iPad Scaler 2 + Cubasis 2 Tempo bug

This is a bit of a weird one. I added an instance of Scaler 2 to a track in Cubasis 2 on the iPad. The Cubasis project tempo is 120 BPM and Scaler shows that BPM but the performances play back at a higher tempo, maybe 10% or 20% too fast. It’s completely consistent. I even tried starting with a blank Cubasis project and just added one track with Scaler 2 on it. The weird aspect is that if I load up the “Lite” version of Scaler 2 the tempo is spot on!

I’ve found a reference to a similar problem with Logic that said the cause was the 48 kHz sample rate but my iPad is fixed at 48kHz and cannot be changed. Is this a known bug? Is there a workaround (apart from using the Lite version)?

Scaler 2 and Cubasis 2 versions are latest. iPad is 9th Gen. iPadOS is version 17.1.2

Im not sure what is going on here but clearly a sample rate issue. We don’t have a problem in Cubasis 3 but maybe there’s something going on between apps on your pad causing a sample rate conflict?

Thanks Davide. It seems you can’t change the sample rate on this generation of iPad hardware unless you use an external audio interface. The internal rate is locked at 48 kHz.
Having investigated further it seems the problem is not unique to Cubasis 2. I get the same problem in Drambo. In both cases changing to the “Scaler 2 Lite” version of the app works fine. Cubasis and Drambo both work fine with other plugins that sync to tempo. Other apps such as Beatmaker 3 and Nanostudio 2 do not exhibit the problem so there is something odd going on. I tried to test it in iMPC Pro 2 but I couldn’t figure out how to enlarge the Scaler 2 plugin to make it usable. I can’t test it in Cubasis 3 - Steinberg opted not to provide any upgrade path from Cubasis 2 so I opted to not give Steinberg any more of my hard-earned cash! (perhaps a lesson for any company that might be planning to release, say, Scaler 3 on iOS…)

Can you draw any conclusions from the fact the the Lite version of Scaler 2 works OK in all instances?
Is this something you’d hope to fix in a future release?

@Tristan Can you see if you can find anything on our end. Everything seems fine for me. @boingy Is it pitched up or is it just the tempo that is different, the latter would mean it’s not related to sample rate. Also have you tried running through AUM or Audiobus as a process of elimination?

OK, more info. It’s not pitched up but the tempo is faster and I can confirm that it is related to sample rate. Below is a screenshot of Cubasis 2 with two tracks. Track 1 is loaded with Scaler, Track 2 is loaded with ScalerLite. The sample rate is 48kHz. Both instances of Scaler are set to C Major Scale with Performances ON and set to “Common Performances/Basic Perf 1”.

I’ve recorded the MIDI for a couple of bars for each instance, just holding the C Maj pad. In the screenshot you can see that track 1 runs faster than the beat whilst track 2 stays bang on.

Now the sample rate bit. I’ve discovered that if I plug in my wired earbuds that have a built-in mic the sample rate changes to 44.1kHz. This does not happen with my wired earbuds without a mic. These are not fancy USB or Lightning things. They just connect to the jack socket so it’s a bit of a surprise that the sample rate changes. But it does give me a way to change the sample rate and Cubasis updates the rate on the fly when the devices are plugged and unplugged. With the 44.1 kHz earbuds connected track 1 is bang on tempo. With the 48 kHz earbuds connected (or with nothing connected) track 1 tempo is higher than it should be.

Audiobus discussion about sample rates is here: More new iPad woes... Can’t switch AUM from anything but 48K sample rate... — Audiobus Forum

So my workaround is to either use ScalerLite or to use my rubbish $1 microphone earbuds for tracking then switch to my decent earbuds after I’ve rendered the MIDI.

None of this explains why ScalerLite works correctly regardles of sample rate or why other plugins are not affected in the same way (I used PlayBeat 3 as a reference) so it’s probably something you folks should dig into a little deeper but I’m happy for now.

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Hi @boingy, not sure what I can add I’m afraid. We’re running Cubasis 3 on iPadOS 17.2 here and I’m not seeing any tempo issues. Both Scaler 2 and Scaler 2 Lite are steadily following the host tempo. I have no external hardware connected and sample rate is indeed at 48 Khz.

I don’t have Drambo however I tried the same scenario in Logic Pro and again both Scaler 2 and Scaler 2 Lite are running perfectly in sync.

Do you have any other hardware attached? The only other variables I can think of are the iPad versions (we’re using an iPad Air 4th gen) and the fact that we’re on Cubasis 3.

Thanks @Tristan.
No external hardware. No other apps running in the background.
It’s just one of those odd ones I guess - some strange interaction between Cubasis and Scaler. If you wanted to look at it I would suggest focussing on the code differences between Scaler 2 and ScalerLite 2 because the latter does not exhibit the fault.

I don’t believe the problem existed on my previous iPad (6th Gen) with Cubasis 2 but I no longer have that iPad and it was probably an earlier version of Scaler 2 (and I’ve no idea what sample rate that would have been running with). I’ve no plans to upgrade to Cubasis 3 so I’ll stick with my two workarounds described above.