Feb 24th, 2016
Q) Between the Symetrix 522 and a pair of 501s, which would be better for vocals, guitars, and bass guitar? Why such a wide price range for the 501s you have for sale? Can the 501s you have for sale be master-slaved for stereo?
A) These compressors are almost the same but the 501 will have more adjustment controls and range over the 522. Although sharing the same VCA, the 522 does not have as sophisticated RMS circuit (which looks at the incoming audio). The better audio detection circuit in the 501 (often call somewhat erroneously RMS detector) can allow a wider range of dynamics to be recognized and more carefully tracked or "voiced" to control the VCA, (voltage control amplifier, which affects compression of audio dynamics). The 522 main claim to use is it’s versatility to duck, noise gate and other VCA acrobatics. Both units are the older style compression techniques like Drawmer, Ashley, Orange County, etc., but personally I think they did it better. Other companies priced their products and marketed More! More! More!
A distinctly different approach to compression was done by companies like DBX, Digitech older Behringer even boss used virtually carbon copies of the best DBX designs, with DBX parts and approval but were unheralded (no fancy marketing). DBX style compressors were notable for their "over easy" "soft knee" or more graceful way of compressors music and it transients. Somewhat less compression apparent to the Ear and more forgiving. The Symetrix although better I think than many other of it's design era type was mostly a hard knee compressor being that once the music dynamics go to a certain threshold point, which the engineer would carefully set, the music would squash a little more obviously. This could be good thing especially on drums, bass, anything you wanted to flatten out the dynamics and place deep behind the mix. Such compressors if not carefully set can pump the audio level, causing breathing of signal level. If wanted, this effect can be good. I've used it on "electric" compositions to create texture and character. Such pumping of the compressor will be audible only if you set a compression ratio greater than 6 to 1 and/or a set a fast release rate, thereby turning the compressor on and off fast. Some newer well know compressors seem like they don't pump but the truth is the controls on the front panel (regardless of the marked indications) don't allow compression rates of over 12 to 1 or actually the release rate knob is virtually useless. People think such will sound better, but actually the circuit is not sufficiently designed to range far enough to create this effect OK I suppose but their claim is made to be a better sound at a high price, when in fact the products functions are limited. Symetrix and others mentioned will allow more adjustment range.
As for the prices, some units have been modified in subtle ways, or are new in box, or some have scratches on the rack holes. All Equipment is clean and tested and I only want good low hours use equipment to resell. I don't buy from 25 year old studios with equipment which has smoke and heat and long use on it. That's for Ebay usually. What I like about equipment from this era is that it was well built and usually no much trouble to keep operational.