key click

[larryjanca]

just wondering if key click becomes more pronounced with the amount of usage on the organ and the age of the organ. did the new hammonds have key click? also is there a way on a Hammond to increase or decrease key click. just wondering. thanx......Larry

[crysalis]

Dirty busbars will cause it to get "worse".

http://www.dairiki.org/HammondWiki/KeyClick

[OneWatt]

just wondering if key click becomes more pronounced with the amount of usage on the organ and the age of the organ. did the new hammonds have key click? also is there a way on a Hammond to increase or decrease key click. just wondering. thanx......Larry

Larry,

No doubt you're asking about REAL Hammond real click, so pardon this minor step off to the side of the topic...

It is a bit ironic that, while Laurens Hammond regarded key click as an unfortunate idiosyncrasy he couldn't eliminate, on today's digital clones that clicking sound is a feature you can dial up to suit your taste.

On my Hammond XK3c I use a fairly healthy dose of "key click" when playing jazz/blues tunes. Although, in fairness, I turn it all the way down when playing classical organ pieces, which is what Laurens apparently was originally aiming for.

OneWatt

[muckelroy]

Key click can also be exasperated by grounding problems throughout the organ. (loose TG tray screws, dendrite growth in the manual bins, bad/contaminated ground around the matching transformer, drawbar mounting screws, etc.)

On a tonewheel organ, just desolder the ground strap going from the generator to the mounting transformer and play / listen. You'll hear what I'm talking about. ALL key click, very little bass response.

As for new keyboards offered by Hammond, the B3 mk2, A-162, and Hammond's other large console high-end offerings claim to use some type of mechanical key contact mechanism that intrinsically reproduces key click. I believe you can turn it up or down to taste, but I have never tried to find out for-sure.

[kziss]

just wondering if key click becomes more pronounced with the amount of usage on the organ and the age of the organ. did the new hammonds have key click? also is there a way on a Hammond to increase or decrease key click. just wondering. thanx......Larry

Hi Larry.
Whilst dirty key contacts or busbars and also deteriorated grounding connections can enhance the key click, the key click is always present even with perfectly functioning and clean key contacts and busbars and perfect grounding connections so therefore Laurens Hammond and the subsequent Hammond designers tried to suppress the key click sound right from the start in 1935 until the end of Hammond tonewheel production in 1975.

Hammond reduced the key click by calibrating the tonewheel generator to have the "pre-emphasis" in the midrange and the treble TG notes which meant that the midrange and the treble TG notes were set to have a progressively upward rising output curve in their output levels.

The secondary winding of the drawbar matching transformer on the early era organs of the 1930's and 40's such as the Model A, AB, B, BA, BC, BV, CV, D, E, G and the RT organs had a very simple treble cut filter consisting of a 0.001 uf ( 1 nf) capacitor wired in series with a 20K or 22K resistor between the output wire of the secondary winding and the ground.

This 20K or 22K resistor/ 0.001 uf capacitor treble cut filter reduced the key click by rolling off the treble response, as well as bringing down the levels of the "premphasized" midrange and treble TG notes so that their volume levels through the preamplifier were better balanced with the lower frequency TG notes.

The B2, C2, and the RT2 organs with the AO10 preamplifier, and the A-100 series, B3, C3, D150 series and the RT3 organs with the AO28 preamplifier and the M3 and the M-100 series organs with the AO29 or the AO67 amplifier used a treble cut filter consisting of very small value capacitors in series with very high value resistors wired as part of the negative feedback circuit between the input grid and the output plate of the input tube of the non vibrato channel and the input tube of the vibrato channel.

The other tonewheel organ models including the E-100 series H-100 series, L-100 series, Porta-B, R-100 series, T-series, XTP and the X-77 organs also had treble cut filtering in the amplifiers acting as the "key click filter", and the treble cut / key click filtering on these particular organs was more severe than what it was on the previously mentioned organ models.

A lot of us Hammond enthusiasts love the key click sound so therefore we like to undo Hammond's attempts to reduce the key click.

If you have a copy of the Hammond organ schematics or the service manuals, and if you are competent and confident to work on Hammond organs, and especially when it comes to the organ preamplifiers with the dangerous high voltages inside them, then you can increase the key click effect by disconnecting the treble cut / key click filter.

On the 1930's/ early 1940's Model A, AB, B, BA, BC, C, D and E organs, you can disconnect either the C4 0.001 uf capacitor or the R4 20 K resistor which are located inside the rheostat box.

On the 1940's BV, CV, G and RT organs you can disconnect either the C1 0.001 uf capacitor or the R1 22 K resistor which are located inside the rheostat box.

On the B2, C2, and RT2 organs with the AO10 preamplifier you can disconnect the C2 40 pf feedback capacitor of the V1 6SJ7 tube of the non vibrato channel, and the C7 25 pf feedback capacitor of the V2 6SJ7 tube of the vibrato channel.

On the A-100 series, B3, C3, D-150 series and the RT3 organs with the AO28 preamplifier, you can disconnect the C2 39 pf feedback capacitor of the V1 6AU6 tube of the non vibrato channel, and the C7 24 pf feedback capacitor of the V2 6AU6 tube of the vibrato channel, and also the C33 0.0033 uf (3.3 nf) treble cut grounding capacitor of the percussion output filter so that the resulting brighter sounding percussion signal will then be better matched with the modified main organ signal as well as have more key click.

On the L-100 series and the Porta-B organs with the AO42 "Percussion amplifier" which is also the straight organ signal preamplifier, you can disconnect the C203 39 pf feedback capacitor of the V1 12AX7 input tube, and you can disconnect the C208 0.01 uf (10 nf) percussion treble cut grounding capacitor wired after the Q201 2N306 transistor so that the resulting brighter sounding percussion signal will then be better matched with the modified main organ signal as well as have more key click.

On the Model M organs you can disconnect the C2 15 pf feedback capacitor of the V2 6J5 tube.

On the M2 organs you can disconnect the C6 25 pf feedback capacitor of the V2 6SJ7 tube of the non vibrato signal, and the C1 25 pf feedback capacitor of the V1 6SJ7 tube of the vibrato channel.

On the M3 and the M-100 series organs with the AO29 or the AO67 amplifier you can disconnect the C6 30 pf feedback capacitor of the V2 6AU6 tube of the non vibrato channel, and the C1 20 pf feedback capacitor of the V1 6AU6 tube of the vibrato channel, and also the C33 0.0022 uf (2.2 nf) treble cut grounding capacitor of the percussion output filter so that the resulting brighter sounding percussion signal will then be better matched with the modified main organ signal as well as have more key click.

Please note that with all the above mentioned modifications to disconnect the treble cut / key click filter, that this will result in the whole organ sound becoming brighter or more trebly which means that the recapped pre 1964 organs and the red mylar capped post 1964 organs can become too bright or too shrill sounding which would necessitate the tonewheel generator to be recalibrated in order to bring down the levels of the midrange and the treble TG notes so that they are better balanced with the lower frequency TG notes.
On the other hand some people will like this brighter, more "edgy" or "biting" organ sound.

The above mentioned modifications to disconnect the treble cut / key click filter are best suited for the pre 1964 organs with the original wax paper capacitors on the tonewheel generator, because the output levels of the TG notes 49 to 91 on the pre 1964 wax capped organs have noticeably decreased from what they were originally set at the factory because the wax paper capacitors have drifted up in uf value and therefore they are no longer properly filtering and emphasizing the TG notes 49 to 91.

Because of this, the treble boost effect created by disconnecting the treble cut/ key click filter will have the dual beneficial effect of boosting the key click sound for a nicer, more "spitty" characteristic as well as boosting the treble response of the whole organ signal, which means that because the wax capped TG notes are at reduced levels, the organ will now have a nice spitty key click but without the excessive brighhtness or shrillness that would be produced with the recapped pre 1964 organs and the post 1964 red mylar capped organs.

In fact these key click boosting modifications are a good alternative for those who consider their pre 1964 wax capped organs to sound dull or muddy, but they do not feel confident enough or they do not want to have to go to the very delicate and time consuming task of recapping the tonewheel generator.

All the best.
Kon.

[geoffbrown]

Regarding the C3 type amps, shorting out R9 gives more volume to the non vibrato channel and also more boom to the bass notes and a brighter more shrill organ ,I assume this mod also makes the key click filter much less effective at removing key click.

[kziss]

Regarding the C3 type amps, shorting out R9 gives more volume to the non vibrato channel and also more boom to the bass notes and a brighter more shrill organ ,I assume this mod also makes the key click filter much less effective at removing key click.

Hi Geoff.
Yes, shorting out the R9 820K resistor in the AO28 preamplifier does cause the Non Vibrato channel signal to more or less sound as bright as the Vibrato Channel does with the C1, C2 and C3 Chorus settings. Some people short out the R9 for this reason.

The key click in the Non Vibrato channel is likewise increased when the R9 is shorted out.

A very effective way to controllably increase the treble response and thus the key click of the WHOLE organ signal in the AO10 and the AO28 preamplifiers is by wiring up a 1 mega ohms or a 2 mega ohms linear taper potentiometer in series with the C15 feedback capacitor ( 75 pf in the AO10 and 51 pf in the AO28).

You can also controllably increase the treble response and thus the key click of the WHOLE organ signal by wiring up a 1 mega ohms or a 2 mega ohms linear taper potentiometer in series with the 24 pf to 90 pf gain trimmer capacitor (C21 in the AO10 and C22 in the AO28).

When these treble boost potentiometers are set to the shorted out zero resistance setting, the C15 feedback capacitor and the C21 or C22 gain trimmer capacitor are fully in circuit so therefore the normal stock sound is produced, and then as you turn up the potentiometer dial, the series resistance increases and this series resistance reduces the negative feedback produced by the C15 and the C21 or C22 gain trimmer capacitor which consequently causes the treble response of the whole organ signal to be gradually increased.

I have wired up these two treble boost potentiometers in the AO28 preamplifiers of my 1962 and 1965 C3 organs, and these work very well without creating hum or hiss noise issues, and they really are a very good way to increase the brightness of the pre 1964 wax capped organs without the excessive shrillness that can result in the recapped pre 1964 organs or the red mylar capped post 1964 organs when the treble boost controls are turned up.

Alternatively instead of using a potentiometer, you can use a fixed resistor value that produces the desired level of treble boost.

CAUTION: If you do wire up this treble boost, then it is very important that you wire up the treble boost potentiometers or the fixed resistors in series with the INPUT SIDE of the C15 feedback capacitor and the INPUT SIDE of the C21 or C22 gain trimmer capacitor that are connected to the towards the input grids of the V4 tube ( 6SC7 in the AO10 and 12AX7 in the AO28).

The reason for this is that there are dangerous high voltages present on the output side of the C15 feedback capacitor and and on the output side of the C21 or the C22 gain trimmer capacitor that are connected to the output plates of the V4 tube.

The C15 feedback capacitor and the gain trimmer capacitor prevent these high voltages from passing through to their input side so therefore it is safe to wire up these treble boost potentiometers to the input side of the C15 feedback capacitor and the input side of the gain trimmer capacitor.

All the best.
Kon.

[geoffbrown]

Kon
Thanks for the detailed and extremely useful reply
I had been rather disappointed with the overall insipid tone of my C3, the clue something was wrong, was the lower volume on the non vibrato channel, I tried all sorts of fixes swapping tubes etc nothing worked
However now the C3 is sounding great now and I will try your suggestions as well
Thanks for the info
Geoff

[larryjanca]

still messing around with my newly installed Hamptone BBEQ unit on my A-100. I noticed that my key click is more pronounced. adjusting the EQ on the unit brings in more key click. love the sound, what an improvement with the Hamptone unit....Larry

[MihevicB3]

still messing around with my newly installed Hamptone BBEQ unit on my A-100. I noticed that my key click is more pronounced. adjusting the EQ on the unit brings in more key click . . .

The Hamptone has corner frequencies at 1.6 KHz (Treble) and 115 Hz (Bass) in addition to a Gain adjust. There is both “Boost” and “Cut” adjustment at the corner frequencies, so you can get more key click with “Boost” and reduce the key click with “Cut”. The new model also has Pre and Post overdrive.

John M.

[bnelson218]

I wish I could find information and/or schematics on any type of key click (white noise) generator that people may have designed, perhaps keyed by grounding a terminal and with an adjustable key click level. Any DIY'ers out there? I have the key click PCB from a B3000 but really can't make sense of what they were doing. haha Just throwing this out there....

[Tonewheel]

Hi Kon,

This was a masterful post with vital information.

My 1955 B3 has had the TG recapped shortly after getting it 3 years ago. I thought that the percussion needed to sound a bit "woodier" so I had a pot installed, so I could vary the tone. There is a nice key click already, but it would be great to control that (I suspect that if I followed all steps as outlined in your post, I might end up with too bright a sound). Should I just leave it alone, or would a pot across one of those suggested connections do the trick without messing things up?

Thanks for your very good insights.

Dave

[kziss]

Hi Kon,

This was a masterful post with vital information.

My 1955 B3 has had the TG recapped shortly after getting it 3 years ago. I thought that the percussion needed to sound a bit "woodier" so I had a pot installed, so I could vary the tone. There is a nice key click already, but it would be great to control that (I suspect that if I followed all steps as outlined in your post, I might end up with too bright a sound). Should I just leave it alone, or would a pot across one of those suggested connections do the trick without messing things up?

Thanks for your very good insights.

Dave

Hi Dave.

You can experiment with a pot, ( or pots of different values) and listen to how they affect the tonality, and if you do like the resulting tonal changes, then you can install the suitable value pot on to the AO28 preamp so that you can then adjust it to taste.

All the best.
Kon.

[Hoaxel]

Kon, here you mean C1 not C7 ?:
On the B2, C2, and RT2 organs with the AO10 preamplifier you can disconnect the C2 40 pf feedback capacitor of the V1 6SJ7 tube of the non vibrato channel, and the C7 25 pf feedback capacitor of the V2 6SJ7 tube of the vibrato channel.

[kziss]

Kon, here you mean C1 not C7 ?:
On the B2, C2, and RT2 organs with the AO10 preamplifier you can disconnect the C2 40 pf feedback capacitor of the V1 6SJ7 tube of the non vibrato channel, and the C7 25 pf feedback capacitor of the V2 6SJ7 tube of the vibrato channel.

Hi Hoaxel.
Sorry for my error.
Yes I meant the C1 feedback capacitor from the V1 (non vibrato channel), and the C7 feedback capacitor from the V2 ( vibrato channel).
All the best.
Kon.