Sound very quiet
  • So I had my synth for a couple of months now and all was working fine. But then out of no where the sound just conked out. When I have the volume all the way up It makes a puhh noise before the actual synth sound like the filter is closed or something but it is all the way open. The sound is very very quite. Any help would be awesome thank you

  • Heeey, you have found the secret “champagne mode”, congrats !!!

    (No, this is not a thing..)

  • Lol @v’cent I wish but seriously any help

  • I would love to het my synth up and running agin soon please any feed back would be much appreciated.

  • Check the connections between the boards and look for suspicious looking (oxidized) solder joints and check every chips seating.
    Theres no miracle trick i can offer you due to your description.

  • A simple thing to try is to re-seat all the ICs in their sockets – they should not slide out too easily, but a contact within an IC socket that was barely made could now be open (after taking the synth somewhere, dropping it, etc. etc.).

    Perhaps simply try pressing all the ICs (especially the eight-legged guys) a little … see if they move.

  • So I checked all the points and made sure all the ics are properly connected but still the sound is very quiet. I remember the last time I plugged in the synth the polarization was backwards does that have some thing to do with it? Could that have messed up a ic or something?

  • In principle the two diodes near the power connector are protecting you from reverse polarity, but it is worth measuring the negative voltages (as indicated by the green points on the build page ), in case the LT1054 died …

    As you did not say which synth you have, I assumed a Shruthi …

  • @eelco this was posted in the Anushri sub-forum, so I’d assume it’s an Anushri that is misbehaving :)

  • Ah …
    I’ll blame an early morning without coffee …

    But the Anushri has a similar power circuit, although with just a single protection diode. Still worth checking the green points (-5V), but on this build page :-)

  • So I just check all the voltages and everything is good except the diode. Point 1 is 8.99 and point 2 is 8.18. I know point 2 is suppose to be negative. Could that be the root of my problem? all the other IC’s voltages where good.

  • Your measured value at point 2 is ok. It’s just the input voltage from point 1 minus the voltage drop of the diode.

  • So what should I do now?

  • Do you think it is my at mega ic. Because all of the digital stuff works fine it’s just the analog side that’s messed up

  • The atmega328p is responsible for the digital side. So if the digital side is working, the problem is certainly not with this chip!

  • I had a similar experience and it turned out I had omitted the 330k resistor on the filter board. Maybe refloated the solder here.

  • Michael, if all the voltages check out OK, it must be an issue with soldering or a bad IC.

    When I built my first Anushri (I’ve done two now …) I actually forgot to solder four of the eight legs of one of the OpAmps (the TL072 on the far left). Silly me, of course, but it did result in a very quite synth …

    This is not your problem, most likely, but if this happened suddenly, you might have killed one of the OpAmps somehow.

    The next step would be to follow the signal path (next step after checking voltages on the build page).

    Of course the simplest thing might be a bad setting: remember that the Anushri saves your settings after 15s or so, and you might have done something that produces very little sound.
    So have you tried the ‘factory reset’ option ?
    From the manual:
    “Keep the Run/stop key pressed while Anushri is powered on to revert all synthesis and system settings (including tuning compensation!) to their default values.”

  • I have the same problem with my anushri. Its lower than all the synths in my modular case.

    I have built three successfully and only one of the them is doing this. The other two i built for friends say they have no issues, but the digital drums is the problem with mine. Sometimes they are just playing fine and then they completely cut out. Then about 20 seconds later they come back.

    Gets in the way and has prevented me from using the drums in live performance. The synth side seems to work fine, its just the drums. I have voltage tested all three and they all have exactly the same voltages. SO strange, I build modules for my day job with 4ms and i have a large amount of experience with building and testing modules.

    I hope there is a update to the Atmel chip in the future to fix the drums. Over all the module is fun, just wish the drums had some punch. In typing this mail the drums have cut in and out at least 4 times….

  • > I hope there is a update to the Atmel chip in the future to fix the drums.

    Stick a scope probe on IC23 pin 5 next time the drum disappears, and trace the problem from there.

    I guarantee you, the drums run continuously on hundreds of units, including mine.

  • I noticed the regulators are extremely hot. The 5 volts is “burn my finger hot” which is telling me unplug it. I’m going to put it on the Rigol tomorrow and check everything. Its like the Drum Out Jack is not working either.

    I may have to take the faceplate off and look around. Took the module apart and checked every IC and every solder point. I also looked at every part and the placement is correct for everything.

    It weird i never noticed how hot the 5 volt regulator was.

  • What is the voltage rating of your PSU ? And what do you actually measure when you switch on the Anushri (at the plug) ?

    9v works best, 12v is a little hard on the 7805 (unless you cool it properly).

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