Studer A800 Multichannel Tape Recorder Manual

The Rich Analog Sound of the World's Most Popular Multichannel
Tape Machine and Four Tape Formulas in a Single Plug-In.


Authenticated by Studer, and modeled by UA's world-renowned team of DSP engineers and AES magnetic recording expert Jay McKnight over a 12-month period, the Studer A800 Multi-Channel Tape Recorder plug-in for UAD is the first and only product of its kind. This plug-in faithfully models the entire multitrack tape circuit path and electronics of an A800 machine — plus the distinct sounds of multiple tape formulas. Put simply, it's the world's most accurate representation of professional analog tape recording.

As the first microprocessor-controlled tape machine, the Studer A800 marked a new generation of professional multitrack recorders when it was introduced in 1978. Years ahead of its time, the A800 remains a sonic benchmark, and can still be found in studios all over the planet. However, with their massive steel frame and meter bridge, twin half-horsepower motors and cast alloy deck plates, original A800 units tip the scales at a backbreaking 900 pounds (408 kg) — not to mention the space required to house such a device. The UADx plug-in version poses none of the hardware hassles of manual calibration and maintenance, nor the potential for tape degradation — while retaining all the beautiful sonic qualities that make tape such a beloved recording medium. Just drop the A800 in your first insert on every track desired, and enjoy the benefits of having recorded to tape.



Operational Overview

The Studer A800 for UAD provides all of the original unit's desirable analog sweetness; like magnetic tape, users can dial in a clean sound, or just the right amount of harmonic saturation using the Input and Output controls. The reel deck IPS control steps through the three tape speed choices available on the original hardware (7.5, 15, or 30 IPS), each with distinct frequency shift, head bump and distortion characteristics. The Tape Type control lets users choose from four of the most popular magnetic tape formulas of the last three decades, each with their own subtle sonic variation and tape compression characteristics. The Cal control allows the user to choose between +3 dB, +6 dB, +7.5 dB, or +9 dB calibration levels, which can be used at their recommended settings, or tweaked for additional tonal options. Input, Sync and Repro paths, plus Thru (bypass) are available for authenticity, providing all available circuit options of the A800. 

Secondary controls are hidden behind the reel deck, and can be exposed by clicking on the Studer badge or Open label of the plug-in GUI. The Equaliser control allows the user to select between the American (NAB) and European (CCIR) standardized EQs, providing regional pre-emphasis/de-emphasis filtering at 7.5 and 15 IPS, each with its own sonic qualities — plus the AES EQ at 30 IPS. The HF Bias calibration parameter allows the user to tune the HF oscillation voltage feed to the magnetic record head, striking a balance between record sensitivity and distortion. This can also be used creatively as an effect — from warm, overbiased sounds, to voltage-starved distortion and chatter. HF Record is a calibration filter that allows for HF makeup when the ideal Bias leaves a high frequency deficiency; both HF Bias and HF record are fed into the tape nonlinearity. Sync and Repro HF and LF calibration EQs allow for adjusting for a flat playback response, or can also be used creatively. All Secondary Controls can be automatically calibrated to the manufacturer's recommended settings via the A800's Auto Cal feature, or may be disabled. Finally, separate controls for Hiss and Hum are available — each tuned to default settings to match the hardware behavior — with a global noise bypass option.

Multitrack Tape Machine

The primary purpose of Studer A800 is to obtain multichannel tape sonics within the DAW environment. To obtain the classic multitrack tape sound, the plug-in should be placed as the first insert on individual tracks, before other processing is applied. Creative "non-standard” results can be obtained by placing the Studer A800 in subsequent inserts after other processors or on buses in a send/return configuration. Mixdown to two tracks can be emulated by placing the plug-in on the stereo output bus.

Primary & Secondary Controls

The primary controls (those that are typically most used) are on the main panel at the bottom portion of the interface. Additional (typically less used) controls are available on the secondary panel. The secondary panel is accessed by clicking the Studer A800 label or the OPEN text label above it.


Studer A800 interface showing exposed secondary controls

Mono/Stereo Operation

The UAD Studer A800 is designed with a single-channel interface, to emulate the individual channels of a multitrack tape recorder. However, when the plug-in is used on a stereo track, the "mono” controls affect both channels of the stereo signal identically.



Primary Controls


Path Select

The Path Select buttons specify which of the four possible signal paths is active in the A800. The active mode is indicated by an illuminated button.


Thru is a bypass control. When enabled, emulation processing is disabled and processor usage is reduced. Thru is useful for comparing the processed settings to the original signal. Thru is identical to the OFF position in the IPS (Tape Speed) control.


Input mode emulates the sound of the A800 through the machine electronics only, without tape sonics. This is the scenario when the machine is in live monitoring mode but the tape transport is not running.


Sync mode models the sound of direct recording and playback via the sync/record head, plus all corresponding machine electronics.


Repro mode models the sound of recording through the record head and playback through the reproduction head, plus all corresponding electronics.

Tape Type

Tape Type selects the active tape stock formulation. Four of the most popular 2” magnetic tape formulas are modeled in the A800 plug-in: 250, 456, 900, and GP9. Each type has its own subtle sonic variation, distortion onset, and "tape compression” characteristics.

Generally speaking, the lower the Cal Level for each formula, the higher the signal level required to reach saturation and distortion.

Cal Level

Cal Level automatically sets tape calibration/fluxivity. The Cal Level setting takes care of the setup one would need to make under equivalent hardware operation, and sets the reference tape/flux level without disturbing the (unity) gain of the plug-in.

The record, repro, and sync gain trims found on the A800 channel cards are not present on the plug-in. Instead (when Auto Cal is enabled), these controls are amalgamated into this single Cal Level gain control.

As tape formulas advanced, their output level increased, thus lowering relative noise floor. +3, +6 and +9 dB output formulas were available in the 2” format. Under normal use, the machine would be calibrated to the tape's output level. However, users would sometimes under-calibrate to leave more headroom for a broader sweet or to prevent electronics from clipping. Therefore, the user can go traditional and calibrate to the recommended levels, or select a non-corresponding calibration setting with Cal Level.

As an example, if 456 is the selected Tape Type and when Cal Level is set at +6 (6 dB higher than the NAB tape standard), the reference fluxivity level is 355 nW/m (nanoweber per meter) and is 10 dB below the point where THD reaches 3% (referred to as the maximum operating level). Therefore, with a 1 kHz test tone at -12 dBFS sent to the plug-in, with Tape Type set to 456, Cal Level set to +6, and Auto Cal enabled, output levels of the plug-in will match the input level and fluxivity on the tape will be 355 nW/m.

The manufacturer's recommended calibration settings for each Tape Type are as follows:

  • 250: +3 Calibration (251 nWb/m)
  • 456: +6 Calibration (355 nWb/m)
  • 900: +9 Calibration (502 nWb/m)
  • GP9: +9 Calibration (502 nWb/m)

Note: The noise floor is affected by Cal Level when Noise Enable is active.

Tip: The UAD Studer A800 default bank offers a variety of preset Tape Type, Tape Speed, CAL level, and EQ configurations that are commonly used for the recording of specific genres.

IPS (Tape Speed)

The IPS (Inches Per Second) control determines the speed of the tape transport and the associated "head bump.”

(Head bump is bass frequency build-up that occurs with magnetic tape; the dominant frequencies shift according to transport speed.)

15 IPS is considered the favorite for rock and acoustic music due to its low frequency "head bump” (low frequency rise) and warmer sound, while 30 IPS is the norm for classical and jazz due to its lower noise floor, greater fidelity and flatter response. 7.5 IPS is also available for an even more colored experience, with even greater frequency shift.

Tip: Click on the "IPS” text label to stop/start the spinning reels animation.

The OFF position is a bypass control. When set to OFF, emulation processing is disabled, the VU Meter and control LEDs are dimmed, and processor or DSP usage is reduced. OFF is useful for comparing the processed settings to the original signal. OFF is identical to the Thru position in the Path Select control.


Input acts as an outside gain control (like an external console fader), and adjusts the signal level going into the tape circuitry. The available range is -12 dB to +24 dB.

Just like real magnetic tape, lower Input levels will have a cleaner sound, while higher levels result in more harmonic saturation and coloration.

Higher Input levels will also increase the output level from the plug-in. The Output
control can be lowered to compensate.

Tip: Click the "0” control label text to return to the Input value to 0.


Output acts as an outside gain control (like an external console fader) and adjusts the gain at the output of the plug-in. The available range is -24 dB to +12 dB.

Tip: Click the "0” control label text to return to the Output value to 0.

VU Meter

The VU Meter provides a visual representation of the signal levels after the virtual tape. TheInput control affects how "hot” the signal is.

Higher VU levels typically indicate more harmonic saturation, coloration, and/or distortion. However, this will depend on the other control values.

The plug-in operates at an internal level of -12 dBFS. Therefore a digital signal with a level of -12 dB below full scale digital (0 dBFS) at the plug-in input will equate to 0 dB on the plug-in meters.



Secondary Controls

The Secondary Controls are exposed by clicking the "Studer A800” label or the OPEN text above it.

Tip: The last-used state of the Secondary Controls panel (open or closed) is retained when a new Studer A800 plug-in is instantiated.


The Equaliser buttons determine the active Emphasis EQ values and the frequency of the hum noise. Click the equaliser buttons to alternate between the two different types.

NAB or CCIR curves can be selected when the Tape Speed is 7.5 or 15 IPS. When the Tape Speed is 30 IPS, neither value is available (the LEDs are dimmed) because the EQ is fixed with the AES emphasis curve.

When the value is set to NAB, the Hum Noise frequency is 60 Hz (the United States standard). When set to CCIR, the Hum Noise frequency is 50 Hz (the standard in Europe and other regions). See Noise Enable and Hum Noise for additional information.

Note: When IPS (Tape Speed) is set to 30 IPS, the yellow LEDs are not illuminated, indicating that the Emphasis EQ is set to AES. However, in 30 IPS mode, the Equaliser switch can still be changed to set the frequency of Hum Noise.

Tape Speed and Emphasis EQ were originally practical controls for record duration vs. noise and local standards. It is important to note that historically, the origin of the tape machine (US or European) dictated the built-in EQ emphasis, but later machines like the A800 had both circuits available.

While the hardware A800 has discrete controls for tape speed and emphasis EQ, the user has to recalibrate the machine for various speeds and re-jumper the whole machine for 30/15 or 15/7.5 IPS usage. The A800 plug-in has three speeds and related EQ pre-emphasis/de-emphasis filtering, presented as two easy to use controls for simple auditioning of the sonic variations.

CCIR (also known as IEC) is the EQ pre-emphasis made famous on British records and is considered the technically superior EQ; many say this EQ was part of the "British sound” during tape's heyday. NAB (also referred to as IEC2) was the American standard with its own sound. AES is truly standardized for 30 IPS and is the sole EQ found on the Studer A800 for 30 IPS.

Noise Enable

The Noise Enable buttons are a global enable/disable control for the individual hum and hiss components of the A800 model. The amount of hum and hiss noises are continuously variable and are set with the Hum Noise and Hiss Noise controls. Click the Noise buttons to alternate between OFF and ON.

While noise is historically considered a negative, and was the attribute that pushed the technical envelope for better machines and formulas, noise is still an ever-present component of the sound of using tape and tape machines.

Auto Cal

The Studer A800 has individual parameters for Bias, HF Record EQ, and Sync/Repro EQ. On the hardware tape machine, these calibration controls are usually adjusted whenever Tape Type, Tape Speed, or Emphasis EQ is changed.

When Auto Cal (Automatic Calibration) is ON in the plug-in, these calibration controls are automatically adjusted to the calibrated values whenever the Tape Type, Tape Speed, and Emphasis EQ are modified. After Auto Calibration occurs, the automatically adjusted parameters can then be modified to any value if desired.

When Auto Cal is OFF, the calibration parameters do not change values when Tape Type, Tape Speed, and Emphasis EQ are modified.

Note: Auto Cal is enabled by default.

Tip: When making manual calibration settings, consider disabling Auto Cal so the manually calibrated settings are not accidentally lost if another control is modified.

Calibration Controls

The calibration controls are automatically adjusted when Auto Cal is active, or they can be manually modified as desired.

The "flat” calibrated position for these controls is determined by Tape Type and Tape Speed; therefore the available ± range for these controls is dependent on the current calibration.

Tip: Clicking the text label for any of the HF Record EQ, Bias, and Sync/Repro EQ controls will return that parameter to the calibrated value.

Note: When making manual calibration settings, consider disabling Auto Cal so the manually calibrated settings are not accidentally lost if another control is modified.


The calibration controls

HF Record EQ

HF (High Frequency) Record EQ is provided to make up for common residual HF loss due to Bias optimization and system filtering. It is used to tune HF content into the incoming signal prior to the tape non-linearity. The control provides a continuous "boost filter” gain and affects saturation characteristics.

Note: This filter is prior to the tape record circuit, while the other EQs (Sync, Repro) are for tape playback only.

HF Driver Bias

Bias is defined as an oscillator beyond the audible range applied to the audio at the record head, allowing for adjustment of the record behavior. Ideal bias voltage settings provide maximum record sensitivity and low distortion. Intentionally overbiasing is a common technique especially for "tape compression” of drums, giving a warmer, gently saturated sound. Underbiasing can also be used to add distortion and other nonlinear responses, similar to gate chatter or cold solder joints; extremely low voltages may even cause audio to drop out entirely. Bias voltage, HF Record EQ, and fixed Emphasis EQ (CCIR, NAB, AES) work together to provide a linear response to the recorded signal.

Sync/Repro EQ

Sync and Repro Playback EQ Controls are available for tape playback calibration. They affect the signal coming out of the tape circuitry.

With the hardware machine, these controls enable compensation for any tape frequency loss or head wear. Under hardware use, the Sync and Repro playback heads are calibrated to normal operating standards and are nearly identical when set correctly. However, they may be tuned incorrectly to achieve a desired sound. Sync EQ and Repro EQ are used as filters to shape the frequency response of the system in maintaining a flat response, but they may be used on their own for high or low frequency adjustment.

Sync HF EQ

Adjusts the high frequency content when Path Select is set to Sync. When Path Select is not set to Sync, the control has no effect.

Sync LF EQ

Adjusts the low frequency content when Path Select is set to Sync. When Path Select is not set to Sync, the control has no effect.

Repro HF EQ

Adjusts the high frequency content when Path Select is set to Repro. When Path Select is not set to Repro, the control has no effect.

Repro LF EQ

Adjusts the low frequency content when Path Select is set to Repro. When Path Select is not set to Repro, the control has no effect.


The Noise controls allow the user to control the Hum and Hiss elements found on the original hardware. Separate controls for Hum and Hiss are available and each can be adjusted for creative purposes.

Tip: Click the control label text to return to the Hum or Hiss value to 0.

Hiss affects the signal at the tape head; Hum is added after the tape circuitry. Hum and Hiss values default to comparative levels found on the original hardware. The available range for both controls is ±25 dB.

Note: The global

Hum Noise

The Hum Noise frequency is dependent on the setting of the Equaliser (Emphasis EQ)control. The frequency is 60 Hz when set to NAB (US) and 50 Hz when set to CCIR (European).

Note: When IPS (Tape Speed) is set to 30 IPS, the yellow Equaliser LEDs are not illuminated, indicating that the Emphasis EQ is set to AES. However, in 30 IPS mode, the Equaliser switch can still be changed to set the frequency of Hum Noise.

Hiss Noise

Just like the hardware, the amount of hiss is dependent on settings of the various
controls. Overall Hiss Noise is set with this control, but may change based on the Path Select, Tape Speed, Tape Type, Emphasis EQ, Cal Level, Bias, Playback EQs, and Output Level controls.

Because hiss noise is an element of tape playback, Hiss is disabled when Path Select is to INPUT.

Note: Hiss timbre and level can change with Tape Type.


All visual and aural references to Studer products and all use of Studer trademarks are being made with written permission from Harman International Industries, Inc. Any references to third party tape formulations are used solely for identification and do not imply any endorsement by, or affiliation with, any tape manufacturer.

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