FAIRCHILD STUFF... I am not old enough to have used Fairchild gear when it was NEW... I could have but I was - like - twelve - and really excited to have a reel to reel that would do 7-1/2 ips two channel with sound on sound (Sony... big... tubes... green winky vacuum tube "clapping" meters...) and a couple Lafayette "Dynamic" mics... but there was a lot of Fairchild around when I started working in real studios in the mid-late '70's. In 1977-78 I bought a custom Langevin/Fairchild console that originally came out of Media Counterpoint via another studio and had it rigged into the loft building where I lived and had a "studio". Right around the same time some poor guy (who later became a friend and asked me to be Best Man at his wedding) bought a Fairchild console based completely on Integra modules and Lumiten attenuators. He had chopped the thing in half and hauled it out to South Dakota and after a month or two of not getting anywhere with it he flew to New York with a very heavy suitcase full of stuff and started looking for me. Apparently the same broker was involved in the console I bought and the one he bought. I never called and asked for help and I guess that made me an "expert"... right. So he just showed up and I fixed some of the broken stuff in my micro-shop (it was basically a closet) on 45th street while he told me about his console. Eventually I flew out to Rapid City to get the console going for him. This studio was owned by one of the New Christy Minstrels (I think). Oh - it was sad - we were the only guys within 500 miles with satin studio jackets and long hair - almost got killed a couple times just trying to have some breakfast. Anyway we got the console going and then modded the fader system, which were based on remoted Lumiten optical attenuators, to do VCA style subgroups... it worked - it was awful but it worked... and I guess they did some records... on a Scully 280 1" TWELVE track... ah those were the days... (not really). When someone says Fairchild I say "mostly junk - but a few gems..." When I see Fairchild modules come up the are nearly always from the Integra Series of sound system and console building blocks. 661 - Noise attenuator (Auto-Ten fairly slow optical noise gate) 662 - Preamp/Line Amp (15 to 50dB gain - big output transformer - very grainy) 662TXI - Preamp/Line Amp as 662 with input transformer added 663 - Compressor (optical 2 millisecond attack time... ssslllloooooowwwwwww) 663 - Compressor as above but Stereo 664 - Program EQ (3 band switched freqs mid band - passive 17dB insertion loss) 665 - Program EQ w Amplifier (662 and 664 mounted together - never seen one) 665TXI - Program EQ w Amplifier as 665 with input transformer added 667 - Power Supplies for Integra Series... various versions There were also the actual console modules which were mostly the same thing but mounted as all in one channel strips... really cheesy knobs and matt finish blue Formica unless you ordered it with a different color... I had to engineer a couple dates on one... headroom was certainly an issue... and it was in New Jersey... a long way to go to have no fun. Of the Fairchild Integra modules... The dynamics modules 661 and 663 are based on an optical attenuator that used an incandescent light bulb and an LDR (Light Dependent Resistor). The light bulb would light up and shine on the LDR and the LDR resistance would drop down pretty low and act as the shunt leg of an attenuator. This is the same thing an LA-2 does but there is a critical difference. The LA-2 uses an Electro-Luminescent panel (EL panel) as the light source. It take very little time at all for that panel to light up whereas is take quite a bit longer for the filament of the light bulb to light and to go dark... beyond that the single LDR used in the Fairchild attenuator was itself not very speedy. The circuits around this were very simple transistor circuits that were not remarkable in themselves - as I recall the internal clip level (sinewave) was +17dBu. For comparison the discrete Neve stuff was +22dBu. Because 663 modules are so incredibly slow and mushy they are useless for dynamics control but as an effect... a racked pair for a few hundred bucks may be worth it... or not... The 662 Amplifier is kind of cool because it does have a color - a very grainy mostly PNP transistor amplifier followed by a big beefy output transformer. The console I had used about forty of these and they worked... though if I could bypass most of them things sounded cleaner. I think that if you want another color and can pick these up CHEAP then why not... you would need some input transformers and 600 ohm attenuators to make them more useful... The 664 EQ was actually not bad... nor is it a Pultec or a Lang. The 664 is a passive module that needs to be fed from a 600 ohm source and look into a make up gain amplifier that presents the EQ with a 600 ohm load.... maybe a 662 Amplifier... which is what Fairchild packaged up and sold with the EQ as the Model 665. I wouldn't bother with the Fairchild power supplies. The Integra modules might be useful but the problem is that they are really not worth anywhere near what they are being sold for... and then the cost of getting them mounted in to a rack and powered up has to be added. Say you buy a pair of 663's for $450 each and pay a tech to do a decent packaging job... you are into it for $1200... I'd rather have a couple RNC's... or any number of other things... Of course the Fairchild name was "made" by the two or three things they made that were... gems. These are the things that command the money and get used all the time. 670 - Stereo Limiter (originally sold for around $1600 USD...) this is the classic Fairchild limiter that all the mastering places had when tubes ruled... 660 - Single Channel version of the 670 Limiter (originally sold for about $950 USD) and the lesser known... 666 - "Devil's Limiter" - 2U rackmount - I have only seen three 666's in my life. These are rare and the ones I saw had hand-drawn meter faces so I imagine they did not make very many of these... they are good - not worth what they sell for in my view - start with a nice UA 175/176 as a reference point - the 666 could take more abuse and was a little cleaner sounding... Your mileage may vari... all this stuff is old and a lot of it is broken AND... Fairchild stuff that was not so great... 600 "Conax" Series... over-modulation limiter... which is really just a peak clipper... this thing works in a chain where one had H.F. pre-emphasis as in a disk cutting chain or at the front end of a radio transmitter. Basically it clips the "hair" off. Great for transmitters as long as you don't trim off more than 6dB of hair. By the time you hear it doing anything it is pretty terrible. Sadly too many people have bought these thinking they were related to the 660/670... Really only worth the chassis, transformers and other components and maybe useful as a color if you rip out the EQ and clipper and replace it with an attenuator or some other gain control device that you would have to build nearly from scratch. The 600 was mono "unity gain", 601 was mono with 40dB gain, 602 was stereo version of 600, 600A was set up for doing "opticals" (recording optical film tracks)... I remember the smell of the film stock whenever I think about opticals... 658 / 658A "Reverbertron" I had one - actually it did NOT suck - it was based around several spring tanks mounted on a big rack panel and a sounded lot like a MasterRoom but thicker, darker and noisier. Mine sounded pretty good and it had an optical attenuator that did... something... can't remember what. I'd like to find another one to replace the one I sold but not at "Fairchild" prices... I certainly don't "need" it. 673 "Dynalizer" Dynamic Equalizer - does a Fletcher Munson Loudness curve equalization and boosts highs and lows as level drops - like an automatic loudness control. This uses the same optical system as 661 and 663... kind of slow and stupid but - who knows - possibly useful as a "thing". You would have to get the gain structure around this right to make it work "well". 676 Disc and Tape Head Preamps... based on the 662 preamp... not great... and the LUMITEN SERIES attenuators... Fairchild - in the late 1960's - was big in using light bulbs and LDR's (Light Dependent Resistors) to control level. There were the 668 series linear faders... the fader themselves were just turns of wire around a plastic tube and the fader knob would slide a wiper along the turns - a wire wound linear potentiometer. This would control lightbulbs that were in little plastic boxes (light proof) either in the fader unit or remoted in little octal plug-in cans. The way I remember it (and memory is a funny thing) there were two lightbulbs in each Lumiten and each bulb shined on an LDR. One was in series and one was in shunt and one brightened while the other dimmed so it was a variable "L" pad I guess - or a "T" - depending on how they did it. The 669 Series were rotary controller versions... both 668 and 669 were low impedance attenuators and there were high impedance versions 677, 678, 679... There was other Fairchild gear and it comes up from time to time... 510 was a consumer compander based on the 661 and 663 - this is noise reduction box and conceptually like dbx in that it's companding action is done on one full spectrum band (unlike Dolby A or Telcom that broke up the audio band in to four or five regions and companded those). The 510 today is useless for the original target market - home hi-fi - but kind of cool for the odd effect in the studio because it is all packaged up... it sits on a shelf real nice and once a year you can just plug it in and go (unbalanced). 610 was a 5 or 10 watt power amplifier... There are a number of small transistorized amplifier modules and one full rack sized power amplifier they made. None were particularly great though if anyone stumbles across a vacuum tube one I'd like to know about it. It could be good if they made it with the same care they applied to the 660/670... So... Fairchild - mostly junk and a few gems... junk is not useless... but it may be of such limited usefullness that you really have to look at how much you are going to invest. The one 663 module I have left gets powered up and connected with alligator clips to be used about once every three years and for those times it does it's job badly in just the right way...