TELEFUNKEN 6072A Vacuum Tube Triode A

Product overview

The TELEFUNKEN 6072A Vacuum Tube Triode A is the TELEFUNKEN "Green Diamond" 6072A replacement tube tested for Triode A, for the TELEFUNKEN TF51 and AR-51.

The TELEFUNKEN 6072A is a premium, low-noise vacuum tube engineered for demanding professional microphone and pro-audio applications. It is built to the highest standards and rigorously tested for noise, microphonics and consistency, and it provides stable gain and an exceptionally smooth, linear response. In microphone circuits, the 6072A excels at preserving transient detail, harmonic richness and depth, contributing to a sound that is clear, dimensional and musically balanced.

TELEFUNKEN Green Diamond	6072A
For the TF51 and AR‑51	Triode A
Tested for noise and microphonics	Low noise
Recommended warm‑up	10 min

Key features

• TELEFUNKEN "Green Diamond" 6072A premium low-noise vacuum tube
• Tested for Triode A: the version TELEFUNKEN lists for the TF51 and AR-51
• Rigorously tested for noise, microphonics and consistency
• Stable gain and an exceptionally smooth, linear response
• Preserves transient detail, harmonic richness and depth
• Made for the TELEFUNKEN TF51 and AR-51

Tested for Triode A

TELEFUNKEN offers its 6072A in three tested versions so each microphone receives the tube it was designed around. This version is tested for Triode A, the version TELEFUNKEN lists for the TF51 and AR-51. In the TF51, an edge-terminated TK51 capsule, a TELEFUNKEN 6072A tube and a custom German-made output transformer give a beautifully open, smooth and lifelike sound, with three polar patterns selected on the M 903 power supply.

The sound of the 6072A

TELEFUNKEN describes the sound the 6072A brings to a microphone as clear, dimensional and musically balanced. Its reliability and refined sonic performance make it a trusted choice for critical recording environments where accuracy and character are equally essential. Fitting the 6072A TELEFUNKEN specifies keeps each microphone sounding as it was voiced.

Choosing the right TELEFUNKEN tube

TELEFUNKEN lists a dedicated replacement tube for each of its tube microphones: the 5654W for the CU-29, TF29 and TF39 Copperhead models; the 5840W on a PCB mount for the TF47; the 5840W with flying leads for the AK-47 MkII and ELA M 260; the 6072A in Triode A, Triode B and Balanced versions for the TF51, AR-51, ELA M 251E, C12 and stereo tube microphones; and the VF14K for the U47 and U48. This listing is the 6072A tested for Triode A, for the TF51 and AR-51. Ordering the tube listed for your model keeps the microphone sounding exactly as TELEFUNKEN designed it.

When to replace the tube

Vacuum tubes are wear parts. Replace the tube when TELEFUNKEN or an authorised service centre advises it, during planned maintenance on a busy microphone, or keep this tube as a spare so a session or tour can continue. TELEFUNKEN has published tube change videos for the TF51 and the AR-51.

Fitting and care

• Switch off the power supply and disconnect the tube microphone cable before opening the microphone
• Let the fitted tube cool before handling it
• Follow TELEFUNKEN's official TF51 or AR-51 tube change video, or have an authorised TELEFUNKEN service centre fit the tube
• Handle the tube by its glass body, never by its pins, and keep it clean and dry
• Reconnect, switch on the power supply and let the system warm up for 10 minutes before use

What's included

Included	One TELEFUNKEN 6072A vacuum tube, tested for Triode A
Not included	Microphone, power supply, cable and tools

In the box

• TELEFUNKEN 6072A Vacuum Tube Triode A

Choose the 6072A version listed for your microphone: Triode A for the TF51 and AR-51, Triode B for the ELA M 251E and C12, Balanced Triode for the AR-70, ELA M 270 and C24 stereo tube microphones.

TELEFUNKEN 6072A Vacuum Tube Triode A: frequently asked questions

Which microphones is this version for?

TELEFUNKEN lists this version for the TF51 and AR-51.

What is the difference between the Triode A, Triode B and Balanced versions?

TELEFUNKEN offers the 6072A in three versions: tested for Triode A (TF51, AR-51), tested for Triode B (ELA M 251E, C12), and a Balanced Triode tube for stereo tube microphones (AR-70, ELA M 270 and C24). Order the version listed for your microphone.

Can I change the tube myself?

Follow TELEFUNKEN's official tube change video for your microphone where one is available, or have an authorised TELEFUNKEN service centre do the change.

How long should the microphone warm up after a change?

TELEFUNKEN recommends letting its tube microphone systems warm up for 10 minutes after the power supply is switched on.

Is a microphone included?

No. This product is the replacement tube only.

Where can I buy the TELEFUNKEN 6072A Vacuum Tube Triode A in India?

The TELEFUNKEN 6072A Vacuum Tube Triode A is available from Shivansh Electronics, Kolkata, West Bengal, India, with delivery across India.

Workflow 1: TF51 tube replacement

Changing the tube in a TF51 when service is due.

Connections

Connect	To
6072A tested for Triode A	Tube socket inside the TF51
TF51	M 803 7‑pin tube cable to the M 903 power supply
Power supply output	3‑pin XLR to the mic preamp input

Setup

1. Switch off the power supply, disconnect the tube microphone cable and let the tube cool.
2. Open the TF51 as shown in TELEFUNKEN's TF51 tube change video and remove the fitted tube.
3. Fit the new 6072A and close the microphone.
4. Reconnect, switch on and let the system warm up for 10 minutes, then check the signal.

Tip: If in doubt, have an authorised TELEFUNKEN service centre do the change.

Workflow 2: AR-51 tube replacement

Owners of the AR-51 due for a tube change.

Connections

Connect	To
6072A tested for Triode A	Tube socket inside the AR‑51
AR‑51	Its tube microphone cable to its power supply
Power supply output	3‑pin XLR to the preamp

Setup

1. Power the AR-51 down, disconnect it and let the tube cool.
2. Follow TELEFUNKEN's AR-51 tube change video to remove the old tube.
3. Fit the new 6072A and reassemble the microphone.
4. Reconnect, warm up for 10 minutes and check the signal.

Workflow 3: Spare tube for sessions

A ready replacement so a recording day is never held up.

Connections

Connect	To
Spare 6072A tested for Triode A	Microphone flight case or studio parts drawer
TF51	Its tube microphone cable to its power supply
Power supply output	3‑pin XLR to the preamp

Setup

1. Store the spare tube in its packing, away from dust and moisture.
2. If the fitted tube needs changing, mute the channel and power down.
3. Swap in the spare following the TELEFUNKEN procedure for the microphone.
4. Warm up for 10 minutes and check the signal before resuming.

Workflow 4: TF51 Stereo Set and matched pair upkeep

Owners of TF51 matched pairs and Stereo Sets.

Connections

Connect	To
6072A tested for Triode A	Each TF51 of the pair
2x TF51	Two M 803 cables to their power supply
Power supply outputs	Two 3‑pin XLR to two preamp inputs

Setup

1. Note the gain settings that match the two channels before the change.
2. Fit the tube following the TELEFUNKEN procedure, or at an authorised service centre.
3. Warm the system up for 10 minutes.
4. Compare both channels on the same source and match gain; contact TELEFUNKEN service if re-matching is needed.

Workflow 5: Touring spares kit

Engineers taking TELEFUNKEN tube microphones on the road.

Connections

Connect	To
Spare 6072A tested for Triode A	Touring spares case
TF51	Its tube cable to its power supply
Power supply output	3‑pin XLR to the stage box or console

Setup

1. Pack and label a spare tube with each microphone.
2. Keep it in its packing, protected from knocks.
3. Change a tube only with the power supply off and the tube cool.
4. Warm up for 10 minutes and line-check before the show.

Workflow 6: Studio and rental maintenance

Studios and rental companies with several TF51 and AR-51 microphones.

Connections

Connect	To
6072A tested for Triode A tubes	Parts stock, one spare per microphone
Microphone under test	Its tube cable to its power supply
Power supply output	3‑pin XLR to a test preamp

Setup

1. Keep a service log per microphone.
2. After each booking, warm up for 10 minutes and check noise and output.
3. Replace the tube when the check shows it is due.
4. Record which tube went into which microphone.