Cougar ASM-2 Construction Notes

Transcription

1 Cougar ASM-2 Construction Notes May 25 th 2008 Please note that this document is still currently under revision and we apologise for any errors or omissions. Readers should feel free to any comments to me at the address given below. 1 of 23

2 Introduction The ASM-2 combines a set of fairly traditional analog synthesiser modules on to a single printed circuit board. The modules are:- Two Voltage Controlled Oscillators (VCO's) sawtooth, variable rectangular (pulsewidth modulated), triangle and psuedo-sine outputs One Voltage Controlled State-Variable Filter (VCF) low-pass, band-pass, high-pass and notch outputs One Voltage Controller Transistor-Ladder Filter Two 2 Voltage Controlled Amplifiers (VCA's) - Linear response Two ADSR Envelope Generators - exponential curves Two Voltage Controlled Low Frequency Oscillators (VCLFO) - triangle and square outputs One Noise Source - white, variable coloured and random outputs One CV Glide Buffer - exponential glide One Sample & Hold circuit One Ring Modulator Regulated dual-rail power supply (+15, 0V, -15V at 400mA) Most of these modules are, in the most, minor variations to the Electronotes EN76 series, and have been incorporated with the relevant owners permission. These circuit sections can be considered "modules" as they are not interconnected in any way on the circuit board other than by power and ground busses. Therefore the builder has the freedom to use the ASM-2 in any type of design desired, from a small hard-wired system to a fully patchable semi-modular system. In addition to the ASM-2 board, most builders will need to supply the following additional circuit modules:- Case and front panel. The ASM-2 should be housed in a suitable enclosure to ensure that the unit does not get damaged. Once wired to its front panel controls there will be a large number of wires that can easily be damaged should the unit not be suitably housed. Panel controls (knobs, pots and switches) to allow operation of the modules and configuration of the inputs and outputs. Audio amplifier to allow the user to hear the sounds you create Although the unit can be configured to play itself you will usually require an external control source such as a MIDI keyboard and a MIDI-CV converter. 2 of 23

3 Assembly Instructions Included with your ASM-2 pcb is a large drawing which is a blow-up of the silkscreen showing the location for each component as per the various schematics. Builders should use this in conjunction with both the schematics and the Bills Of Materials provided on the Support CDROM, to determine which component goes where. Builders should also read the other documentation provided on this CDROM and also follow the web links to other constructors for additional ideas and notes on constructing your ASM-2. When assembling the board we recommend one of the following two strategies:- 1) Assembly of the full board by component type. In this method the board is built up in layers starting with resistors and diodes, then ICs, capacitors, trimpots and transistors. One disadvantage of this approach is that the unit cannot be tested until the complete board has been assembled. I use a PCB Assembly Jig (see photograph) which means that I can insert components and solder them without having too bend the legs over to retain them. This is a big bonus if you wish to experiment with the board as it makes component removal a lot easier. 2) Assembly by module. In this method each module is assembled in its entirety one at a time. Once assembled, the module can be tested with, in many, cases minimal external componentry being added. One disadvantage of this method is that you will need to connect some external components to some of the modules for testing and this will require some connecting and disconnecting to allow for easy assembly of the next stage. This approach does not work with my PCB Assembly Jig and the previous method as the variations in component heights affects the height of the components on the board preventing the component retainer from working properly. Option (2) may suit users with less confidence in their assembly skills as they can quickly determine if a module works properly and as to how things are going. Once you have figured out what components you want to stuff, mark up the drawings to show this. Occasionally some components may become obsolete or very difficult to get hold of. In these instances, substitute components are provided. Wherever possible, these will be pin compatible (as well as functionally compatible) allowing them to be inserted in to the PCB without modifications. However, this is not always possible and some components may need to have their legs bent to fit the PCB location. We are continually on the lookout for alternative substitutes and will replace components in our kits as approved substitutes become available. 3 of 23

4 General notes on the assembly of the ASM-2 PCB (3D Model): All resistors on the PCB are on a 0.4 pitch whilst most diodes are on a 0.3 pitch and so these components can be generally preformed before insertion in to the pcb. Capacitors in the range 1nF to 1uF are normally on a 0.2 pitch whilst smaller capacitors are either 0.2 pitch (generally ceramics) or 0.4 pitch (polystyrene). Tantalums and electrolytics are generally on a 0.2 pitch. A resistor colour code chart is on the CD included with your kit. Integrated Circuits (IC) may be socketed if desired (a kit of sockets is available) but is not required in normal use. If you wish to experiment with the modules then we recommend the use of IC sockets. If used, we strongly recommend using machine-turned-pin sockets as these offer better long-term use. Wiring to the boards is made easier by having all of the module connections at the edges of the PCB. We recommend running your cables around the outside of the boards in a loom leaving the centre of the board clear. This will be a boon when setting up and adjusting the modules and will also simplify debugging should it be needed. This will result in slightly longer cable runs but this should not adversely affect the quality of the system through induced noise. Colour coding of cables is not a pre-requisite but once again using colour-coded cables will simplify tracing faults. The table below gives two examples of suggested colour schemes:- Cable Colour Function Or Cable Colour Function Red +15V Red Black Ground Black Yellow -15V Yellow Orange Control Voltages - In Orange VCO* Pink Control Voltages Out Blue ADSR Green VCA* Grey Signals In* Brown VCF* White Signals Out* Grey NOISE* White LFO Pink GLIDE * Audio signals are better wired using screened audio cable. The first scheme on the left will have the advantage of allowing you to bulk buy a handful of cable colours but will make fault finding a little harder. The second scheme, on the right, will require smaller quantities of more cable colours but will allow you to trace wires for a given module more easily. I would recommend this second approach for beginners. For the choice of wire type and sizes I would suggest:- 7/0.2mm (24AWG 7/32AWG) for control wires 16/0.2mm (22AWG 7/30AWG) for power rails (NB: 7/0.2mm is also fine for this purpose Single-core screened audio cable for all signal wires 4 of 23

5 When selecting audio cable, choose the smallest outside diameter possible. I use 10/0.12mm with an OD of 1.6mm. Larger cable OD will result in a larger cable loom. When connecting screened cable you should only connect one end of the screen to GND. In the ASM1-Genie this GND connection was provided by running a length of tinned copper wire around the outside of the pcb. This was achieved by placing eyelets on each corner of the pcb (using the pcb fixing holes to support the eyelets) and then attaching the wire to the free end of the eyelets. This approach means that the screen terminations are evenly spread around the board making it easier to maintain the wiring. The free end of the screen is cut flush with the end of the outer sleeve of the cable and either shrouded with a piece of heatshrink or masked by teasing the outer sleeve over the exposed wire. Nowadays its is recommended that you treat all semiconductor parts as static-sensitive, especially the CA3140s (that s why they get soldered in last). Be really careful with these they are unbelievably easy to blow up. You can, optionally, use ic-sockets for the IC s if you want. It is recommended to use sockets for the CD4002 and LM358 chips in the ADSRs, and for the output buffer op-amps in the VCF. Also, you may want to socket the CA3140s in the VCOs since they are so easy to blow up. Component Substitutions and Your Own Modifications: If you know what you re doing, go for it. If not, stick with the recommended parts. TEMPCO s: The ASM kits include a TEMPCO resistor for each of the VCO s. A TEMPCO can also be used in the VCF but is not included in the kit as this is less critical. The ASM kits provide a 1% metal film resistor for the VCF. The pcb has positions for the TEMPCO on the pcb but builders are referred to the photo which shows one method for improving the thermal bonding between the TEMPCO and the MAT-02. In this approach the TEMPCO is actually placed directly underneath the MAT-02. Thermal contact is improved through the application of some heatsink compound. The current design of the VCO modules requires TEMPCOs with a Positive Temperature Coefficient (PTC) of 3300ppm. Your VCO module kits will contain one of the following configurations for this component:- 1. A 3300ppm resistor. In this case resistors R137 and R187 should be replaced with a wire link 2. A 3500ppm resistor. In this case your kit will also include 2 off 62R 50ppm resistors which should be fitted in positions R137 and R187 Thermal contact: All of the critical exponential converter components are physically placed next to each other so that they can be in physical contact. The transistors and the TEMPCO resistors (if used) should, ideally, be thermally bonded together with heatsink compound, for best thermal results. This is totally optional and only for those who are after perfect performance. 5 of 23

6 Bills of Materials (BOMs): Components are given 3 or 4 digit identifiers such as C301, R221 and Q1201. The first of these three digits (two in the case of 4-digit numbers) relates to the schematic sheet number on which the component can be found whilst the last 2-digits are a sequence number for that component category on the sheet. When building your own order for components you should note the following points:- 1. All resistors are 1% 0.5W Metal Film (MRS25 Series). In most cases these can be replaced by lower tolerance (up to 10%) resistors. Also in most cases you can also use Carbon Film. 2. Capacitors in the range 1nF and 1000nF are generally Polyester (BF or MKS2 Series). Substitutes should be of a low-noise, high-stability type. 3. Capacitors below 1nF are generally 2.5% 160VDC Polystyrene (FCS Series) but Silvered Mica will also work fine. In some cases it is possible too use a high-stability NPO Multilayer Ceramic capacitor. 4. Decoupling capacitors are listed as 100nF X7R Multilayer Ceramics. Values in the range of 47nF to 150nF can be freely used in these positions and any good quality capacitor that will fit the RAD-0.2 footprint can be used. 5. Capacitors of 1uF and above are polarised and should either be MDT or TAP Series Tantalum or low-impedance Aluminium Electrolytics. Some schematics include panel-mounted components. Where shown, these components are required for the proper operation of the circuit. These components are NOT included in ASM2 kit. Additionally, some schematics include some control voltage input controls. These controls are, again, not included in our kits but have been included to show nominal component values and wiring details to assist the user in building/designing their modules. The values shown are similar to those that are being used in the ASMx-Genie and, as such, will be made available in kits when the ASMx-Genie is released. 6 of 23

7 TEMPCO VCO - Voltage Controlled Oscillator For optimum performance the VCO uses a temperature compensation circuit that utilises a TEMPCO resistor. For best results the TEMPCO should beb thermally bonded to the matched transistor pair Q101. The picture to the right shows how the TEMPCO should be mounted. If desired, thermal bonding can be improved further by the addition of some heatsink compound. Power up, Testing and Calibration Procedures Setting up of the VOLT/OCTAVE requires an accurate and stable voltage source. If using a MIDI-CV device then you should use that to ensure that the VCOs are tuned to your MIDI device. 1. Disconnect all control inputs (2 x PWM, 2 x LIN FM and 6 x LOG FM) 2. Open LK100 (LK150), if not already done, to disable the `INIT FREQ trimpot 3. Monitor the SAWTOOTH output with a frequency counter or scope 4. Using P101 (P151) adjust the output to read 880Hz 5. Apply 5.0V (MIDI Note = 60) to one of the LOG FM inputs 6. Adjust VOLT/OCTAVE to give a frequency of 28.16kHz Having set the VOLT/OCTAVE characteristics of the VCO, we can now finalise the setting up of the VCO. 7. Insert LK100 (LK150) 8. Apply 5.75V (MIDI Note = 69) to one of the LOG FM inputs 9. Adjust `INIT FREQ (P100/P150) to give a reading of 440Hz. 10. Remove the 5.75V on the LOG FM input 11. Confirm that the output frequency is 8.176Hz It is worth repeating these steps to ensure that the settings are stable. This completes the setting up of the VCO. Reconnect all control inputs. The VCO can now be connected to a 1V/Octave MIDI-CV module and will play the correct frequency for a given MIDI Note Number as per the MIDI Note Table included with this documentation (assuming all other control voltages are at 0.0V). Square Waveform Adjustment 1. The Square output does not need adjustment. Monitor the Square output on J102 (J152) and check that the waveform is centered around 0V. 7 of 23

8 Triangle Waveform Adjustment 1. Monitor the Triangle output on J102 (J152) and using P103 (P153) adjust the output until it is centered around 0V. 1. Using P105 (P155) adjust the output until the positive and negative slopes are identical, 2. Using P104 (P154) adjust the output to minimise the glitch at the bottom of the waveform, 3. Finally, using P106 (P156) adjust the output until is centered around 0V. Sine Waveform Adjustment 1. Monitor the Sine output on J102 (J152) and using P102 (P152) adjust the output for a peak-peak output of 10V. 8 of 23

9 VCF - Voltage Controlled Filter (VCF 1) Power up, Testing and Calibration Procedures: NB: This procedure assumes that the ASM-1 modification has NOT been implemented. There are three trimmers on the PCB:- V/OCT (P201): This adjusts the scaling of the exponential inputs. Adjust this so that there is an octave jump in cut-off frequency when the 1V/OCT input is raised by one volt. Plug a 1V/octave source into one of the CV inputs. This may be your keyboard s pitch CV output, or from the CV output of a midi-cv converter. Set the Resonance pot P204 fully clockwise to get the filter oscillating. Now listen to the output coming from the low pass output. You may find it best to use the Frequency pot on the front panel to set the filter oscillating at quite a high frequency tone. Somewhere around 1KHz will do. Now play a note on your keyboard and then the same note an octave above. Repeat this again and again and adjust the V/OCT trimmer to get the filter s oscillations to jump an octave too. Don t worry about the actual pitch the VCF is producing. Just concentrate on getting roughly one octave difference between the low note and the high note. It is a fiddly adjustment and it takes a while to get it right. But remember that this is a filter and not a VCO, so you don t have to be too accurate. OFFSET: The two OFFSET trimmers (P202 and P203) control the amount of DC on the output. Use a scope or a voltmeter to measure the voltage at pin 1 of U204. Rotate the Frequency pot until the voltage is approximately zero volts. Without any audio input, measure the voltage at the BP output. Set OFFSET 2 so that the voltage at the BP output is as close to zero as you can get it. You should be able to get it down to +/-5mV or less. Now measure the voltage at the LP output. Set OFFSET 1 so that this voltage is as close to zero as you can get it. Again aim for +/-5mV or less. Electronotes ENS76: The standard configuration as shown in the schematics remains true to the original Electronotes VCF design. Should the reader wish to build the ASM-1 modified variant then they should note the following points:- 1. Add R230 (100K), R231 (10K), R232 (47K), D201 (1N4148) and D202 (1N4148), 2. Replace R243 with a wire link 3. Change C201 and C203 to 33pF These components where added by Gene Stopp per the following reasoning: duplicated from the schematic for the Oberheim SEM, these components form a feedback limiter and help keep the Q oscillation from clipping. 9 of 23

10 VCF - Voltage Controlled Filter (VCF 2) Power up, Testing and Calibration Procedures: Here's a procedure without a scope. The basic idea is that you use the VCF as an oscillator, with Emphasis all the way up. A well-tuned VCO acts as a reference, so the VCF should follow the VCO when CV changes. Apply a control voltage (CV) to the VCF and a VCO Turn the Emphasis (P805) pot all the way up so that the filter starts to oscillate: you'll hear a sine wave without any input signal to the filter Tune both VCO and VCF to the same frequency for a key on the keyboard, say 1000Hz, so you have zero beatings. Press a key two octaves up. Adjust P802 so that you get zero beatings again, thus the filter gives the same frequency as the VCO. Press a lower key and tune the filter manually to the VCO frequency again with P801 (Frequency). Press the higher key again and adjust P802 so you get zero beatings. Repeat this process a few times. Emphasis Trim (P804) and VCF Balance (P803) don't have much effect. You only need to adjust them when you're very picky otherwise turn P804 to minimum resistance and P803 to the mid position. P807 should be set to its center position. Addendum A pcb error requires that the transistors Q801 to Q806 be re-orientated. Refer to the pcb overlay for details. 10 of 23

11 ADSR (1) (2) Envelope Generator Power up, Testing and Calibration Procedures: P406/P456 is set to determine the maximum voltage attained in the ATTACK curve, P400/P450 is set to define the maximum SUSTAIN level that can be set by the panel control P402/P452 For general synthesiser compliancy, control signals should be from 0V to +10V. To comply with this the voltage at the clockwise pin of P402/P452 should be set to 10V by adjusting P400/P450. The reader should note that, in this case, when P402/P452 (SUSTAIN) is set to maximum, there will be no DECAY curve and the envelope will follow an ASR curve. Readers may wish, therefore, to set the SUSTAIN LEVEL to a slightly lower level than this thus ensuring that the DECAY portion of the curve has a positive action. With P400/P450 set we can now set P406/P456 (ATTACK PEAK) which determines the maximum voltage that the ATTACK curve will reach before switching to the DECAY portion of the curve. Set P405/P455 (ATTACK), P403/P453 (DECAY) and P404/P454 (RELEASE) to minimum and P402/P452 (SUSTAIN) to maximum. Set P406/P456 fully clockwise 1. apply a low-frequency squarewave (around 1-5Hz will be fine) to the GATE input 2. the ENVELOPE OUT signal should exhibit a squarewave in time with the frequency of the GATE signal 3. The rising edge of the ENVELOPE OUT will probably have some overshoot or undershoot. Adjust P406/P456 to minimize this, The aim of these steps is set a level at the output of P406/P456 which will cause the flipflop, built around U404/U454, to go from a Logic `0' state to a Logic `1' state at the same time that the envelope curve reaches the desired ATTACK PEAK level. This completes the setting up for the ADSR module. The current values given for R403/R404 (R453/R454) set the minimum trigger input voltage to ~2.4V. By adjusting either or both of these resistors, the builder can tailor this input threshold to suit their own requirements. Generally you should aim to keep the total resistance value to between 70K and 100K. Also remember to include the diode voltage drop in your calculations 11 of 23

12 VCA (1)(2) - Voltage Controlled Amplifier 12 of 23

13 Noise Module Power up, Testing and Calibration Procedures: The noise source "Level" trimpot will adjust the noise level from zero to max - somewhere in between is a good setting. We would recommend adjusting it so that the coloured noise output sounds about as loud as a VCO waveform. The ear is much better than a scope for noise, since to see the whole picture on the scope you'll probably need to set the vertical to 5 volts/div and the horizontal to a real slow sweep just to get a band of fuzz across the scope screen. A socket should, ideally, be fitted for T601 so that a range of transistors can be tried to obtain optimum noise levels. The white noise output should be between 2.0 and 2.8V peak-to-peak. Different transistors should be tested along with varying the value of P601. If using the ASM-1 arrangement then R607 can be adjusted so as the output level of the Pink/Coloured noise output is approximately the same as the White noise output. 13 of 23

14 VCLFO (1)(2) - Low Frequency Oscillator Power up, Testing and Calibration Procedures: Offset Adjustment 1. Disconnect R508 from the wiper of P503 and connect it to ground. 2. Monitor the output voltage of U502A with a multimeter. It will probably exhibit a tendency to drift positive or negative, and the voltage will settle at +15V or 15V. 3. Reset the output voltage to zero by discharging C501 through a 1K resistor. 4. Adjust P504 until the voltage remains stable at zero volts for a period of several seconds (without the discharge resistor in circuit). 5. Repeat steps (3) and (4), progressively switching the multimeter to more sensitive ranges, until the drift is only a few hundred millivolts in several seconds. LED Adjustment P505 should be adjusted so that the brightness of the LED follows the amplitude of the triangle output, i.e. the LED brightness should be at minimum brightness when the triangle is at its most negative, and at maximum brightness when the triangle is at its most positive. Selection of R507 The only other adjustment possibly required would be an adjustment to the value of R507. Readers wishing to get very low frequencies from the VCLFO may wish to experiment with smaller values of R507 however, making this value very small (or even zero) may result in the VCLFO `stalling when the frequency control is set to minimum. R508 is the main frequency-determining component, other than the capacitor itself. A larger resistor here will shift the VCLFO's range lower, and a smaller resistor will shift it up. The RATE pot value is really not a factor as it is used as a voltage divider in this circuit. For switchable frequency ranges it is recommended that R508 be replaced with a wire link and that the connection from R508 to P503 be taken through a panel switch where additional resistors can be switched in circuit as desired. 14 of 23

15 Glide Buffer 15 of 23

16 Ring Modulator Power up, Testing and Calibration Procedures Setting up the circuit is quite straight-forward but needs to be done carefully. You will need a sine or triangle wave of about 1kHz and either an oscilloscope, sensitive AC voltmeter or an audio amplifier. 1. Connect the oscilloscope to the OUTPUT of the Ring Modulator module (J1601 pin 3). 2. Apply the test signal to the CARRIER input (J1601 pin 1). 3. Adjust P1601 until the output signal is at minimum. 4. Apply the test signal to the SIGNAL input (J1601 pin 2). 5. Adjust P1602 until the output signal is at minimum. 6. Repeat steps (2) to (5) until no further improvement can be made. The level of feed-through obtained will vary between IC s. Typically, with a 10V p-p signal the feed-through for the CARRIER input may be trimmed to between 10mV (-60dB) and 20mV (-54dB). For the SIGNAL input this will, typically, be between 40mV (-48dB) and 80mV (-42dB). 16 of 23

17 Sample & Hold The Sample & Hold circuit needs a couple of small modifications to optimise the operation of the sampling circuit. Firstly we need to add a bias voltage to U901D. C901 has been replaced by a 20K resistor and we need to add a 30K resistor from U901_5 to U901_4. The second modification is a bit messier and requires 2 tracks to be cut and a wire link added to bypass the cut tracks:- Cut the track between U901_13 and U901_14 and also the track leading away from U901_13. Using a piece of fine wire connect U901_14 to the top end of R903. Now fit the 2 resistors R921 and R922. Fit R921 to U901_4 and U901_13 and R922 between U901_13 and U901_ of 23

18 PSU A track error has resulted in the 2 regulators U3 and U4 having the wrong footprint.the picture below shows these 2 components as they should be installed. 18 of 23

19 Minimum Panel Controls The following section lists recommended values for pots to be used in conjunction with the ASM-2 and are needed to allow proper calibration of the ASM-2 to be performed. VCO - Voltage Controlled Oscillator (VCO1 & VCO2) Recommended Minimum Panel Controls: CV1 - Fine Tune - 100K Linear CV2 - Coarse Tune 100K Linear PWM1 - Initial Pulse Width 100K Linear Additional controls: All remaining inputs, where used, should have 100K Linear pots. VCF - Voltage Controlled Filter (VCF1) Recommended Minimum Panel Controls: CV1 Cut-off Frequency 100K Linear Q - Resonance 100K Linear Additional controls: All remaining inputs, where used, should have 100K Linear pots. VCF - Voltage Controlled Filter (VCF2) Recommended Minimum Panel Controls: Enhance 50K Logarithmic Additional controls: All remaining inputs, where used, should have 100K Linear pots. VCA - Voltage Controlled Amplifier (VCA1 & VCA2) Recommended Minimum Panel Controls: CV1 - Initial Gain 100K Linear Additional controls: All remaining inputs, where used, should have 100K Linear pots. ADSR Envelope Generator (ADSR1 & ADSR2) Recommended Minimum Panel Controls: Attack 1M Linear Decay 1M Linear Sustain 100K Linear Release 1M Linear Additional controls: There is no need for any additional controls on this module. 19 of 23

20 Noise Module Recommended Minimum Panel Controls: Red 100K Linear Blue 100K Linear Additional controls: There is no need for any additional controls on this module. LFO - Low Frequency Oscillator (LFO1 & LFO2) Recommended Minimum Panel Controls: Rate 100K Linear Additional controls: Tuning 100K Linear CV 100K Linear Glide Buffer Recommended Minimum Panel Controls: Portamento (Glide rate) 1M Linear Additional controls: There is no need for any additional controls on this module. Ring Modulator Recommended Minimum Panel Controls: None Additional controls: Recommend inputs, where used, have 100K Linear pots. Sample & Hold Recommended Minimum Panel Controls: Sample Clock 1M Linear Additional controls: There is no need for any additional controls on this module. 20 of 23

21 Additional PCBs The first release of the ASM-2 Cougar used a number of support boards to provide the extra functionality incorporated in to the ASM2-Cougar design:- 1. MonoDAC MIDI-CV 2. CGS36 Pulse Divider 3. ED122 Power Unit MonoDAC PCB The MonoDAC is a scaled down version of our PolyDAC offering all the same features and functions but providing for only one channel of MIDI output. CGS36 PCB The CGS36 pcb includes some additional unused sections which should not be populated. Unfortunately due to the design of the pcb the identification of the unused parts is somewhat messy. A marked up overlay is provided in the WebTek section. ED122 PCB The ED122 power unit allows the ASM2-Cougar to be powered from a single output power brick. The ED122 provides the +/-15V rails for the ASM-2 as well power for the CGS36 and MonoDAC boards. These boards have now been replaced by the Cougar Expander. 21 of 23

22 Appendix A Please note that this document is still currently under revision and I apologise for any errors or omissions. Readers should feel free to any comments to me at the address given below. 22 of 23

23 The first step is to populate the front panel with all of its components. Orientate the pots so that their legs point to the right (when the panel is viewed the right way from the back) except for the MIDI and GLIDE pots which should point downwards and VCO2 INITIAL PW which should point left. The panel is designed to accept either 3.5mm jacks or 4mm banana jacks. Fit all the jacks with their legs pointing upwards. LED lenses should be carefully pushed in to position. LEDs snap-fit in to these and should not need any further securing but a small dob of a rubber-based glue can be added if desired. NOTE: The 2 power LEDs do not have lens mounts. The ADSR Manual switches should be mounted horizontally With all the components mounted you should start by inter-wiring all relevant connections (0V, +12V and - 12V connections). If you do not intend to interface the ASM2-Cougar with any external equipment (other than an audio amplifier) then you do not need to connect the 0V tabs of the jacks together (only the audio out jacks VCA1 OUT and VCA2 OUT need grounding). If you will be expanding the ASM2-Cougar then you should connect all the 0V tabs together. This is best done using fine tinned copper wire and running it left to right across each row. Both of the legs nearest the panel can be connected to simplify wiring. I recommend taking a piece of wire equivalent to 6x the width of the panel (approximately 2.8m) and starting from the 0V tabs on the ADSR2 GATE jack, run the wire to the right going up and over every alternate tab until you reach the MIDI NOTE jack, then run down to the MIDI VELOCITY jack and repeat all the way to the VCA2 OUT. The ASM2-Cougar panel is designed as a full modular synth and as such has no pre-patching. This means that the synth MUST be patched before you can get any usable sounds out of it. If preferred, you could prepatch a number of connections to allow the synth to generate some basic sounds without patching. These pre-patches, of course, can easily be overridden by simply inserting a patch lead in to the relevant normalized jack. Obviously the front panel markings will not indicate which points are patched and to where the patching goes. Terminate the DC Power Connector with 2x 5cm pieces of a thick gauge wire (we recommend 16/0.2 or 24/0.2). For consistency with other ELBY Design projects we use Tip = Positive, Yellow = 15V and Black = 0V. Solder the free ends to the 0V and +15Vsw pads on the ASM2-Cougar Expander Board Populate the enclosure with the pcb mounting components. Insert the M3 x 12mm bolts and secure using the 5mm spacers. Add the pcbs and secure using the M3 nuts. To maintain maximum serviceability we recommend that you place the front panel face down above or below the box and about 1cm away from the box. Once fully wired, this will allow the panel to be swung out and rested on the bench freeing up both hands for servicing and minimizing stress on the wiring. This will also help keep the wiring to its shortest practical length. We also recommend running all the wiring around the edge of the boards to maximize access to the components on the boards 23 of 23