1. Introduction

パンチの効いたクラシックスタイルのコンプレッサーが必要なら、FET-A78の出番です。このコンプレッサーは、ポップ、ロックには必ずと言っていいほど使用され、楽器それぞれに対して使用するとさらに効果です。どんな音源にも使用できるほど柔軟性に富み、特にドラム、ギター、ボーカルに頻繁に使用されてきています。ステレオモードも搭載、ドラムのトップマイク、シンセサイザー、楽器をまとめたバストラックなどにかけても効果的でありながら、激しいベースラインにも最適でミックスの中でも埋もれることのない存在感を演出してくれます。

2. Features

  • 無数のレコードに使用されるクラシックコンプレッサー&リミッター。
  • 様々な楽器、ボーカル、ミックス全体に適した、多種多少な操作。
  • 極端に遅いタイムから非常に速いタイムの調整が可能な Attack & Release time.
  • シンプルで直感的な操作性。

3. Original Hardware Specifications

Maximum Input Level
+20 dB maximum

Maximum Output Level
+24 dBm

Maximum Gain
45 dB

Frequency Response
20Hz – 20kHz, +/- 1dB

Distortion
Less than 0.5% THD (50Hz to 15 kHz with limiting, at 1.1 seconds release setting)

Signal To Noise Ratio
Greater than 81 dB at threshold of limiting (30Hz to 15kHz)

Attack Time
Less than 20 microseconds, adjustable to 800 microseconds

Release Time
50 milliseconds minimum, 1.1 seconds maximum

Threshold vs Output Level
Please consult the table below:

Compression Ratio Setting
20:1
12:1
8:1
4:1
Input Level at Minimum Limiting Threshold
-24 dB
-25dB
-26dB
-30dB
Relative Output at Threshold *
+10dBm
+9dBm
+8dBm
+7dB

* with output gain control set to provide a reserve of approximately 10 dB.

4. Layout

1. Power On/Off Switch & LED

When it’s turned on, the effect is bypassed and the LED lights up.

2. Input Knob

Adjusts input gain.

3. Output Knob

Adjusts output (make-up) gain.

4. Attack Knob

Adjusts the compressor Attack time — the length of time between the input signal reaching the compression threshold and commencing compression. Ranges between 20 microseconds to 800 microseconds.

5. Release Knob

Adjusts the compressor Release time – the length of time between the signal dropping below the compression threshold and the compressor returning to 1:1 ratio. Ranges between 50 milliseconds to 1.1 seconds.

6. Gain Reduction Meter

Monitors the gain reduction occuring as the result of compression.

7. Ratio Buttons

Select the compressor ratio. The choices are: 4:1, 8:1, 12:1, 20:1. Holding Ctrl on Windows (Command on Mac) and clicking lets you “push” all the buttons in, emulating the famous “all-buttons-in”/UK Mode sound of UREI limiters.

8. Output Gain Meter

Visualizes output gain.

5. Functionality Explained

Following are explanations and tips regarding the FET-A78 controls and operation.

5.1 Ratios
  • With the FET-78, ratios up to 8:1 achieve a moderate form of gain reduction where the dynamic range is controlled without obvious alteration. The average signal level is incrased and the softer passages become louder.
  • Ratios from 12:1 to 20:1 push the FET-78 into limiting. The dynamic range is significantly reduced and high-level peaks are minimized. The output signal cannot exceed a preset level due to practical considerations.

⦁ With the FET-78, ratios up to 8:1 achieve a moderate form of gain reduction where the dynamic range is controlled without obvious alteration. The average signal level is incrased and the softer passages become louder.

⦁ Ratios from 12:1 to 20:1 push the FET-78 into limiting. The dynamic range is significantly reduced and high-level peaks are minimized. The output signal cannot exceed a preset level due to practical considerations.

⦁ The relationship of the average input level and the threshold determines the amount of gain reduction and how much of the signal envelope is affected by the limiter action.

⦁ The 1178 allows raising the signal level without introducing distortion.

⦁ Adjusting the input gain so that the average signal level is consistently above the threshold means the entire signal will be compressed.

⦁ While mixing or mastering, start with the Attack knob set to noon and experiment with different settings to find the best one for your material.

⦁ Choose a fast attack time for material with fast transients and high frequencies with large peak-to-peak amplitudes. This way, potential overshoots and overload problems are kept minimal.

⦁ Limiting with a fast attack time will alter the musical quality of some instruments with a characteristically sharp percussive attack.

⦁ Slow attack times let the initial transients of instruments with fast amplitude changes pass through unaffected. This maintains the punch of percussive-sounding instruments like drums, bass, piano, and guitar at the cost of some amplitude control.

⦁ A good starting point for both individual instruments and mixing or mastering purposes is half-rotation (setting the knob to noon).

⦁ The best practice for adjusting Release Time is to strive for a quick response of the FET-A78 to dynamic changes of the signal while avoiding unwanted “pumping” and “breathing” effects.

⦁ With very short release times, the FET-A78 will return the gain reduction to 0 dB every time the signal drops below the threshold. This can happen between cycles of individual notes and beats — the gain comes up each time, along with the softer passages or the background noise.

⦁ Warning — extremely short release times may introduce harmonic distortion if the gain reduction changes between cycles.

⦁ Very long release times maintain the initial gain reduction caused by large amplitudes, but the dynamic range of the following passages gets strongly affected. If the gain reduction continues through a soft program section, this section may be made inaudible because of the gain reduction. Furthermore, short dynamic changes will be ignored due to the continuous gain reduction.

Using the FET-A78 on full mixes as a limiter

⦁ When using the FET-A78 as a limiter, its effect is made most apparent on full mixes. As always, it is important to dial in the appropriate Attack and Release times for optimal results.

⦁ For live recordings, use a slower attack time to maintain a high average level.

⦁ For material with relatively little low frequency content, use a fast release time to increase the short interval average level. The highest apparent average level may be achieved with the shortest release time before overt “pumping” occurs.

⦁ For material with above average low frequency content, the release time should be increased until no low frequency distortion is apparent. Another option is slightly reducing the amount of limiting in favor of slightly faster release time — obtaining a higher average level as a result.

⦁ Adjusting the Attack time also affects the amount of sibilance. Be careful with extremely slow attack times, they may result in full gain being applied to the sibilants and reduced gain to the vowels, ending up with exaggerated sibilants as a result.

⦁ You are encouraged to experiment until you find appropriate settings that work for your material.

7. Contacts

Having difficulties with the FET-A78 or anything else Antelope? Get in touch with us by the following means:

European Direct Support Line
+44 2039578550
10:00 a.m. – 10:00 p.m. (EET), Monday – Friday

USA Direct Support Line
+1 734 418 8661
7:00 a.m. – 6:30 p.m. (EST), Monday – Friday

Online (live chat and e-mail)
Antelope Audio Support Page

8. Glossary

Attack: Adjusts how quickly the compressor starts to work after the signal exceeds the compression threshold.

Release: Controls how soon the compressor will stop after the signal goes below the compression threshold.

Ratio: Controls how much compression is applied. For example, a 3:1 ratio means that every time the input signal crosses the threshold by 3dB, output signal will be attenuated 1dB.

Threshold: The Threshold is the level above which the compressor considers the signal too loud and starts applying compression.

Knee: Knee and Attack have a lot in common, but they are not the same. Like Attack, Knee controls how the compressor will react once input signal passes the threshold. Hard Attack makes the compressor engage immediately while Soft Knee shapes its attack time to make it slower and smoother.