Finally, the
AC701 Gold Dot

Phædrus Audio Supertubes™ are modern emulations of tubes for precision audio applications using our second-generation electronic-tube technology. Supertubes™ are specifically designed to model the top one per-cent of tubes of any particular type and thus surpass the performance of the vast majority of real vacuum tubes available today.

New in 2023 is the AC701 Gold Dot Supertube™, which faithfully reproduces the performance of the best of the best of the original AC701 vacuum tubes.

Applications information

The Phædrus Audio AC701 is suitable for direct replacement of the AC701 (AC701k) tube in any of the three versions of the M49 (the original and the b and c versions.). Variations of these three circuits are used in virtually all other Neumann microphones employing this tube. For example: the Neumann KM54, KM56, M249, M49, M50, SM69, M269c, Schoeps M211b, M222 and others. See technical specification below. For more information and enquiries, email

The body of the Phædrus Audio AC701 Gold Dot mimics the original “bottle shape” of the Telefunken devices. However, the Phædrus Audio AC701 is shorter by 5mm than the Telefunken part. This makes it an easy fit, even in the tightest applications of the AC701(k). The Phædrus Audio AC701 is supplied with long 38mm leads. The electrodes are marked on the base of the tube, so that lead-identification is very straightforward.

We can accept orders for this part... NOW! Address all mail to

".....the AC701 Gold Dot Supertube™.... faithfully reproduces the performance of the best of the best of the original AC701 vacuum tubes."

AC701 Electronic TubeTM Technical Specifications

Recommended operating conditions

Heater voltage: 4V (not <3.8V)
Heater current: 75mA
HT Supply: 115V (nominal)
Anode load: 100k - 200k
Grid voltage: 0V to 1.4V (this covers the various circuit configurations)
Grid resistor: 150MΩ
Cathode circuit: Suitable for M49 original, b and c variants. No modifications required.

A full datasheet for the AC701 Gold Dot is available.

The new Phædrus Audio Electronic TubesTM AC701 Gold Dot compared with our best selling AC701 Red Dot.


Back to home page

Address all mail to

Maidstone . Kent . UK .

© Phædrus Audio 2023. All rights reserved.