Anyone using Amplitube Leslie with B5?


I bought Amplitube Leslie to use specifically with B5 but I’m experiencing periodic large spikes (and accompanying crackles/dropouts). The Profiler shows occasional random readings of up to 230% though mostly it’s around the 95-110% mark. Sometimes Profiler shows that UVI is the higher reading but when Amplitube is not in use the B5 behaves itself very well, especially since Acoustic Samples reduced the cpu overhead dramatically.

Is anyone else here using this combination (which incidentally - apart from this particular issue - works brilliantly? Anyone found similar results? For some reason it’s worse with ASIO4ALL than with the UR22’s own driver.



New Leslie Vst from IK Multimedia

I have the T-Racks Leslie and tried it with B5 on ASIO4ALL. The highest load I got was 63%. From what I understand, it is the same as the Amplitube version, except the graphics are much more substantial in Amplitube, which I assume would cause a higher load. Also, I can run T-Racks plugs separately. Correct me if I am wrong, but I think you have to run Amplitube to get to it’s Leslie plug. That would also cause more load than mine.


Thanks for the reply. Amplitube runs as a vst plugin and the Leslie amps/cabs are loaded into that. This morning it ran for five minutes of playing before it went a bit wild with overload! I did wonder if it’s to do with Amplitube’s graphics. Below are a couple of Profiler snapshots. I’ll download the demo of T-Racks and see if that solves the issue.


Just a thought - can I run AmpliTube outside of Cantabile and send the B5 signals to/from it? I know that should still use the same amount of cpu but maybe it’s worth a try. Not sure how to do this though.


It can be done, but I personally would try to correct the problem in C3, instead of using another program to rewire everything. C3 is not the culprit. Not knowing your setup, and looking at your examples, I would load Amplitube plugin (no rack), and B5 plugin (no rack), and simply route them together, and try it that way first. (going back to basics). See what your load does with just those 2 plugs. In your screenshots, your strings are maxing at 86% and B5/Amplitube rack is maxing at 111%. Also, just as an experiment, run your buffer at 512 instead of 192. You may experience some latency, so back it down from 512 if needed. I was able to get my backup laptop to perform properly by increasing buffer and modifying C3 engine options. I am, by far, no genius at this, but I know by simplifying, and using tools within C3, I was able to get reasonable results. I found less cpu hungry plugs the key for smooth live performance, and I didn’t have to sacrifice great sounds to do it.

PS: I liked the T-Racks Leslie. Very nice for smooth, laid back sounds. However, I think the Leslie in B5 is just as good, and provides better dirty sounds. If you have VB3, try it thru Amplitube Leslie. Very nice.


Back to basics it is! New song, B5 into Amplitube Leslie and 512 buffer (actually I don’t feel there is a latency issue with this setting). CPU down to normal levels, showing between 16-28%. In Profiler I see occasional UVI (B5) momentary spikes of 50-60%, sometimes Amplitube 45-50%. Normally not at the same moment but even when it is it’s never a combined total of more than 100% and no glitches are audible. I added in my Lounge Lizard Rhodes and the cpu usage stays low. So far no nasty glitches and the sound of the B5 with the Amplitube Leslie is excellent. I use it for solo organ rather than in a mix situation so the quality is very important (and I have a real B3/Leslie to compare it with).

Next I’ll go back to my original setup and see if I can discover where the problems are occurring. I can also keep adding in plugins to the new song and see what happens.

Incidentally, I was using my Leslie 147 with the B5 but was looking for a way to use my smaller Bose L1s to save some weight. Normally they are too ‘hifi’ for the organ sound but the Amplitube Leslie amp sim really makes the Bose speakers work, hence my disappointment when it all seemed to be unusable. If I find the underlying cause of the previous high cpu usage, and the new setup continues to be glitch free, I’ll report back.



Hi Paul,

Glad that worked for you. Also try using options>audio engine>prevent memory paging>normal or aggressive . That also gave me more headroom on the high load I was getting on my backup computer.