Modifications & 222A Photo's

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Stereo Spatial Enhancer
Model 222A


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There are produced only two "stereo enhancers units" which designed specifically for broadcast use. First was the StereoMaxx at about 1985 by Mr. Eric Small of MODCSI (he co-operates with Bob Orban for Optimod’s 8000 & 8100) and then at about 1988 the stereo spatial enhancer 222A by Bob Orban. In general, the broadcast enhancers manipulate the stereo difference signal (L-R) only, so they don't have the mono compatibility problems that the general-purpose boxes have.

The Orban 222A works by detecting attack transients in the L+R domain and momentarily increase or left as is the L-R content when this occurs, so stereo information stay’s always “constant”, the level of this constant varies from the user giving threshold on front panel knob.
This exploits the fact that the ear tends to localize on transients while minimizing the average amount of L - R gain increase. L-R gain increase, while not directly impacting the mono signal, can reduce L+R loudness because it increases the peak modulation of the left and right channels in FM Stereo forcing the average modulation to be reduced to ensure that the peak modulation remains within the limits set by the government authorities.

If the intelligent inputs monitor circuit see that comes a track with already wide enough stereo image then automatically minimize or defeat the enhancement L-R process, the same will happen if the monitor see only one channel or mono information on inputs, both states are indicated by minimum or no lit of front panel LED’s meters, by that way 222A did not exaggerate stereo image neither produce any kind of phase problems at high freq. on mono reception.

Orban 222A Or StereoMaxx? That’s the question
Orban 222A and StereoMaxx are identical on overall design. Orban 222A is more on “purist” side as Bob Orban is, simplicity & effectiveness dominates on 222A.

On StereoMaxx dominates more the “fancy” tricks with its accompaniment side-effects. The listening results from StereoMaxx impressive, generally has that popular “wow factor” but on other hand “overdone” his job and “steal” the mono information from a music program. MPX FM Stereo broadcasting needs the “mono” information, like the color photo needs the white, can color photo exist without white? definitely  NO.

StereoMaxx If I must name it I may give him the name of “kitsch-y”:) on lot people like that way especially the Netherlander’s, even his face plate is “kitsch” with that “fancy blink” LED’s, practically that popular “kitsch-y” over-stereo imaging effect can heard on all of Omnia’s boxes, to listen that “the stereo is steal my mono” effect do that, just when you hear a super wide music i.e. an old 60’s track simply switch your fm tuner to mono and vise versa, easily can you notice an about 40% lowering of audio especially at HF region where stereo enhancer acts, StereoMaxx’s L-R action region is from 50Hz-18Khz, Orban 222A L-R action region is from about 900HZ-4Khz, please do not confused by the more extend frequency range here, on stereo spatial enhance techniques the opposite is true, so that “narrowed” 900HZ-4Khz L-R action region of Orban’s 222A means in general “lesser” artifacts, stereo image width has more natural results than of any unnatural “baggy stereo image” except if you want this “kitsch-y”:( look for your radio station, don’t forget radio means “image”, but if your “goal” is that “fancy” & “kitsch” look for your radio station then Orban 222A is NOT for you. By the way the principles of 222A & StereoMaxx now is on all latest processors of Orban or Omnia as a software.

I really need this or other brand Spatial Enhancer?
Actually Yes & Not. The Orban 222A by himself did not solving you any separation problems. Like other similar units simply add an effect an illusion that the stereo image is larger than life :-) "is more noticeable on cars and not on headphones" with its “pro and con”, so it’s a matter of taste to use this or other brands stereo spatial effect. 
If you thing that your overall on air stereo image is not so wide & solid as others on air radio stations, first thing to do is to make a detailed separation test, from console trough exciter including STL & Processing Box. Or you must need to upgrade all your audio side chain (if it’s old) including the Tx path i.e. STL fm exciter etc.

Beware: Do NOT make separation test with the Enhancement knob of 222A at IN position due the accidentally On & Off of mute FET, if you cut one audio channel L or R saying by the mixing console on other dead channel may you listen enough sound (cross-talk) along with that “swishhhy” sound when the mute FET goes On & Off state thus your on air separation will suffer.

My results & opinions
I use this unit for about 3 years it was ahead of my Orban Optimod 8200. Definitely and without any doubt I find his sound results much better and for that reason 222A stays longer on my air chain than of StereoMaxx. Of course nothing is perfect, as StereoMaxx have his weakness so and 222A is not completely Free from nasty things as for example the noticeable on some cases the ON-OFF action of control FET that will heard as “swishhh” also with some unusual music tracks may accidental triggering the ON-OFF FET which open or close unnecessary the L-R VCA produces that  noticeable (at quiet passages) “swishhh” sound. The same ON-OFF FET action is present and on StereoMaxx with more noticeable side effects especially on quiet music, overall 222A is more quieter here,  audio path on 222A is DC and more simpler than of complex StereoMaxx, this means that audio passes trough lesser IC’s thus audio has lesser quality degrade due lot IC’s & passive parts as is transformers, capacitors etc.
Construction of the unit follows the typical high quality of good old analogue Orban i.e
. Silver Mica capacitors, Tantalum by pass capacitors, precision metal resistors, selected IC Signetics NE5532, excellent PCB with great shielding. Balance In & Out’s, sufficient NON “fancy blink” metering LED’s.
Recommended settings. Due his clever monitor circuit there is nothing much to do, for most music formats without any problem with mono or multi-path the giving setting for enhancement front panel knob is from 3-4 point, the internal width limit pot at 1:1 this always give the best of 222A L-R results.
Orban 222A match perfectly with every kind of know processing. As any gear on processing world I must remind you the golden rule  “Less is More”. Good luck.

XFon 261fm