Steel drum patch?

[LoboLives]

I’m having a difficult time trying to recreate, what sounds like to my ears, this steel drum type patch on my Prophet 6. It’s the lead arpegiated bell type tone which was originally done on the Prophet 5. Anyone have any suggestions?

[jdt9517]

It's been decades since I had my P-5, but if I remember right you have to use the poly mod to create a ring modulated sound.  Steel drum, marimba, etc., are all essentially the same basic patch.  The short sound is created by a short decay of the ADSR to the cutoff filter with almost no sustain.  Steel drum has a short, but noticeable release in the VCA.

[LoboLives]

It's been decades since I had my P-5, but if I remember right you have to use the poly mod to create a ring modulated sound.  Steel drum, marimba, etc., are all essentially the same basic patch.  The short sound is created by a short decay of the ADSR to the cutoff filter with almost no sustain.  Steel drum has a short, but noticeable release in the VCA.

I figured it would be a short decay on the ADSR. I thought maybe the ring mod sound came from the sync oscillator option. I just can’t seem to get it right.

[Paul Dither]

A steel drum was part of the later revision's 120 factory patches. The patch was stored as preset 8 in bank 3. Audio example: http://www.synthmania.com/Sequential%20Circuits%20Prophet-5%20(Ver.3)/Audio/Factory%20Patch%20demos/File%203%20Programs/38%20Steel%20Drums.mp3

According to this archive (https://sites.google.com/site/klmar016/home/synth/prophet5), the settings on the Prophet-5 were as follows:

[LoboLives]

A steel drum was part of the later revision's 120 factory patches. The patch was stored as preset 8 in bank 3. Audio example: http://www.synthmania.com/Sequential%20Circuits%20Prophet-5%20(Ver.3)/Audio/Factory%20Patch%20demos/File%203%20Programs/38%20Steel%20Drums.mp3

According to this archive (https://sites.google.com/site/klmar016/home/synth/prophet5), the settings on the Prophet-5 were as follows:

How would I approximate the oscillator frequencies from the P5 to the P6? Like what would 79% be exactly?

[jdt9517]

I don't think there is any exact conversion factor.  I think it would be safe to look at it as a ratio.  79/49 is about 1.6:1.  A 2:1 ratio would make the 2nd osc one octave higher than the 1st.  So, as a starting point, I would put osc 2 about a minor 6th higher than osc 1 and work from there.  That also jives with my dim memory of tuning using the poly mod from back in the day.  It won't be a "perfect" minor 6th.  It will need to be detuned from there to get the ring mod sound. 

[Paul Dither]

A steel drum was part of the later revision's 120 factory patches. The patch was stored as preset 8 in bank 3. Audio example: http://www.synthmania.com/Sequential%20Circuits%20Prophet-5%20(Ver.3)/Audio/Factory%20Patch%20demos/File%203%20Programs/38%20Steel%20Drums.mp3

According to this archive (https://sites.google.com/site/klmar016/home/synth/prophet5), the settings on the Prophet-5 were as follows:

How would I approximate the oscillator frequencies from the P5 to the P6? Like what would 79% be exactly?

The values on the sheet are in the range of 0-127, so 79 means 79/128, not 79%, so rather roughly 62%. The oscillators of the Prophet-5 have a full range from C0 to C9. The VCO frequency knob allows for dialing in frequencies over a range of four octaves in semitones, which makes for 49 steps (I don't know at what C this range starts). 62% of that range would be roughly around 30, which should equal the 3rd F you can dial in from the four octave range via the VCO frequency knob.

[LoboLives]

A steel drum was part of the later revision's 120 factory patches. The patch was stored as preset 8 in bank 3. Audio example: http://www.synthmania.com/Sequential%20Circuits%20Prophet-5%20(Ver.3)/Audio/Factory%20Patch%20demos/File%203%20Programs/38%20Steel%20Drums.mp3

According to this archive (https://sites.google.com/site/klmar016/home/synth/prophet5), the settings on the Prophet-5 were as follows:

How would I approximate the oscillator frequencies from the P5 to the P6? Like what would 79% be exactly?

The values on the sheet are in the range of 0-127, so 79 means 79/128, not 79%, so rather roughly 62%. The oscillators of the Prophet-5 have a full range from C0 to C9. The VCO frequency knob allows for dialing in frequencies over a range of four octaves in semitones, which makes for 49 steps (I don't know at what C this range starts). 62% of that range would be roughly around 30, which should equal the 3rd F you can dial in from the four octave range via the VCO frequency knob.

I'll give it a shot thanks. I always find it difficult to determine what frequency I should use when trying to recreate an original P5 patch on the P6.

[Paul Dither]

I'll give it a shot thanks. I always find it difficult to determine what frequency I should use when trying to recreate an original P5 patch on the P6.

One more correction, as it makes more sense to follow the approach of jdt9517. Let's assume the frequency value of 49 for oscillator 1 would equal the default C2 (= 65,4064 Hz), then multiplying it by 1.6 in order to get to 79 would lead to roughly 105 Hz, which is a tiny bit more than G#2 (103,826 Hz). Also consider some compensational tuning for both oscillators, as positive amounts of FM can cause a pitch shift upwards. And also consider that the PolyMod intensity is much stronger on the Prophet-6, so you'll need a much lower amount than the one on the sheet suggests.