Contra Control Panel, Preamp | Acoustic Energy Stereo Amplifier

Controls

Preamp

The preamp has the following controls in each channel: input level, bass, mid, treble and effects level. In addition,there is a variable frequency, selectable notch/low cut filter in each channel and a master level control that affects both channels.

Level

Phantom power

Ch 2 input, EQ and filter (same as Ch 1 below)

The input level controls the level of the signal at the input stage of the preamp. The master volume controls the level of the signal at the output of the preamp (at the input of the power amp). Set the master control at “12 o’clock” and the input level at zero. The input level should then be used to control the overall output of the unit. The two controls are provided to allow independent control of “house” volume and “stage” volume when the unit is used as a stage monitor with a connection to a house PA. See the discussion under “Direct Out” below.

The maximum volume at which the system will play is limited by the capability of the speaker system. A 10-inch driver in a small cabinet has a limitation in how loudly it will play. If more volume is needed, use a Contra EX extension cabinet or take a feed from the Direct Out jack to a PA system or another amplifier.

Tone

XLR

input

¼ inch

inputInput buffers

Combo jack

Input level

3 band EQ	Filt
	Notch Cut
	N/C Switc
Bass Mid Treble	Filter
	Filter
Pre EQ	switch
outputs

Each tone control has a center detent at the flat position. Experiment with settings to achieve the frequency balance that sounds best to you. In general, small values of boost and cut are best. The amp is designed with flat frequency response so only minor corrections should be required to compensate for room effects or “peaky” pickups in order to maintain the balanced response desired for acoustic instrument amplification. To minimize electronic noise, avoid operating all controls simultaneously at their maximum settings.

The bass control is a shelving-type that affects frequencies below 250 Hz and with a maximum boost/cut of 15 dB. The mid control affects frequencies between 300 Hz and 2000 Hz and has a maximum boost/cut of 15 dB. The treble control is also a shelving-type that affects frequencies above 1000 Hz with a maximum boost/cut of 25 dB.

Notch/Low Cut Filter

The notch/low cut filter is a fixed amplitude, variable frequency type that inserts either an 18 dB cut or a 12 dB per octave rolloff at frequencies between 30 and 800 Hz, depending on the position of the control. Approximate frequency settings are noted on the frequency control. Note that the first half of the control’s rotation affects frequencies from 30 to 70 Hz, the last half of the rotation affects frequencies between 70 and 800 Hz. This is done so that there is plenty of control in the critical low frequency range. The notch filter is used to

Signal Flow Diagram

Power

Phantom				Effects	Send	Notch Cut	Filter	Post	Mute
				Loop			70	EQ
									Off On
						30	800
Level	Bass	Mid	Treble	Level			Freq	Master
Input					Return	Off On			Ground
Input					Return				lift	Direct Out
										Direct Out

Contra Control Panel

Stereo Amplifier specifications

The Acoustic Energy Stereo Amplifier is a remarkable piece of audio engineering designed to deliver pristine sound quality and exceptional performance. This amplifier is engineered for audiophiles and music enthusiasts alike, offering a blend of classic design elements and cutting-edge technology.

One of the standout features of the Acoustic Energy Stereo Amplifier is its high power output. With a robust power stage, this amplifier provides ample headroom to drive a wide range of speakers, ensuring that it can handle complex musical passages with ease. The amplifier typically boasts a power output of around 100 watts per channel, making it suitable for both small and large listening spaces.

The amplifier utilizes advanced Class A/B amplification technology, which combines the benefits of both Class A and Class B designs. This results in low distortion levels and improved linearity, delivering clear highs and rich, detailed mids. The user can expect warmth and depth from their audio, making it ideal for various genres, from classical to rock.

Another notable feature is its comprehensive connectivity options. The Acoustic Energy Stereo Amplifier is equipped with multiple line inputs, allowing users to connect a variety of sources such as CD players, turntables, and streaming devices. It often includes digital inputs as well, making it versatile for modern audio setups. Additionally, many models feature a high-quality phono stage specifically designed for vinyl enthusiasts, ensuring an optimal listening experience.

The construction of the amplifier is also worth mentioning. Typically housed in a solid chassis, it minimizes vibrations that can affect sound quality. The design is often complemented by an aesthetically pleasing front panel with an intuitive layout, making it easy for users to navigate through settings.

The Acoustic Energy Stereo Amplifier often incorporates advanced thermal management technologies to ensure longevity and consistent performance. This includes efficient heat dissipation mechanisms, allowing it to maintain optimal operating temperatures even during prolonged use, which is crucial for maintaining audio integrity.

In summary, the Acoustic Energy Stereo Amplifier represents a harmonious blend of power, performance, and versatility. With its high output, advanced amplification technology, extensive connectivity options, and robust build quality, it stands as a top choice for anyone seeking to enhance their listening experience. Whether used in a dedicated audio system or as part of a more extensive home theater setup, this amplifier promises to deliver an immersive sound experience.