If you crave the vintage API sound but the budget is a little tight, this might be worth a look...
Back in 2011, Black Lion Audio (BLA) took inspiration from API’s legendary 1960s Model 312A to launch the B12A microphone preamplifier, and they’ve now updated this to the B12A MkII. The major difference is the change to Cinemag’s version of the original API 2622 input transformer and an Edcor API-style 600Ω output transformer. Like its predecessor, the B12A MkII is not an exact clone of an API 312, but is rather a re-engineered recreation. Although surface-mount capacitors and thick-film resistors are present, the audio path is populated with full-size capacitors that have been chosen for their sonic performance. An API 312 card is not exactly a complex piece of circuitry, being basically a transformer, feeding a discrete op amp (the API 2520), feeding an output transformer. The B12A MkII, which is available in both 1U half-rack-width and 500-series versions, with identical facilities, follows this basic topography, and adds the additional circuitry required to provide an instrument DI input and switchable 48V phantom power. In addition to the latter are the usual switches for power, polarity invert and pad (-18dB), plus a large red gain knob. A high-impedance quarter-inch TS instrument DI input jack and its switch complete the picture. On the rear of the rack version, where you might expect to see an XLR, the balanced, line-level output appears on a quarter-inch TRS jack. The idea is that this simplifies the connection to consoles and audio interfaces, most of which have quarter-inch-jack line inputs. Power for this version is delivered via a 24V AC wall-wart power supply.
The effect of pushing the gain of a mic preamplifier with a transformer-balanced output is much of the attraction of owning one (or several). The B12A MkII has no output level control or metering, though, so if you wish to do this you’ll need an external means of padding down the output, to avoid unwanted overload further along the signal path.
I’ve always thought of the API 312, with its characteristic forward mid-range, as being the Neve 1073’s slightly brasher American cousin, and the B12A MkII carries on in that vein. Its bottom end feels tight and deep, although not overly warm, and the top end sounds open but not harsh. Combined with the forward mids, these give the B12A MkII a clear and punchy character that works really well on vocals and acoustic instruments. Another characteristic of the B12A MkII is the amount of headroom available which, coupled with its fast transient response and low noise floor, make it ideal for use on drums and percussion. As an instrument DI, the B12A MkII puts a driving edge into both electric guitar and bass, especially with the gain control wound up a bit to drive the output transformer.
If you’ve ever wondered what all the fuss is about, the B12A MkII will give you much of the flavour of a vintage 312 preamp without the price tag the original commands. At its price, I think that the B12A MkII is actually a bit of a bargain, and if you’re looking for a new mic pre it’s one that you ought to listen to. Bob Thomas

FEATURES

Cinemag Input Transformer
Edcor Output Transformer
70dB Gain
Hi-Z Input (passive, unbalanced)
Phantom Power
18dB Pad
Phase Switch
XLR Microphone Input
TRS Line Output (balanced)