Hydrasynth Analog Feel Analysis and Vintage Voice Variances
Vintage voice variances on the Hydrasynth, Explorer and Deluxe
Firmware version 2.0, released in March 2023, introduced some new VoiceMod features and functionality that allows Hydrasynth to now do vintage voice modeling.
Per voice variances are a key aspect of the organic, realistic analog poly synth sound. Small offsets to oscillator tunings, filter parameters, envelope timings, lfo rates and other attributes can turn a harsh, technical digital sound into a lush, organic analog sound. The previous version of Hydrasynth firmware had the Analog Feel control, but there are various reasons why it was not well suited to getting a realistic vintage analog poly sound. However, the new VoiceMod table functionality, combined with the associated Mod Matrix sources, allow Hydrasynth to get very good vintage voice variances.
In the final part of this video, starting at 7:54, the Analog Feel control is discussed:
Analog Feel Issues
Hydrasynth has had the Analog Feel control since the original firmware. We have analyzed it in depth, to determine how it works. While it is set up in a good conceptual way, with separate intonation based tuning offsets to each oscillators frequencies and filter cutoff, there are several factors that make the Analog Feel not ideal.
Firstly, Oscillator two and three are collated with negative offsets as you go up the keybed, but oscillator one is inversed, with positive offsets going up. They should all be aligned with the same polarity, but different values in order to be more usable up and down the keybed. As-is, you can dial in a larger amount of Analog Feel to get a good desired character in the middle of the keybed, but when you play up a couple octaves, or down a couple octaves, you will get highly dissonant sounds. This is due to Osc 1 having a different polarity of note num offsets, leading to extreme phasing.
Second, the overall amount of offsets is very high. If you measure up from the pivot note (which is by the way different per oscillator - which is good), you will get tuning variances of almost -20 cents per octave on Osc 3. That is extreme, and way beyond anything we have ever measured on vintage analog synths. Up four octaves, that's about a -80 cent offset, which just results in crazy dissonance. This makes it so that the real, usable range of the Analog Feel control is like 25% of its total throw.... if you want a realistic vintage poly synth type of performance like MemoryMoogs, without sounding broken. The max variances to filter cutoff are also high, and create a lot of dissonance when using a higher amount of resonance.
Third, the Analog Feel control doesn't affect Envelope ADR timings, which is one of the key aspects to vintage organic poly synth sound.