TKB Build Notes - Index - The Human Comparator Kit.
This is the main Index for the build notes for the Serge TKB (Touch Keyboard Sequencer).
Many thanks to Zthee (The Human Comparator) for making this build possible.
I'm documenting my experiences as I put the TKB together to help me trouble shoot in the future .
Hopefully, this will also help others in their quest to build the TKB & more importantly, to learn the
Art of Electronics & of Electronic Music.
1. Pics of the kit before starting.
2. Some pics and info of a vintage TKB.
3. Starting the build - main PCB - resistors, diodes, headers, caps, etc.
4. Main PCB - Transistors & ICs
5. Pot boards.
6. The Touch Keyboard (Installing the LEDs)
7. Front panel assembly.
8. Wiring up the touch keyboard
9. Installing the S2 & S3 Ribbon cables.
This index will be updated as the project progresses.
The official build notes of the Human Comparator
http://build.thehumancomparator.net/
The original build notes for the TKB kit from the 1970's are here:
http://serge.synth.net/documents/kit/tkb.html
Official modifications to the TKB from the1970's are here:
http://serge.synth.net/documents/kit/tkbmod.html
Intro to the Serge Modular Music System
http://www.serge.synth.net/documents/Intro_To_SMMS_Part_1.pdf
Muffs has a great thread here:
https://www.muffwiggler.com/forum/viewtopic.php?t=104513&start=575
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Zthee's previous project was the TTSH (Two Thousand Six Hundred).
This is a clone of one of the greatest synthesizers of all time, the mighty ARP 2600.
My build notes for the TTSH are here:
TTSH Build Notes
Wednesday, 28 January 2015
TKB Build - Part 3A - Main Board
TKB - Touch Keyboard Sequencer - Build Part 3 - Main Board. (Resistors, Caps, etc).
*** Click here for the TKB Build Index ***
Before we begin there are some preliminary pics of the PCB
I'll start of with least temperature sensitive components such as the IC header sockets, resistors & diodes.
These modern headers connect the Main PCB to the rest of the keyboard. In vintage TKBs, the headers used were slightly different:
Notice the silver arrow which is used to check the header orientation.
Looks like the four 22pf caps on the left need to be swapped for 100pf.
According to one of my tech friends, you can experiment a bit here. Serge used 82-100pF,
but you could even go as high as 220pF. Apparently the caps are filtering some unwanted noise from the clock driving the keys, and 100pF suppresses it OK. ....but even higher values might do a better job. The only problem is - go too high and it might start to slew your signal… ????
I'll def do some experimenting with this. (Many thanks to my friend for this advice).
Looks like the surface mount 100n caps need to be soldered to the underside of the PCB across pins 5/4 & 11/10. of the LM 324s --- SEE PIC BELOW
There are 5 surface mount 0.1uF / 100nF caps to solder to the underside of the PCB.
The soldering points are a bit tricky to see at first. They lie across two of the LM 324s - pins 5/4 & 11/10.
and underneath the LM324 just below the MM74C150
*** Click here for the TKB Build Index ***
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*** Click here for the TKB Build Index ***
Before we begin there are some preliminary pics of the PCB
I'll start of with least temperature sensitive components such as the IC header sockets, resistors & diodes.
| Mouser #: | 571-5103308-3 | |
| Mfr. #: | 5103308-3 | |
| Manufacturer: | TE Connectivity | |
| Desc.: | Headers & Wire Housings 16P 2 ROW HEADER LP | |
Notice the silver arrow which is used to check the header orientation.
Vintage TKB headers.
Back to the Modern PCB:
Looks like the four 22pf caps on the left need to be swapped for 100pf.
According to one of my tech friends, you can experiment a bit here. Serge used 82-100pF,
but you could even go as high as 220pF. Apparently the caps are filtering some unwanted noise from the clock driving the keys, and 100pF suppresses it OK. ....but even higher values might do a better job. The only problem is - go too high and it might start to slew your signal… ????
I'll def do some experimenting with this. (Many thanks to my friend for this advice).
Looks like the surface mount 100n caps need to be soldered to the underside of the PCB across pins 5/4 & 11/10. of the LM 324s --- SEE PIC BELOW
The LM 324 is a low power quad Op-Amp
There are 5 surface mount 0.1uF / 100nF caps to solder to the underside of the PCB.
The soldering points are a bit tricky to see at first. They lie across two of the LM 324s - pins 5/4 & 11/10.
and underneath the LM324 just below the MM74C150
The SMD caps lie under the three LM 324s on the top right
Notice the bud box below is self powered.... in fact it has two PSUs, and was once part of a much larger system.
Top pics of the main TKB PCBs (vintage on left)
The underside of the PCBs.
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Almost finished the easy part ... soldering the resistors, diodes, caps & headers..
I think its a good time to stop and compare this board to a vintage TKB main board. This one is a unrestored TKB -- also from the late 1970s.
Top pics of the main TKB PCBs (vintage on left)
The underside of the PCBs.
Part 4. Main PCB - Transistors & ICs
*** Click here for the TKB Build Index ***
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Monday, 26 January 2015
KORG Rhythm 55 (KR-55) Drum Machine
Korg released both the KR-33 & KR-55 in 1979. They are the successors to Korg's successful Mini Pops series of drums. The KR-55 looks a bit like a old school calculator, but don't let it's appearance fool you.
This was quite cutting edge for its time. There is a micro-processor involved in rhythm making. Gone are the days of the old diode matrix.
Its built in sequencer has 48 preset patterns (Waltz, Samba, Cha Cha, Afro, Enka, Rhumba, Bossa Nova, Tango, Slow Rock, Swing, Rock, etc.). There are 16 Intro patterns & 16 Fill-In patterns though sadly you can't program your own patterns. (Roland had just brought out the CR-78 one year earlier which had this feature as did the Roland TR-606 which wouldn't come out till 1981).
There are 12 analog sounds: Bass Drum, Snare Drum, 2x HiHat, Cymbal, Low Conga, High Conga, Rim Shot, Claves, Cowbell, 2x Tom Tom. The sounds are commonly described as snappy & metallic.
Here is a great video I found on youtube which gives a really good example of these sounds.
The rhythms are not mixable like on some of the old Minipops drums, but the tempo and volume knob do allow for a little tweaking. There is also a "swing" control to add a bit of spice to the groove.
In his excellent SOS review, Gordon Reid discusses the TR-33 & TR-55 "History of Korg - Part 1"
"More successful [than the Sigma] were the KR33 and KR55 rhythm units, which replaced the ageing Mini Pops series. These were more sophisticated than their predecessors, generating analogue sounds that were far more realistic than the noise-based thumps and hisses offered by the earlier DoncaMatics, Mini Pops, and units from competitors."
Here is the Korg KR-55 manual
There is a Trigger out , but no trigger in. Thus un-modded, it's impossible to sync with external gear. There are several triggering modes: I understand that The KR-55 runs at 8ppqn so you will need to use a clock divider if you wish to sync it to midi or sync24.
It can also be externally controlled via the footswitch jack for the Start/Stop & Intro/Fill switches.
There are no individual outs for the 55 but there are faders for most of the drum sounds.that allow you to mix the volume levels of the bass, snare, cymbal, hi hat, conga/TT, Rim Shot/Cow Bell/Claves.
There are lots of mods on the net on how to get individual outs.
The Korg Rhythm 55 was used by Jean-Michel Jarre (Magnetic Fields) and Depeche Mode in 1981 (Speak and Spell) & Cabaret Voltaire.
Modding:
Analogue solutions midi kit looks nice but has a fee of £109 for the kit. I may end up doing it but would love individual outs along with it.
http://www.analoguesolutions.org.uk/mods/kr55.htm
http://www.youtube.com/watch?v=33zfpZ9RBK8
Here is a great place for some modding (esp for multiple outs) :
http://alienatedsynthesist.blogspot.com.au/2011/10/kr-55-clock-in-mod.html
https://www.flickr.com/photos/31603983@N05/sets/72157628641466671/
This was quite cutting edge for its time. There is a micro-processor involved in rhythm making. Gone are the days of the old diode matrix.
Its built in sequencer has 48 preset patterns (Waltz, Samba, Cha Cha, Afro, Enka, Rhumba, Bossa Nova, Tango, Slow Rock, Swing, Rock, etc.). There are 16 Intro patterns & 16 Fill-In patterns though sadly you can't program your own patterns. (Roland had just brought out the CR-78 one year earlier which had this feature as did the Roland TR-606 which wouldn't come out till 1981).
There are 12 analog sounds: Bass Drum, Snare Drum, 2x HiHat, Cymbal, Low Conga, High Conga, Rim Shot, Claves, Cowbell, 2x Tom Tom. The sounds are commonly described as snappy & metallic.
Here is a great video I found on youtube which gives a really good example of these sounds.
The rhythms are not mixable like on some of the old Minipops drums, but the tempo and volume knob do allow for a little tweaking. There is also a "swing" control to add a bit of spice to the groove.
In his excellent SOS review, Gordon Reid discusses the TR-33 & TR-55 "History of Korg - Part 1"
"More successful [than the Sigma] were the KR33 and KR55 rhythm units, which replaced the ageing Mini Pops series. These were more sophisticated than their predecessors, generating analogue sounds that were far more realistic than the noise-based thumps and hisses offered by the earlier DoncaMatics, Mini Pops, and units from competitors."
Here is the Korg KR-55 manual
There is a Trigger out , but no trigger in. Thus un-modded, it's impossible to sync with external gear. There are several triggering modes: I understand that The KR-55 runs at 8ppqn so you will need to use a clock divider if you wish to sync it to midi or sync24.
It can also be externally controlled via the footswitch jack for the Start/Stop & Intro/Fill switches.
There are no individual outs for the 55 but there are faders for most of the drum sounds.that allow you to mix the volume levels of the bass, snare, cymbal, hi hat, conga/TT, Rim Shot/Cow Bell/Claves.
There are lots of mods on the net on how to get individual outs.
The Korg Rhythm 55 was used by Jean-Michel Jarre (Magnetic Fields) and Depeche Mode in 1981 (Speak and Spell) & Cabaret Voltaire.
Modding:
Analogue solutions midi kit looks nice but has a fee of £109 for the kit. I may end up doing it but would love individual outs along with it.
http://www.analoguesolutions.org.uk/mods/kr55.htm
http://www.youtube.com/watch?v=33zfpZ9RBK8
Here is a great place for some modding (esp for multiple outs) :
http://alienatedsynthesist.blogspot.com.au/2011/10/kr-55-clock-in-mod.html
https://www.flickr.com/photos/31603983@N05/sets/72157628641466671/
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For more info on the history of Korg Drum Machines Click Here
Sunday, 25 January 2015
Korg SR-120 (Mini Pops 120) Drum Machine.
The Korg SR-120 came out in 1976.
In that same year Korg also produced the Mini Pops MP120, the Mini Pops MP35 & the Mini Pops MP 45 Rhythm Machine.
The SR-120 is identical to the MP-120. This was the final drum which Korg produced under the mini pops label.... and was supposed to be their best. It has all the bells and whistles.
She boasted 6 sounds (BD, SD, Cy/HH, low conga, high conga, claves) and 16 presets (slow rock, swing, bossa nova, beguine, rumba, mambo, samba, waltz, tango, polka, foxtrot, march, rock 1 to 4).
making 32 patterns.
The sounds esp the Kick are awesome.
This version has a wood case, but they also came covered with tolex.
The cube shape also seems to be catching on both with Roland & Korg. Roland's CR78 is just two years away.
Korg, in addition to the tolex version, re-branded these as Univox SR-120s which came in a road case with lid & handle (the 120-P).
https://www.youtube.com/watch?v=bb9n2PhmfCo
Another important point to make about the 120 is its use of a ROM (read only memory) chip to store the patterns. Looks like the identity of the ROM is a AmericanMicro Semiconductor uPD471D
Earlier machines of both companies used what's called a diode matrix to store the patterns.
The mini pops 120 schematics indicate the use of both a diode matrix and a ROM chip.
The diodes are easy to fix. However replacing a integrated circuit made in 1976 is much trickier, if you can't find a replacement chip.
There are lots of mods for this machine if you can find one that works.
A good place to start is here:
http://www.estecho.com/gear/Korg_Mini-Pops_120.php
-----------------------------------------------------------------------------------------------------------------
For more info on the history of Korg Drum Machines Click Here
In that same year Korg also produced the Mini Pops MP120, the Mini Pops MP35 & the Mini Pops MP 45 Rhythm Machine.
The SR-120 is identical to the MP-120. This was the final drum which Korg produced under the mini pops label.... and was supposed to be their best. It has all the bells and whistles.
She boasted 6 sounds (BD, SD, Cy/HH, low conga, high conga, claves) and 16 presets (slow rock, swing, bossa nova, beguine, rumba, mambo, samba, waltz, tango, polka, foxtrot, march, rock 1 to 4).
making 32 patterns.
The sounds esp the Kick are awesome.
The Korg 120W
This version has a wood case, but they also came covered with tolex.
The cube shape also seems to be catching on both with Roland & Korg. Roland's CR78 is just two years away.
Korg, in addition to the tolex version, re-branded these as Univox SR-120s which came in a road case with lid & handle (the 120-P).
https://www.youtube.com/watch?v=bb9n2PhmfCo
Another important point to make about the 120 is its use of a ROM (read only memory) chip to store the patterns. Looks like the identity of the ROM is a AmericanMicro Semiconductor uPD471D
UPD471D
The Roland CR-68 & 78 also followed this trend with ROM chips too.Earlier machines of both companies used what's called a diode matrix to store the patterns.
The mini pops 120 schematics indicate the use of both a diode matrix and a ROM chip.
The diodes are easy to fix. However replacing a integrated circuit made in 1976 is much trickier, if you can't find a replacement chip.
There are lots of mods for this machine if you can find one that works.
A good place to start is here:
http://www.estecho.com/gear/Korg_Mini-Pops_120.php
-----------------------------------------------------------------------------------------------------------------
For more info on the history of Korg Drum Machines Click Here
Udaipur - India
This is such an underrated place.
So very very beautiful. Reminds me of Venice.
It's quite a big city with lots to see.
Give yourself at least 4 days. A week would be nice.
Some pics of the water front:
So very very beautiful. Reminds me of Venice.
It's quite a big city with lots to see.
Give yourself at least 4 days. A week would be nice.
Some pics of the water front:
Panorama from one of the bridges.
It's New Years Eve: the calm before the storm.
Udaipur is very romantic. It is the historic capital of the kingdom of Mewar,
in the state of Rajasthan
Udaipur was founded in 1559 by Maharana Udai Singh. With the emergence of artillery warfare in the 16th century it was decided to move the capital to a more secure location... away from the old fortress of Kumbhalgarh.
Roof top nightclub. The perfect place to see the New Year in.
Lobby of the Lake Pichola Hotel
The lake Palace is in the distance.
The Lake Palace covers an entire island in the Pichola Lake.
For more travel postcards click here:
Elektron Party : MM,A4 & Rytm drum
The boys are back together.
A Elektron MonoMachine SFX-6 (keyboard version) ,
a Analog Four and the Rytm Drum
A Elektron MonoMachine SFX-6 (keyboard version) ,
a Analog Four and the Rytm Drum
Friday, 23 January 2015
Roland TR 330
Roland TR-330 (late 1972 / early 1973 ??)
This is a bit of an odd one with respect to the name. It's pretty rare too. The TR label belies its roots - it's from the Roland family of Transistor Rhythm Machines.
Did Roland base it on the TR-33 and add a zero - thus TR-330 ??
She probably lies between the TR-77 which came out in 1972 & the TR -66 which was first manufactured in 1973. (It's definitely not as advanced technically as the TR-66 which is why I think it comes before the 66 & after the 77).
And I think it sounds a lot like my TR-77 too.
Take special note of the wooden cube shape. The 330 was the first of Roland's drum machines to take this appearance which would finally evolve into the ground breaking CR-78 in 1978.
There is heaps of bass and great analog percussion - claves etc. There are 8 drum sounds.The Kick is very very good. Reminds me of my TR-808. Lots of bottom end.
The voice board has trimmers (variable resistors) for tuning the oscillator's pitch & resonance....and/or for some very nice distortion. Nice warm & round analog sounds.
The circuit boards & speaker slide out of the wooden sleeve very easily They are held in with just 4 screws on the bottom.
And it has it's own built in speaker which you won't find on any other Roland drum of this vintage.
The speaker isn't of the highest quality but if you like rather cheezy distortion you will love it.
I don't have any service manual or schematic so if anyone out there has one I'd be forever grateful.
The tempo slider is unusual. It displays the tempo both in modern BPMs (40 to 280) and in the traditional classical way ..... in Italian, as was the custom before the invention of the metronome.
The old way is def more romantic. Largo (rather slow; stately), andante (walking speed) & presto (Very fast) are words you rarely see on a drum machine.
There is one "Balancing" knob which sets the volume of the Kick & Hi hat. It can completely mute the hi-hat or totally remove the kick which I think is very useful.
There are 10 Preset patterns. Waltz, Slow Rock, Rock Beat, Bossa Nova, Mambo, Cha-Cha, Beguine, Rumba, March, Swing.
Size: 9-1/2" wide, 7" high, 12" deep. Weight 10-1/2 lb.
On the rear panel we have a jack for an external amplifier. There is also a jack for a foot-pedal control.
The speaker is on the top. Tempo switch to the left. To the right is the transformer. Careful with this if you open your 330 up. There are high voltages here which can be lethal.
This is the underside of the machine. On the right we have the voice board. The left is the pattern board. I haven't opened it up but I understand that its completely made from diodes..... the famous diode matrix where we have a network of intersecting horizontal and vertical buses. All discrete logic. Nice !!!
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For more info on the history of Roland Drum Machines click here
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