it back so that you can listen on speakers or accurate headphones — free from the hum and vibration of the lathe environment. -
Frame-Accurate A/B in the DAW
Record your test cut back into your DAW and line it up with the original digital file. This lets you do proper level matching and phase-accurate switching between the two. Now you’re truly hearing how your system is translating signal to groove. -
Loop Specific Phrases
This gives the ability to loop a section and compare it over and over, switching instantly between source and vinyl. This can be good when trying to identify problems.
At the end of the day, vinyl cutting isn’t just about the hardware — it’s about how you use your ears. And your ears can only work at their best when you remove the noise, sync your signals, and give yourself the space to focus. Real-time A/B might feel like a shortcut, but it’s a distraction at best and misleading at worst.
In short: Make test cuts. Record them. Compare critically.