TELEFUNKEN U48 Stereo Set

Product overview

The TELEFUNKEN U48 Stereo Set is a frequency and gain matched pair of U48 tube microphones with a dual power supply: the historically accurate recreation of the figure-8 variant of the classic German large-diaphragm tube microphone, with cardioid and figure-8 on each microphone, supplied as two identical systems in one locking flight case.

The U48 is celebrated for its authoritative midrange, smooth low-end depth and the added flexibility of figure-8, and delivers on everything from vocals and electric guitar to lush orchestral and chamber performances. In the Stereo Set, two hand-matched U48 microphones share one M 940HS dual power supply. Figure-8 on both microphones makes the pair ideal for a Blumlein crossed pair, cardioid and figure-8 together make a ready-made Mid-Side pair, and cardioid on both gives XY or ORTF.

Matched microphones	2x
Dual power supply	M 940HS
Sensitivity	24.5 mV/Pa
Max SPL (1% THD)	127 dB SPL

Key features

• Two U48 microphones, frequency and gain matched: capsules, tubes and transformers hand-selected and tested
• One M 940HS dual power supply powering both microphones
• 2 polar patterns on each microphone: cardioid, figure-8
• All the classic stereo techniques: XY, ORTF, spaced pair, Blumlein and Mid-Side
• VF14K vacuum tube and BV8 output transformer in each microphone
• Point-to-point wired in the USA, true to the original design
• Complete stereo system in one FC40S locking flight case, with two cables, two shock mounts and two wooden boxes

Sound character

The U48 shares the classic punchy, mid-forward sound with pleasing bite and the legendary extended low end of the U47; in cardioid the two are sonically identical. Figure-8 picks up equally from the front and rear while rejecting sound from the sides, which TELEFUNKEN notes is very helpful for controlling ambient and indirect sound when recording ensembles or in less-than-ideal rooms. In a matched pair, those qualities are identical on both channels.

Matched for stereo

Every TELEFUNKEN tube microphone Stereo Set is built around two meticulously matched microphones. For the U48 Stereo Set, all critical components, including the capsules, tubes and transformers, are hand-selected and tested for matched gain and frequency response, so both microphones give identical responses for the most critical stereo recording. A balanced stereo image, a stable centre and pan positions that behave as expected follow directly from that matching, and the two microphones can also be used side by side as identical mono tools on a session.

Capsule, tube and transformer

Each microphone uses the M7 centre-terminated, dual-diaphragm capsule, which combines the mechanical design of the earliest German condensers with a modern, more stable tensioning material, made by hand in limited quantity in South Windsor, Connecticut. The VF14K is TELEFUNKEN's drop-in solution to the dwindling supply of the original tube: a new old stock military-grade glass tube and a passive circuit in a plug-and-play casing, with sonic characteristics extremely close to the original and a 5-year manufacturer's warranty. The BV8 is a hefty, nickel alloy core, twin-coil output transformer wound in America to vintage specification, with a 6.5:1 ratio, very low distortion and a wide, flat frequency response.

Patterns and stereo techniques

The pattern is selected on each microphone with the red polar pattern switch. Set both to figure-8 and cross them at right angles for a Blumlein pair, with a natural blend of direct and room sound. Set one to cardioid (mid) and one to figure-8 (side) for Mid-Side, with stereo width adjustable in the mix. Set both to cardioid for XY or ORTF. The matched capsules, tubes and transformers keep every arrangement balanced and accurate.

Dual power supply, cables and mounts

The M 940HS dual power supply is American-made and powers both microphones at the same time. Like every TELEFUNKEN tube power supply, it is hand-built in Connecticut with premium components, calibrated to the specific microphone system it comes with and burned in with it as a complete unit. It uses vintage-correct locking connectors and pinout. Two M 840TH cables, made by TELEFUNKEN technicians in the USA with oxygen-free copper conductors and 100% shielding (a dense helical copper screen plus metallised foil), are 10 m long each, and two M 740 vintage-styled clasping elastic shock mounts with durable metal cages hold the microphones.

Flight case and build

The FC40S locking flight case is designed with delicate capsules, vacuum tubes and electronic components in mind. Its shell is made of a blend of seven hardwoods and wrapped in a durable travelling fabric, with dual combination locks and nickel trim, an embroidered TELEFUNKEN diamond logo inside the lid and an engraved logo plate (with matching serial number when applicable). It holds both microphones in their wooden boxes, the stereo power supply and both tube microphone cables. Every Diamond Series microphone is reverse engineered from the original design, hand built and point-to-point wired (no circuit boards) at the TELEFUNKEN facility in South Windsor, Connecticut, USA, in small production runs. Most metalwork and mechanical parts are custom tooled and machined in the USA, and every power supply is calibrated to the microphone system it comes with and burned in with it as a complete system. Each wooden microphone box is made in the USA of solid white oak with a satin lacquer and carries a metal name plate with the model and serial number.

What's in the set

• 2x matched TELEFUNKEN U48 microphones
• M 940HS dual tube microphone power supply
• Power cable for the power supply
• 2x M 840TH tube microphone cables, 10 m
• 2x M 740 shock mounts
• 2x WB40 wooden microphone boxes
• FC40S locking flight case

The VF14K tube carries a 5-year manufacturer's warranty; register each microphone at t-funk.com/warranty for TELEFUNKEN's limited warranty plan. Two standard 3-pin microphone cables from the power supply outputs to the preamps are not included.

TELEFUNKEN U48 Stereo Set: frequently asked questions

What does the Stereo Set include?

Two frequency and gain matched U48 microphones, one M 940HS dual power supply, two M 840TH 10 m cables, two M 740 shock mounts and two WB40 wooden boxes in an FC40S locking flight case.

Which stereo techniques can I use?

With cardioid, figure-8 on each microphone, the pair covers XY, ORTF, spaced pair, Blumlein and Mid-Side.

Does the Stereo Set need phantom power?

No. Both microphones are powered by the included M 940HS dual power supply. Connect each XLR output of the power supply to a mic preamp with a standard 3-pin microphone cable.

Can I use just one microphone from the set?

Yes. Each microphone is a complete, identical system, so either can be used on its own as a mono microphone.

Is the U48 available as a single microphone?

Yes, the TELEFUNKEN U48 is listed as a separate product at Shivansh Electronics.

Where can I buy the TELEFUNKEN U48 Stereo Set in India?

The TELEFUNKEN U48 Stereo Set is available from Shivansh Electronics, Kolkata, West Bengal, India, with delivery across India.

Workflow 1: XY coincident pair

Acoustic guitar, piano and small ensembles recorded with a precise, mono-compatible stereo image.

Connections

Connect	To
2x U48 microphones	M 940HS dual power supply via two M 840TH cables
M 940HS XLR outputs	Two mic preamp / audio interface inputs (standard 3‑pin XLR cables)
M 940HS power cable	Mains power, 115 V or 230 V as set

Setup

1. Fit both U48 microphones in their M 740 shock mounts on a stereo bar, capsules as close together as possible and angled apart.
2. Set both microphones to cardioid on their pattern switches.
3. Connect both cables to the M 940HS, switch on and allow 10 minutes of warm-up.
4. Match gain on both channels, pan hard left and right and record.

Tip: Coincident capsules avoid timing differences between the channels, so the pair sums cleanly to mono.

Workflow 2: ORTF drum overheads

Drum kits recorded as a balanced stereo picture of cymbals, toms and the whole kit.

Connections

Connect	To
2x U48 microphones	M 940HS dual power supply via two M 840TH cables
M 940HS XLR outputs	Two mic preamp / audio interface inputs (standard 3‑pin XLR cables)
M 940HS power cable	Mains power, 115 V or 230 V as set

Setup

1. Mount the pair above the kit in the standard ORTF near-coincident arrangement, centred on the snare.
2. Set both microphones to cardioid on their pattern switches.
3. Connect both cables to the M 940HS, switch on and allow 10 minutes of warm-up.
4. Set gain on the loudest cymbal crashes (the U48 handles up to 127 dB SPL), match both channels and record.

Tip: Measure from the snare to each capsule so both are the same distance away and the snare sits in the centre.

Workflow 3: Ensembles in difficult rooms

Ensembles and less-than-ideal rooms where ambient and indirect sound needs controlling.

Connections

Connect	To
2x U48 microphones	M 940HS dual power supply via two M 840TH cables
M 940HS XLR outputs	Two mic preamp / audio interface inputs (standard 3‑pin XLR cables)
M 940HS power cable	Mains power, 115 V or 230 V as set

Setup

1. Place the pair in front of the ensemble with the side nulls of each microphone facing the problem reflections.
2. Set both microphones to figure-8 on their pattern switches.
3. Connect both cables to the M 940HS, switch on and allow 10 minutes of warm-up.
4. Match gain on both channels and record.

Tip: Figure-8 rejects sound arriving from the sides of the microphone.

Workflow 4: Blumlein crossed figure-8

Rooms, choirs and acoustic ensembles recorded with a natural blend of direct and room sound.

Connections

Connect	To
2x U48 microphones	M 940HS dual power supply via two M 840TH cables
M 940HS XLR outputs	Two mic preamp / audio interface inputs (standard 3‑pin XLR cables)
M 940HS power cable	Mains power, 115 V or 230 V as set

Setup

1. Mount the two microphones one above the other on a stereo bar, capsules aligned and crossed at right angles.
2. Set both microphones to figure-8 on their pattern switches.
3. Connect both cables to the M 940HS, switch on and allow 10 minutes of warm-up.
4. Face the pair at the centre of the source, match gain on both channels and record.

Tip: Place the pair where the room sounds best, as the rear lobes capture the room as much as the front lobes capture the source.

Workflow 5: Mid-Side stereo

Piano, acoustic instruments and rooms where stereo width should stay adjustable after recording.

Connections

Connect	To
2x U48 microphones	M 940HS dual power supply via two M 840TH cables
M 940HS XLR outputs	Two mic preamp / audio interface inputs (standard 3‑pin XLR cables)
M 940HS power cable	Mains power, 115 V or 230 V as set

Setup

1. Mount one microphone facing the source (mid) and the other directly above or below it, turned sideways (side).
2. Set the mid microphone to cardioid and the side microphone to figure-8.
3. Connect both cables to the M 940HS, switch on and allow 10 minutes of warm-up.
4. Set gain on both channels and decode the mid and side signals in your mixer.

Tip: Raising or lowering the side signal in the mix widens or narrows the stereo image.

Workflow 6: Grand piano in stereo

Grand piano recorded with detail and a wide, even stereo image.

Connections

Connect	To
2x U48 microphones	M 940HS dual power supply via two M 840TH cables
M 940HS XLR outputs	Two mic preamp / audio interface inputs (standard 3‑pin XLR cables)
M 940HS power cable	Mains power, 115 V or 230 V as set

Setup

1. Position the pair over the strings with the lid open, one towards the bass strings and one towards the treble.
2. Use cardioid on both for a close, direct sound or figure-8 on both for a more open sound.
3. Connect both cables to the M 940HS, switch on and allow 10 minutes of warm-up.
4. Match gain on both channels on the loudest passages and record.