Tube 47 - Braingasm Custom

My Neumann U47 needed functional restoration, and once it returned back, shining like the sun, it gave us an idea: a Braingasm-branded valve U47.

Aware that we were stepping onto the field for the Champions League final, we got to work for many months, studying the original schematics and various "clone" projects, testing the Neumann in all its aspects to discover its versatility, and soldering away. Finally, we are ready to present it.

Like other handmade microphones born in the lab, this is not just another U47 clone or replica in circulation. We aim to create something innovative, inspired by the genius of our predecessors. Always keeping in mind that the Braingasm Lab’s mission is to offer high-quality sound at an affordable price for everyone. We seek to move forward, not sideways.

Before diving into the usual technical details, we are publishing the beta test of the finished microphone, compared to the original Neumann and a Braingasm Deluxe with a Gefell M7 capsule, the flagship model of our transistor series. The microphones are positioned as close as possible to each other, about 3 meters from the drum kit. The preamp used is a Tubetech. Check out the sound:

We have a long testing session planned where we aim to be as comprehensive and precise as possible, appreciating the performance of our new tube microphone on vocals, electric, and acoustic instruments. For now, we'll settle for these three tracks. Follow us to hear the rest.

After treating your ears with some snare and kick, let's finally move on to our beloved technical details:


Let's start with the body, made in Europe with CNC machines. Like the original model, the grille has three levels of mesh, the basket is made of copper, and the body is anodized aluminum. We experimented with other models, shapes, colors, and materials, but the nuclear torpedo has always been the hands-down winner.

Braingasm Tube 47 - Long Body

Braingasm - Laboratorio Microfoni Artigianali - U47 Custom

Neumann U47 Short Body (1960)

1960 Neumann U47

We've maintained the original layout and point-to-point wiring on the sides of the transformer, ensuring that the high-impedance area is as close as possible to the capsule and valve. Our electronic design differs from the original in many aspects, including the capsule biasing circuit and the tube’s power supply voltages. Among various options, we've chosen a Telefunken EF800, powered according to specifications.

NOS Telefunken EF800 tube, AMI BV8 transformer, MKP film capacitors

Braingasm - Custom Studio Micorphones - U47 Custom

VF14 M tube, BV8 original transformer

Neumann U47 inside tube VF14 BV8 transformer Bosh capacitors

Finally, the capsule is a Thiersch STW7 transducer (M7 Red Line). Soon, we'll also test fitting a vintage M7 Gefell. The original Neumann U47 mounts a KK47.

Thiersch M7 Red Line capsule

Neumann K47 capsule

Neumann U47 KK47 capsule

Decca Tree 47

Three identical microphones in cardioid/omni versions for Decca Tree recordings. With this matched trio of 47s, we've raised the bar even higher, implementing a subminiature switch on the circuit for polar pattern selection.

The directivity and slight emphasis on high frequencies (typical of pressure gradients in omni configuration) nod to the behavior of the M50s, absolute protagonists of the traditional Decca Tree setup.

Another special feature is the very strict matching (the capsules were selected from a stock of 20 transducers).

Microphones for singers and songwriters- In studio with Pino Marino

Pino Marino Microfono Braingasm Deluxe 12

The 47 and 12 capsules are two complementary transducers, very different in character and intended use, and they adapt well to both vocals and instruments.

The first is a rather neutral capsule across the spectrum, with its natural emphasis on the high-mid range, displaying the typical mid-focused timbre of the 47. On the other hand, the second has a more 'loud' attitude, more pronounced at the extremes of the audio band thanks to a greater proximity effect and a bell curve shifted towards 8-10kHz.

When it comes to vocals, my advice is to choose the Deluxe 47 for rock vocals (vintage tone) and the Deluxe 12 for softer productions (modern tone).

This approach promotes the correct placement of the vocals in the mix without many artificial adjustments, as a rock song will naturally be very 'loud' due to the presence of distorted guitars and prominent drums, leaving the upper midrange open for our vocal track recorded with the 47 to comfortably sit without hindering or being hindered. On the other hand, in a pop production (or any softer genre), the vocal recorded with the Deluxe 12 will have its space within the spectrum and can be the reference instrument for the entire arrangement—full, present, and pleasant.

P.S. Pino chose the Deluxe 12.

The purchase of a studio microphone often relies on habit, sometimes on reading (controversial) technical specifications, and almost never as a result of an awareness derived from in-depth listening tests.

The opportunity to test a microphone on your own instrument (in this case, the voice) is a rare commodity in the global 'add to cart' market. However, it is an immense resource when dealing with the boutique market.

I met Pino Marino, an evergreen figure in Italian singer-songwriter music (as well as a keen ear), to record a song in the studio and conduct tests on our Braingasm Deluxe 12 and 47 large-diaphragm microphones.

 

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