Single purpose: verify phono cartridge functionality (both channels alive, sane balance/polarity, no obvious severe faults) using in-browser audio measurement (Web Audio API).
Recommended signal chain: turntable → phono preamp → stereo line‑in / USB audio interface → this tool. Avoid mic inputs.
1) Connect + start
- Connect phono preamp output → stereo line‑in / USB audio interface (avoid mic inputs).
- Disable OS “enhancements” (AGC, noise suppression) if possible.
- Click Start, choose the right input, and confirm the L/R meters move.
2) Cartridge functionality health check
- — Overall
- — Hard clipping
- — Soft clipping (likely)
- — Input looks mono / channels identical
- — Channel swap (L/R)
- — Noise floor (crosstalk reliability)
3) Visual tools
Phono cartridge troubleshooting guide
“My turntable is only playing out of one speaker” is the classic phono panic. The tricky part is that the cartridge is only one link in a chain: turntable → headshell leads → tonearm wiring → RCA cables → phono preamp → audio interface → this tool. The goal is to use repeatable checks (ideally a test record) to narrow the problem down without randomly swapping parts.
Start simple: play any music and confirm both input meters move. If one side is dead, don’t jump straight to “bad cartridge.” First reseat the headshell leads and RCA plugs (oxidation is real), and confirm your interface is truly taking a stereo line‑level signal (not a mono mic input with “enhancements”).
Once both channels are alive, use a steady 1 kHz band (or any stable tone) to check channel balance. A tiny mismatch is normal, but a big imbalance usually points to wiring, a loose clip-on lead, a partially open coil, or a preamp/interface gain mismatch. If you can safely swap left/right at the headshell (or swap the RCA inputs), do it: if the problem moves, the cartridge/headshell side is implicated; if it stays put, look downstream.
Next: polarity / phase. A mono in‑phase band should show high correlation. If correlation is strongly negative (or the “center image” sounds weird on speakers), you may have a polarity inversion on one channel (miswired headshell lead, swapped pins, or a cable adapter that flips polarity). Fixing this is often a “wow, that was it” moment, especially for bass and center imaging.
For test records that include left‑only / right‑only bands, measure crosstalk (separation). Nobody gets infinite separation, but if your “left-only” band bleeds heavily into the right channel, double-check wiring first. If wiring is correct, low separation can be caused by stylus/azimuth issues, cantilever misalignment, or simply a mediocre/worn test record. Use separation as a relative tool (compare after adjustments), not as a lab-grade absolute.
Finally, if the problem you’re chasing is “distortion,” decide whether it’s mistracking or overload/clipping. Mistracking often gets worse toward inner grooves and reacts to tracking force/anti‑skate. Overload/clipping is more about gain staging: it changes when you reduce gain or switch to a lower‑gain phono setting. This tool can flag obvious clipping and unusually high THD as a hint, but it can’t magically tell you which component is “at fault” without good test signals.
About the Built-in Stereo Test Record Database
This page (and my other Web‑Audio test‑record tools) ships with a starter reference database of common stereo test records. The idea is simple: many measurements rely on specific bands (stereo tone, mono/in‑phase tone, left‑only/right‑only, sweeps, pink noise, etc.). If you know which test record you own, you can quickly find the closest matching bands and run the right measurement mode without guessing.
The database is a convenience layer, not a gatekeeper. You can still use this tool with any record (or even music) for basic “is it alive?” checks. But if your record is listed, the presets help keep troubleshooting repeatable: same band, same workflow, easier before/after comparisons. Like any hobby database, it’s compiled from public sources and may not capture every pressing variation—so treat it as a starting point and verify against your jacket/insert when it matters.