Thomas Henry TCL555 based LFO Controller (e-m.com)
i am taking orders until 14 JUN 2013.
just contact me via this thread or PM or email, telling me how many PCBs of each (circuit=CB, frontpanel=FP) you would want. be honest about your interest, please.
for the front panel i need a minimum interest of 30pcs.
i won't take any money before i hold the PCBs in my hand. as soon as the PCBs arrived from manufacturer i will contact all who indicated interest concerning payment. paypal preferred.
now to the numbers.
each PCB (circuit or frontpanel) = 10.-USD/7.50 EUR
printed front panel = 13.-USD/10.-EUR
shipping outside europe:
1 PCB = 3.-USD, 2+ PCBs = 6.-USD
1 PCB = 2.-EUR, 2+ PCBs = 4.-EUR
1 PCB = 1.-EUR, 2+ PCBs = 2.-EUR
since i need a minimum of 30pcs for the front panels be clear about your interest (i.e. what do you need/want if the minimum of 30pcs for the front panel is NOT reached?).
thanks for your understanding
what does it do? refer to thomas description in the link above, here is a quote:
I have the permission from Thomas to do a PCB run for this project. i will offer the actual Controller LFO Circuit PCB, providing MTA-100 headers for easy wiring-up any format.In triggered mode, as long as keyboard triggers are appearing, the LFO is quiescent. When the triggers eventually stop, the output signal smoothly ramps up to full amplitude but only after a desired interval. This creates the so-called delayed vibrato effect when used to frequency modulate a VCO (voltage controlled oscillator).
In gated mode the LFO is quiescent as long as no keyboard gates are present. But when a gate is finally detected, again the output ramps up.
Footswitch mode is similar, but now it is an ordinary short-to-ground footswitch which enables or disables the LFO.
Finally, with neither a keyboard trigger nor gate present, the unit behaves as a standard freerunning LFO.
All in all, with these basic modes, in addition to a variety of panel knobs, switches and jacks there is hardly a synthesizer control task that canÃ¢â‚¬â„¢t be accommodated. Experimentation will probably uncover other valuable uses.
Additionally i will offer a frontpanel component PCB, which can be mounted piggyback to the circuit PCB. It provides footprints for 9mm vertical mounted potentiometers and vertical mounted sockets (available from earthenvar, however, there are kobiconn fitting the same footprint!?).
i will not provide any building documentations, just refer to the original documentation available from the link above. thomas documentations are very comprehensible, and the PCB lables follow thomas schematics.
the chart below shows how to wire the potentiometers and the jacks, if you don't use the front panel components PCB:
ATTENTION: the PCB omits diode D2. i found the trigger to be fine without it.
however, if you experience occasional double triggers, solder it in parallel to R44.
ATTENTION: the P-JFET 2N5461 comes in different pinouts!
so check the datasheet of the specific brand you use!
(thanks to rosch for this find)
here are some pictures of the prototype i built:
and a very short demo of the Controller LFO, showing the gated and the trigger/delay functionality.
NOTE: on the frontpanel i mixed up the labels of the mode switch: Trigger should read Gate, and Gate should read Trigger.
Frontpanel Measures (if you decided to use the additional front panel components PCB), a FPD file is also available:
i tend to use oversized drills to make the marriage of front panel and components PCB more comfortable.
here is a 16HP sketch that would fit the upcoming eurorack panel (if there is enough interest) for the LFO (and the one for the 555-VCO and ADSR is still to be made):
and here is the silkscreen of the circuit PCB:
BTW I have the permission from Thomas to do a PCB run for this project. It is the same as the VCO: i made a proto PCB months ago, when i had the privilege to a test build for new projects. it is tested and working very well (see pic in link above). however, the PCBs aimed for something else, so i might do some design alignments to allow piggyback mounting with a frontpanel components PCB in eurorack format, which became very popular lately...[/img]