High Performance Audio Transformers | DATA SHEETS
Moving Coil Step-Up, Microphone, DI Box & Line Transformers
… audio transformers at a glance;
- Moving Coil Cartridge Step-up transformers
- Microphone Input and Splitting Transformers
- Direct Injection (DI) Box Transformers
- Line Input & Output transformers
High performance audio transformers, designed and manufactured by OXFORD ELECTRICAL PRODUCTS (OEP) OXFORD, ENGLAND. Explore OEP (a Carnhill Group company) one of the UK’s leading and globally respected wound component manufacturers.
OEP Moving Coil (MC) Step-Up Transformers
Step-up Moving Coil Transformers match low-output, low impedance moving-coil pickups to standard phono pre-amps. Harmonic distortion in Moving Coil Transformers is greatest at the lowest frequencies and falls rapidly as the frequency rises.
- MC Transformers – Harmonic distortion falls rapidly as the frequency rises.
- In transistor amplifiers, distortion usually rises as the frequency rises.
Transformers aren’t absolutely free of distortion, however the distortion produced by many transistor amplifiers is very benign compared to the distortion of transformers-less amplifiers.
Moving Coil (MC) Transformers CLICK HERE
| MODEL | APPLICATION | Fitment | TURNS Ratio | Maximum Load Signal | DATA SHEET | |
| A187A16C/1 | MC step-Up | PCB Mounted / Through Hole | 1 C.T. : 7 or 10 | @ 20Hz for <1% THD: -4.6dBu | CLICK HERE | |
OEP Microphone INPUT Transformers
Microphone transformers are used for;
- impedance matching to the pre-amplifier stage
- mic pre-amp input circuits to match microphones to pre-amp,
- in tube microphones for matching high impedance tube circuits to normal output impedance
- in ribbon microphones to transform very low voltage, very low impedance ribbon motors to normal microphone output levels.
Microphone transformers CLICK HERE
| MODEL | APPLICATION | Fitment | TURNS RATIO | Impedance ratio | Maximum Load Signal | DATA SHEET |
| Z30A23C | Microphone INPUT Transformer | PCB Mounted / Through Hole | 1+1 to 5 | 150Ω (primaries in parallel) 600Ω (primaries in series) | @ 20Hz for <1% THD: -6dBu, primaries in parallel :0dBu primaries in series | CLICK HERE |
| X187B | Microphone MATCHING Transformer | Chassis mounted | 1 CT : 9.13 | 200Ω or 600Ω CT to 50kΩ | Maximum input level for <1% THD: 0dBu | CLICK HERE |
| J30A19C | Microphone INPUT Transformer | PCB Mounted / Through Hole | 1 to 7 | 200Ω to 10kΩ | @ 20Hz for <1% THD: 9dBu | CLICK HERE |
| J30A11C | Microphone INPUT Transformer | PCB Mounted / Through Hole | 1+1 : 5 | 150Ω to 10kΩ | @ 20Hz for <1% THD: +4dBu | CLICK HERE |
| J30A03C | Microphone INPUT Transformer | PCB Mounted / Through Hole | 1+1 : 1+1 | 150Ω (primaries in parallel), 600Ω (primaries in series) | @ 20Hz (1% max. THD): +0.5dBu, primaries in parallel +6dBu, primaries in series | CLICK HERE |
| A187A36C | Microphone INPUT Transformer | PCB Mounted / Through Hole | 1+1 : 10 | 150Ω / 600Ω to 15kΩ | @ 20Hz <1% THD: -2.5dBu | CLICK HERE |
| A187A18C | Microphone INPUT Transformer | PCB Mounted / Through Hole | 1 : 5 | 200Ω to 5kΩ | @ 20Hz <1% THD: -4dBu | CLICK HERE |
| A187A15C | Microphone INPUT Transformer | PCB Mounted / Through Hole | 1 C.T. : 10 | 150Ω to 15kΩ | @ 20Hz (8-5) < 1% THD: -5dBu | CLICK HERE |
| A187A14C | Microphone INPUT Transformer | PCB Mounted / Through Hole | 1+1 : 8 | secondary loaded with 7360Ω : 150 parallel / 600 series | @ 20Hz for <1% THD: -6dBu (primaries in parallel) | CLICK HERE |
OEP Microphone SPLITTING Transformers
Transformers designed to split microphone signals, providing isolation that will keep components from reacting with each other in unpredictable ways. These audio transformers provide two isolated balanced outputs.
| MODEL | APPLICATION | Fitment | TURNS RATIO | Impedance Ratio | Maximum Load Signal | DATA SHEET |
| J30A09C | Microphone SPLITTING Transformer | PCB Mounted / Through Hole | 1 to 1:1:1 | 150Ω | @ 20Hz (1% max. THD): +11.6dBu | CLICK HERE |
| A187A11C | Microphone SPLITTING Transformer | PCB Mounted / Through Hole | 1 : 1 : 1 | 578Ω | @ 20Hz for <1% THD : 1.2dBu | CLICK HERE |
OEP Direct Injection (D.I.) Transformers
Transformers designed for;
- DI for electric Guitar
- coupling instrument pick-ups to low impedance microphone inputs
- Converts unbalanced line level (high impedance) instrument signals to balanced microphone input level for direct connection to a mixing desk
- Long Cable runs without HF loss
DI Box transformers CLICK HERE
| MODEL | APPLICATION | Fitment | TURNS RATIO | Impedance Ratio | Maximum Load Signal | DATA SHEET |
| A187A10C | Direct Box (D.I.) transformer | PCB Mounted / Through Hole | 11.5 : 1+1 | 40kΩ to 1kΩ | @ 20Hz with <1% distortion: +21.5dBu | CLICK HERE |
OEP AUDIO LINE INPUT Transformers
Typically used to balance any high impedance unbalanced input. For eliminating hum and buzz in line-level signals, Faraday-shielded input transformers are the preferred solution.
Electrically hostile environments can cause “breakthrough” noise in transformer-less inputs, whereas trasnformer inputs remain unaffected.
LINE INPUT transformers CLICK HERE
| MODEL | APPLICATION | Fitment | TURNS Ratio | Impedance Ratio | Maximum Load Signal | DATA SHEET |
| Z1643E | Line Input Transformer | PCB Mounted / Through Hole | @ 6 kHz, 0.1Vrms): 1 : 1 C.T. | 10kΩ to 10k C.T. | @ 30Hz for <1% THD: +4dBu @ 20Hz for <1% THD: -1.5dBu | CLICK HERE |
OEP AUDIO LINE OUTPUT Transformers
Line output transformers allow any balanced or unbalanced output stage circuit, to drive any balanced or unbalanced equipment input. This type of audio line transformer provides sonic isolation and thereby substantially reducing hum. These transformers are typically used for high performance output stage circuits.
LINE OUTPUT transformers
| MODEL | APPLICATION | Fitment | TURNS Ratio | Impedance Ratio | Maximum Load Signal | DATA SHEET |
| coming soon | Line Output Transformer |