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Filter not closing all the way?

Filter not closing all the way?
« on: August 06, 2017, 07:09:24 PM »
I am having an issue with my rev2. I can only notice it when I'm listening with headphones, but if I initialize a new patch, and then close the filter all the way I still hear a faint sound. This is noticeable when playing pluck sounds because there is always a faint note ringing after the eg closes the filter. It's very annoying. Has anyone else noticed this?

Re: Filter not closing all the way?
« Reply #1 on: August 07, 2017, 08:41:03 AM »
I am also having this issue. I haven't tested it with any output other than than headphone out, but I definitely still hear the oscillators even when the filter is completely closed. Don't know what the deal with that is. I can't imagine that's how it's supposed to be.

Re: Filter not closing all the way?
« Reply #2 on: August 07, 2017, 09:06:35 AM »
Just adding to the choir here, I too hear a faint note ringing when the filter is closed!

Re: Filter not closing all the way?
« Reply #3 on: August 07, 2017, 09:28:24 AM »
Yes, this is correct and all our synths that use the Curtis chips behave similarly. The Curtis chips have about an 80db signal to noise ratio, so even when the VCA is closed it's possible to hear the oscillators in the background when no other signal is present. Fortunately, 80db below the primary audio output is so low it does not affect the signal quality under normal playing and recording conditions.
SEQUENTIAL

Re: Filter not closing all the way?
« Reply #4 on: August 08, 2017, 10:56:05 AM »
Is this something that is only noticeable, then, when listening through the headphone jack? Because it is *very* noticeable through there.

Re: Filter not closing all the way?
« Reply #5 on: August 08, 2017, 06:22:13 PM »
The headphone amp more gain than the main outs, and having a speaker directly on or in your ear makes most sounds more noticeable, so generally speaking the answer is yes. As already mentioned, you will not be able to hear the bleed separately from the program material when you are actually playing notes or sequences, and that includes the headphones. An 80db difference in gain is a very large difference.
SEQUENTIAL

Re: Filter not closing all the way?
« Reply #6 on: August 14, 2017, 11:22:14 PM »
However, with TETRA or P08, if you set the cutoff to zero, the main out sound will be almost inaudible.
Why does not REV 2 do so?
Prophet6, Prophet12, Prophet REV2, TETRA, PRO2, PRO3,  Moog Minitaur, Moog Mother32, Nord Lead 2x, YAMAHA EX5

Re: Filter not closing all the way?
« Reply #7 on: August 14, 2017, 11:43:58 PM »
After resetting the global parameter, it became normal by calibration.
However, as a whole the program has an unstable impression.
Prophet6, Prophet12, Prophet REV2, TETRA, PRO2, PRO3,  Moog Minitaur, Moog Mother32, Nord Lead 2x, YAMAHA EX5

Re: Filter not closing all the way?
« Reply #8 on: August 15, 2017, 03:28:51 AM »
I love my rev 2 especially because it's my first hardware Synth but my impressions regarding the program stability are also mixed. Yesterday I recalled the init preset and played around with the filter cutoff. When closing the filter (not to much) there suddenly was some crackling sound like little distortion. Levels on the output of the rev 2 and inputs on my interface are very conservative so no problems here. I had to restart 3 to 4 times and then it was gone again. My rev 2 is not for live use so no problem for me to restart a few times but in a life situation I guess it's not the best....
So yes, it's some kind of unstable...
IMac Mid 2013, Cubase 9Pro, Prophet Rev 2 8voice

Re: Filter not closing all the way?
« Reply #9 on: August 15, 2017, 10:22:48 AM »
The Rev2, like all our other instruments, is "stable" regarding the filter. Unlike most manufacturers, we don't limit the signal path much from the oscillators all the way to the output because often times things can break in "interesting" ways. In that way, the synth is capable of a broader sonic palette, but it also means the musician has to be more mindful of their settings.

Conversely, if you think you have an issue with your synth, please contact our dedicated support channel: support (at) davesmithinstruments.com

There shouldn't be any need to restart to "fix" an issue, and the Rev2 is 100% stable for live use.

SEQUENTIAL

Re: Filter not closing all the way?
« Reply #10 on: August 18, 2017, 12:11:03 AM »
In Prophet 6, when you set the cutoff to zero and set the key amount to Full, you can not hear the sound.
However, if you set the same setting on REV 2, you hear a sound from the main out as well.
Why?
Prophet6, Prophet12, Prophet REV2, TETRA, PRO2, PRO3,  Moog Minitaur, Moog Mother32, Nord Lead 2x, YAMAHA EX5

Re: Filter not closing all the way?
« Reply #11 on: August 18, 2017, 01:33:21 AM »
It's a different filter. The Prophet-6 filter is a discrete design based on the SSM 2040 filter whereas the Rev2 has a Curtis filter residing on a custom IC.
SEQUENTIAL

Re: Filter not closing all the way?
« Reply #12 on: August 18, 2017, 06:51:38 AM »
It's a different filter. The Prophet-6 filter is a discrete design based on the SSM 2040 filter whereas the Rev2 has a Curtis filter residing on a custom IC.

Thank you. I understood.
Is TETRA the same filter?
Similarly, TETRA sounds even when the cutoff is minimum.
However, the sound is smaller than REV 2.
Prophet6, Prophet12, Prophet REV2, TETRA, PRO2, PRO3,  Moog Minitaur, Moog Mother32, Nord Lead 2x, YAMAHA EX5

chysn

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Re: Filter not closing all the way?
« Reply #13 on: August 18, 2017, 08:07:28 AM »
Yeah. The DSI instruments with this filter are:

Evolver and all variants
Mopho and all variants
Tetra
Prophet 08 and all variants
REV2
Tempest, I think
Prophet 12, I think
DSI: DSM03; previously: Mopho Keyboard, Desktop Mopho, Evolver, DSM01
Hardware: Eurorack, Arturia MicroBrute
Software: macOS, Ableton, MuseScore2
Modular Grid: https://www.modulargrid.net/e/racks/view/354385
GitHub: https://github.com/chysn

Re: Filter not closing all the way?
« Reply #14 on: August 18, 2017, 11:43:44 AM »
Chysn is correct on the instruments list.

Even though our Curtis filter resides on an IC, it's still an analog filter so it's not uncommon to have some degree of variation between instruments.
SEQUENTIAL

Re: Filter not closing all the way?
« Reply #15 on: August 26, 2017, 09:05:46 AM »
because there is always a faint note ringing after the eg closes the filter.

Play with the VCA env a little more. With the sustain down and low release the sound should be cutting off 100%.

If you have interesting stuff going on in the EG on the filters and don't want to end the VCA so soon but don't want that sloping attack or decay, use the delay! I think this will get you where you want to go.

Underlying tone always present
« Reply #16 on: September 08, 2017, 05:15:33 AM »
Hi all,

While trying to program some sounds today I've found that my Rev2 is constantly kicking out an underlying tone under whatever patch I try to make, or edit. For example, say I've programmed a short pluck sound, if I hold the note there's a sustained note below it that keeps playing until I release the note. This is the same on EVERY patch, and is preset ata ll times when playing.

Is this normal? I'm attaching a recording so you can see what I mean. I've used a factory sound so anyone here can compare if need be. I used F1 P25 - PlushPluck. This is an unedited factory sound, and this same sound below the actual pluck is present in every sound on my board.

This is just something I've noticed today - I don't recall having this problem before, but I've only really just got into programming new sounds today, so who knows.

**EDIT** I should also add that this is also present on patches set to UNISON. The patch itself plays in unison fine, but beneath it is this same sound, in poly mode.

It seems abnormal. Why would you want an underlying sound playing while trying to play a totally different sound?

Any thoughts would be much appreciated.

Martin
« Last Edit: September 08, 2017, 05:31:01 AM by martinlroberts »

Propheteer

Re: Underlying tone always present
« Reply #17 on: September 08, 2017, 07:07:32 AM »
well that preset is a stacked sound, and layer A and B have the sustain env (amp and filter) not at zero so will hold a note while the key is held! dial sustain down then hit 'edit layer b' to remove the sustain on layer B also.

If you've been using this as a starting point for your own sounds that could be why, and no it isn't normal to have a sound just there, it was specifically programmed that way.

Try programming your own sound from scratch (hold octave up/down + hold to make a 'basic program'), dial in a patch (non stacked mode) and test it, should be fine!

I can't comment on what you mean by 'on every patch' as the patch you used to demonstrate is just programmed that way (normal).
« Last Edit: September 08, 2017, 07:18:54 AM by Propheteer »

Propheteer

Re: Underlying tone always present
« Reply #18 on: September 08, 2017, 07:12:03 AM »
.. also in case you didn't know, hold down edit layer b button until it flashes so you can control both sounds at once, dial in your env there (move the amplifier sustain knob down to zero - increase the decay a bit and up the filter sustain) and you should get a normal pluck/bass sound with no underlying/held note. If your synth does that ok then it's just a patch thing not a synth fault.

Re: Underlying tone always present
« Reply #19 on: September 08, 2017, 07:46:55 AM »
Thanks Propheteer.

What I mean by "every patch" is it is happening on literally EVERY patch. User, factory... All of them. This patch was only used as an example because it was a short pluck sound so you could hear the other underlying note, but this is on every patch, whether it's a stacked patch or not.

Also, as above this also happens on patches that are set to Unison, so therefore should be monophonic. This isn't the case, and this underlying sound is still polyphonic, and not in Unison mode, when playing.