I guess I’ve always noticed this to some extent, but now that I’m taking the time to look at it more carefully, all the pots on my two Mixup modules and my Outs module are noisy. When they are not passing audio, they are pretty much quiet when I turn them. But when they are passing audio, they are noisy. For the Mixups, the noise is especially apparent from around 2:00 to fully CW, and for my headphones out on the Outs module, it’s more apparent closer to fully CCW and fully CW. I tried using two pairs of headphones (monitoring both the headphone out and the main out). I’m also taking care to make sure I’m not clipping. It’s not really a loud crackling, more of a soft whooshing at times, other times more crackly, but never really horrible–which is probably why I kind of ignored it for so long.
So why is this the case? Can anything be done to fix it?
Note: On my Quad VCA, none of the attenuator pots have this problem.
Happy to send audio samples if needed.
PS: It’s only really audible with lower frequency signals like sine or triangle waves or filtered stuff.
What you are experiencing is the effects of listening to DC or signals with DC offset through potentiometers. The OUTs and Mixup modules have AC coupled inputs that help block DC but if you have low frequency, pure waveforms like Sine and Triangle (which are closer to being DC), it is very difficult to mask the effects of this. The reason this problem is more pronounced on Mixup and Outs vs. Quad VCA is that on Mixups and Outs the audio is going through a potentiometer, specifically audio is going through the wiper of potentiometer and this is always much more sensitive to DC. In contrast, the audio path on a Quad VCA is entirely through the VCA cells (and opamps) and the potentiometers only act as voltage controls of the vcas. This is a much better way to dynamically alter a signal without creating these sharper discontinuities.
Hello Intellijel, I thought I’d be bold and re-open this can of worms. I have continued using my Mixup modules, but for a song I made recently with a very “warm” (low-frequency) stereo signal, I was hearing the crackling a little bit when I was adjusting the volume with the Mixup live. As for your comment about using a VCA (which have opamps apparently) instead for live attenuation, the problem is that these are stereo audio signals I am mixing.
So I wanted to ask you all: If you don’t have a mixing module that will mix stereo signals with one control (knob) for each stereo signal that also won’t make this crackling noise, can you please make a suggestion, at the very least maybe offer a spec I should look for in an alternative? I don’t know what an opamp is lol but should I be looking for something like the Mixup that uses opamps instead of pots, if that even makes any sense?
It is super easy to make a stereo VCA. For example, on the Quad VCA, the CV inputs are normalled in a cascade.
So put your left signal in Ch1, right signal in Ch2, patch a single CV source to the first CV input and then make sure the CV attenuator is open the same amount for ch 1 and 2. Now one CV source is controlling both channels equally.
Ok but what if I simply want to control the volume of the stereo signal manually by turning a single knob? Pair it with a Triplatt or similar attenuator module with at least two channels?
I have this same experience using the 1u Stereo Mixer and the 1u Line Out modules. If the potentiometers cause the problem what’s the reason for them being there if the best method is to use VCAs, the crackling is causing me real issues.
I’m using a 62hp Palette so space is limited. In order to mix two stereo signals I have a 1u Stereo mixer whose outputs go into a 1u Line out and into my sound card.
Just came to say I use my 1u Stereo Mixer and Stereo Line Out constantly and happily. As implied above, potentiometers are great for set-level mixing, outputting final signal, attentuating a part while working on another, etc. You can also use them just fine for dynamic control on many sounds sources that don’t cause issue, though perhaps you wouldn’t experiment with a new sound in a live situation. The current HP width also works great since it can link with so many of the 1u tools.
VCAs are a better choice for dynamic “performance” mixing. I think maybe some brands package this as an “active mixer” but as detailed, it is super simple to do for stereo on a quad VCA. You could also mix two monos in 1u using the Dual VCA 1u channels with your favourite offset knobs.
Would the Mixup module have the same characteristics?
Also a I using the 1u modules in the best way, can the 1u Stereo Mixer go straight into my sound card or is it best to go from the 1u Stereo Mixer into the 1u Line out (which is currently connected to the palette jacks)
I’ve had issues with Mixup, Outs, and Multi FX. On both modules it appeared to be the stereo pots specifically that had the crackling/fuzzy “swooshing”. With the Multi FX, I could “shake it out” and it would go away but then it would always come back.
I have more recently had Stereo Out 1U, Headphones Out 1U, and Stereo Mix 1U and haven’t noticed anything.
I don’t feel this workaround should be necessary. Every other mixing device I have used in my life does not have this issue, not when working as intended/as new.
hi
IMO that is a perfectly reasonable expectation that it should either be made clear up front or simply work like other “mixers” for any signal that can be listened to. I would buy a v2 that cleans up DC crackle on any of the mentioned modules. To be fair though I have several other brands’ modules that do this under knob control …
With modular product lines there is inherent slice and dice and desire not to bury any potential functionality. So you might have a manufacturer with the philosophy “we don’t include vca components if it won’t have CV jacks” or “we don’t call it an active mixer if it is basically a generic VCA that can do much more”.
I have continued using my Mixup modules, but for a song I made recently with a very “warm” (low-frequency) stereo signal, I was hearing the crackling a little bit when I was adjusting the volume with the Mixup live. As for your comment about using a VCA (which have opamps apparently) instead for live attenuation, the problem is that these are stereo audio signals I am mixing.
