Sample Pitch Tracking Issues

[icedcreameyes]

I recently took delivery of a new bitbox mk2, I had previously owned the mk1 and decided to upgrade. I have noticed that when pitching a sample using the v/Oct setting for EXT1 I am getting a very noticeable portamento effect as the sample slides it's pitch between the notes. This is especially noticeable when pitching samples beyond a fifth.

I am able to get clean and precise pitch changes if I add some silence just prior to the sample but this obviously effects the timing of the trigger. I don't recall ever having this issue on my mk1. Playing samples melodically is a big part of what I'd like to do but this sound is not really usable to my ears.

I noticed that the latest firmware update mentioned an issue with the v/Oct setting that had been rectified, but my unit has not changed with this update.

When pitching samples via MIDI everything is ok but with CV and trigger signals it is noticeably slewing the pitch.

[Steve]

can you confirm that you are using the most current firmware? Which device are you using to send CV + Gate to the mk2?

[icedcreameyes]

Apologies for initially posting this in the wrong place, I didn't realise there was a specific MK2 forum

[icedcreameyes]

I'm running firmware 1.0.9 I have confirmed the issue while sending cv/gate from Mutable Instruments Marbles, Westlicht Performer and Monome Teletype.

I get really good tracking when using MIDI or the audio inputs to control pitch but the EXT inputs have a lot of glide.

I'm aware that the audio inputs offer better performance for v/Oct tracking but I remember the EXT inputs performing very well on my mk1.

[Aaron]

As you already know, on the MK2, In1 and In2 are much better for controlling audio. They are sampled at 48KHz and use 24-bit ADCs. The EXT inputs are 12-bit, use a much lower rate, and use averaging to clean up the values.

In other words, I'm not surprised the EXT inputs are less than ideal for pitch tracking. Please use them for gate or non-pitch related CV. Use In1 and In2 for 1V/Octave control of pitch.

[MattDrago]

Hey Aaron, is this pitch tracking problem going to be addressed in the next patch release? I've been using the Ext. Inputs for pitch tracking ever since I got it, but the slew has never really been a big problem for me.

[icedcreameyes]

Thanks for the advice.

Is this the same on the mk1 units? I'd never experienced this on my old bitbox and I didn't even know the audio input could be used for cv control so I'd never tried that.

[Aaron]

The MK1 doesn't have DC coupled inputs, so no it is not the same. It's possible the EXT inputs behave a little different. But, the are very similar.

[icedcreameyes]

That's disappointing, it's gonna be hard to use this with only 2 reliable pitch controls (which will also sacrifice recording). Thanks for your support and advice.

[rayultine]

this makes no sense. The ornament and crime CV input DACs are 12 bit and no one would use them if they slewed all over the place. Wouldn't stepped LFOs slew too? EXT inputs are useless if they can't even handle these simple cases.
icedcreameyes - you should post a video demonstrating this problem because I have never observed it.

[icedcreameyes]

I'll try and throw something together tomorrow to demonstrate.

[icedcreameyes]

Here is a video where I switch this same sequence between midi and cv via the EXT inputs. You can here some slewing on the bigger intervals.

https://www.dropbox.com/s/ybghxaryjc...35732.mp4?dl=0

[rayultine]

that's ... not even a fast or complicated sequence. You are 100% positive that Marbles is not slewing? Step knob is 100% clockwise?

[icedcreameyes]

The sequence is being provided by my Westlicht Performer not Marbles. Definitely no glide or slew is set.

[rayultine]

It's absurd that the EXT inputs can't handle that sequence

[icedcreameyes]

It's very disappointing, yes.