Author Topic: TX81z W1-W8 + Feedback Waveforms .txt Download  (Read 139 times)

prephylve1

  • Team member
  • *
  • Posts: 2
    • View Profile
TX81z W1-W8 + Feedback Waveforms .txt Download
« on: November 18, 2017, 01:58:12 AM »
Many people have asked for feedback as an option and compared the PFM2 to Yamaha synths like the TX81z. While this is a completely different instrument I thought it might be interesting to add waveforms from the TX81z and varying feedback levels for each waveform. This took a very long time to get right. Considering the TX waveforms are 4096 samples and the PFM2 has a max 1024 samples they aren't 1:1 but sound basically the same.

The feedback levels only start getting interesting at higher levels. Looking at the waveforms in an oscilloscope I noticed feedback acts a little like a wavefolder + distortion. The highest feedback level without distortion  is level 5. I've included 3 versions of the waveforms. One set without feedback, another set at level 5 feedback, and a final set at level 7 feedback.

Each waveform was recorded in Reaper at 48k 24bit around 46.87hz or F#1 tuned sharp. One cycle at that frequency gives you exactly 1024 samples. I had to fix one of the waveforms at feedback level 7 because it was incredibly unstable and would not stay in tune. Very analog like!

All waveforms are included in the zip file with images that show each waveform.

Enjoy!  8)
« Last Edit: November 19, 2017, 02:23:36 AM by prephylve1 »

alien_brain

  • Team Member
  • **
  • Posts: 88
    • View Profile
Re: TX81z W1-W8 + Feedback Waveforms .txt
« Reply #1 on: November 18, 2017, 06:48:15 AM »
thank you!

observer

  • Team member
  • *
  • Posts: 8
    • View Profile
Re: TX81z W1-W8 + Feedback Waveforms .txt
« Reply #2 on: November 18, 2017, 12:57:04 PM »
wow, very nice! can't wait to try these out!

thanks a million!  8)

matrix12x

  • Team Member
  • **
  • Posts: 54
    • View Profile
Re: TX81z W1-W8 + Feedback Waveforms .txt
« Reply #3 on: November 18, 2017, 01:35:51 PM »
@prephylve1 thanks!

Xavier

  • Administrator
  • Hero Member
  • *
  • Posts: 1234
    • View Profile
Re: TX81z W1-W8 + Feedback Waveforms .txt
« Reply #4 on: November 18, 2017, 03:56:10 PM »

Great work !  :)
Thanks.

feijai

  • Team member
  • *
  • Posts: 25
    • View Profile
Re: TX81z W1-W8 + Feedback Waveforms .txt
« Reply #5 on: November 18, 2017, 07:04:04 PM »
Many people have asked for feedback as an option and compared the PFM2 to Yamaha synths like the TX81z. While this is a completely different instrument I thought it might be interesting to add waveforms from the TX81z and varying feedback levels for each waveform. This took a very long time to get right. Considering the TX waveforms are 4096 samples and the PFM2 has a max 1024 samples they aren't 1:1 but sound basically the same.

I was looking for exactly this today.  However I'm a bit confused with the screenshots of the waveforms WITHOUT feedback.  The eight waves are just made up of pieces of cosine quadrants.  Waves 1 and 5 look basically right, and waves 3 and 7 look *roughly* like Yamaha claimed.  But waves 2, 4, 6, nd 8 look quite wrong.  Do you have any idea why this might be?  Was Yamaha's DAC that bad?

prephylve1

  • Team member
  • *
  • Posts: 2
    • View Profile
Re: TX81z W1-W8 + Feedback Waveforms .txt Download
« Reply #6 on: November 19, 2017, 10:24:12 PM »
I was looking for exactly this today.  However I'm a bit confused with the screenshots of the waveforms WITHOUT feedback.  The eight waves are just made up of pieces of cosine quadrants.  Waves 1 and 5 look basically right, and waves 3 and 7 look *roughly* like Yamaha claimed.  But waves 2, 4, 6, nd 8 look quite wrong.  Do you have any idea why this might be?  Was Yamaha's DAC that bad?

There is nothing wrong with the waveforms.

As is often the case the purpose of a waveforms graphical representation is not an exact image of the true waveform. For instance on the Waldorf Blofeld the "sawtooth" wave is actually a ramp and the trough is curved. Similarly the "sawtooth" wave of the Dave Smith Mopho looks more like the tooth on a chainsaw.

Please look at the image I attached to see the examples I gave.