Completed Assembly - Concerns

So, I finished my Anushri kit over the weekend, and I’m pretty excited about it. I haven’t powered it up yet - still waiting on a power adaptor and cables (in the mail). I followed the instructions meticulously, and I’m fairly confident that all my solder joints are good (despite re-learning to solder with lead-free solder o_O), so my friends, do I have a good chance that this little machine will work when I fire it up later this week? Do I run the risk of serious damage when turning it on? All my chips are definitely in the correct position and orientation. If all goes well, I’ll add my kit to the roll over on the successfully completed kits thread. Anyway, it’s a fun build, and I can’t wait to make some music with my Anushri!


If you are really unsure about this, remove all chips except the LT1054, and check that the +5V / 5V are fine by doing so, there’s nothing valuable and hard to replace you’ll damage if you have made a mistake in the power supply section.

Just an update, now that I got all my cables in and I was finally able to fire up the Anushri. It works! Well, kinda. I can send MIDI, and sound comes out, but some things seem a little unusual. I set it up to send a C-major scale from Ableton, but it doesn’t go through smoothly.

1) That is, I don’t hear “do-re-mi-etc.”, the scale comes out sounding a little chopped up / broken. It’s not smooth. Is this a feature of Anushri, or am I hearing latency issues that I need to iron out in Ableton?

2)When I flip the filter type switch from LP to BP to HP, the sound goes away. With HP/LP I can get sound again if I move the cutoff pot. but I get almost no sound when in the BP mode. It’s very faint. Could this point to a bad soldering job on that switch?

3) Last question (for now): when I move some of the pots, I get some static-like /white noise sounds in the output. More soldering issues? I feel as though by the time I got to the pots, I was making really good solder joints.

Even in the current state, I’m enjoying this little machine. I can’t wait to output some actual, useful music! Tons of fun!


Is your sustain/release stage set long enough for the note to complete?
If not, that would explain the chopped notes :slight_smile:

Static from pot sounds like a scratchy pot,
not much to do, except trying some of the methods mentioned on google
(“scratchy pot fix”<- Depending on your prior search history, this may lead to drug related items…:D), or replacing them :frowning:

Thanks! Both responses are helpful!

I think, in my excitement, I forgot about simple ADSR settings, and I think that might be why my notes sound funny/chopped. I guess I’m still learning about synthesis. Hardware is a whole new world for me.

Scratchy pot - I’ll have to look that up. It might not be too big a deal. I think I can source some replacement at the big electronics store here.


> That is, I don’t hear “do-re-mi-etc.”, the scale comes out sounding a little chopped up / broken

If the synth sounds out of tune, take the time to adjust the V/Oct and Offset trimmer of the VCO (or auto-tune it - see the section about VCO tuning in the build instructions).

Also, check that the VCO mod pot is at 12’o’clock (no modulation).

> When I flip the filter type switch from LP to BP to HP, the sound goes away

It might not be a problem… The band-pass emphasizes a range of frequency set by the cutoff pot and throws away the rest of the frequencies… So if the sound that goes into the filter has no frequency at the position dialed on the cutoff setting, very little will go through…

> Last question (for now): when I move some of the pots, I get some static-like /white noise sounds in the output

Which pots are affected by this problem?

Thanks again! I’m probably going to re-tune the machine tonight. I think I was a little excited when I turned it on and rushed into things. I think I’m starting to understand how the cutoff is connected to the LP/BP/HP switch - makes sense. As for the static-y pots, it’s the cutoff and the resonance pot, I believe. Again, it could just be my noob-ishness not recognizing the effects of these pots on the sound.

Thanks for the assistance, and sorry if my questions are totally noob questions.

You could record the noise, & put it on soundcloud? :slight_smile:
Cutoff and resonance are vital parameters, particularly if you’re making dubstep… (lol (nothing against dubstep, just seems a lot of people only focus on those two parameters))

Hi guys - well, after re-listening to some of the Anushri samples out there. I’m convinced I did something wrong when building mine. I made a video ->

I guess it’s time to pop the case off and do some snooping with the multimeter. Or, should I try to reset the Anushri and try the auto tune sequence again? It makes sounds, but it seems rough, and all over the place. I’m definitely not getting anything smooth and acid-y like some of the samples I’ve seen out there.

Thanks again for your help, I appreciate it!

Ooooooo I like it!
Please document what you did wrong as a possible mod :smiley:
That being said, I’m at a loss as to what’s happened :confused:

I’ll do my best! It’s a bit busy, but I’m off work next week, so I should have some free time to repair the Anushri. I like that it makes crazy sounds, but at this stage, I want to start with it working properly. I have a suspicion that some of the earlier soldering (before my skills came back) to the ground plane aren’t as solid as they should be. I’ll probably start with inspecting my solder joints.

(Happy Armageddon!)

I have poor internet access for a while and no sound, so if someone is willing to help me, please do it!

Especially, if someone can describe what’s the problem with sound in the video and which module (VCO, VCF, VCA) seems to be wrong…

For now, disable the automatic tuning (if the VCO is not working, the auto-calibration routine might do weird things).

What are the voltages at the VCO DAC output when you play C2, C3, C4? It should have a 0.5V/Octave scale. Point A in the troubleshooting section?

Can you hear sound at point F (VCO saw output)? Even if it is not exactly in tune, you should hear a loud, clear sawtooth wave here. Next step is the mixer section at point K.

the sound is kind of crunchy/distorted in some settings it reminds me of an “atari punk console” the filter doesn’t seem to work right. vca seems to work. not sure if the unfiltered vco is supposed to sound like that, but it is definetely doing something.
by the way - aren’t you on holidays?

@cold_fashioned… Do you have the sync switch on in the whole video? It look like it but i’m not sure. The ‘distortion’ sounds a lot like synced oscillators. The filter is the only thing wich doesn’t seem to work right.

Thanks guys! I truly appreciate the help. I do have the “Sync” switch on the entire time. I thought that would be preferred, but I guess I have a lot to learn about hardware. I’m not sure when I’ll have a chance to run through the voltage checks, it might be a few days to 1 week. For now, I’ll try the following:

  1. disable auto-tune
  2. turning off the the synch switch.
  3. “listening” at various points on the board, as suggested.

Thanks again!

maybe also check the filter for bad solder joints or wrong resistors.
(around ic5, ic6 )

And by “check” he means re-heat(until the solder flows nicely around the leg) them all… :wink:

Turning off “sync” seems to have really helped. The sounds are definitely more agreeable. I think I still need to test some things out, but I’m pretty confident that I built a good one.

Side note - the drums are an absolute blast to play with! How does one set ableton up to record drums output?