CV outputs: unwanted slew!!

[Dragulasbruder]

A friend lent me his BSP for the week to see if I liked it and wanted to buy it. He's all MIDI, and I wanted primarily to use it to control my Eurorack modular synth.

Everything worked great except for one crucial function--the CV out. There's a really super-fast slew (or glide/portamento/slur call it whatever you want) when I program in any kind of stepwise jump that's bigger than a fifth. I suppose it's always there but the distance is too short for me to notice when I program smaller intervals. Once you start programming notes an octave or more away, it gets very noticeable and very, very annoying. If I wanted portamento, I'd patch it.

I've tried it with mutiple power sources, I've tried all manner of gate lengths from zero-tie. Does it every time, on both CV outputs. Has anyone had a similar problem? Were they able to solve it? I was considering reinstalling the firmware and seeing if that helps. Anyone else have any ideas?

[vykaar]

Yes I posted about this a while ago and assumed it was just my problem as no one replied - so I removed the post . I don't think reloading the firmware will do anything as this is probably a hardware design limitation ? 

[Dragulasbruder]

I doubt they would have released the product with a flaw like this. I've combed the internet for other people having the same problem and so far it's only been you, me, and a guy with a youtube video about it. Seems like a problem with individual units?

Any moderators/Arturia staff care to chime in?

[Dragulasbruder]

And vykaar, what did you do to try and resolve the problem? As you're still on the board, I assume you found a way to make things work?

[vykaar]

I did not find a solution ( many people would not detect that fast glide but I bet all BSPs do it) and now use it midi only and mostly for drums and midi control.

[wartaler]

So you're saying that contol voltage transitions are slow enough to hear them as a quick slide*.
I usually have some sort of envelope or gate, so I wouldn't have noticed, I will check again later. Whatever you use to translate MIDI > CV is fast enough apperently (?)
So I guess it can't be the response of your VCO right? I bet most VCOs can be controlled at audio rates (like FM stuff) anyway -


*(without using the Slide option of course)

[vykaar]

Yes it sounds like a bird like chirrup sometimes before the note.

[Dragulasbruder]

So you're saying that contol voltage transitions are slow enough to hear them as a quick slide*.
I usually have some sort of envelope or gate, so I wouldn't have noticed, I will check again later. Whatever you use to translate MIDI > CV is fast enough apperently (?)
So I guess it can't be the response of your VCO right? I bet most VCOs can be controlled at audio rates (like FM stuff) anyway -

No, I tried every VCO I own, including a digital model that should have no sort of tolerance to its response at all.

Vykaar is spot on, it sounds like a bird chirping on each note attack. Also, I'm not using a MIDI-CV interface with the BSP at all. I do have a MIDI-CV converter, and have zero problems with pitch from it. I bet if I used MIDI from the BSP to control it, it would be fine. But I didn't get the BSP to talk to my MIDI box, I got it to sequence two more voices beyond what I can do as it stands--and the bird-chirp is not really acceptable unless I'm using a longer attack--it certainly can't do 16th notes at 140 bpm without some very noticeable slide

[Dragulasbruder]

update: I have used every firmware revision on it now, it is definitely not a firmware problem. After more tests and general horsing around, I've concluded that the slew is happening all the time, it's just more noticeable on octave jumps. What's more, it's way more discernable when the pitches being sounded are high. And I don't mean that it's just when notes are programmed high, though. For example, I could write a sequence from C-2 to C0, and I wouldn't be able to hear the slew that much if I tuned the oscillator to the notes being programmed. But if I tuned the oscillator up to C6, you could still hear the slew. It's the same with every oscillator I own, from a digital Synthtech E350 to analog Bubblesound vcob, to Intellijel Dixie. Same with temperature-compensated OTA filter. Even happens to Arturia's own Microbrute.

Please, will someone at Arturia let me know what's going on? Is it a problem with my unit or is this problem endemic to all BSPs? I've written to tech support and gotten no answers either.

[klstay]

Any further word on this? This is possibly a power related issue more than firmware. Transitioning a CV from one setting to another as close as possible to "instantly" without drooping any of the other signals in your setup is a matter of a good power supply in the "real" modular world. Precise CV is as much a challenge as anything else in circuit design.

[vykaar]

I hope this can be resolved by a firmware update.
Here is a short video showing the glide between notes.
https://youtu.be/Yglt0CLl1gY

[Dragulasbruder]

I hope so too, very disappointing that there has been no response from Arturia on this issue. I sold mine to someone who only needed to use it for MIDI. I'd buy it again in a heartbeat if the CV problems were fixed.

[vykaar]

I sold my first BSP because of this fault but bought another at a good secondhand price because I liked the random midi control of drum patterns and use it as a midi controller for my old Doepfer maq16/3 - both BSPs I have owned have had a slow CV pitch transition which causes a very noticeable fast glide on double octaves - midi out of bsp via kenton midi to cv = no problem.
If it is not caused by slow demultiplexing of the CVs I suspect the glide circuit capacitors could be removed if it is done in the old analog way... Loss of a function for the sake of crisp pitch transitions.
I would add a switch to mine if that would fix it but lack of schematics means this is all conjecture. This is such a useful tool and it is frustrating that it is still not all finished. Love to Arturia for your constant creativity however...

[I grec]

Hi guys,
Just wanted to know if the issue is still there with the latest firmware.

Regards,
Y.