Post by MotoModular » Tue Apr 03, 2018 9:03 pm

Hello,Prototyping is about to commence. I am opening up the forum for any suggestions and questions about electronic performance specs and specific features' designs.It's ready to be critiqued.I only want to send something out that is going to be able to make the widest variety of connections and instigate the highest number of musical applications.This unit has been in loose development behind the scenes for a very long time. At first probably a couple years worth of reflecting upon the guts of the TE-1. Then later all sorts of breadboarding and experimenting was periodically hacked out whenever i'd completely lose my mind struggling with a TE-1 and this provided a bit of vacation type relief. The final concept solidified perhaps January 2017. Then all year last year the feature sets finished themselves slowly and eventually a whole wave of CV communications at the end of the year forced me to truly once and for all discover the unpredictable limitations of the TE-1 chassis and then secondly buck up and break out the TE-2.So please, feel free to comment. This is the final round. Hoping to cut the first plate soon.And on that note, here's a HUGE thank you to DSC here. Chris is a generous professional and a wellspring of knowledge. Million Machine March is the real deal and the things that come out of his workshop that i visited in Denver are created with the highest integrity. His regular communications with me have given a lot of grounding to the TE-2, in regards to all aspects of musical instrument development from the ground up.This is a long post below, so i'm trying to keep the introductory element short, but I also want to deeply thank those of you who have committed to the Space Case and endured the wild feeling wait that is usually involved with the TE-1. That unit has been kicking my butt for a few years now, and has definitely caused me to question the future. It is simply impossible to fully convey what it's like to make, and especially finish in the last stages, a single TE-1. As a testament to this, i still only own one myself. And to be honest i've parted it out several times to finish some extraordinarily stubborn units of yours. It's back together now though.Below is the general rundown sheet, although largely incomplete and definitely doesn't display all of the uses of this instrument...Mind you, the artwork/labeling is all temporary so i apologize for some awkwardness of word positioning and indication approaches.The hardware is more or less locked.WMD Devices is making the PCB's, something I'm very much looking forward to after all this time handling 30 year old boards.--------------------The TE-2 is the result of over 5 years of considering all ways to push directly beyond the TE-1 and enter more liberating territories. This nearly finalized musical instrument arrives as a combination of creative toolset development and 2 1/2 years of TE-1 user response.The TE-2 is a low profile, 325mm x 139mm x 50mm compact tabletop unit. The case is oiled hard maple with bevelled edges.The 21 sliders have soft small cap, similar to the classic ARP sliders, and sit low profile about 7mm above the surface. The main parameter knobs are around 19mm, and the 11 smaller knobs are around 14mm high. The 1-8 buttons are shallow quiet tactile switches. The 8 aluminum pole slider switches come up around 5mm from surface and in addition to appearances also prove nicer to handle than typical black slider switches. The transport buttons are flush with the surface and press down as traditional casstte buttons. The top face of the clear acrylic cassette lid rests flush with the surface of unit. The layout is designed so that the main parameters are front and center, and a little higher than the rest of the unit. This sets up a clear engagement with the core of the machine.The unit is self sufficient, and requires no patching for any of the features. But it is also meant to give unique expressive tool sets to all individuals in all musical environments.Aside from being a standalone unit, the hardware device is also a self contained eurorack module which can be removed from this case and installed into any eurorack system and powered as any eurorack module. If desired, other modules may be installed in this now vacant case if proper power considerations are taken. Vector rails are present. It is a shallow case, however, so only shallow modules will fit. The unit is a 62HP width. A large unit indeed, but providing a universal case for other modules can offer a perk to counter the intrusion into your system. Or simply leave the unit in its case and operate it as if it were any module.Banana jacks are a strong possiblity for being an option as opposed to euro/3.5mm. This is a late addition, made by request, and is near to being confirmed. More info below.----The core of the TE-2 is a tape echo, with many fundamental refinements taken beyond the TE-1 in this regard.Some new things..a 24db/oct OTA 4 pole high pass filter and low pass filter, with a resonace for the low pass filter. This is an expansion upon the successful engineering tool of the simple high pass filter on the TE-1 which assists greatly in sculpting the sound on tape, and the tone knob on the TE-1 which provides general high eq tailoring. The two filters are structured in a similar manner of classic roland 4 poles of the late 70’s. The higher “que” or “pole structure” allows for tighter focus of shaping.The high pass is located just prior to the record head, so that adjustments have an impact on the resulting tape saturation itself. In general, low frequencies are the first to cause tape saturation. In a setting where saturation or overload is not wanted, tapering away some low frequencies prior to hitting tape can allow for more headroom and signal to noise separation since levels can be sent in hotter to tape.The low pass filter includes a resonance amount, allowing for creating a wide multitude of results coming from tape. It reaches self oscillation, and can be used as its own tunable 8 pitch sound source (more below).Time modulation is introduced. The modulation is a sine wave shape, which allows for smooth dark motions within the echo time domain.The output drive circuit embellishes upon and refines the output distortion of the TE-1, with more gradual tunability and contained resulting levels.The interfacing of the TE-2 is as flexible as possible.. Line Level balanced +4dBu , Line Level unbalanced -10dBv, Hi-Z Guitar Level, and 10V point to point Modular level, are selectable and all jacks are usable at the same time. Inputs get mixed and outputs are properly multed. There are two modular level inputs to allow for the intense patching environment.----Originally inspired by the TE-1’s resulting character of motion when flipping the motor speed live between three different TIME settings, and also inspired by the concept of “parameter locks” that became popular in relatively recent sequencers/instruments, the heart of the creative architecture of the TE-2 is that there are 3 “sets” of selectable parameters, White, Grey, and Black, each with 8 “steps” that have placeable sliders. Up top, one can choose to activate any one of the three “sets” independantly, choose what parameter it controls, and also utilize any of the “steps” either at will with buttons or in patterns of motion with the Cycle function. Musically this opens up new toolsets for creation.To simplify... at it’s most basic use, press one of the 1-8 buttons on the left, and the step becomes active and illuminated and remains the active step until another is pressed. If you select TIME and activate it, and then move from Step 1 to any other step, the White slider then is the active hardware placement setting for TIME. If you’ve activated all three sets up top, and you have the White set to TIME, the Grey set to FEEDBACK, and the Black set to Tape Level, then you may use those respective White, Grey and Black sliders to have up to 8 different freely tuned positions for each parameter just mentioned. You can engage or disengage various combinations of the three parameter sets, and use or ignore any 1-8 steps you like.To give motion to the span of settings now controllable with hardware sliders, the TE-2 contains a “Cycle” function, which is a sequencer that rotates through the steps.. Press the button in the Cycle and it will run. Using the rotary selector switch toward the right, you may select the max number of this cycle, so that you may choose to rotate between just 2 steps, or up to all 8 steps. 1 step may be selected as well, and can be considered as a cycle pause function, where the 1st step stays put until you select a quantity from 2 to 8 again. The rotary switch rotates fully around and does not have a stop point, so flipping between 8 and 1 is physically possible.The Cycle rate knob allows for extremely slow speeds, and all the way up well into audio range of high speeds. The slow speed is around 10 total seconds PER STEP. The higher speed is around 1kHz PER STEP or .001 seconds.On the slower end, this allows for very long and gradual musical phrases to take place, and for a total phrase of 8 steps to perhaps take around 1 minute and 20 seconds to go through its cycle. As a basic example, during basic echo use with a healthy dose of feedback, use a slow speed cycle of 8 steps of TIME and you then have a motion of feedbacks midly pitching upwards or downwards over a long stretch of time. This quickly develops rich hypnotizing swells. It sounds the same as slowly moving the Time knob with your hand, but is widely controllable.This raises the next musical inclination.. about the musical manner in which the unit switches between step to step and thus parameter setting to parameter setting. For instance, how abruptly will the TIME amount change each step?... The TE-2 contains a Drift knob for each of the three sets. This is a logarhythmic slew setting independantly tunable for each Set. Meaning, the White set’s TIME can have a different Drift amount than the Grey set FEEDBACK or the Black set’s parameter. Each their own.The Drift amount is adjustable from 0 to around 8 seconds. This means that if you Cycle is rotating slowly, you may have the parameter move from stage to stage with a motion that takes 8 seconds to achieve. For slow moving Cycles, this smooths out motions overall, allowing for organic phrases to occur. For faster speeds, up in the audio range, this allows for the creation of smooth waveform points...For instance you can use maybe 4 steps to create a 4 point waveform moving at 1kHz per step which cycling around translates to a 250Hz waveform for modulation applications, and turn up the drift a small amount to make the 4 points not be squared off but something softer.If this is to be considered modulation, which it is, then the modulation capabilities of the TE-2 are expansive. With those basic meat and potatoes tools implemented with extreme ranges in all directions from slow to fast, there are many musical possibilities to look forward to. The slower cycles will open up dark movements and osclillations, and the faster cycles will introduce a highly tailorable modulation paired with the LED light show accurately representing it.Each of the three sets also contains a CV output jack that directly represents the sets activity, to be connected to external devices. So for example if you are running the cycle rapidly to “modulate” the low pass filter with a complex but drifted 6 point wave form, you may patch this same exact CV signal to other musical instruments to have that same modulation apply to other things. You may also cross patch to a few places within the TE-2 itself, effectively turning the TE-2 into a semi modular musical device. For example you could choose to patch the CV from White sliders over to TP LVL, so that your TIME sliders are also doing the same exact thing to TP LVL.The TE-2’s Cycle also contains a jack, which has selectable input or output steps, with all steps present. You can have this be an output jack and each TE-2 step will send a rising edge gate to trigger things like synthesizer arppegiators. If you have this switched to input, however, you can have external equipment send in triggers to step along the cycle of the TE-2 step by step. In this manner you may use a sequencer to control the TE-2 cycle rate or also just create irregular stepping under the control of your external device. An example would be taking the trigger out from a drum machine and having it step the TE-2’s sets along, having TIME be set differently for each step, and thus creating delay time variation from bar to bar perhaps.There is also an Anomaly feature, which creates either a positive or negative skip in Time, giving us the ability to create the same sound as a broken tape deck that has a slight lilt or wobble every so often. It is triggered by the final step count you have selected with the rotary selector, and can be active even when all 3 sets are not active so if you want to dedicate the Cycle to just the Anomaly you may do so. An example of use would be to play back a pre recorded tape of a sustained drone and give it an irregular mild hiccup once ever 5 seconds or so. If it is set for step 8, this means you can create the hiccup to be very frequent/rapidly, or to occur as infequently as once every minute or so. (more info below)The TE-2 may also be used for all forms of recording and playback. Simply recording something and playing it back in a much slower speed gives inspiring results, but incorporating features such as the Anomaly and a subtle cycle of a parameter or two can create sounds never before heard, all coming from tape. Connected a CVcable keyboard allows one to play the playback itself like a live instrument/sampler, have keyboard gate engage the motor at will, and keyboard CV control the pitch (speed).Using a long pre recorded sound and setting 8 different TIME settings for each of the 8 buttons will quickly turn the TE-2 into a “cassette synthesizer” to play different pitches of the precorded sound. Add some LPF and TP LVL to the buttons (sets) and you have a dynamic musical instrument where each pitch can also have it’s own volume and tone color.The unit can also be used for processing of external audio. Using a 1/4” (6.3mm) unbalanced TS cable patched into the Insert jack, you can send in sound and utilize most of the features on board of the TE-2 for sound processing.The unit is entirely analog, and all complex settings are acheived with transistor switching matrix circuits. There is no memory or complex IC on board.As mentioned above, one final addition that is about 75% confirmed possible is the option for banana jack connections for all CV jacks and modular level audio jacks. This can’t be 100% guaranteed as ofApril 3rd 2018 but is looking likely. All measures have been taken on faceplate and hardware is chosen. PCB adaptibilty is the only remaining design aspect to confirm, but it is looking to be possible. Either 4 or 5 of the jacks would require switches on the rear case panel to overcome the electronic switching obstacle inherent in converting any switching jack to banana jack. There would also be a banana ground jack on the rear panel. The banana option would hopefully be zero cost difference to buyer, but may require a nominal installation fee. It is unlikely that the end user will be able to perform the installation, but if possible then the banana option might be shipped as a DIY add on package of components.-----CONTROLTIME - 0-5v - Hard insert CV, and passes directly through the TIME knob so you may scale down your source to result in the speed/time/pitch scaling that you like. A fun and straight forward example is using a keyboard that has CV output to play the speed and tailor the amount in which each different musical key increases or decreases speed. Leave the TIME knob fully up for a straight 0-5V control.MOD - 0-5v - Hard insert CV, and passes directly through the MOD AMT knob for attenuation. The MOD signal gets added to the TIME control, so it never interuppts the TIME function and only modulates it ( as you’d expect!). Use the MOD AMT knob to attenuate how much signal is sent to modulate Time.FDBK- includes attenuation and is mixed with the on board Feedback setting. This allows for a very tailorable interaction with the feedback of the TE-2. A signal down to -5V with attenuation set fully up will always bring feedback down to 0 no matter where the onboard Feedback knob is set. An active expression/CV pedal may be patched in and with the attenuation you may dial in the performance balance you wish. Keeping the on board feedback knob down to 0 or just little above is likely the best balance for things like guitar.LPF - includes attenuation and is mixed with the on board LPF, used to modulate the LPF as desired. A signal down to -5V with attenuation set fully up will always bring resulting LPF down to 0 no matter where the onboard LPF knob is set.RES - includes attenuation and is mixed with the on board LPF, used to modulate the LPF as desired. A signal down to -5V will always bring resulting RES down to 0 no matter where the onboard RES knob is set.TP LVL - includes attenuation, and is mixed with the on board LPF, used to modulate the LPF as desired. A signal down to -5V will always bring resulting TP LVL down to 0 no matter where the onboard TP LVL knob is set.MTR - (START/STOP) - 0-5V Gate - This also allows for positive gates to be used to activate/deactivate the playback, such as in the event you hook a keyboard’s GATE to this jack and the same keyboard’s CV to the hard TIME jack, you may “play” the speed and on/off of playback like a cassette sampler being cued as notes are pressed. This jack is the same as the MTR button in the bottom right of the unit, however the polarity is reversed for quicker musical application. If you patch into this jack, you will immediately kill the motor. A sustained 5V signal engages the motor and a sustained 0V signal disables it. You may send in reversed polarity gates if you wish to stop the motor upon gate action rather than enable the motor upon gate action. There is a small panel adjustable screw next to the MTR button to tailor how quickly the motor comes to stop and starts back up. Having slower speeds here results in classic wind up and wind down effects.MTR CLK - More information soon. It is important to note that this is a tape machine with gears, pulleys, rubber belts, a pinch roller, and rotating shafts. There is no chance for “nearly phase accurate” audio clocking from tape machine sync technology on machines like Studer or Otari or MCI. But, it can be clocked and musically applied. More to come. This isone of the very last electrical additions to the TE-2, and is still being finalized in terms of performance specs. The reason this is even possible, as well as tap tempo, is that the motor is now a brand new sensor based BLDC motor, with rotary substages readable and auto adjustable with the motor control circuit.More on the motor...The motor is a great improvement upon the capabilities of the TE-1. Extreme care is given to each and every TE-1 basic DC motor, and sometimes up to 10 different motors will need to be fully treated and swapped/installed and auditioned to acheive the best stability of sound during the longer echo times. Great artistic results are achievable and each them turn out a little different sounding in the longer speeds. But the TE-2 sensor based BLDC motor and the entire motor and clocking circuit introdue a new level of sonic performance. None of the cassette coloration and vibe is lost, only stabalized and explored further. This motor type and motor circuit also ushers the world of tape delay into the world of clocking.TRANSPORTSTP/EJ - stop when pressed once, eject when pressed againREC/ECHO - engages record and echo functionPLAY - press alone to only use machine for playback manipulationRW - rewind, or reverse playback if pressed and held during playback operation. TIME has control over speed, and it is proportionally faster than playback speed so adjustment will need to be madeFF - fast forward, or high speed playback if pressed and held during playback operation. TIME has control over speed, and it is proportionally faster than playback speed so adjustment will need to be madePAUSE - pause. this lifts transport from tape, and can be used for hard stops and starts while retaining exact speed“1-8” MOMENTARY PUSH BUTTONS- choose a set to be activePARAMETER KNOBSTIME - time/speedFDBK - feedbackTP-LVL - this is the echo level during echo use, and the tape playback level during play useMOD AMT - from zero to full sine waveform effect on pitch/speed of motorMOD SPD - speed of sine waveform for modulationDRY LVL - throughput of source sound, to be balanced with echo levelDRIVE - output opamp overdrive/distortion/timbre, applied to both echo/tape and dry. This replaces the need for using four knobs on the TE-1 to achieve the same result.HPF - 24 db/octave, 4 pole OTA filter applied to echo/tapeLPF - 24 db/octave, 4 pole OTA filter applied to echo/tapeRES - resonance of LPF. There is also a gate switch, which links resonance on/off to all of the 1-8 buttons. This allows you to play the self oscillating filter, which is of course a sine wave, with a gate function as if it were a synthesizer oscillator. In fact it is exactly this, and so if you set a different LPF for each of the 1 through 8 steps of sets, this LPF setting makes it a different pitch for each 1-8 button you press like a keyboard. So you can play the TE-2 with its own internal synth oscillator with 8 pitches and all echoes and other sonic parameters are still in place. Kind of like a mini 8 pitch sine wave synthesizer with a built in TE-2 tape delay. SCI FI soundtracks?MTR - press to stop motor, causing pitch drag effect down to dead stop. Release to allow running of machine, causing pitch ramp-up effect back to current speed.ANMLY - Standing for “anomaly,” this feature allows for the real creation of a single irregularity in the speed/time of the playback. Use this to create a subtle blip in the stability of sound, like an old broken tape machine that has an error in the rotation. When engaged, this anomaly occurs on the final step that is selected in the cycle length. Therefore, if you are running a 5 step cycle, each time step 5 is engaged from the cycle the anomaly occurs. The severity of the anamoly is represented with an AMT (amount) knob, adjustable from being a very quick blip in speed to a long singular wobble. The polarity can also be selected to choose from the pitch rising up a bit to the pitch rising down a bit. When this same toggle switch is in the middle position, the anomaly is turned off. You may use this feature even when all three sets are turned off. Run the cycle as usual and the anomaly will still occur on the last selected step with the 1-8 knob. You can also change the step number live during use, so that your skip happens at changing time periods at will.There is a small front panel user customization embedded screw for adjusting one additional performance behavior of this, in addition to the polarity switch and amount knob ... which will relate to severity of anomoly and will be further specified in the near future spec lists.INTERFACETAPE IN - level of source sent to tape/echo, after proper input connections are made. Vu meter indicates tapeN C M : (TAPE TYPE) - select normal, chrome, or metal tape type to match what tape you are using. Or use this selector for unusual eq effectsIN, Out 1/4“ (6.3mm) Audio Jacks - selectable levels for each independently. “G” is guitar, “10” is -10dBv Line Leve unbalancedl, and “4” is +4dBu Line Level balanced.Insert 1/4“ (6.3mm) Audio Jack - The level selected for insert will apply to both ths send and return of this jack. “G” is guitar, “10” is -10dBv Line Leve unbalancedl, and M is modular 10V point to point.* The insert jack may be used as an input for using the TE-2 as an audio processor, including most of the features usable for modulation of the external audio. Connect an unbalanced input cable, and this mutes the tape functions and retains all of the sound processing.M-IN x 2 - Two modular level inputs, 3.5mm jacks. 10V point to pointM-OUT - Modular level output, 3.5mm jack. 10V point to pointFSW- jack... custom cable connets to external footswitch (included) and contains Tap Tempo, True Bypass, and Step advance. The Step Advance feaure will be convenient for cueing up 8 different settings for songs via footswitch. It may also be used for live switching between steps for musical purposes.