It's Not a Record Until it's Mastered on an Ampex® Tape Machine.

The Ampex ATR-102 Mastering Tape Recorder plug-in provides the final "analog glue" for your music, turning your recordings into records.

The only emulation that's fully authenticated by the Ampex Corporation, and trusted by producers and engineers the world over, the Ampex ATR-102 puts the colorful saturation, warmth, and harmonics of this industry-standard tape machine at your command.

• Mix and master your music with the most popular professional 2-track tape machine ever made

• Get classic Ampex tape saturation, selectable tape types, and color to "glue" your mix together

• Use the entire ATR-102 circuit, including its transformers, amplifiers, Repro, Sync, and Input paths

Ampex ATR-102

All visual and aural references to the Ampex Product and all use of Ampex's trademarks are being made with written permission from Ampex Corporation. 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.

History

Introduced in 1976, the Ampex ATR-102 2-Track Tape Recorder was a near-instant hit, thanks to its revolutionary servo-controlled reel motors and capstan, which provided smooth, continuous tape tension and handling. The large capstan, and absence of pinch rollers, provided nearly non-existent speed drift and ultra-low flutter. The clever ATR-102 design allowed users to change out heads and guides in mere minutes, with a 1" head being a very popular "hot-rod" modification in more recent years — especially when running at 15 IPS (inches per second). The ATR's role in modern recording history is so prevalent, that it would be easier to list classic albums that weren't mixed down on this machine, rather than to try to list all those that were.

Plug-In Parameters

Like the ATR-102 hardware, the plug-in allows you to choose between various Signal Paths (Input, Sync, Repro), different Tape Speeds / Emphasis EQs (NAB, CCIR, AES) and Tape Formula combinations, even including home/consumer tape. The Input (Record) Gain knob and the Cal button are the primary controls for regulating levels, and even saturating the tape, and can be used to deliver a heavily colored sound if desired. Other ATR-102 features include: 1/4," 1/2," or 1" Head Select, Biasing/Calibration controls (auto and manual), crosstalk, adjustable wow and flutter, and adjustable tape delay, which can be used for Automatic Double Tracking effects on vocals, guitars, and more.

In Use

The primary use for Ampex ATR-102, and the recommended method for evaluating this plug-in, is as the last stereo insert on your master fader (or possibly the second-to-last insert before a brick-wall processor such as the UAD Precision Limiter). Set up the plug-in by first adjusting Tape Speed, Tape Formula, Cal Level, and Emphasis EQ, or simply select a preset. Note that as you lower the tape speed (i.e. 15 IPS, 7.5 IPS), the tape "sound" becomes more audible. Once this basic setup is made, adjust the L/R Record (input gain) levels for more or less tape/circuit coloration and saturation.

Other common uses for the Ampex ATR-102 are as individual mono or stereo insert effects, or as an auxiliary group effect where the user wishes to apply it only to specified sources or groups (e.g., drums, guitars, etc). Check out the ATR-102 Tips and Tricks blog article below to learn more.

• www.uaudio.com/blog/ampex-atr-102-tips-tricks

Operational Overview

Famous Tape Sound

The UAD Ampex ATR-102 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.

Mixdown Tape Deck

The primary purpose of the UAD Ampex ATR-102 is to obtain tape mixdown sonics within the DAW environment. To obtain the classic tape mixdown sound, instantiate the plug-in as the last insert on the output bus, after other processing is applied (or possibly as the second-to-last insert, before a brick-wall processor such as the (UAD Precision Limiter). Of course, creative "non-standard" results can be obtained by placing the Ampex ATR-102 in any channel insert or on buses in a send/return configuration.

Multiple Tape Types

The UAD Ampex ATR-102 models seven popular magnetic tape formulas. Each type has its own subtle sonic variation, distortion onset, and tape compression characteristics. The tape types that can be selected depend on the active tape speed and head type; all tape types are not available for all tape speeds and head types. Lower fidelity types are included to facilitate more signal coloration options.

Multiple Tape Heads

The original hardware machine was manufactured with an interchangeable head block system which enabled the system to be quickly converted to use either 1/4" or 1/2" tape stock by simply swapping out the heads and recalibrating the electronics. As track width increases, subtle improvements to stability, fidelity, and noise become apparent. A popular custom aftermarket tape head is available which enables the use of 1" tape stock, enabling even higher fidelity with its greater track widths. All three tape head widths are accurately modeled and selectable in the UAD Ampex ATR-102.

Multiple Tape Speeds

All four tape speeds in the original hardware are modeled in the UAD Ampex ATR-102. Speeds of 3.75, 7.5, 15, and 30 inches per second (IPS) are available. Each speed provides distinct frequency shift, head bump, and distortion characteristics. Higher speeds have higher fidelity; 3.75 IPS has a distinctively "lo fi" character.

Multiple Calibration Levels

Tape machines can be setup with different calibration levels, which entails setting unity gain from input through output based on the magnetic flux (amount of magnetic field) of a given tape formulation. Different calibration levels provide different tape response characteristics for a given level into the recorder. Four selectable calibration levels are available in the UAD Ampex ATR-102.

Ancillary Noises

Tape recorders have inherent signal noises that are a by-product of the electro-mechanical nature of the machine. While "undesirable" tape system noise is historically considered a negative and was an attribute that pushed the technical envelope for better machine design and tape formulas (and ultimately, "noiseless" digital recorders), noise is still an ever-present characteristic of the sound of using tape and tape machines.

The UAD Ampex ATR-102 models the hum, hiss, wow, flutter, and crosstalk characteristics of the original hardware. These noise components can be individually disabled, adjusted, and/or exaggerated for creative purposes (even though the servo-controlled, direct-drive capstan tape transport of the original hardware provides excellent wow and flutter specifications).

Modeled Transformer

The original hardware was manufactured with isolation transformers, which can color the signal. A common modification to the hardware tape machine eliminates the transformers from the signal path to produce a (subjectively) "cleaner" sound. UAD Ampex ATR-102 simulates the behavior of the transformers in the hardware circuit, and can be optionally disabled in the plug-in, providing both sonic options.

Tape Delay

A popular application of multi-head tape recorders is to employ them for slapback tape echo effects. If the machine is running in record mode but the recorded signal is monitored from the repro head (as opposed to the sync head), the physical space between these two heads results in a short delay between the signal sent to the recorder and the monitored signal. When these signals are combined with mixer routings, the classic slapback echo is manifest. The UAD Ampex ATR-102 implements the ability to reproduce this classic effect with a simple set of controls, and expands the capabilities by extending the available delay times beyond what is possible in the physical realm.

Automatic Calibration

The ability of a magnetic tape recorder, which has inherently non-linear response characteristics, to accurately reproduce an audio signal with a minimum of noise and distortion requires precise adjustments to the system electronics. The calibration settings are based on the current tape speed, formulation, emphasis EQ, and tape width. The hardware must be meticulously re-adjusted each time a different tape, speed, emphasis EQ, or head width is used (and for system wear and drift, even if these variables are not changed). UAD Ampex ATR-102 has an automatic calibration feature that tunes all calibration electronics with a single button.

Low Level Tuning

Even though automatic calibration is available, the individual controls that adjust calibration are exposed for sonic manipulation. Playback EQ, record (tape) EQ, and record bias can easily be altered for manual calibration and/or creative purposes.

Manual Calibration Tools

UAD Ampex ATR-102 includes the full suite of tools required to manually calibrate the recorder. Manual calibration tools are provided so expert users can calibrate the system to their preferred methods for obtaining desired results. The manual calibration tools consist of a tone generator (with multiple test tones and levels), a distortion meter with digital readouts, and a full suite of Magnetic Reference Laboratory (MRL) alignment tapes, which are used to calibrate playback electronics.

Mono/Stereo Operation

While the UAD Ampex ATR-102 is a true stereo processor designed primarily for use in stereo-in/stereo-out configurations, it will also operate in mono-in/stereo-out and mono-in/mono-out modes.

When used in a mono-in/stereo-out configuration, the mono input signal is sent to both channels of the processor, which can then be adjusted independently. When used in a mono-in/mono-out configuration, adjusting any left or right control will change both the left and right controls (the left/right controls are always linked in mono mode).

Quick Setup

Set up the plug-in by first adjusting Tape Speed, Tape Type (tape formulation), and Tape Speed, or simply select a factory preset. Note that as you lower the tape speed, the tape "sound" becomes more audible. Once this basic setup is made, adjust the L/R Record (gain) levels, for more or less tape/circuit coloration/saturation.

Artist Presets

Presets from prominent Universal Audio artists are included. You can access the artist presets using the UAD preset browser.

Primary & Secondary Controls

The graphical interface panel has two modes; Open and Closed. In Closed mode, the primary controls (those that are typically most used) are available on the main panel interface and the tape reels are visible. Additional (typically less used) controls are available on the secondary panel in Open mode. The secondary controls panel is accessed by clicking the OPEN button beneath the AMPEX label.

Ampex ATR-102 interface in Open mode showing secondary controls

Primary Controls

Meters

The two Meters display signal levels of the plug-in for the left and right channels. Meter ballistics of the original hardware are modeled. The Meters can be switched to display input or output levels in peak or VU modes.

The Ampex ATR-102 "penthouse" showing meters and I/O controls

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 Meters when Reproduce is in its calibrated position, which is marked with the "red arrow sticker."

When Path Select is set to Thru, the Meters indicate signal levels at the input of the plug-in prior to processing.

Note: Although there are separate left/right Meter controls for VU/Peak and Input/Output, these controls are permanently linked and cannot be switched individually for the left and right channels.

Input/Output

These switches change the Meter to display levels at the input or output of the plug-in. Input metering is a UAD-only feature which is unavailable in the original hardware.

Input

When in Input mode, the Meter reflects the signal level after the Record (input) gain when Path Select is set to Sync or Repro. In Input mode when Path Select is set to Thru, the Meter reflects the pre-processed (raw input) signal level.

Output

When in Output mode, the meter reflects the signal level at the output of the plug-in, which is just after the Reproduce (output) gain.

Peak/VU

This switch is used to change Meter behavior between Peak or VU modes.

Clip LED

The left and right channels each have a Clip LED, just above the Meter. The Clip LED is not in the original hardware; it is a UAD-only feature.

The Clip LED illuminates only when the machine's audio electronics clip. The Clip LED is not affected by the recorded tape signal, even if the tape is overloaded and distorting.

Reproduce

Reproduce adjusts the signal level coming off the virtual tape before the signal is sent to the Meters. There are two Reproduce controls, one each for the left and right channels. The left/right Reproduce controls can be adjusted individually, or simultaneously adjusted when Link mode is active.

The available range is -∞ dB (off) to +9.48 dB. The default value of 0 dB is the "calibrated position" which is marked with a "red arrow sticker." Reproduce is not affected by Auto Cal.

Tip: Click the "REPRODUCE" label text to return Reproduce to 0 dB.

The Meters accurately reflect the output level (when set to Output mode) even if Reproduce is not in its calibrated position. However, if Reproduce is moved from the "cal" position, the Meters will no longer correspond to a particular level being recorded onto the virtual tape. In this case, the Meters will not reflect the actual "operating level" of the tape because Reproduce changes the signal level coming off the tape before it is sent to the Meters.

Note: The graphical interface panel values for Reproduce, which range from 0 - 10, are arbitrary and do not reflect a particular dB value.

Record

Record adjusts the signal level into the plug-in and the tape circuitry. There are two Record controls, one for the left channel and one for the right. These left/right Record controls can be adjusted individually, or simultaneously when Link mode is active.

The available range is -∞ dB (off) to +9.3 dB. The default value is 0 dB. The graphical interface panel values, which range from 0 - 10, are arbitrary and do not reflect a particular dB value.

Tip: Click the "RECORD" label text to return the Record value to 0 dB.

Record is a primary "color" control for the plug-in. Just like genuine magnetic tape, lower Record levels will have a cleaner sound, while higher levels result in more harmonic saturation and coloration. Higher Record levels will also increase the output level from the plug-in. The Reproduce control can be lowered to compensate if unity gain operation is desired.

Reproduce/Record Controls Arrangement

Note that the Reproduce control is to the left of the Record control, which is atypical of most signal flow designs, where inputs usually precede outputs (flowing from left to right). This quirky arrangement of the Ampex ATR-102 I/O controls, where the input control "follows" the output control, is true to the original hardware design. In Controls View, the Record (input) control precedes the Reproduce (output) control.

Open/Close

The Secondary Controls are accessed by clicking the OPEN button beneath the AMPEX label. Conversely, the panel is closed by clicking the CLOSE button.

Link/Unlink

Link mode is a software-only addition that enables controls that are identical for the left and right channels to be linked for ease of operation when both channels require the same values, or unlinked when independent left/right control is desired. In other words, left/right channel controls are ganged together in link mode.

The Link parameter is stored within presets and can be accessed via automation.

Note: Although there are separate left/right Meter controls for VU/Peak and Input/Output, these controls are permanently linked and cannot be switched individually for the left and right channels, even if Unlink mode is active.

Link

In Link mode, modifying any left or right channel control causes its adjacent stereo counterpart control to snap to the same position.

Important: When Unlink mode is active and Link is enabled, the left channel control values are copied to the right channel. Control offsets between channels are lost in this case.

When Link is active, automation data is written and read for the left channel only. In this case, the automation data for the left will control both channels. Additionally, changing the right channel parameters from a control surface or when in "controls only" (non-GUI) mode will have no effect.

Unlink

When Unlink is active, the controls for the left and right channels are independent. When unlinked, automation data is written and read by each channel separately.

Emphasis EQ

The Emphasis EQ buttons determine the active Emphasis EQ values and the frequency of the Hum noise. 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, per the original hardware. At 3.75 IPS, only NAB is available (as it is with the hardware).

NAB

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

Tape Speed and Emphasis EQ were originally practical controls for recording duration versus noise and local standards. Historically, the origin of the tape machine (US or European) dictated the built-in EQ emphasis, but later machines like the Ampex ATR-102 had both circuits available.

CCIR

CCIR (also known as IEC1) 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 known as IEC2) was the American standard with its own sound. AES is truly standardized at 30 IPS and is the sole EQ found on the Ampex ATR-102 at 30 IPS.

Power

Power is the plug-in bypass control. When set to OFF, emulation processing is disabled, the Meters and control LEDs are dimmed, the Bypass LED illuminates, and DSP usage is reduced. Power is useful for comparing the processed settings to the original signal.

OFF is similar to the Thru position in the Path Select control except that the Meters are still active when the Thru control is used. However, in this state, the Meters indicate signal levels at the input of the plug-in prior to processing.

Note: DSP usage is reduced only when DSP LoadLock is disabled. If DSP LoadLock is enabled (the default setting), activating OFF will not reduce DSP usage.

Tape Speed

The Tape Speed control determines the speed of the tape transport, in inches per second (IPS). Tape Speed affects the recorder's fidelity and associated "head bump" sonics. Head bump is bass frequency build-up that occurs with magnetic tape; the dominant frequencies shift according to transport speed.

To change the Tape Speed value, click the IPS text values, or drag the knob, or click the knob then use the mouse scroll wheel.

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 and 3.75 IPS are also available for an even more colored experience, with even greater frequency shift and other artifacts.

Note: The available parameter ranges of Tape Type, Head Width, and Emphasis EQ are affected by Tape Speed.

Tape Type

Tape Type selects the active tape stock formulation. Seven Tape Types are modeled in the UAD Ampex ATR-102. To select the Tape Type, click the TAPE button to cycle through the available types, or click directly on the Tape Type value label. The active Tape Type is highlighted in yellow.

Note: The available Tape Types and defaults are dependent on the current Tape Speed and Head values.

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.

To select the Cal Level, click the CAL button to cycle through the available levels, or click directly on the calibration value label. The active Cal Level is highlighted in yellow. The default value is +6 dB.

Because Cal Level affects the operating levels in the plug-in, it can be used to compensate for overly high (or low) levels at the input of the plug-in. For example, if the input is too hot, lowering the Cal Level will reduce the signal level without changing Record, which can affect the tape saturation characteristics.

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

As tape formulas advanced, their output level increased, thus lowering relative noise floor. Under normal use, the machine would be calibrated to the tape's output level. However, sometimes the machine is under-calibrated to leave more headroom for a broader sweet spot or to prevent electronics from clipping. Therefore, one can "go traditional" and calibrate to the recommended levels, or select a non-corresponding calibration setting.

As an example, if 456 is the selected Tape Type and when Cal is set at +6 (6 dB higher than the NAB tape standard), the reference flux level is 355 nWb/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 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 nWb/m.

The tape manufacturer's recommended calibration settings for each Tape Type are shown in the table below.

Tape Manufacturer's Recommended Calibration Levels

Tape Type	Calibration	Flux Level
111	+0 dB	177 nWb/m
35-90	+3 dB	251 nWb/m
250	+3 dB	251 nWb/m
456	+6 dB	355 nWb/m
468	+6 dB	355 nWb/m
900	+9 dB	502 nWb/m
GP9	+9 dB	502 nWb/m

Tip: The UAD Ampex ATR-102 default presets 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.

Head Width

This control specifies the active tape head model. Head Widths of 1/4," 1/2," or 1" can be selected.

To select the Head Width, click the HEAD button to cycle through the available values, or click directly on the value label. The active Head Width is highlighted in yellow.

Note: At tape speeds of 3.75" and 7.5" only the 1/4" head can be used. At these speeds, the 1/2" and 1" heads cannot be selected.

Path Select

The Path Select buttons specify which of the four possible signal paths is active in the Ampex ATR-102. The active mode is indicated by an illuminated LED above its associated button. The default value is Repro.

Sync

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

Sync mode is generally not used for playback due to its poorer frequency response, but it is included for authenticity and creative purposes.

Repro

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

Input

Input mode emulates the sound of the Ampex ATR-102 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.

Thru

Thru is a processor bypass control. When Thru is enabled, all controls are inactive, emulation processing is disabled, and DSP usage is reduced.

Thru behavior is similar to that of the OFF position in the POWER control, except that the Meters are still active in Thru mode. In this state, the Meters indicate signal levels at the input of the plug-in prior to processing.

Note: DSP usage is reduced only when DSP LoadLock is disabled. If DSP LoadLock is enabled (the default setting), activating Thru will not reduce DSP usage.

Tape Reels Animation

When the secondary controls panel is closed, by default the graphical tape reels "spin" if the DAW transport is running. The tape reels animation can be disabled by clicking the capstan graphic. Re-clicking the capstan will re-start the animation.

The "spin state" is saved until it is changed again.

Note: Spinning reels automation is not supported in all hosts. In Sonar, the plug-in must be configured as a "tempo-based effect" for reels animation.

Secondary Controls

The secondary controls adjust the various calibration, ancillary noise, tone generator, and tape delay parameters. The secondary controls panel is accessed by clicking the OPEN button beneath the AMPEX label.

Ampex ATR-102 secondary controls

Auto Cal

The Ampex ATR-102 has individual calibration controls for adjusting sync (record) EQ, reproduction (playback) EQ, and record bias, which are used to compensate for the inherent non-linearities of tape systems. On the hardware, these controls are typically adjusted to calibrate the system for optimum response compensation due to tape non-linearities whenever the tape type, tape speed, emphasis EQ, or head width are changed.

When the Auto Cal (Automatic Calibration) ON button is clicked, the calibration EQ and bias controls are automatically adjusted to their "flat" calibrated position for the currently active Tape Type, Tape Speed, Emphasis EQ, and Head Type. The Auto Cal ON LED illuminates green when the calibration parameters (Shelf EQ, HF EQ, Repro HF, Repro LF, and Bias) are in their calibrated position.

Auto Cal is enabled by default. When Auto Cal is ON, the calibration parameters (Shelf EQ, HF EQ, Repro HF, Repro LF, and Bias) change values whenever Tape Type, Tape Speed, Emphasis EQ, or Head Type is modified. When Auto Cal is OFF, the calibration parameters do not change values when Tape Type, Tape Speed, Emphasis EQ, or Head Type is modified.

Important: Any calibration settings made manually are lost when Auto Cal is activated. Consider saving manual settings as a preset before activating Auto Cal.

After Auto Calibration occurs, the automatically adjusted parameters can be modified to any other value if desired. If a calibration parameter is adjusted while Auto Cal is ON, the ON LED illuminates in red instead of green, indicating that the system is no longer in the calibrated state. If the moved controls are subsequently returned to their original position, the LED will return to its green state, indicating the unit is back in calibration.

Tip: To return any of the individual calibration controls to their "flat" (calibrated) position, click the label text adjacent to the control (or, simply re-click Auto Cal to return all calibration controls to their "flat" position).

The Manual Calibration Procedure has instructions for performing system calibration manually.

Record EQ

The Record EQ controls (HF EQ and Shelf EQ) are applied in the tape recording circuit and affect tape saturation characteristics. They compensate for common residual HF loss due to bias optimization and system filtering, and affect HF content in the signal prior to the tape non-linearity.

HF EQ

HF EQ provides high frequency emphasis in the signal recorded to tape.

Shelf EQ

Shelf EQ is another control (in addition to HF EQ) provided to compensate for tape non-linearity. Although adjustment of this control is not part of the Ampex factory calibration procedure, it can be used for customized manual calibrations or creative purposes.

Repro EQ

The Repro EQ controls (Repro HF and Repro LF) are post-head controls for tape playback calibration. They affect the signal coming out of the tape circuitry in both Repro and Sync modes.

The Repro EQs are used as filters to shape the frequency response of the system in maintaining a flat response and enable compensation for any tape frequency loss or head wear.

Repro HF

Adjusts the tape playback high frequency content when Path Select is set to Sync or Repro.

Repro LF

Adjusts the tape playback low frequency content when Path Select is set to Sync or Repro.

Bias

This control adjusts the amount of bias in the record signal. 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" which produces 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/Shelf EQ, and Emphasis EQ (CCIR, NAB, AES) all work together to provide a linear response to the recorded signal. The "flat" (calibrated position) is determined by tape speed, tape type, emphasis EQ, and head width.

Noise Enable

This is a global enable control for the Hum and Hiss effect. When Noise is ON, the level of Hum and Hiss can be independently adjusted using the Hum and Hiss Level controls.

The default values of 0 dB for Hum and Hiss are the actual modeled level in the original hardware. Noise is not affected by automatic calibration.

Hum

Determines the amount of Hum in the signal. Hum is added after the tape circuitry. This control affects both the left and right channels. Noise Enable must be ON for the Hum control to function.

The default value of 0 dB for Hum is the actual modeled level in the original hardware. This default value can be offset by ±25 dB.

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

When Tape Speed is set to 30 IPS, the green Emphasis EQ LEDs are not illuminated (and cannot be switched), indicating that the Emphasis EQ is set to AES. However, the Hum frequency can still be set for 30 IPS mode by setting Emphasis EQ to NAB (for 60 Hz) or CCIR (for 50 Hz) prior to setting Tape Speed to 30 IPS.

Note: When Tape Speed is 3.75 IPS, only 60 Hz is available.

Hiss

Hiss determines the amount of tape hiss in the tape playback signal. The default value is 0 dB and can be offset by -25 dB to +50 dB for creative purposes. Noise Enable must be ON for this control to function.

Like the hardware, the amount of hiss is dependent on settings of the various controls and may subtly change based on the values of Path Select, Tape Type, Emphasis EQ, Cal Level, Bias, Playback EQs, and Output Level.

Hiss Level is not affected by automatic calibration, so its level does not change with Tape Speed. When Hiss Level is at its default position (0 dB), the amount of hiss present in the signal is as if the Tape Speed is 15 IPS. To emulate the amount of hiss at the other tape speeds, enter the offsets from the table below.

Tape Speed	Hiss Level Setting
30 IPS	-8 dB
15 IPS	0 dB
7.5 IPS	12.5 dB
3.75 IPS	17 dB

Hiss level offsets

Note: Because hiss noise is an element of tape playback, Hiss is disabled when Path Select is set to Input.

Wow & Flutter Enable

These buttons are global enable/disable controls for the Wow and Flutter effects. When Wow & Flutter is ON, the level of Wow and Flutter can be independently adjusted using the Wow and Flutter Level controls.

Wow and Flutter are "undesirable" pitch modulations induced by the mechanical components of the tape transport. Wow is a by-product of capstan irregularities, while flutter is a by-product of tape stretching and sticking. Both can be effectively used for creative purposes.

Wow usually refers to very low frequency fluctuations, while Flutter refers to faster fluctuations. Wow and flutter is measured as the percentage of deflection from the original pitch. Both are more pronounced at lower tape speeds.

Note: Wow and Flutter levels change with Tape Speed, but they are not affected by automatic calibration.

Wow

Determines the amount of Wow in the signal. Wow & Flutter Enable must be ON for this control to function.

Flutter

Determines the amount of Flutter in the signal. Wow & Flutter Enable must be ON for this control to function.

Crosstalk Enable

These buttons are global enable/disable controls for the Crosstalk Level (XTALK) parameter. When Crosstalk is ON, the amount of Crosstalk can be adjusted using the Crosstalk Level control.

Crosstalk is the amount of signal bleed between the left and right channels. Crosstalk sonics can vary based upon the Tape Speed and Head Width parameters, however the amount of crosstalk does not vary with these settings.

Crosstalk Level

This control determines the amount of signal crosstalk. Crosstalk Enable must be ON for the Crosstalk Level control to function. The default value of -45 dB is the actual modeled level in the original hardware. The available range is -50 dB to -10 dB. Crosstalk Level is not affected by automatic calibration.

Transformer Enable

These ON/OFF buttons enable and disable the transformer circuit of the Ampex ATR-102. For an overview of this feature, see Modeled Transformer.

Tape Delay

These parameters control the built-in Tape Delay, which creates tape echo effects. For an overview of this feature, see Tape Delay. The Tape Delay controls are not available in the original hardware.

Note: Tape Delay is not available when Path Select is set to Input or Thru, nor when the Manual Calibration Tools are active.

Tape Delay Enable

These buttons are global enable/disable controls for the Tape Delay effect. When Tape Delay is ON, its red numerical display is active, and other Tape Delay parameters can be adjusted.

Dry/Wet Mix

The Dry/Wet push buttons control the mix of the Tape Delay effect. The amount of dry and wet signals are displayed as percentages.

Click the Dry button to increase the dry signal level by 1%, or the Wet button to increase the delayed signal level by 1%.

Tip: Hold the Dry/Wet buttons down to rapidly change the mix values. For fine control in increments/decrements of 0.1%, hold down Shift while changing values.

Delay Time

The left and right channel delay times can be independently adjusted with these controls. Click the "+" or "-" buttons to change the delay times in increments of 10 milliseconds. The available range is 0 - 1000 milliseconds.

Tip: Hold the +/- buttons down to rapidly change the delay times. For fine control in increments/decrements of 1ms, hold down Shift while changing values.

The default Delay Time values depend on the current Tape Speed, and represent the actual delay time that would occur in the physical realm, reflecting the elapsed time between the signal put on tape at the record/sync head and its reproduction at the playback/repro head. These "physical" default times are shown in the table below.

Tape Speed	Delay Time
30 IPS	62 ms
15 IPS	124 ms
7.5 IPS	248 ms
3.75 IPS	496 ms

Delay Time default values

Important: When the tape speed is changed, the current delay time is changed to reflect the new "physical time" between the sync and repro heads for the new tape speed, and previously set values are lost if the tip below is not used.

Tip: To retain custom delay times when changing Tape Speed, hold Shift when changing Tape Speed.

Manual Calibration Tools

These controls are the suite of tools included to perform manual calibration of the recorder. These UAD-only tools are not in the original hardware. Manual calibration is entirely optional, as the Auto Cal feature can quickly and automatically calibrate the system.

The manual calibration tools consist of an "external" tone generator with multiple test tones and levels, a distortion meter with digital readouts, and a full suite of modeled Magnetic Reference Laboratory (MRL) alignment tapes.

Note: The Manual Calibration Tools are operational only when Path Select is set to Sync or Repro. Additionally, the tools may not operate in some hosts unless audio is present on the track containing the plug-in and the transport is running. Placing the plug-in on an aux, bus, or master output may eliminate this host limitation.

This section describes the functions of the manual calibration tools. For instructions on how to use the tools to perform a manual system calibration, see the Manual Calibration Procedure.

About MRL Alignment Tapes

Alignment tapes are carefully recorded with accurate and consistent flux levels and test tone frequencies. They are constant companions to all well-maintained professional tape machines. Different alignment tapes are required for each tape speed, head width, equalization standard (CCIR/IEC or NAB), and fluxivity level.

Alignment tapes are required for system calibration and adjustment so that playback of previously-recorded session tapes will have correct and consistent equalization and levels, regardless of when, or where, the session tape was originally recorded.

After tape playback system EQ and levels are calibrated to match the known-to-be-correct values of the alignment tape(s), the record-side alignment is performed. The entire record/playback system will then have proper EQ and gain structuring.

Magnetic Reference Laboratory ("MRL") is a company that produces alignment tapes. The MRL tapes used in the UAD Ampex ATR-102 are fringing compensated. In-depth discussions about fringing compensation and system alignment are beyond the scope of this manual; thorough resources are available from the MRL website:

• www.mrltapes.com

Manual Cal Knob

The Manual Cal knob performs two functions: it sets the signal level of the "external" test tone generator for record calibration, and specifies when alignment tapes are to be used for playback calibration.

When set to -16 dB, -6 dB, or +4 dB, a generated sine wave test tone at the frequency specified by the Tones buttons is sent to the input of the record circuitry. This mode emulates sending external test tones into the system. The level of the test tone is set by the knob position and remains static regardless of other parameter values.

When set to MRL, a test tone from the "alignment tape" is sent into the playback circuitry. The MRL frequency is also specified by the Tones buttons, but the levels used are from the calibrated alignment tape. Therefore the MRL tone levels are dependent on other tape parameter values.

Tones

The Tones buttons set the frequency of the "external" test tone generator and the MRL tape test tones. Tone frequencies of 50 Hz, 100 Hz, 1 kHz, 2.5 kHz, 5 kHz, 10 kHz, 15 kHz, and 20 kHz are available.

Click a button to specify that frequency; the active frequency's button is shadowed gray as if in the "down" position.

Distortion Meter

The red numerical display, between the Manual Cal knob and the Tones buttons, represents the amount (displayed as a percentage) of third harmonic distortion present in each of the left and right channels. This feature can be useful for custom calibration techniques.

When the Manual Cal knob is set to -16 dB, -6 dB, or +4 dB, the value represents third harmonic distortion in the tape playback circuit. Generally speaking, increasing Record (input) will increase distortion while in this mode, as tape saturation increases. If Bias is set very low, distortion may increase at lower Cal Levels.

Note: When the Manual Cal knob is set to MRL, the Distortion Meter is inactive (there is no distortion display in this mode).

Manual Calibration Procedure

Manual calibration tools are provided so expert users can calibrate the system to their preferred methods for obtaining desired results. For example, some technicians may prefer adjustments for lowest distortion at a certain frequency; setting bias for maximum sensitivity (instead of overbiasing); or other non-standard techniques.

The calibration procedure described here is the most commonly used technique, and is the (albeit simplified) method recommended by the Ampex Operation and Service Manual.

Important: Manual calibration is not required to use UAD Ampex ATR-102. Following this procedure will result in the same (or nearly the same) values obtained by simply using the Auto Cal feature.

Tip: When making manual calibration settings, consider disabling Auto Cal so the manually calibrated values are not accidentally lost if any of the controls that force automatic calibration (Tape Type, Tape Speed, Emphasis EQ, and Head Width) are inadvertently modified.

Preparation

• Reduce monitoring system volume to avoid loud sine wave Tones.
• Insert UAD Ampex ATR-102 on the DAW output bus (see note below).
• Set Path Select to Repro mode (Sync mode is not supported for manual cal).
• Set left and right Meter Input/Output switches to the "OUTPUT" position.
• Set left and right Meter Peak/VU switches to the "VU" position.
• Set Tape Speed, Tape Type, Cal Level, and Head Width to desired values.
• If Tape Speed is set to 3.75 IPS, set Cal Level to +3 dB.
• Disable Noise Enable (excessive Hiss may contribute to incorrect results).
• Do not change the above settings throughout the procedure.
• For related information, see the Manual Calibration Notes at the end of this chapter.

Note: The Manual Calibration Tools are operational only when Path Select is set to Sync or Repro. Additionally, the tools may not operate in some hosts unless audio is present on the track containing the plug-in and the transport is running. Placing the plug-in on an aux, bus, or master output may eliminate this host limitation.

Repro Level Calibration

1. Set the Manual Cal Knob to the MRL position. The built-in alignment tape tone will sound and its level can be viewed on the Meters.
2. Set the Tones frequency to 1 kHz.
3. Adjust Reproduce (output) so the Meters display 0 dB.

Repro EQ Calibration

1. Set the Tones frequency to 10 kHz.
2. Adjust Repro HF (not to be confused with HF EQ) so the Meters display 0 dB.
3. Set the Tones frequency to 100 Hz.
4. Adjust Repro LF so the Meters display 0 dB (or as close as possible).*

*Because the MRL alignment tapes we used have fringing compensation, it may not be possible to increase Repro LF enough to make the meter reach 0 dB at low frequencies. If a flat response is desired, you can switch the Manual Cal knob from MRL mode to the "external" tones then readjust Repro LF for flat response (0 dB) using the external tones instead of the MRL tones.

Note: If Repro HF and/or Repro LF EQs are adjusted by a large amount, it may be necessary to recalibrate the output level (steps 1-3).

Record Bias Calibration

1. Set the Manual Cal Knob to the tone level positions below (the tone level depends on tape speed).
2. Set the Tones to the values below (the frequency depends on tape speed).

Tape Speed	Tone Frequency	Tone Level
3.75 IPS	2.5 kHz	-16 dB
7.5 IPS	5 kHz	-6 dB
15 IPS	10 kHz	+4 dB
30 IPS	20 kHz	+4 dB

Record Bias Calibration Frequencies and Levels

3. Adjust Bias throughout its range until the Meters reach the maximum level achievable with the Bias control.*
4. *If the meters reach their maximum "pinned" value, you may temporarily reduce the Reproduce level to lower the meters, so the maximum achievable level can be accurately viewed (the maximum achievable level may be higher than the pinned value of 3 dB).
5. Increase Bias (clockwise) until the meter level is reduced by -3.5 dB from its maximum (for 3.5 dB of overbias; see Manual Calibration Notes.*
   *When calibrating at 3.75 or 7.5 IPS, the tone generator is at a lower level, therefore meter resolution is decreased. To increase meter precision when adjusting bias at the lower tape speeds, consider temporarily increasing the reproduce level.

Record Level Calibration

1. Set the Tones frequency to 1 kHz.
2. Adjust Record (input) so the Meters display the levels for Record and HF EQ Adjustments below (the level depends on tape speed).

Tape Speed	Meter Level
3.75 IPS	-20 dB
7.5 IPS	-10 dB
15 IPS	0 dB
30 IPS	0 dB

Meter Levels for Record and HF EQ Adjustments

Record EQ Calibration

1. Set the Tones frequency to the values below (the frequency depends on tape speed).

Tape Speed	Tone Frequency	Tone Level
3.75 IPS	5 kHz*	-16 dB
7.5 IPS	10 kHz	-6 dB
15 IPS	15 kHz	+4 dB
30 IPS	20 kHz	+4 dB
*Note: 7.5 kHz is specified in Ampex manual.

Record HF EQ Calibration Frequencies and Levels

2. Adjust Record HF EQ (not to be confused with Repro HF) so the Meters display the level above (the level depends on tape speed).
   Note: If HF EQ is adjusted by a large amount, it may be necessary to recalibrate the record level.

The manual calibration procedure is complete.

For related information, see Manual Calibration Notes.

Manual Calibration Notes

• 0 dB on the output meter represents +4 dBm (and -12 dBFS digital) when Reproduce is in its calibrated position, which is marked with the "red arrow sticker."
• For proper calibration, follow the entire calibration procedure in order.
• This example uses 3.5 dB overbias. The amount of gain reduction in step 12 determines the amount of overbias. In some cases we used more than 3.5 dB of overbias to achieve a flatter response.
• Generally speaking, higher Cal Level values will have higher Distortion Meter values for a given reading on the Meters. If Bias is set very low, distortion may increase at lower Cal Levels.
• We recommend leaving the record SHELF EQ control in its default position.
• The Ampex ATR-102 hardware has an additional gain control via a setscrew (like Repro HF/LF, Bias, etc) which is usually used for manual gain calibrations. This control is not available in the plug-in because it would be redundant - the Reproduce control performs the same function.
• We chose to calibrate our reference machine using MRL fringing-compensated calibration tapes, without later adjusting the Repro LF EQ for unity gain using external test tones. Therefore the calibrated values in the plug-in reflect this alignment method. In-depth discussions about fringing compensation and system alignment are beyond the scope of this manual; thorough resources are available from the MRL website: www.mrltapes.com
• Tape Type 111 uses a calibration level of 0 dB. This value is not available in the plug-in, but it can be emulated by setting the CAL level to +3 dB, then reducing the input level (Record knob) by -3 dB and increasing the output level (Reproduce knob) by +3 dB.
• 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 represent 0 dB on the plug-in meters (if the plug-in is calibrated).
• The included Artist Presets demonstrate how manual calibration can be used to obtain sonic variations.

Tip: For easy recall in future sessions, save unique calibrations as a preset.

Parameter Dependencies

Available Settings

Some ATR-102 parameter value ranges depend on the value of other parameters. These dependencies are listed in the table below.

Ampex ATR-102 parameter dependencies

Tape Speed	Head Width	Tape 1	Tape 2	Tape 3	Tape 4	Emphasis EQ
30 IPS	1"	250	456	468	GP9	AES
30 IPS	1/2"	250	456	900	GP9	AES
30 IPS	1/4"	250	456	900	GP9	AES
15 IPS	1"	250	456	468	GP9	NAB
15 IPS	1"	250	456	468	GP9	CCIR
15 IPS	1/2"	250	456	900	GP9	NAB
15 IPS	1/2"	250	456	900	GP9	CCIR
15 IPS	1/4"	250	456	900	GP9	NAB
15 IPS	1/4"	250	456	900	GP9	CCIR
7.5 IPS	1/4"	250	456	35-90	111	NAB
7.5 IPS	1/4"	250	456	35-90	111	CCIR
3.75 IPS	1/4"	250	456	35-90	111	NAB
3.75 IPS	1/4"	250	456	35-90	111	CCIR
*Note: 7.5 kHz is specified in Ampex manual.

Original Ampex ATR-102 Mastering Recorder brochure