01
Connect the measurement chain
Connect the system’s stereo REC OUT or PRE OUT to a compatible class-compliant USB audio interface, then connect the interface to the iPhone using the appropriate USB-C or Lightning adapter.
Groove Scope
Resonance Lab is a free tonearm and cartridge compatibility app for iPhone and iPad.
Portable turntable analysis for iPhone
See what every adjustment changes.
Groove Scope uses paired left- and right-channel 1 kHz test-record signals to evaluate cartridge alignment, channel separation, distortion and rotational stability—directly on your iPhone.
Upgrade to Groove Scope Pro for €59.99 — introductory lifetime price.
Groove Scope
1 kHz analysis
Azimuth Quick Check
Signal ready · paired reference capture
Live stereo input
Ready
L
-8.4
R
-9.1
Reference trace
Stable
Channel separation
27.8 dB
Mean speed
33.34
Balance
0.4 dB
Repeatability
High
Measurement, not guesswork
Every result comes from a captured reference signal.
Portable reference chain
Interface input, guided capture and saved evidence.
A specialist measurement instrument for vinyl enthusiasts, hi-fi owners and turntable technicians.
1 kHz
Paired reference tracks
L + R
Channel-resolved capture
Repeatable
Evidence across adjustments
Measurement instead of guesswork
A clearer way to set up a cartridge.
Small adjustments can change crosstalk, channel balance, harmonic behaviour and speed evidence. Groove Scope makes those changes visible through a guided, repeatable workflow.
02
Capture the paired references
Play the required left- and right-channel 1 kHz tracks from a supported test record. Live input meters and signal-readiness checks help establish a clean, safe recording level.
03
Review the evidence
Follow the guided capture, inspect the resulting measurements and use the evidence to inform cartridge or turntable adjustments. Pro users can save sessions and export standard PDF reports.
Required signal path
Turntable
→
Phono stage / amplifier
→
REC OUT or PRE OUT
→
USB audio interface
→
iPhone
Start with the essential azimuth check.
Capture the paired 1 kHz reference tracks and see the measured channel separation. Groove Scope Free also helps verify signal readiness and set a safe input level before every capture.
- Guided 1 kHz Azimuth Quick Check
- Left- and right-channel reference capture
- Signal-readiness and input-level checking
- Channel-separation result
- Live stereo input meters
- Guided connection instructions
- Supported-record reference information
The complete 1 kHz reference analysis.
Groove Scope Pro reveals directional crosstalk, channel balance, harmonic distortion, RPM accuracy and speed stability. Save every session, revisit results and generate a professional standard PDF report.
- Directional crosstalk and asymmetry
- Channel balance in decibels
- THD with H2–H5 harmonic profile
- Rotation-to-rotation reliability evidence
- Mean RPM, error and settled range
- Wow, flutter and raw speed variation
- Saved sessions and measurement history
- Standard shareable PDF reports
Pro analysis
More than a single separation number.
The paired left/right captures reveal how the two channels behave independently, how repeatable the result is and how the 1 kHz carrier changes over time.
Directional crosstalk
Reports left-to-right crosstalk, right-to-left crosstalk, average channel separation and asymmetry.
Channel balance
Measures the left/right output-level difference in decibels, helping identify cartridge, alignment or signal-chain imbalance.
THD and harmonic profile
Provides channel-resolved total harmonic distortion with H2, H3, H4 and H5 components.
Reliability evidence
Shows rotation-to-rotation repeatability so the user can judge how stable the captured result is.
Accurate RPM analysis
Uses the phase-tracked 1 kHz carrier to report mean platter speed, RPM error, settled range and rotation consistency.
Speed-stability diagnostics
Derives wow, flutter, raw speed variation and short-term rotational stability from the captured 1 kHz reference signal.
Saved sessions
Maintain a measurement history and revisit earlier results to follow turntable performance over time.
Standard PDF reports
Generate complete, shareable reports using the built-in Groove Scope and Direct Sound Records branding.
Guided capture workflow
Live input meters, readiness checks and clear left/right capture guidance support repeatable measurements.
Measurement results
Clear evidence, presented as an instrument.
Replace the three panels below with real Groove Scope screenshots from the WordPress Media Library. Keep each image’s crop and proportions consistent for a premium, stable layout.
Add the main results screenshot
Recommended: directional crosstalk, channel balance or the full analysis summary.
Add the THD screenshot
Use the real H2–H5 channel-resolved measurement screen.
Add the RPM screenshot
Use the real mean speed, error, range or wow/flutter display.
Free versus Pro
Begin with a useful tool. Upgrade for the full evidence.
| Feature | Free | Pro |
|---|---|---|
| Live stereo input monitoring | ✓ | ✓ |
| Signal-readiness check | ✓ | ✓ |
| Guided left/right 1 kHz capture | ✓ | ✓ |
| Azimuth quick check | ✓ | ✓ |
| Channel-separation result | ✓ | ✓ |
| Directional crosstalk | — | ✓ |
| Crosstalk asymmetry | — | ✓ |
| Channel balance in dB | — | ✓ |
| THD and H2–H5 profile | — | ✓ |
| Rotation reliability evidence | — | ✓ |
| Mean RPM and speed error | — | ✓ |
| Settled RPM range | — | ✓ |
| Wow, flutter and speed variation | — | ✓ |
| Saved sessions and history | — | ✓ |
| Standard shareable PDF reports | — | ✓ |
Supported reference records
Use dedicated left/right 1 kHz tracks.
Groove Scope is compatible with supported records containing dedicated left- and right-channel 1 kHz reference tracks.
Ortofon Test Record
Use the paired left- and right-channel 1 kHz reference tracks presented by the app.
The Ultimate Analogue Test LP
The app directs the user to Side 1, tracks 2 and 3.
Compatibility should not be assumed for every test record. The record must provide
the required dedicated left/right 1 kHz reference signals.
Hardware requirements
Groove Scope measures the electrical signal.
The app does not analyse the turntable through the iPhone’s built-in microphone. It forms part of a proper stereo measurement chain.
- An iPhone
- A compatible class-compliant USB audio interface
- A suitable Lightning or USB-C connection or adapter
- Stereo REC OUT or PRE OUT from the audio system
- A supported test record with paired left/right 1 kHz tracks
Groove Scope for iPhone
Start with the essential check. Unlock the complete evidence when you’re ready.
Download Groove Scope Free for the guided 1 kHz azimuth quick check. Upgrade to Groove Scope Pro for complete cartridge, distortion, RPM and speed-stability analysis, saved history and shareable PDF reports.
Groove Scope provides measurement evidence derived from supported test-record signals and the connected audio chain. Results can be affected by record condition, interface configuration, gain structure, electrical noise and mechanical setup. Measurements should be interpreted as part of a careful adjustment process.