Ted Fletcher’s New PYE 4061S Levelling Amplifier

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The new PYE 4061S analogue levelling amplifier with feed-forward technology.

Pye 4061S analogue limiter-compressor

Designed by Ted Fletcher, the PYE 4061S is a cutting-edge recording and mastering device with the same ease of use as the equipment from the 1960s. Back then, time and budget constraints forced engineers to rely on gear that got the job done quickly and effectively. Fast forward to today, and we have access to digital equipment, exceptional audio quality, and seemingly limitless time. Or do we?

In the past, our go-to compressors included classics like the Altec 436C, and later, the JoeMeek SC2. While these devices were user-friendly and performed admirably, they also had their limitations, occasionally introducing unexpected alterations to the sound.

Enter the PYE 4061S—a 21st-century analogue levelling amplifier that preserves the core essence of your audio. It tames analogue electronics, effectively manages unwanted peaks, applies transparent levelling, and realizes the clarity engineers need today.

While modern digital systems promise the ability to reproduce any audio effect, they often come with a steep learning curve. How long does it take to fine-tune all the parameters for the desired effect? In contrast, the old Altec was a ‘one-knob’ wonder – turn up the gain, and it worked its magic quickly and effortlessly. The PYE 4061S takes inspiration from this simplicity, adhering to the most important design principle: “keep it simple.”

What It Does

A ‘LEVELLING AMPLIFIER’ is a specialist compressor or limiter designed to maintain a comfortable volume level across different audio sources. The PYE 4061S seamlessly combines levelling, stereo compression and limiting functions within a single unit. After months of careful development, we’ve crafted a design that corrals unruly sounds, enhances clarity, refines dynamics, and delivers expertly processed audio that sounds right.

Pye 4061S analogue limiter-compressor diagram

The diagram shows how the 4061S controls output volume level smoothly. Increasing input gain adds compression but has no effect upon maximum output level (controlled by gain make-up).
Transient peak sounds are sensed as soon as they appear, they feed through to the control section and even the smallest momentary overloads are prevented.

Key Functions

  • INPUT GAIN: The input control provides up to 20dB of clean gain through balancing transformers, with useful calibrations for precise adjustments.
  • STEREO WIDTH: Utilizing sum and difference technology, a single control lets you tailor the stereo image’s width, from a mono output to an expansive 150%.
  • BALANCE: For fine-tuning left/right balance when needed.
  • COMPRESSOR: Our feed-forward analogue limiter/compressor design adjusts its compression ratio dynamically, reminiscent of the classic Altec, but without the low-frequency bumps and overshoots of old tube technology. An illuminated button allows you to bypass the entire unit, letting you hear the unaltered original sound.
  • THE METERS: A pair of vintage-style moving needle meters, featuring specially developed Peak Programme electronics (inspired by the BBC PPM), display audio output levels for both left and right channels or a mono mix, along with compression metering.
  • ATTACK: The ‘feed-forward’ configuration ensures extremely fast attack times, and an 8-way switch sets the initial attack time.
  • RELEASE: A variable control governs the recovery time after compression for smooth transitions.
  • GAIN MAKEUP: Balanced output amplifiers, drive audio through output transformers made in the UK by Stevens and Billington. They maintain zero distortion output and offer an adjustable audio output level, reaching up to +28dB when necessary.
  • CONNECTIONS: Inputs and outputs are on both XLR and TRS connectors, all are transformer balanced.
  • POWER: The mains power input accommodates various voltages, and internal power supplies are encapsulated for maximum safety, with a total power requirement below 6 watts.

Rear sockets of the Pye 4061S analogue limiter-compressor

Mastering with PYE 4061S

While recording engineers aim to capture the authentic sounds of artists, mastering engineers are tasked with presenting those sounds in a format that suits the chosen distribution medium. The PYE 4061S serves as an ideal finishing tool, capable of delicately compressing audio to retain the artist’s subtleties while also taming the most challenging peak transients.

The following audio track is an example of PYE 4061S clarity. The first and third stanza are plain uncompressed, the second and fourth are via the levelling amplifier.

The reading is ‘Do not go gentle into that good night’ by Dylan Thomas, read by Ted Fletcher.

Ted Fletcher is a director of Alice Ltd. The PYE trademark is owned by Alice Ltd. The PYE 4061S is now available from Alice Ltd. For pricing and availability, please contact us at [email protected] or [email protected].

You can also read the PYE 4061S manual here.

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