Anushri Power Adapter question/ troubleshooting
  • Hope everybody has been having happy holidays.
    I just finished putting my kit together, and am excited to turn it on, but I have yet to order it’s own power supply. So, meanwhile I wanted to just power it on and make sure it’s working, and I have this 9V 2000mA adaptor. Is this ok to use? I understand the Anushri calls for a 7.5V or 9V 200mA supply, and I’m not very knowledgeable on this subject. If it helps, the specs of the adapter are here .
    Thanks for any help on this shamefully noobish question, I’m still learning things as I go.

  • 200mA is what the Shruthi draws, 2000mA is not what a Power Supply tries to push thru a device, so you should be fine. Please measure although the Voltage with the Shruthi attached, some WallWarts tend to deliver a higher voltage when not fully loaded. YOu should exceed 9V for to much, the regulators 7805 + 7905 might get to warm.

  • When I plug it in and turn it on, no LED’s come on, nothing indicates that it is even on at all. Should I look around with the multi meter to find the problem?

  • The filter board has two pads for a power supply switch, if you’re not using one you solder a bridge wire across instead. Have you done this?

    Did you follow the voltage tests? honestly, do not cut corners, follow the assembly guide to the letter, you will save yourself a lot of pain, blown chips etc.

    Oh sorry, your post is about Anushri, well I’ve not built one of those.

  • I don’t see two pads, nor do I see anything about it in the instructions. Perhaps you think I’m referring to a shruthi (you mentioned the filter board), but this is an Anushri. Sorry for not specifying earlier, I should’ve made it more clear than just putting it in the subforum.

    edit: changed the title for you all :)

  • Toggle the Power Switch ;-)

  • I was going to start my own thread about this but I’ll contain my question here since it is along the same lines.

    I’ve pretty much finished my Anushri at this point, just need to sandwich the boards together and power it on for the first time, and while I order a power supply that will most likely be perfect for an Anushri, I want to make sure I’ve covered all my bases in terms of not royally screwing myself if I power on and have wired something incorrectly.

    I read in some other threads and they advised removing a few of the ICs if you’re unsure of your power supply and want to avoid frying any chips, but my question is are there any other precautions that should be taken before attempting to power on for the first time if I know my power supply will be fine for the instrument? All of the parts are in the right places, though I’m a little skeptical about some of my solder points. I have a feeling that when I put everything together it will show no signs of life but I want to avoid making a more costly mistake.

    Unfortunately I discovered I need to purchase a new multi meter, so I won’t be able to test the voltages for a few days, though I’m itching to use the Anushri ASAP.

  • Please don’t! If you’re skeptical about some soldering job, at least measure the obvious things like resistance between the voltage outputs of the regulators and ground while powered off. Then, go on with plugging it in without ICs and test that the voltages are as expected.

    Or, be prepared for some desoldering and pain you could avoid.

  • Frank, I toggled the switch at first assuming that would be my initial problem, and no LED’s came on either way. As pathetic as this sounds, I can’t even be sure which position is the “on” position. And I tried running the software tuning with my headphones in after toggling the switch both times, and nothing either time. And yes, the volume is up :)

  • i can’t see on the pic if the power supply is center pin positive.

  • I thought I remembered reading in the specs that the Anushri can take either type of plug type. For the Ambika it’s definitely center pin positive

  • For the Ambika its “Center pin doesn’t matter as its AC”, for all other MI Gear its Center Pin Positive which is important to DC. Read here about the difference. The Adaptor you are referencing to has excellent technical specs on this Website (*none!*) so i took a quick google search ( “roland psb 1 pinout”) and found all Roland PSUs have Center Pin Positive. So your PSU is right, you must have scrambled up something else… As we have no further hints other than “doesn’t work at all” please post High Res Pics of the PSU Section of the Board from both Sides, maybe we can spot something.

    There are some pictures of the PSU. They are as good of quality as I am able to get, hopefully they will suffice. On a side note, the dark blue translucent case came in today, and looks fantastic!

  • Can you please measure the Voltages at the Pins of the 7805 and 7905 regulators?

    The pics look ok, just maybe you should cut the leads a bit shorter – at this length you could have shorted something somewhere.

  • None of the colored points return anything on the two regulators however, I had the point “2” on the 7805 returning .25V but now that’s even stopped. Just out of curiosity, I measured the “power supply protection diode” and its pin 1 reads -9.12V and pin 2 flickers from 0.000 to -0.007, not sure if that helps any though.

  • Look like the polarity of your power supply is incorrect…

  • Well, after obtaining the proper power supply, all voltages check out, and it makes noise! I will post again after further experimentation if I come across any problems. Looks like I’m going to have to desolder the jacks for it to fit in the case as well :(

  • you need to desolder the jacks in order to get it in the case?

  • yup, I probably should have waited for the case to come in before I soldered them, but I wasn’t really thinking ahead.

  • oh ok now i get it, the 1/8” jacks

  • Alright, so I’ve had little time to play much with it over the past few days, but the first thing that comes to my attention is that it’s not stereo. Audio only plays in the left ear of my headphones, is this how it is supposed to be? Also, there’s still a small driftiness in the pitch which I don’t have a problem with (as of now), but it would probably be good to know how to fix it should I want to later. Those 1/8 inch jacks are a pain to desolder, still haven’t finished :(

  • Ladies, this is an Audio Output, not a Headphone Jack (clearly stated in the Manual!). You can be lucky your hearing didn’t get damaged!

  • As Frank said, the Shruthi is meant to be connected to an audio interface or a mixer (both of which are perfectly fine with mono, line level signals); not to headphones. You’ll probably get a lot of distortion when trying to drive low-impedance headphones (2V pp at 8 ohm -> 250mA, that the TL072 of course cannot deliver).

    Please post a recording of the pitch driftiness. It is very surprising because the Shruthi oscillators are digital! Maybe it’s because the patch you were playing has a modulation (LFO) to the oscillators pitch?

  • Well to specify, this occurs when Anushri is run into my soundcard, and my headphones are in the headphone jack. Is this just something I have to sort out with my soundcard then?

    Olivier, this is an anushri that we’re discussing

  • What I said applies to all my products – which all have line-level mono outputs, not headphones output.

    What is your audio interface? Does it have mono / instrument inputs?

  • Right but the Anushri’s oscillators aren’t digital, so I was just pointing that out. Otherwise, I’m using an m-audio firewire 410 as my interface. I think it may just be something I have to sort out in the software interface.

  • Considering that both jacks for input/output shown in the BOM (on the DIY ressources part of the Anushri page) are mono, I would be VERY surprised if you somehow got a stereo output out of your Anushri :D
    (Manuals are handy.. And made for reading!)

  • I still have my old ProFire 410 still here in stock, it has definetely the capability to switch to intrument input, as i used to record tracks of synths and guitar…and these are switchable pre-amplified mono inputs (between line and mic).

  • Pitch driftiness might just be the unit slowly warming up – the temperature dependency curve is a parabola centered at around 30°C – you need to wait a bit for the unit to start to get into the bottom of the pit – but far away from this central temperature you might observe detuning. Or the pitch modulation knob not being set to its central position.

  • V’cent, I figured this was the case, but I didn’t know if somehow the same audio would just be played in both ears. Remember, I’m essentially a noob here ;) But I have it sorted, so everything is well.

    But desoldering the 1/8 inch jacks is a huge pain and I’m kicking myself for it… I’ve been using a braid with little success, what do you all think would be the most effective method to desolder them? My anushri wants its faceplate!

  • Without a good desoldering sucker it surely is pain. I usually heat my soldering station to 300°C and use the sucker. If most of the solder has been removed i then use a small screwdriver and a LITTLE bit of force to move the pin sideways in the hole to break the sweat joint. In most cases this works fine. Never ever use great force…if this doesn’t work out the second option is to cute the legs and remove the audio jack this way. But then you most likely will have to buy a new one.

  • To desolder with DesolderingBra(i)d™ you basically need 2 things: Low temperature (300°) so you don’t overheat the components and a lot of Power. Therefore t you need something like a 60W+ electronically regulated soldering iron that keeps the temperature constant even when you touch a heatsucking Monster like a Groundplane or a piece of desoldering Braid. Conclusion: you can’t properly desolder with a small 15W Iron – either the temperature drops to a point where you solder the Braid to the component or you have to heat your tiny Iron to a temperature where you might burn your PCB and/or Component.

    BTW for the Anushri you don’t have to desolder the whole Jack, just reheat and realign…..

  • what i do with parts like that is first apply some more, then suck it out until it looks clean. then only touch the component lead with the tip of the iron, not the pad and push it to the middle. that way only 1 parts gets heated and chances are better it won’t stick again. a bit of wiggling helps too. works very well with tactile switches too.

  • Thanks for all the suggestions, I will try some of them. I’m not sure how I would reheat and realign unless I somehow got two extra hands with two more irons… which would be awesome, but I don’t know anybody near me who would do that.
    Before I follow through on another faulty assumption, are the LED’s and resistors you included with the case meant to replace the yellow LED’s and resistors that come with the case? I can’t think of what else they would be used for, but I’m just being safe I guess.

  • the easiest way to re align the jacks is to free 2 of the legs from all solder so only one is connected to the board. then you can just reheat the leg of one jack at a time and solder everything in the end when all are aligned.

  • @zhao
    If you use the LEDs i supplied use also the resistors i supplied else you will either get blind or ignite your ceiling

  • Edit: I reread what you put and I understand now, I really need to slow down when I read things .

  • things get out of sync when you read faster than fcd writes.

  • you can’t read as fast as i write because i have an exfilinator.

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