Anushri Fails to autotune itself?

Before I had no issues with doing the autotune function by holding hold and run / stop. I would hear the faint arpeggio and then tuning would be great. Now all I hear is a long sustained low note and then if I keep holding the sequence start playing. No tuning is achieved…

In fact it sounds worse now. What can I do? I tried factory reset, did not do any difference.

As a matter of a fact, it seems that it is after I performed the initial factory reset, I can’t get the autotune function to work normally.
Is there some setting I have to do first after system reset to use autotune?

It could be a defect of the IC transforming the VCO signal into a square wave in the [0, 5] V range, for the MCU to analyze its frequency. Do you see that square wave on IC10 pin 8?

Hey there! Thanks for the answer. Unfortunately I am not the builder, I never opened up this unit.
However, I am not sure what I did, but all of a sudden the tuning process jumped into gear and now it sounds fine. I am not sure how I caused it and what I did to restore it…

Today I turned on the Anushri and again it was out of tune completley. Again I cant get the autotune process to start. When I press HOLD & RUN I do not hear the faint arpeggio taking off. No autotuning is happening.

Is there some system mode which disables this function of being enabled? Is there some deep reset I can do to get it to work again? Sync is set to OFF position of course.

No and no. This is probably a hardware problem - for example a bad solder joint on the circuit transmitting the oscillator output to the processor for tuning.

Well… It seems weird because it worked flawlessy for more than two years. So basically there is a possibility a solder joint broke with time??

Maybe this is a good opportunity for me to get into learning electronics… I have a good multimeter already.

I love the Anushri, its very original modern sounding analog and the filter is great.

Oh yes, absolutely, that’s the problem with a hand-soldered DIY device.

The solution you offered, is it possible I can check it with a good multimeter or do I need another equipment like oscilloscope?

You need an oscilloscope to check that the correct signal is sent to the processor.

So a software oscilloscope would work as well? So how would I measure the square wave on IC10 pin 8? Do I need a special multimeter that can be hooked up to an oscilloscope? Would it work with a software oscilloscope through an audio interface?

If by “software oscilloscope” you mean software displaying the signals received on an audio interface, the answer is no: you won’t see the actual shape of the signal if the interface is AC-coupled, and you won’t be able to measure its amplitude accurately.

Either you use:

  • a multimeter, to get an average value of a voltage. This is a single reading, which is fairly pointless if the voltage fluctuates over time, but which is enough to check, for example, if a circuit receives an adequate supply voltage, or if a CV output produces the right voltage for a given note).
  • or an oscilloscope to graph how a voltage changes with time.

I can’t think of a situation where the multimeter needs to be connected to the oscilloscope!