Project Background
The client is an event equipment rental company. During multi-venue tours, they frequently encountered AC hum and high-frequency crosstalk caused by ground potential differences between mixing consoles and stage power amplifiers. After using ordinary isolators, the low-frequency response degraded noticeably.
Technical Challenges
- Required a 1:1+1+1 multi-winding configuration to support one input feeding two power amplifiers;
- Low-frequency extension must not be compromised after isolation, with attenuation at 20Hz kept below 0.5dB;
- Equipment is frequently transported, requiring resistance to drops and connector insertion/withdrawal impacts;
- Short lead time required, needing off-the-shelf availability.
Our Solution
Built around a permalloy multi-winding audio transformer, combined with a metal shielded enclosure and XLR pass-through design:
- 1:1+1+1 winding structure, with two independent isolated outputs that can be grounded separately to break ground loops;
- Large-cross-section magnetic core ensures no saturation at 20Hz, with low-frequency attenuation controlled within 0.3dB;
- Transformer is fully epoxy-potted in a die-cast aluminum housing, resistant to drops and connector stress;
- Standard models maintained in safety stock, with small batches shipped within 3 days.
Delivered Results
- Ground loop hum and high-frequency crosstalk completely eliminated in on-site field tests;
- Frequency response deviation across 20Hz-20kHz within ±0.4dB, with no perceptible degradation in subjective listening;
- Continuous supply to this rental company for two years, with a return rate below 0.5%;
- The series was later adopted by the client for fixed installation projects.