OP-1 Field first thoughts

After owning the OG OP-1 for some years now, I know pretty well what I’d want in a new version for my specific use.
I’ve been using it like a DAW basically, where most of my music is done recording external synths from the line in, so what I wanted in a new OP-1 was improved audio quality (especially line input) in the broadest sense, no more clicks and pops and the same immediacy.

Physical aspect:

  • As you can see in the first part of the video, the keys make some noises depending on where you press. This didn’t happen in the original one and it annoys me a little. I think the type of material is different too (worse in my opinion), keybed feel is similar though.- Speaker is quite lowder and much more usable than the original.
  • I can’t see any reason to make the keys protrude over the aluminum frame. I can only think of less aluminum = cheaper to build. I wonder if this will give problems at some point, either dust or stuck keys.
  • Volume pot isn’t wobbly anymore.
  • The encoders are a little more clicky, but I find them as good/bad as the original ones.
  • Screen brightness is more or less the same for me. Resolution is obviously increased but what really helps most is that screen is now really on top.


  • From the fast tests done until now, clicks and pops disappeared in the same conditions that caused them in the OG OP-1 (aka hard use of line input). I can’t say they have removed them completely, I just checked that they fixed the ones existing in the OG for my specific use.
  • New dimension synth and mother reverb sound very good.
  • Overall, audio quality has improved in more or less all aspects.


  • The sample zoom function is great to be precise. Maybe a little slow to move to a far position of the sample but maybe there’s some way to move faster.
  • I expect big firmware updates, regardless of fixes, there aren’t really many new things added. Stereo is a great addition but it’s not a new main function like more synth engines or more tracks.
  • I think they already prepared the GUI to handle longer/shorter tape durations, if not they wouldn’t show the 6min limit on each of the tape types (just guessing).


  • Still haven’t charged it even once. After test video, playing a little and full song, current battery is 81%, so pretty good for now.

My first impression:

Does it offer enough to justify the price? No, for me the physical aspect is slightly worse. At this price, “ok” is not enough in any aspect, so I’m not super happy with this (keybed basically).
Do I regret buying it? No. Despite the physical aspect, the most important for me was to see an improvement in both audio input and better sound quality in general, and this has improved.
Is it still fast and inspiring? Yes. It would be a problem if any of the improvements made it slower to make music, so this hasn’t changed.
I still think the OG is amazing and you can get similar results with some extra effort to sort out the issues, but if this your main device to make music it might be worth it.



Chase Bliss Thermae: The missing knob

This time what I wanted to do is create a Time knob for my Thermae pedal, the most wanted control missing in the Thermae due to being so small.

My solution uses Midi clock messages to set the wanted time.

The tricky part is the envelope trigger. Thermae doesn’t accept any midi command to restart the sequence, so the only way I found to sync the interval sequences my music was to engage the pedal just when audio is detected. This is especially useful to get more controlled results when recording for example.

This little box adds:

  • Time select knob, from a few ms to 1s (higher times are more useful with the tap tempo).
  • Two modes (selectable by the switches):
    • Time mode: Select the time with the knob
    • Trigger mode: Knob doesn’t work in this mode. The two buttons add or reduce input audio sensibility.
  • LED to check input trigger in trigger mode.
  • 3.5mm TRS input for incoming audio (trigger)
  • 3.5mm TRS output to connect to Thermae.
  • Toggle slow mode (only in time mode): pressing the two buttons

Midi CC messages:

  • Delay mode:
    • Send the value 248 (decimal) to channel midi #2 (Thermae default). Desired time / 24 is how often you have to send this data to the pedal so it can change the tempo.
  • Disable slow mode: CC #25 = 0
  • Enable slow mode: CC #25 = 127
  • Trigger mode (I ignore midi clock in trigger mode):
    • Disable midi clock: CC #51 = 0
    • Enable midi clock (delay mode): CC #51 = 127
    • Engage pedal: CC #102 = 127

When in trigger mode, I always suppose the pedal is in bypass (not engaged), so if audio is detected the engage pedal message is sent from the box to the pedal via midi.

The commuter is used to physically connect the input audio to the arduino internal analog/digital converter, which also will disconnect the knob in my case (easy fix is use a board with more ADC). Depending on the value read by this converter, we’ll trigger the engage the pedal or not. The LED allows to see easily if the signal was strong enough, but depending on the input instrument (in my case line-level keyboard) the threshold can be trickier to find. I have not tried it with guitars.

Hardware notes:

  • It is necessary an Arduino board with serial pins like UNO or in my case the nodeMCU, but there are many boards that would be ok: https://es.aliexpress.com/item/32824839148.html?spm=a2g0s.9042311.0.0.274263c0kSWu0n
  • Any push buttons or commuters will work, but need pull-up resistors or at least use the INTERNAL_PULLUP flag configured in the input pins of the program.
  • 3.5mm midi output jack is connected to the TX pin of the microcontroller via a 220ohm resistor.

Midi Wiring:

Thermae has a TRS connection. The pedal sleeve pin will go to our 3.5mm sleeve, ring with ring and tip is not connected (it is used for additional footswitch). Remember to use the 220ohm resistor from the ring to the microcontroller TX (transmit) pin.


I am working on improving some of the current drawbacks like having to choose either delay / trigger, and also the threshold select is not the most comfortable to use, but that will imply changing some of the current components.