Retro Instruments 2A3 Dual Program EQ - Stereo All-Tube Equaliser
The Retro Instruments 2A3 Dual Program EQ is a dual-channel, all-tube equaliser inspired by the classic Pultec EQP-1A design - expanded, refined, and optimised for today's mastering and mix engineers.
It combines two complete passive EQ sections with Retro's precision high-voltage tube amplification to deliver rich harmonic warmth, velvety highs, and powerful low-end control.
The 2A3 is a mastering-grade equaliser that maintains all the musicality of the original vintage circuits while offering the consistency, reliability, and stereo precision of a modern professional unit.
Key Features
- Dual-channel design - true stereo EQ with fully independent controls for each channel.
- Classic Pultec-style passive EQ topology with Retro Instruments’ all-tube makeup gain stage.
- Boost and cut simultaneously for the famous Pultec low-end resonance and “push-pull” tone sculpting.
- Three-band EQ with low-frequency shelving, high-frequency peaking, and high cut filters.
- Premium tubes and custom transformers for unmatched clarity, warmth, and harmonic balance.
- High-voltage power supply for maximum headroom and ultra-low distortion.
- Balanced I/O on XLR for professional studio integration.
- Hand-built in the USA with military-grade components for long-term reliability.
- Perfect for mix bus, mastering, and tracking applications where musical tone shaping is essential.
Applications
- Mastering: Add analogue depth, smoothness, and air to full mixes with classic tube warmth.
- Mix Bus: Enhance low-end weight and top-end clarity for mix cohesion and polish.
- Vocals: Shape tone and presence naturally without harshness.
- Bass & Drums: Add punch, thickness, and analogue character to rhythm sections.
Technical Specifications
| Unit Type | Dual-Channel / Stereo All-Tube Equaliser |
|---|---|
| Circuit Type | Passive EQ network with Class A tube amplification |
| EQ Bands | Low Shelf Boost/Cut, High Shelf Boost, High Cut |
| Low Frequency Selection | 20, 30, 60, 100 Hz |
| High Frequency Boost | 3, 4, 5, 8, 10, 12, 16 kHz |
| High Frequency Cut | 5, 10, 20 kHz |
| Tubes | Matched high-voltage NOS dual triodes and pentodes |
| Transformers | Custom Retro Instruments input and output transformers |
| Frequency Response | 20 Hz - 20 kHz ±0.5 dB |
| THD + N | 0.05% typical (1 kHz @ +4 dBu) |
| Input/Output Impedance | 600 Ω balanced |
| Power | Internal universal power supply (100-240V AC) |
| Form Factor | 3U rackmount chassis |
| Weight | Approx. 9.5 kg |
| Origin | Hand-built in the USA |
Why Choose the Retro Instruments 2A3?
The Retro Instruments 2A3 Dual Program EQ captures the legendary Pultec-style tube tone in a precise, stereo-matched format built for modern studios.
Its ability to simultaneously boost and cut frequencies, combined with Retro's impeccable tube amplification, produces the signature silky highs, solid lows, and open midrange that define world-class analogue equalization.
Whether on the mix bus, mastering chain, or individual tracks, the 2A3 delivers vintage warmth with modern fidelity - a must-have for professional engineers seeking timeless musicality.