TELEFUNKEN TF51 Matched Pair

Product overview

The TELEFUNKEN TF51 Matched Pair is two complete TF51 large-diaphragm tube condenser microphone systems from TELEFUNKEN Elektroakustik's Alchemy Series, frequency and gain matched, each with its own M 903 power supply, cable, mounts, sleeve and ZC03 case.

Each TF51 delivers a fresh take on the classic "Austrian" tube sound: a smooth midrange, a balanced low end and an airy, open top end. Capsules, tubes and transformers are hand-selected and tested for matched gain and frequency response. Because each microphone has its own power supply and case, TELEFUNKEN points out that a matched pair can be split and used independently: two separate systems with identical response, at separate locations, with the same performance.

Maximum SPL (1% THD)	128 dB SPL
Self‑noise	8 dBA
Sensitivity	19 mV/Pa
Frequency and gain matched	2 x TF51

Key features

• Two frequency and gain matched TF51 microphones for identical left and right channels
• Capsules, tubes and transformers hand-selected and tested for matched gain and frequency response
• TK51 edge-terminated capsule and TELEFUNKEN Elektroakustik 6072A vacuum tube in each microphone
• Cardioid, omnidirectional and figure-8 on both microphones
• 128 dB SPL maximum level and 8 dBA self-noise per microphone
• Two complete systems, each with its own M 903 power supply, M 803 cable and ZC03 case
• Can be split and used independently with identical response
• Designed and hand assembled in the USA

Sound character

The TF51 carries forward the "Austrian" microphone sound that TELEFUNKEN is closely associated with. Its smooth midrange and airy top end bring out detail and space, while a balanced low end keeps the sound natural. TELEFUNKEN describes the result as open, smooth and lifelike, a character that suits stereo pictures of acoustic instruments, strings, piano and drum overheads.

Capsule, tube and transformer

Each TF51 is built around the TK51 edge-terminated large-diaphragm capsule, a TELEFUNKEN Elektroakustik 6072A vacuum tube that is tested, burned in and screened by TELEFUNKEN, and a custom German-made output transformer (T31). Each microphone delivers 8 dBA self-noise, 86 dBA signal-to-noise ratio and 128 dB SPL maximum level.

Matched for stereo

All the electronic components in each pair are matched sonically and electronically, including the capsules, transformers and vacuum tubes. Both microphones are tested for matched gain and frequency response, giving you the confidence that the left and right channels will respond identically in coincident, near-coincident and spaced stereo techniques.

Two power supplies, cables and mounts

Each microphone comes with its own M 903 multi-pattern power supply with 3-position pattern switch, designed and assembled in the USA with premium-quality capacitors, improved regulation and RF suppression, switchable for 115V or 230V mains. Each connects through its own M 803 7 m 7-pin tube microphone cable, with high-purity copper conductors, low capacitance and a dense copper braid shield. Each M 903 has an on-board 3-position switch for cardioid, omnidirectional and figure-8, so the pattern of each microphone is set independently.

Recommended applications

TELEFUNKEN recommends the TF51 for vocals, acoustic guitar, violin, drum overheads, grand piano, mandolin and percussion. As a matched pair, it is ready for the stereo side of that list: drum overheads and room, piano, acoustic guitar, strings, choirs and ensembles, and any source where a stable, detailed stereo image matters.

Designed and hand assembled in the USA

The Alchemy Series is designed, hand built and tested in Connecticut, USA, in the same facility as TELEFUNKEN's Diamond Series, by a small, dedicated team of engineers and technicians. Each microphone is individually tested and listened to, with hand-plugged circuit boards, which keeps tolerances extremely tight from one microphone to the next.

What's in the set

This product is the TF51 Matched Pair: two complete, matched TF51 systems, each with its own M 903 power supply, M 803 cable, M 703 shock mount, M 782 stand mount, MS01 sleeve and ZC03 case.

In the box

• 2 x TELEFUNKEN TF51 microphones, frequency and gain matched
• 2 x M 903 multi-pattern power supply with 3-position pattern switch
• Mains power cable for each power supply
• 2 x M 803 tube microphone cables, 7 m (7-pin XLR)
• 2 x M 703 elastic shock mounts
• 2 x M 782 stand mounts
• 2 x MS01 microphone sleeves
• 2 x ZC03 lightweight zipper carrying cases

TELEFUNKEN Elektroakustik warranty: 90 days on the capsule and tube and one year parts and labour on the amplifier and power supply. Register the microphones at TELEFUNKEN to extend this to one year on the capsule and tube and four years on the amplifier and power supply. Alchemy Series warranties are fully transferable between owners.

TELEFUNKEN TF51 Matched Pair: frequently asked questions

What is the difference between a Matched Pair and a Stereo Set?

Both contain two frequency and gain matched microphones, two tube microphone cables, two shock mounts and two stand mounts. The Matched Pair has two individual power supplies and two zipper cases; the Stereo Set has one dual power supply and a locking hard-shell case.

Can the two microphones be used separately?

Yes. TELEFUNKEN notes that matched pairs can be split and used independently: two completely separate systems with identical response, even at separate locations.

Does the pair need phantom power?

No. Each microphone is powered by its own included M 903 power supply. Connect each power supply's XLR output to your preamp with a standard 3-pin microphone cable.

How long should the microphones warm up?

TELEFUNKEN recommends letting each system warm up for 10 minutes after switching on the power supply.

Is a TF51 Stereo Set available?

Yes, the TELEFUNKEN TF51 Stereo Set is listed as a separate product at Shivansh Electronics.

Where can I buy the TELEFUNKEN TF51 Matched Pair in India?

The TELEFUNKEN TF51 Matched Pair is available from Shivansh Electronics, Kolkata, West Bengal, India, with delivery across India.

Workflow 1: Blumlein figure-8 pair

A natural, enveloping stereo image of an ensemble in a good-sounding room.

Connections

Connect	To
TF51 microphone 1	First M 903 power supply via an M 803 7‑pin tube microphone cable
TF51 microphone 2	Second M 903 power supply via the second M 803 cable
Both M 903 XLR outputs	Mic preamp / audio interface inputs 1 and 2 (standard 3‑pin XLR cables)
Both M 903 power inlets	Mains power (115V or 230V as set)

Setup

1. Mount both TF51 microphones on a stereo bar, one capsule directly above the other, angled apart left and right.
2. Set the 3-position switch on both M 903 power supplies to figure-8.
3. Connect each microphone to its own M 903 with an M 803 cable, switch on both supplies and let them warm up for 10 minutes.
4. Set identical gain on both preamp channels, pan them left and right, and check the image on headphones and speakers.

Tip: The rear lobes of the figure-8 patterns capture the room, so place the pair where the room sounds good.

Workflow 2: Mid-side (M-S) stereo

Stereo recordings whose width can be adjusted after the session.

Connections

Connect	To
TF51 microphone 1	First M 903 power supply via an M 803 7‑pin tube microphone cable
TF51 microphone 2	Second M 903 power supply via the second M 803 cable
Both M 903 XLR outputs	Mic preamp / audio interface inputs 1 and 2 (standard 3‑pin XLR cables)
Both M 903 power inlets	Mains power (115V or 230V as set)

Setup

1. Point the first TF51 (mid) at the source and place the second TF51 (side) directly above it, its front facing the side.
2. Set the mid microphone's M 903 to cardioid and the side microphone's M 903 to figure-8.
3. Connect each microphone to its own M 903 with an M 803 cable, switch on both supplies and let them warm up for 10 minutes.
4. Record both channels, then decode the mid and side signals to left and right in your mixer and set the width by ear.

Workflow 3: Drum overheads

Recording the whole kit from above as a balanced stereo picture.

Connections

Connect	To
TF51 microphone 1	First M 903 power supply via an M 803 7‑pin tube microphone cable
TF51 microphone 2	Second M 903 power supply via the second M 803 cable
Both M 903 XLR outputs	Mic preamp / audio interface inputs 1 and 2 (standard 3‑pin XLR cables)
Both M 903 power inlets	Mains power (115V or 230V as set)

Setup

1. Place the two TF51 microphones above the kit on boom stands as an XY or spaced pair, fronts facing down towards the drums.
2. Set the 3-position switch on both M 903 power supplies to cardioid.
3. Connect each microphone to its own M 903 with an M 803 cable, switch on both supplies and let them warm up for 10 minutes.
4. Set identical gain on both preamp channels, pan them left and right, and check the image on headphones and speakers.

Tip: Keep both microphones the same distance from the snare so the centre of the kit stays focused.

Workflow 4: Piano in stereo

Grand piano with a full, even spread from bass to treble.

Connections

Connect	To
TF51 microphone 1	First M 903 power supply via an M 803 7‑pin tube microphone cable
TF51 microphone 2	Second M 903 power supply via the second M 803 cable
Both M 903 XLR outputs	Mic preamp / audio interface inputs 1 and 2 (standard 3‑pin XLR cables)
Both M 903 power inlets	Mains power (115V or 230V as set)

Setup

1. Position the two TF51 microphones over the strings, one towards the bass and one towards the treble.
2. Choose cardioid on both for a close, focused sound or omnidirectional on both for a more open sound with the room.
3. Connect each microphone to its own M 903 with an M 803 cable, switch on both supplies and let them warm up for 10 minutes.
4. Set identical gain on both preamp channels, pan them left and right, and check the image on headphones and speakers.

Workflow 5: Choir, ensemble and room with spaced omnis

Choirs, string groups and rooms recorded with width, depth and a full low end.

Connections

Connect	To
TF51 microphone 1	First M 903 power supply via an M 803 7‑pin tube microphone cable
TF51 microphone 2	Second M 903 power supply via the second M 803 cable
Both M 903 XLR outputs	Mic preamp / audio interface inputs 1 and 2 (standard 3‑pin XLR cables)
Both M 903 power inlets	Mains power (115V or 230V as set)

Setup

1. Set the two TF51 microphones on tall stands in front of the group, spaced apart.
2. Set the 3-position switch on both M 903 power supplies to omnidirectional.
3. Connect each microphone to its own M 903 with an M 803 cable, switch on both supplies and let them warm up for 10 minutes.
4. Set identical gain on both preamp channels, pan them left and right, and check the image on headphones and speakers.

Tip: Listen in mono as well as stereo and adjust the spacing until both sound natural.

Workflow 6: Acoustic guitar in stereo

Singer-songwriters and session players recording acoustic guitar with width.

Connections

Connect	To
TF51 microphone 1	First M 903 power supply via an M 803 7‑pin tube microphone cable
TF51 microphone 2	Second M 903 power supply via the second M 803 cable
Both M 903 XLR outputs	Mic preamp / audio interface inputs 1 and 2 (standard 3‑pin XLR cables)
Both M 903 power inlets	Mains power (115V or 230V as set)

Setup

1. Place one TF51 towards the neck and the other towards the body of the guitar, both facing the instrument.
2. Set the 3-position switch on both M 903 power supplies to cardioid.
3. Connect each microphone to its own M 903 with an M 803 cable, switch on both supplies and let them warm up for 10 minutes.
4. Set identical gain on both preamp channels, pan them left and right, and check the image on headphones and speakers.