Some questions before ordering last few parts

So its been a long time since i first ordered my boards and then later parts, i never got to getting the quad amp, broke 3 resistors and a cap.
First the Capacitor at c7 on the digital board needs to be replaced, i was just wondering what voltage it needs to be? The only one i have found on mammoth is 100v. I think i should have everything i need but a power chord from there.
2nd i plan on using a dark blue new new haven LCD nhd-0216k1z-nsb-fbw-l just wondering if you think i will run into any issues with brightness with the normal resistor installed and no modification made to compensate for the different LCD color.

Now i also have PCB’s for the yellow magic boards i was wondering if i should order any special IC’s now or if that boards IC’s are available at mousers? I would really like to get some of this filter parts started and stock piled while i am spending money on this stuff to beat shipping.

Thanks alot hope to get this going and finish it (a year later) this up coming month.

Take a look at all the BoM lists. Anything that requires specific mechanical parts (Anushri, Ambika etc) like the stackable Arduino headers, audio outputs, power input sockets, button caps, knobs etc are worth getting in advance. Also, any special ICs, like a few extra LT1054 are worth getting ahead of time. Basically, if it’s a precision capacitor or resistor - get a few of it. Any IC more specialized than a TL074 - get it.

And for the unspecialized ones like the mentioned TL074 - get them by tens.

Haha, tru dat. I was just thinking that it’s possible to get those locally, but it makes no sense not to hoard them dar opamps at any rate…

…expect when you have a late night soldering paroxysm. Imagine you need to have that dsvf filterboart NOW and have V2164s at hand but no vanilla TL072 :wink:

So i ended up just placing an order for an encoder knob, the missing resistors, two v2164d (one for YM) and the pt2399. Now i was wondering if a boss guitar pedal power supply will work for the power or if its to strong its 9.6v and do i need a midi cable or is that just to controll it externaly/

Boss pedal PSUs have the wrong polarity. You’ll need to get another one, or a polarity reversal adapter.

“and do i need a midi cable or is that just to controll it externaly/”

Öhm - what do you intend to do with a Synthesizer that has no Input Device whatsoever without a MIDI Cable to connect a Keyboard, Sequencer or any other device that sends commands?? Just use it with the (rudimentary) step sequencer???

i was hoping to just tune it i guess an yeah basically, i have to wait to get my hands on a keyboard (toke me a year to source parts hate to see how long this takes), also thanks pich i stumbled over the wiki and found the spark fun power supply so i hope to pick one up.

Cheap 9v center-positive 2.1mm adapters ebayed from china typically work fine too, although it’s worth checking that the voltage is actually close to 9v with a multimeter, since manufacturing standards are probably not stellar.

I’ve got several like this one, and they’re all fine:

Thanks borfo i might go that route may just use the wiki site and add a midi cable. found some funds today, also a lame pawn shop in my area has a microkorg xl synth i cant find any info if this is midi in/out but it does look neat any input on this little guy? If not a keyboard maybe under 250. would this work if say i had something on my pc along the lines of abelton?

I’ve never used a microkorg, so I can’t say, but you don’t need a keyboard with a built in synth to run the Shruthi - you just need a MIDI controller. I know you can find old M-Audio Oxygen 8 25 key keyboards on craigslist or ebay for really cheap if you’re just looking for something cheap to operate the shruthi with. They’ve got DIN MIDI outs. The M-Audio Axioms are excellent midi controller keyboards too… They cost more, but they’re very playable if you’re looking for a decent keyboard.

You could also run it off a software sequencer on a computer or ipad if you’re not looking to use it with a keyboard.

This may be a stupid question, but on the subject of having lots of TL074 on hand, what is the difference between a TL074CD and a TL074D? I keep seeing references to TL074D in schematics, but only TL074CD seems to be readily available.

As long as it comes to Mutable Instruments DIY both are equally fine. You should also have lots of TL072s at hand as you can’t just cut a 074 in half (wrong Pin count….)

TL074 is the name of the part. P is a suffix added by eagle for the DIP version.

The actual reference number for a DIP, non-military TL074 is TL074CN. TL074CD is the non-military SOIC version.

So looking over my remaining chips i seem to have 1 left over i think its one of the programable chips i ordered the small one, is programming it something really hard i have an arduino if that is needed.

In a Shruthi, the programmable part is the largest chip (ATMega644p).

what is the smaller chip that comes with it?

It’s the 512k Eeprom chip for additional Patches.

Parts came in snapped in chips, just one question though. I had trouble finding the 18p capacitor from the digital board labeled c7 so i got a .018uf im hoping that is the same thing but im guessing im wrong.