The Chameleon Labs 7721 Stereo Compressor updates Chameleon Labs' popular stereo bus compressor, the discontinued 7720, to better sounding components, on-board power supply, a new look, and improved sound!
When designing the 7721, Chameleon’s engineers started with a clean sheet of paper and deeply evaluated the details associated with developing a bus compressor for the modern studio. Basing detection and voltage control on a voltage control amplifier (VCA) topology and designing a circuit that provides low noise and transparency the team created an acoustic “glue" that is capable of consistently delivering punch and loudness to the signal.
The 7721 provides a classic set of adjustable settings as well as controls only available on esoteric compressors, including:
- Soft Knee / Hard Knee – Allows you to change between a softer arriving compression effect and a faster arriving, limiting type effect.
- Peak / RMS – This control allows you to choose between the Peak and RMS detection schemes that are quite different. Peak detection engages the compressor by monitoring peak or instantaneous voltage signals. RMS engages by looking at the average energy in the signal and comparing it to the threshold setting. Very different modes of operation that provide great solutions for specific problems.
- High Pass Filter – If you decide to use a Side Chain signal as the compression trigger signal, you can use the High Pass Filter to high the audio signal and avoid pumping effects.
- Classic Controls – Threshold / Attack / Release / Ratio – Low ratios provide a nice starting place for master transparency, 4:1 provides more color and higher ratios for a tougher sound full of character. We like to use Attack and Release controls to respond to tempo and feel of a track.
- Blend – This control allows you to blend, or mix, the original uncompressed signal with the compressed signal providing another tool you can use to obtain your desired objective.
- VU Meter - Monitor Input, Outputs and Gain Reduction levels.
Chameleon Labs 7721 Stereo Compressor Features
- Stereo compressor with VCA-based signal detection
- Super low noise, IC based input section
- Side chain input allows a seperate source to be used as the compression trigger
- IC based, ultra-low noise output stage
- VU meter for Input / Output Level and Gain Reduction monitoring
- Super low noise internal power supply
- Selectable high pass filter
- Threshold, Attack, Release and Ratio controls
- Selectable detection type Peak or RMS
- Selectable compression types: Soft or Hard Knee
- Blend control allows you to mix the compressed audio signal with the original signal
Chameleon Labs 7721 Stereo Compressor Functions
- On Switch: Turn Unit On - VU Meter Light is ON
- Compression: Insert compression circuit or bypass
- Side Chain: Use Side Chain Input for triggering
- Compression: Soft or Hard knee compression type
- Detection: Peak or RMS
- High Pass Filter: 60, 90, 130 or 200 Hz high pass filter applied to Side Chain detection signal
- Threshold: Applied between -15dB and +15dB
- Attack: Attack time in milli seconds - .1 / .3 / 1 / 3 / 10 / 30
- Release: Release time in seconds - .1 / .3 / .6 / 1.2 / 1.5
- Ratio: Compression ratio selection 1.5 / 2 / 4 / 8 / 10
- Blend: Full Dry equivalent to 0% compression, Full Wet equivalent to 100% compression
- Output Gain: -60dB to +20dB Output Level control
- VU Meter controls (L&R): In - Input / Out - Output / GR - Gain Reduction
Chameleon Labs 7721 Stereo Compressor Specifications
- Input Connectors
- Input (Female XLR): 50 kΩ
- Side Chain Input (Female XLR): 50 kΩ
- Output (Male XLR): 200 Ω
- Audio Specifications
- Noise Specification:
- Frequency Response: 20Hz - 20kHz +/- 0.25dB
- Headroom: > 20dB output level
- Dynamic Range: 100 dB per AES17 Standard
- Common Mode Rejection: 100Hz - 10kHz >90dB
- Input and Output Impedance: >10kΩ
- Red Input Gain: Input Overload
- Red Output Gain: Output Overload
- Power Supply
- 100V - 240V (50/60Hz): Switch mode power supply, fully shielded 3 amp peak output capability, quiescent consumption 0.5 Watts
Chameleon Labs 7721 Stereo Compressor Includes
- Chameleon Labs 7721 Stereo Compressor
- Manual & Literature
- IEC Power Cable
6 Reviews Hide Reviews Show Reviews
I own many stereo compressors. I have the Warm’s, like them, have a 33609, very colorful, and this. This is a great take on the SSL. It sounds great! I still have a Revive Modded 7720 that is still used today. Cannot recommend Chameleon Labs enough. Great quality gear!
I was using two PBA 6A's for my mix buses, and decided I needed something more neutral...this box does the job! It gives me a nice glue along with just the right amount of color while still providing some transparency...a great alternative to SSL type stereo comps, and this unit features a mix knob for parallel compressing...highly recommended!
This is my first real analog comressor to sit on my mix bus. I just recently got into outboard mixing. I cant give it 5 stars because i know no better. But, i have to say there is a difference from itb mixing to otb mixing. The compressor gives me clean transparent compression. I find im able to push the overall output higher than plugins befor it starts distorting. The compression of this unit definitely, in my opinion, does sound better than plugins. The unit is well built and knobs feel hefty.
If you're in need of a great stereo compressor that can rival it's top dollar counterparts at a reasonable price, the 7720 is a sound investment. It has very similar compression characteristics as a GSSL, but it's much more flexible due to it's HPF feature and 1.5 to 1 ratio option, which I find to be perfect when you need "just enough" compression. Aside from a mixbus compressor, I've also found it to be quite impressive on drum overheads, and it's become one of my favorite compressors for piano and other percussive instruments. I've also tried it out as a kick drum compressor while mixing a recent EP, and it worked wonders in this application, as it's easy to really control transience without making the low end feel lifeless (utilizing the HPF feature). All in all, it's a great piece of gear due to it's famous circuit design, and my hats off to Chameleon Labs for providing a way to get us engineers into solid sounding gear for budget prices.
So I have quite a few compressors (Purple MC77, Chandler Germ Comp, dbx 160A, FMR Audio RNC, ART Pro VLA, Aphex 651, tfPro p38, etc) and this compressors continues to put a smile on my face. It's perfect on drum bus or anywhere you want just a touch of musically transparent compression. The amount of features for how little it costs is just insane. It obviously won't be the right tool for all applications but I recommend it to all my friends. I should get a commission as many people as I've turned on to this. My only gripe is the ugly power supply but you can always buy the rack mount supply for extra cash. If I'm really being greedy then I would ask for dual mono or stereo operation.
I am falling in love with this compressor more and more every time I use it. It excels on the 2 bus unlike any I've tried so far. The HPF makes it a dream. I can still push the low end as hard as I like, with out it pumping the vocals or other elements in the mix. The sonics of the unit add a cool urgency to the mix that I really enjoy. If you're looking for a stereo compressor, it's more than worth a listen. Check one out.