Source Audio C4 Modular Synth Pedal

Discussion in 'Effects, Pedals, Strings & Things' started by rsmith601, Feb 16, 2018.

  1. Quatschmacher

    Quatschmacher Member

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    I thought not at first but have gone back to some earlier patches and there does seem to be something. I’m getting the double triggering of some envelopes. I’ll see if I can narrow it down to particular shapes.

    Actually, the manual also refers to control knobs 1 and 2 so users will have no clear indication of which knobs are the assignable ones. (I presume it’s the lower two as it is on C4, but it’s not clear.

    @rsmith601 just tagging you in case you overlooked the first point in this post - I realise things have been hectic for you.
     
  2. Intrglctcrevfnk

    Intrglctcrevfnk Supporting Member

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    Forgot about that. I am getting double triggers also. Sometimes on the beginning of a note, sometimes as it’s ringing out. Seems to happen on the ring out on synth patches, mostly on lower register notes (bass guitar). Thought it might be fret buzz overtones but my Lakland’s action isn’t really low enough to cause that...
     
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  3. rsmith601

    rsmith601 Vendor

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    Jesse and Nathan not seeing any changes and have looked carefully.
     
  4. rsmith601

    rsmith601 Vendor

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    Assuming you mean knob assignments in Spectrum here?
     
  5. Quatschmacher

    Quatschmacher Member

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    Yes, sorry, I meant the Spectrum knobs and manual description.
     
  6. Quatschmacher

    Quatschmacher Member

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    Could it be something to do with a sound that has a relatively short envelope decay time such that the envelope has fully run its course but the instrument’s note is still ringing out and causes the envelope to trigger again due to its still being at a volume above the triggering threshold?
     
  7. rsmith601

    rsmith601 Vendor

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    Please send me a very clear PM and perhaps a preset so we can try to see what you are seeing. We have spent lots of time on this and don't see anything.
     
  8. Quatschmacher

    Quatschmacher Member

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    OK, I’ll have a look tonight when I’m back home.
     
  9. Quatschmacher

    Quatschmacher Member

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    @rsmith601 in a future update would it be possible when adjusting the sensitivity knob on C4/Spectrum for the larger LED to flash when the peak has been reached in the way that it does when setting the input level?
     
  10. cocobinga

    cocobinga Member

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    Would some courageous person please make a preset or two for No Doubt's Hella Good? Mainly the sequenced parts.
     
    Last edited: Aug 20, 2019
  11. Auger64

    Auger64 Member

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    I must be doing something wrong as I can't get the LED to flash when setting the input level. Could my guitar be super low output that it never reaches the optimal setting?
     
    Last edited: Aug 20, 2019
  12. rsmith601

    rsmith601 Vendor

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    We need to go into a period of infrequent new features and firmware. Lots of changes to firmware introduces risk and potential preset incompatibility. Not good!
     
  13. rsmith601

    rsmith601 Vendor

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    We were able to do the MF-101. The others use C4 exclusive features and we wasted precious time figuring this out.
    The compatibility between these pedals is not something most companies would do. Don't make me regret it!!
     
  14. Quatschmacher

    Quatschmacher Member

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    Thanks!

    Oh, really? If so, I’m really sorry about that. I only used octave and distortion in the other presets I asked you to convert so could’ve sworn they were compatible. Presumably anything that used monophonic pitch down one octave on voice 1 or 2 would need to have been made into octave 1 and 2 (voice 3 and 4) on the Spectrum. But looking at the presets, I can’t see how these can’t be created on the Spectrum editor. What am I missing?
     
  15. anxiousmofo

    anxiousmofo Member

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    You are not alone on that one. My strat doesn't register.
     
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  16. Quatschmacher

    Quatschmacher Member

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    I should’ve qualified that request. I didn’t mean an immediate update; it was more of a feature request for whenever.

    By the way, I noticed that Spectrum has the ability to assign both envelope speeds, both filter frequencies, both filter Qs simultaneously to a single knob in each instance, and Lo retain. Are these coming to C4 too or are they Spectrum only due to its having more processing blocks left? If these aren’t coming to C4, what will become of having all Spectrum presets be loadable onto C4?
     
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  17. rsmith601

    rsmith601 Vendor

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    Some folks asked for this. I will improve the formatting later.

    ENVELOPES IN THE C4

    8/19/19

    The Source Audio C4 Synth pedal has two envelope followers available. They both have the same capabilities, but their control parameters may be set differently. Input 1 or input 2 may serve as the input signal to either. An envelope follower uses its audio input signal to output a representation of how loud the audio is at the moment. Louder signals get a higher output level from the envelope follower.

    Since the audio signal goes both positive and negative, we first take the absolute value of the audio; negative values are replaced by the same number, but made positive. A certain amount of smoothing is necessary, because the input signal will repeatedly go to zero, but at a rate which we don't perceive as a level change, since it is happening too fast for us to hear like that. Deliberately introducing a slower than necessary smoothing will cause the output to move more slowly than the actual audio signal changes. Different smoothing rates for attack (a rising output) and decay (a falling output) permit more control over the final response.

    Whereas a typical synthesizer has a controllable release time on its envelopes (which begins when one takes their hand off a keyboard note), we have the problem that the guitar sound is over when a note is through. A synthesizer oscillator would still be running, but the pitch detector output tends to lose it as a note is dying away, so the synth oscillator is also not reliably available after note end. So our final release times are always quite short.

    We also offer ADSR type envelopes (attack – decay – sustain – release). The attack segment begins when an attack threshold level is exceeded. When the envelope level gets to 1.0 (full scale ON), the decay segment takes over, dropping until the sustain level is reached. When the input gets below a release threshold, we go into a (fast, as always) release segment. These threshold levels are fixed. One more reason to do the Input Gain Calibration procedure, to make sure your guitar signal is in the proper range, for the fixed thresholds.

    All of these possible envelope controls are not brought out to the user interface. This is partly due to trying to save bits in the preset data (and if you had asked me 50 years ago whether saving bits would still be a thing in 2019, I would have laughed), and also to keep the complexity down. Reasonable people may disagree that boiling down a lot of controls into only a few, with a selection of envelope types, is really simpler. But that's the way it is.

    The Envelope Type definitions:


    The Speed control goes from 0.0 to 1.0, for both Attack and Decay times. This is translated to the following range of what are called "time constants". (After one time constant, a decaying signal has dropped to 36.8% (or -8.7 dB) from its starting value.)



    The Fast-Attack number controls exactly how fast the initial attack can rise. 1.0 is instantaneous; 0.5 is the fastest used. Most are considerably slower. The ADSR envelopes do not use this control.

    Sustain is the ADSR sustain level. Most are 0.0, with two at 0.2.
     
    Last edited: Aug 20, 2019
  18. rsmith601

    rsmith601 Vendor

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    Yup, compatibility was a bad idea!! :)
     
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  19. rsmith601

    rsmith601 Vendor

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    I think Jesse said there was envelope use in the voices.
     
  20. Quatschmacher

    Quatschmacher Member

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    I have reconstructed 1 of the ones I sent on the offline Spectrum editor. I have also reconstructed another that @jibreel thought he’d converted but it seems something went awry. I can’t see anything in the other two that shouldn’t work so I’ll reconstruct those too.

    I’ll PM you with screenshots and the values written in for ease of programming.
     
    jibreel likes this.

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