Hammond Manual Tapering
Hammond XB-2 - Tech Tips Hammond XB-2 - Tech TipsContentsMark Longo has submitted a few postings on modifications andadjustments for the Hammond-Suzuki XB-2. Those commonly asked forare included here.This is a very typical problem, and fortunately, it's veryeasy to fix if you're even a little mechanically inclined. Eachkey in the XB-2 has a small guide under the part of the key thatis closest to you. That guide has a little rubber-like 1/4' longtube (jacket) that slips over it. When that little jacket wearsout (which it eventually will) the key's lateral positioning getssloppy. When you grip the front of the key between your thumb andforefinger and wiggle it very gently from side-to-side if the keyeasily slides up against the adjacent keys, the little rubbertube has either worn thin or has completely worn out and fallenoff. You'll need to replace the tube.
You can get the replacementjackets from Hammond and do it yourself, or pay your dealer/shopto do it. It's better if you can do it yourself as this will keephappening periodically. Replacement jackets can been obtaineddirect from Hammond Suzuki USA via mail.Here's how to replace the jackets:. Take the top off your XB2 by loosening the 5 phillipshead screws underneath the organ (be sure to unplug theAC power first!). Remove the loose key (be careful you don't break it, it'sonly plastic!).
Each key attaches to the organ at the endfarthest from you as you face the keyboard. This end ofthe key latches through a little metal housing. Gentlypress the tip of the key that goes through the metalhousing downward and slightly forward and the key willpop out. It may take a bit of force to do this but becareful you don't break the key. Use your fingers or apiece of hard rubber or something else that's firm butnot rigid.
Replace the little jacket. In the space underneath thefront of the key you just took out, there is a littlemetal tongue about 1/4' wide that's pointing towardthe ceiling.
Remove the old jacket (if it's still inplace at all) from the tongue. Each jacket has a littleridge on each side. When you slide the new jacket on, theridges should point toward the front and rear of theorgan. If in doubt, take off another key to see what aproperly installed jacket looks like. Slide the newjacket on.
The jacket will stretch a bit going on as it'sa tight fit, but it will go on. Replace the key. You do this by carefully fittingthe far end of the key back into the metal housing. Theunderside of the key has some plastic nubs and such thatmust fit into the keyguide just in front of the metalhousing. Watch out that you don't break the key by justjamming it into the housing. This is actually prettysimple, just be careful. Repeat for each loose key, then replace the top.Mark Longo Posted to the Hammond Mailing List on 22 March 95Things have been quiet on the list, so here's something forthe XB2 owners among us to chew on.I finally got around to experimenting with the XB2's internaltrim pots.
You can use these pots to adjust the XB2's overalloutput level, overdrive level and extent, and to modify thevibrato/chorus depth slightly. There aren't any internaladjustments that let you alter the XB2's basic tone, thoughboosting the XB2's output signal to your amplifier may yield asomewhat fatter tone due to natural harmonic distortion realizedin the amplifier's pre-amp section.Below I describe what I discovered by experimenting withdifferent pot settings on my XB2. I should mention that my XB2was made in the first year of manufacture. It's possible that ifyou look inside your XB2 you'll see something different than whatI describe below, or that adjustments to your own XB2 pots willhave slightly different results. Obviously I accept noresponsibility for the accuracy of my below comments as appliedto an XB2 other than my own. Please use caution and common sense.If you're the sort of person who likes to tinker withelectronics and you're not afraid of tweaking with your XB2 abit, you'll probably find that these adjustments allow you totailor the performance of your XB2 a little and you'll have funmonkeying with it in the bargain. On the other hand, if you'rethe sort of person that heeds warnings like:DO NOT REMOVE THE BACK PANEL - NO USERSERVICABLE PARTS INSIDE!!
DANGER OF ELECTRIC SHOCK!!Refer repair work to qualified personel.then you may be better off leaving your XB2 alone. Afterall, they sound pretty cool as they come from the factory andsince you have to make the below adjustments while the XB2'spower is turned on, there IS some danger of electric shock. Also,if you drop something on the circuit board(s) that conductselectricity (like, say, a screw driver), you might shortsomething out resulting in a costly repair bill and your doingwithout your XB2 for a while. WARNING:BEFORE ADJUSTING ANYTHING: Write down the factory-setposition of ALL the trim pots! Be forwarned, Hammond-Suzukiwill not take kindly to your call asking what the factorysettings are since you forgot how yours were originally set yoursand screwed them all up. If you get lost, send me e-mail and I'llsend you my default settings, but they may be different for youif your circuit board is of a different revision than mine.Therefore, take a few seconds to write your settings down andavoid feeling stupid later.
Making Adjustments:The XB2 has several small potentiometers (pots) on the uppercircuit board on the right side of the organ, visible when youremove the cover. My XB2 pots have a white plastic phillips typeadjustment screw head about 1/4 inch in diameter. The name ofeach pot adjustment is screened onto the circuit board in Englishsomwhere near its mounting point. I noticed an unlabeled pot onthe lower circuit board near the AC power recepatacle on the leftside of the organ.
This may be an AC line level adjustment (highvoltage) SO DON'T MESS WITH IT.Some of the pots increase their assigned effect when turnedclockwise, others counter-clockwise. One presumes this is becausesome effects increase with impedance while others decrease. Justmonkey around with the pots and you'll see which way to turnthem.
I tried turning each pot to its full deflection in both theclockwise and counter-clockwise directions and nothing terriblehappenned (my XB-2 didn't blow up!). I did adjust the pots one ata time so at no time were they all max'd at once, though Ipersonally doubt that max'ing everything would harm theelectronics.You use the XB2's left output jack only when plugging into amono amplifier or mixer. This means that when nothing is pluggedinto the right output, a summation of the right and left channelsgoes to the left output. Many of the pots in the XB2 control leftand right channels separately. When listening to mono output(left output only), tweaking a RIGHT channel adjustment affectsthe summed output as much as tweaking a LEFT channel adjustment. R GAIN / L GAIN These pots control the 'clean' output of theorgan, that is, the output of tone generation exclusiveof the overdrive circuit. You can boost the output to thepoint that you can badly overdrive a mixer's line inputresulting in some very ugly distortion.
At first Ithought this was distortion in the output section of theXB2, but I max'd these pots and fed the signal to myLeslie and heard far less distortion than with a linemixer, though some distortion is still present. Note that it may be possisble to dramatically increasethe amplified volume of your XB2 by adjusting these potsand thereby feeding your amplifier a MUCH hotter signal.I have found this to be very useful since my Leslie needsa little help to output enough volume in some livesettings. Be careful though, excessive output may causeyour amplifier to distort in ways that neither you noryour amplifier like. I believe that the XB2's come fromthe factory with the gain pots set to a fairly low outputvalue. OD MIN / OD MAX These pots determine the amount of distortion added tothe output signal by the overdrive unit. OD MIN sets theamount of distortion applied to the output signal whenthe distortion wheel (modulation wheel on the organcontrol panel) is at its full backward deflection.
OD MAXsets the amount distortion applied when the wheel is atits full forward deflection. In theory, setting OD MIN toits lowest value and OD MAX to its highest would supplythe widest range of distortion available. R OD GAIN / L OD GAIN These pots appear to control the overall boost that canbe applied to the output signal by the overdrive circuit.These pots can be used to boost the level of theoverdrive circuit's output, making the organ's outputsignal hotter (and possibly overdriving theamp/mixer/tape you're connected to). Acting in concertwith the OD MIN / OD MAX adjustments, these pots can beused to tailor the effects of the overdrive circuit. Use caution and judgement, it's theoretically possible todamage the input circuit of some types of gear by feedingit too hot a signal from your organ.
If you hear lots ofdistortion with the OD wheel at the minimum position,you've probably overdone it.NOTE: I haven'tmessed much with the OD pots. It would seem possible thatby setting a modest value on the OD GAIN pots you'd beable to add distortion with the mod wheel but NOT volume.Many people have complained that increasing the XB2overdrive level using the mod wheel adds way too muchvolume to the output signal.If anyone tries this, please let us know what youfind. EXP MIN / EXP MAX The settings of these pots control the effect of the fullbackward and forward deflections of the Hammondexpression pedal.
The EXP MIN pot can be set so that fullbackward pedal deflection still allows a healthy outputlevel. Conversely, the EXP MAX pot can be used to limitorgan output when the pedal is at it's full forwarddeflection. Note that the EXP MIN pot can NOT be set tosilence the organ at full backward pedal deflection. Apparently the expression pedal is a simple voltageregulator.
A control voltage is sent to the pedal, thepedal returns a voltage level that is the same or lowerdepending on whether the pedal is deflected forward orbackward. This is distinct from guitar-type volume pedalswhich modulate the amplitude of an audio signal. The EXPMIN and EXP MAX pots appear to set the lower and upperlimits on the voltage returned from the expression pedal.VIB2 / VIB3 There have been many complaints voiced on the Hammondmailing list that the vibrato and chorus on the XB2 areweak when compared against the same effects on a B3. TheVIB2 and VIB3 pots can be used improve this slightly, butbasically, you just have to live with the XB2 vibratosound.
These two pots adjust the depth of V2 and V3 and C1 andC2 respectively. Apparently there is no way to adjust thedepth of V1 or C3.
Max'ing the VIB3 pot will cause C2 tohave the same depth as C3, but with a very tiny bit morelow frequency content. You have to listen hard in a quietsetting to hear the difference. LES This adjustment supposedly effects the sound of the XB2'sbuilt in Leslie simulation, though personally I can'thear that it does much of anything. It seems to changethe 'beating' in the highs coming through theLeslie effect a little, but the change is VERY subtle andyou have to listen carefully in a quiet setting to hearany difference. In any case, I don't find it useful foraudible adjustment.MarkMark Longo Digital Equipment Corp.longo@zk3.dec.com Nashua, NH87 8300 020Mark Longo Posted to the Hammond Mailing List on 05/30/95Hi folks,Having just finished three gigs this weekend using my XB-2through an equalizer and into my Leslie 302, I can tell you thatfor me, EQ'ing the XB-2 is a BIG plus.
Tapering Down
Using the EQ I'm able toremove most all of the XB-2's shrillness and substantially fattenup the low end and low mids, which gets me much closer to myfavorite B3 tone. The details follow.SummaryIf you have a few bucks to spend on a decent graphic EQ, doit. You'll be surprised at how much you can change the sound ofyour XB-2.
If you're one of us folks who thinks the XB-2 tonecould be improved, you'll be surprised at just how good you canmake it sound and you'll have lots of fun doing it.A 15-band unit is sufficient, though a 31-band unit is alittle more fun and has advantages for the very finicky ear. Aconstant-Q unit is highly recommended, and a 120Hz filter is abig plus. Also, ± 15db boost/cut unit is more versatile than a12db unit, but isn't necessarily needed.The EqualizerI bought a high quality pre-owned EQ through the Internet($200 US). It is a dbx 1531X, which is switchable for 31 bandsmono (1/3 octave/band), or two 15-band ranges (2/3 octave/band)for stereo. This EQ has constant-Q circuitry, which means thatthe band width effected by each slider is constant whether theslider is at full boost, full cut, or anywhere in between. Somecheaper EQ's don't have constant-Q, so when you move a slider theeffected band width becomes greater as the slider moves closer toextremes, thereby effecting neighboring frequencies more and moreas the slider approaches full boost/cut. This makes it difficultor impossible to boost/cut a narrow frequency range (such as thetop part of the last octave on the keyboard, for example) withouteffecting many neighboring frequencies.
I strongly recommendgetting a constant-Q EQ. Constant-Q is not always mentioned inadvertisements so when considering an EQ, call the manufactureror look at the manual to be sure it has constant-Q circuitry. Ibelieve all the Rane EQs are constant-Q, as are most good gradeunits.I wanted to get a 1/3 octave unit (31 bands) so I could cutmost highs without cutting the key click and to do that I neededa slider somewhere near 7KHz. The 2/3 octave units (15 bands)don't have a slider near 7Khz as each slider on those unitscovers a wider frequency range.
BUT, it turns out that the XB-2is capable of delivering a loud enough click (especially withV2.0 OS) that I found I could deeply cut the high frequencyovertones and still have plenty of click coming through. Withthis in mind it would should be sufficient to use a good 15 bandunit, which is a somewhat cheaper than the 31-band units, thoughnearly not by half.The dbx 1531X has boost or cut maximums switchable between ±7.5db and 15db. The 7.5db range could be useful when makingsubtle changes to a mix or vocal tones, but for the XB-2 the ±7.5db wasn't enough, so I use only ± 15db. A side note, many EQsoffer ± 12db cut/boost, but I suggest trying to find one with ±15db. I found that 15db of boost causes a bit of audibledistortion with my performance rig. I like this because it letsme control which frequencies growl and which ones are clean. Onmy rig I set the EQ sliders so that the lows in the 500Hz regionhave a little more growl than the high, which I like clean.
Yourmileage may vary since you likely have different equipment, butin MY case, I don't get distortion till I move the sliders PASTthe +12db point, so I'm glad to have the versatility of ± 15db.Signal PathI positioned the EQ after the XB-2 in the signal path, usingthe 1/4' line out jack from the XB-2 (left output for mono)and then into the EQ, then out from the EQ into my Leslie 302's1/4' input. I could not use the 11-pin Leslie cable from myXB-2 because that cable won't plug into the EQ (obviously) and myLeslie 302 has no effects loop.
Al Goff does not recommend usingthe XB-2 effects loop for EQ because more tone shaping takesplace in the XB-2 internal signal path downstream from theeffects loop.Because I'm forced to use the 1/4' XB-2 output, I can notcontrol Leslie speed using the XB-2 Leslie tab switch or a footswitch plugged into the XB-2, as is possible when using the11-pin cable with my Leslie 302. Also, since devices in the XB-2effects loop DO NOT EFFECT the XB-2's 1/4' outputs, I can'tuse the XB-2 effects loop when using the 1/4' output to theEQ. You could place an external device such as a chorus stomp boxdownstream from the XB-2, but these devices are designed toaccept the low voltage levels generated by guitar pickups andwill likely be badly overdriven by the XB-2's hotter outputlevels.120 Hz FilteringMy EQ has a 120hz filter which for me is a BIG help.
The XB-2has a 120Hz buzz (at least mine does) which you only hear whenyou depress a key. It's not normally very noticable (unless youuse headphones) but my EQ boost of the lows made it jump out.
Butthe dbx 1531X has a button to take out the 120Hz frequency only,which removes the buzz almost completely (mmm-mmm good). There isalso a slider at 120Hz, and I found that cutting the 120Hz rangewith the slider removes the buzz, but it also reduces the bassresponse of the organ noticably.
Using the 120Hz cut buttonremoves the buzz but doesn't effect the organ's tone.ChorusMany of us have complained lots about the XB-2 chorus soundingwhimpy. Using the EQ can improve the chorus sound surprisingly.Don't get me wrong, it still doesn't sound like that crunchy B-3chorus so many of us like, but it is definitely improved. I'm notsure, but I suspect that cutting highs (ie: above 6Khz) isresponsible for the improvement.Tone SettingsI find that the EQ is effective in dramatically altering theXB-2 tone in a very wide variety of ways. The tonal changes youmake are obviously a matter of your own taste. I use the EQ totry to more closely emulate a real B-3.The EQ settings I use to do this are specific to my ownperfomance rig, the room I'm playing in, my own personal taste,how many drinks I've had, etc., etc., etc.
Your settings would(and probably should!) vary, maybe a lot. That said, it's alittle silly to mention specific settings, but I'll tell ya how Iset my EQ up this past weekend anyway. I like Jimmy Smith's toneon his recent albums, which I'd describe as sweet and a bitchurchy, yet beefy in the lows and especially in the lowermid-range. The EQ lets me get this tone surprisingly easily. Iuse full cut (-15db) in all frequencies above 6KHz, with abouthalf cut between 4KHz and 6KHz.
Software testing techniques by boris beizer ppt free download. I set 1KHz to 4Khz somewhere nearflat, with gradually increasing boost from 1KHz down through thebass/treble rotor cut off point (800Hz). As I get into the bassrotor range I increase the boost even more.
Hammond Organ Manual Tapering
And I've been addinga little growl by boosting to nearly full throw (+15db) in the400-600Hz neighborhood.If you try this, let me know what you find.Have fun, MarkMark Longo Digital Equipment Corp.longo@zk3.dec.com Nashua, NH87 8300 020Hammond-Suzuki has released an ROM for the XB-2 which upgradesthe old OS from version 1.x to version 2. Following is a reviewof the upgrade with before/after type comparisons describing thechanges the new ROM brings to the XB-2.
After the Review is alist of features found in the version 2 ROM.I installed the ROM upgrade 2 and was pleasantly surprised tofind some unexpected benefits. It turns out that in addition tosignificantly extending the XB-2's functionality (ex: extendedMIDI, better split options, # of presets, etc), V2 actuallyimproves the sound in some important ways, whichI didn't expect. The sound engine itself is not modified by theOS upgrade, but the new OS takes advantage of the sound engine'ssoftware controlability in some important new ways, resulting ina fatter, more B-3 like sound.
It's amazing how much of theavailable software control WASN'T used in v1.x of the OS.There are lots of new features extending theXB-2's programmability (a list follows this review), but to my ear,the most important are:percussion level programmable to 16 levelskey tracking for percussion level taper as pitch risespercussion level can be controlled by key velocitykey click level programmable to four levelsvibrato/chorus rate programmable to 5 levels1' drawbar can be disabled by percussion tabsI feel that the biggest deal here is the enhancements topercussion. The percussion in the old XB-2 was very shrill in theupper octaves, especially in the last octave. This made the XB-2sound piercing and a bit nasal in the top octave. In an attemptto compensate for that I always used the percussion with the'Soft' setting enabled, trading some of the classic Hammondattack transients for tone and high end playability.
A problemwith that is that 'Soft' percussion robs registrations like'888000000' of their punch, leaving you with a choice of shrillhighs or muddy lows.This problem is solved with V2. Selecting percussion 'keytracking' reduces the percussion level in the high end, making itpossible to use louder percussion settings without inducingharshness in the high end. Further, since percussion can beprogrammed to any of 16 levels (plus Soft on/off), it is possibleto set the percussion to satisfy any taste. This has the effectof making the XB-2 a fatter, more playable and versatile organwith improved tone and attack across all registers, making ittonally much more similar to a B-3.Previously, key click level could be set to off, soft, andnormal.
The normal setting was the loudest available, yet stillsofter than some examples of real B3 key click I've heard. V2adds a 'MAX keyclick' setting, which closes the gap. Oddlyenough, MAX Keyclick seems to give the attack transient anoticeably beefier low end, so using 3rd Percussion at level 16with MAX Keyclick will give you all the attack snap you'll everwant (and probably a lot more than you'd want). You might not useMAX Keyclick in all presets, but it's mighty nice to have thisoption.The velocity control of percussion level is subtle, butintroduces some interesting possibilities for expressive playing,especially when used in ballads or slow blues. When usingvelocity triggering for percussion I find that the percussion ispretty soft unless you really lean on the velocity. This can becompensated for by programming presets with velocity triggeringto have slightly higher percussion levels. Since this featureisn't found on the B-3, purists probably might not use it and Imyself find it of limited value, but some folks might consider itto be an important feature.The percussion on a B-3 is single triggered, meaning that youonly hear the percussion on the first note played after anall-notes-off state.
This requires B-3 players to play non-legatoif they want percussion to trigger on each note played. Whenplaying fast licks, this can be a challenge. The XB-2 also playsthis way, but in V2 you also have the option of having percussiontrigger on ALL key strikes, not just the non-legato ones. So ifyour non-legato technique sucks, V2 gives you the option ofcheating by triggering percussion on all keystrikes, rather than just the non-legato ones.Presets can be programmed so that the 1' Drawbar will bedisabled when percussion is turned on, like a B-3.In my opinion, the version 2 software provides majorimprovements to the sound, playability, and versatility of theXB-2. I consider the upgrade to be worth it's cost and much more.Any XB-2 player who is at all serious about getting a bettertraditional Hammond sound should consider this upgrade amust-have.If an XB-2 has had version 2 installed, when you turn on thepower the version number is displayed in the XB-2 LCD display. Ifyou do not see the version number you are running an earlierversion.The upgrade includes two new ROM chips, a new and improvedowners manual, and instructions on how to do the upgrade.The XB-2 ROM upgrade is easily installed. The installationrequires that you take the top of your XB-2, unplug two ROM chipsfrom the sockets, and plug the two new ROM chips into the nowempty sockets.
Hammond Manual Tapering
You need to be careful that you don't bend the ROMchip legs when unplugging the old chips and plugging in the newone's or otherwise damage the chips, but anyone of even moderatemechanical skill should be able to manage this.Various dealers are charging various prices for the upgradehardware and installation labor. Some of the prices I've heardare unfairly high, especially outside the US, so beware. If youcan install the upgrade yourself you can get it via mail orderfor $149 US plus the return of your old ROM chips. Ask on theHammond mailing list as to where it's currently available viamail.Following is a list of features in the version 2 upgrade witha note as to whether this is an enhancement over previousversions or a new feature.