LANG Electronics P.LANE Type 436

Through the ’50s and ’60s, Altec’s 436 compressors were often modified and hugely influential. But this keenly priced homage does more than clone these vintage devices.

The LANG Electronics name is now owned by Heritage Audio, and with the P.LANE Type 436 variable‑mu valve compressor they’ve moved the brand’s focus from New York to a “London studio” where a “particularly talented band from Liverpool” recorded during the 1960s. It doesn’t take Sherlock Holmes to figure out the reference to EMI’s recording studios on Abbey Road, and omnipresent in those studios during the 1960s were a number of Altec Model 436A & 436B valve‑based variable‑mu compressors, imported from the USA in 1958 and modified in‑house by the EMI engineers. Heritage Audio’s engineers have taken their inspiration from a slightly different variant, the Altec 436C, which was developed in the early 1960s by Altec themselves, in response to the widespread practice (on both sides of the Atlantic) of modifying their earlier units.

Vibe & Valves

Aesthetically, the P.LANE 436 nails the 1950s vibe of the vintage units, with a 2U grey fascia, chicken‑head knobs, circular analogue meter and red jewel power indicator lamp. To the far left of that meter, which displays up to 30dB of gain reduction, sits a detented, passive rotary input level attenuator, followed by a smaller vertical pairing of Attack and Recovery (release) selection switches. Each gives access to six settings, but the Recovery switch has an additional five Hold positions too, of which more later.

To the right of the VU meter another vertical control column consists of a six‑position DC Threshold control and two screwdriver‑adjustable trim pots: one called Zero, to set the meter’s 0dB point, and the other Balance, to rebalance the triodes of the P.LANE 436’s variable‑mu valve, to minimise any low‑frequency artefacts that may arise as that valve ages. Sitting next to these you’ll find the detented, passive rotary Output Attenuation control, and this is followed by an on/off toggle switch and the jewel lamp. At the rear are the expected XLRs and the less expected parallel 6.35mm jack sockets carrying the balanced audio I/O, a 220/110 V mains voltage selector, and a fused IEC mains socket.

As with all of the Heritage Audio products that I’ve reviewed, the PCB layout, its components (all full‑size, through‑hole) and the overall construction are of exemplary quality. A compact toroidal mains transformer is bolted vertically to the right‑hand end of the chassis. The main PCB carries the analogue power supply, side‑chain and audio circuitry, together with the P.LANE 436’s three valves. The Heritage Audio‑designed, LANG‑branded input transformer features a high‑nickel alloy core and a mu‑metal shielding can, and sits on a small board at the left‑hand end of the chassis. The output transformer, another in‑house design this time equipped with an M6 silicon steel core, to help create colour and harmonic distortion at the output stage, is bolted down behind the main PCB next to a large heatsink.

The increasing lack of availability of quantities of reasonably priced, high‑quality NOS (new old stock) vintage valves in both the short and long term is a growing challenge, for both equipment manufacturers and guitarists like myself. Heritage Audio, though, seem adept at overcoming this challenge, as illustrated, for example, by the substitution of 16 6BA6s for eight 6386s in their Herchild 670 compressor. Such availability...