{ "product_id": "product:emiuzek-q7", "reported_on": "2026-09-29", "measurement_date": "2026-09-29", "attribution": "SoundPath Lab tester Rojas; test date confirmed by site owner on 2026-10-07. Measurements were supplied by the tester, not performed by the software agent.", "method": { "input": "USB; computer Type-C", "signal_hz": 1000, "signal_dbfs": -3, "dac_volume": 100, "meter": "UNI-T UT61E+", "xlr_contacts": "pins2–3; explicitly confirmed for unit B", "sample_rate_hz": 48000, "bit_depth": 24, "audio_file_status": "Generated24bit/48kHz tone available in preceding task; exact played file checksum not recorded", "load": "Pending confirmation: no external load value supplied", "meter_range": null, "calibration": null, "os": null, "player": null, "system_volume": null, "player_volume": null, "uncertainty": "Unknown; displayed digits do not establish accuracy. No calibrated analyzer or clipping test." }, "measurements": [ { "sample_id": "Q7-A", "output": "RCA", "L": 1.611, "R": 1.6097, "unit": "Vrms", "source": "user supplied formal summary", "estimated_0dbfs": { "L": 2.2755979843872574, "R": 2.2737616855792475, "method": "V(-3dBFS) ×10^(3/20); assumes linear unclipped behavior; not directly measured" }, "channel_difference_db": 0.007011927309412822 }, { "sample_id": "Q7-A", "output": "XLR", "L": 2.951, "R": 2.915, "unit": "Vrms", "source": "user supplied formal summary", "estimated_0dbfs": { "L": 4.168398294181748, "R": 4.117546942575329, "method": "V(-3dBFS) ×10^(3/20); assumes linear unclipped behavior; not directly measured" }, "channel_difference_db": 0.10661300809853227 }, { "sample_id": "Q7-B", "output": "XLR", "L": 2.936, "R": 2.924, "unit": "Vrms", "source": "latest user test; L/R order and same conditions explicitly confirmed", "estimated_0dbfs": { "L": 4.147210231012407, "R": 4.130259780476933, "method": "V(-3dBFS) ×10^(3/20); assumes linear unclipped behavior; not directly measured" }, "channel_difference_db": 0.03557365916420072 } ], "bluetooth_supplement": { "L": 1.3244, "R": 1.3082, "unit": "Vrms", "output": "XLR", "sample_id": "Unknown", "signal_level": "Pending", "codec": "Unknown", "source_volume": "Unknown", "absolute_volume_setting": "Unknown", "interpretation": "A lower level was observed in that setup. Uncontrolled source/codec/volume settings prevent attributing the difference to an inherent Bluetooth output limit. Not maximum-line-output evidence." }, "observations": [ { "test": "Power-on", "result": "Approximately1.07s; timing method/repeats Unknown", "source_id": "q7-hands-on" }, { "test": "Input memory", "result": "Retained", "source_id": "q7-hands-on" }, { "test": "Volume memory", "result": "Retained", "source_id": "q7-hands-on" }, { "test": "USB", "result": "No manual driver installation needed on tested computer", "source_id": "q7-hands-on" }, { "test": "USB sleep/wake", "result": "Normal in tested setup", "source_id": "q7-hands-on" }, { "test": "Optical", "result": "Recognized and operated", "source_id": "q7-hands-on" }, { "test": "Bluetooth first connection", "result": "Under1s, reported", "source_id": "q7-hands-on" }, { "test": "Bluetooth reconnection", "result": "Under1s, subjectively near immediate", "source_id": "q7-hands-on" }, { "test": "Bluetooth continuity", "result": "1hour without disconnects/stutter", "source_id": "q7-hands-on" }, { "test": "Extended playback", "result": "24hours without stopping/disconnection; input/path and log Pending", "source_id": "q7-hands-on" }, { "test": "Play/pause", "result": "No subjectively obvious delay; not measured end-to-end latency", "source_id": "q7-hands-on" }, { "test": "Input switching", "result": "No audible pops", "source_id": "q7-hands-on" }, { "test": "Mute", "result": "Worked; no audible residual noise", "source_id": "q7-hands-on" }, { "test": "RCA/XLR volume", "result": "Both adjustable", "source_id": "q7-hands-on" }, { "test": "Headphones", "result": "6.35/4.4 at20–50%: no audible hiss,pops or electrical buzz; headphone models/impedances Unknown", "source_id": "q7-hands-on" }, { "test": "Temperature", "result": "No obvious warmth by hand after1hour; not thermometry", "source_id": "q7-hands-on" } ], "diy": { "label": "Three socketed, user-replaceable op-amp positions", "label_zh": "三处插座式可更换运放位", "paths": [ "Stock / Reference", "DIY / Tuning", "DIY / Measurement" ], "owner_reports": [ "Differences between some DIY combinations were repeatedly identifiable to the user; blind/level-matched protocol and trial data not provided.", "Stock op-amp configuration was consistent across batches examined by the user; batch IDs/count and exact markings Pending." ], "stock_marking_issue": "Commercial page lists IRC5535×2 +OPA1642×1; do not silently correct marking or treat it as verified stock BOM.", "compatibility": "Unknown beyond specifically verified combinations; do not infer arbitrary op-amp compatibility or universal improvement.", "pending": [ "Exact part numbers and positions", "Supply/package/pinout compatibility", "Level-matched stock-vs-one-DIY test", "Noise/distortion and stability checks", "Batch IDs and sample photographs" ] }, "external_video": { "source_id": "q7-video", "reported_topics": [ "Frequency response", "THD", "THD+N", "IMD", "Noise", "Dynamic range", "Crosstalk", "Channel balance", "Multitone", "Bluetooth path" ], "original_url": null, "reviewer": "Christian Schwarzbeck / China-HiFi", "timestamps": null, "sample_configuration": null, "measurement_conditions": null, "advertising_or_cooperation_disclosure": "The supplied video visibly displays Werbung (German: advertising). No further commercial terms were supplied.", "numeric_values": [], "status": "Supplied media reviewed for identity and visible disclosure only; numerical measurements were not imported." }, "next_tests": [ "6.35mm loaded voltage/power at32/150/300Ω", "4.4mm balanced loaded tests", "Stock versus one fully documented DIY combination", "Meter range/calibration/source settings", "Direct0dBFS check with clipping assessment if instrument available" ], "tested_by": "Rojas", "date_confirmed_on": "2026-10-07" }