Analog Summing with a Variable Frequency Transformer
Why NE2OX?
NE2OX — named after its signal path: the NE5532 balanced summing amplifier and the Oxford variable-frequency transformer that defines its tone.
At the core are dual Oxford transformers driven by a stereo-balanced NE5532 summing stage. Unlike fixed-character transformer designs, this circuit allows direct control over the frequency emphasis of the analog mix bus — switchable from the front panel in real time.e.
Flat, Dark, and Air shift the operating point of the transformer, shaping the mix bus response without EQ or additional processing.
Currently building to order — contact us for availability.
Technical Design by VintageMaker
The Flat, Dark, and Air modes are created by a precision secondary loading network on the Oxford A2E/A7E transformer. Switching calibrated resistor loads changes the impedance seen by the transformer, producing three distinct tonal responses without any active EQ or DSP in the signal path.
Flat / Dark / Air frequency response
This is not EQ. No frequencies are boosted or cut. Instead, each mode shifts the transformer’s operating behavior by changing the load on its secondary winding.
The result is a natural change in harmonic balance and frequency contour — a tonal character created directly by the transformer itself.
Where the NE2OX Fits in the Active Rack Range
| Unit | Transformer | Character |
|---|---|---|
| NE2OX Oxford | Oxford A2E / A7E variable frequency | Flexible — Flat / Dark / Air switchable |
| Lawo DV975 | Haufe / Pikatron fixed character | Warm, precise, musical depth |
| Filtek DV1175 | Neumann-Haufe fixed character | Transparent, punchy, Swiss precision |
| Neumann V475 2A / 2C / 2B | Genuine NOS Haufe RK292 / RK310 | Vintage German console — 3 harmonic variants |
SEE OTHER Transformer Amp Options
Every VintageMaker active rack summing mixer is built around a genuine vintage transformer amplifier module. The transformer is the source of harmonic character, stereo imaging, and analog depth — choose the one that matches your sonic goals.
Looking for more harmonic density at a lower price point? The Filtek-Neumann SSL-Style and Lawo API-Style also use genuine Neumann-Haufe transformers and deliver comparable harmonic performance.
→ Compare all transformer options →Compatible Interfaces
The NE2OX works with any audio interface with balanced line outputs — UAD Apollo, RME Fireface, Antelope Orion, Focusrite Red, MOTU, Prism Sound, and others. Specify your interface model when ordering for custom calibration.
Frequently Asked Questions
Does the NE2OX require external gain recovery?
No. The NE2OX includes a balanced NE5532 output stage with built-in gain recovery. The unit outputs at standard line level — no external preamp is required after the summing stage.
What is the difference between the NE2OX and a fixed-character transformer unit?
ransformers from Haufe, Neumann, Lundahl, or Carnhill typically have a well-defined tonal signature shaped by core material, winding geometry, leakage inductance, parasitic capacitance, and load conditions. That character is fixed at the design stage and remains constant during operation.
The NE2OX uses a variable-load design. Switching calibrated resistors on the transformer secondary changes the impedance the transformer sees, producing three distinct and measurable frequency responses from a single unit.
Can I order a custom channel count?
Yes. The NE2OX is available in custom configurations with TRS, XLR, or DB25 connectivity. Each unit is optimized for your interface output level. Typical build time is 10–16 working days after configuration approval.
How do the Flat, Dark, and Air modes actually work?
By switching precision resistors on the secondary side of the Oxford A2E/A7E transformer. Each resistor presents a different load impedance, altering the transformer’s frequency contour — no EQ, no DSP. Pure impedance-dependent frequency shaping.
Ready to Design Your Custom Analog System?
Every VintageMaker unit — from desktop mixers to 96-channel systems — is built to work perfectly with your studio.
Browse the full range of Active Rack Summing Mixers → Request a custom build →
