need to start buying components, what to buy!?

[A Dingleberry Monstrosity]

So i've been modeling some ideas in matlab and I think im finally ready to start testing these ideas out... but I have NO components to speak of...

I don't know how to ask this, and I know it sounds like a dumb question... but what should I get?


I dont really know what TYPES of components to get, thin film resistors.. carbon film... ceramic capacitors?

I know material effects audio quality, so I dont want to buy components that will have a negative effect right from the start... or maybe im thinking too much?

Also, is there a range of resister, capacitor, transistor etc etc values that you always find yourself buying? What about op amps or OTAs that you just never seem to have enough of?

thanks all!!!

[Adam-V]

That's a bit of an open ended question!

That being said, I find I use the following the most:

10uF 35V Electrolytic capacitors
100n MKT capacitors
Metal Film resistors - 10k, 100k
1N914/1N4148 small signal diodes
TL072/TL074 Op Amps
100k Lin Pots

Ultimately though. it's going to depend on your designs.

Cheers,
Adam-V

[A Dingleberry Monstrosity]

thanks for the response!! I know, i thought about NOT posting this for that very reason

..but I asked in the hopes that someone who has been doing DIY for quite some time to chime in and say something like "yo, never buy ceramic capacitors!!! Make sure you get _____ instead so you ensure high haronic sine waves!!" or "yo! Get high wattage resistors for reason x y and z!!!"
something in the material itself that has a negative effect on audio that simple simulations can't catch.

my designs are SUPER generic right now, I dont even have component values to speak of. I'll know for sure later on of course...

thanks again!

[Adam-V]

Ceramic caps have their uses. Mainly for their low values. You'll see them in certain op-amp circuits to remove high frequency ocillations that can occur.

Go for 1% metal fim resistors (1/4 watt or 1/2 watt, doesn't really matter for synth circuits). They're more accurate and stable than the carbon ones.

There's a huge wealth of DIY knowledge at your fingertips, don't be afraid to ask questions about particular components even if they seem like silly ones. And don't forget to post pics of your modules in the DIY challenge thread when they're done - we ned more DIY porn!

Cheers,
Adam-V

[paults]

Well, I suggest:

Silicon-based items
100ea 1N4148 diodes
50ea 2N3904 NPN transistor
50ea 2N3906 PNP transistor
5ea LM78L05ACZ +5V regulator (very handy!)
50ea TL072ACP op amps (cover 99% of everything)
5ea LT1013CN8 dual op amp (for DC summers)
5ea OP275GPZ dual op amp (high speed super whiz-bang audio)
5ea red, yellow and green LEDs (no blue ones, I want them to die in a fire)

Resistors (all 1/4W 1%)

Note: It's usually cheaper (in the US) to buy them in 200pc bags

100 ohm
1K
2.2K
4.7K
10K
22K
47K
100K
1M

Caps
25ea 10ud 50V electrolytic
25ea 3.3uf 35V non-polar electrolytic
100ea 0.1uf 50V ceramic axial cap (the infamous "bypass" cap)
10ea 0.1uf film cap
10ea 0.01uf film cap
10ea 0.22uf film cap
10ea 0.022uf film cap
10ea 1000pf polystyrene caps (good for VCFs)

Misc stuff
3ea 1K trim pots (Bourns 3386P)
3ea 10K trimpot
3ea 100K trimpot
25ea 100K linear pots for panels
10ea 100K log pots for panels

That's a good start

[th0mas]

I know your pain.. I haven't designed anything myself, just had to find parts to complete BOMs from board manufacturers, but used to be totally overwhelmed when doing a mouser search.

Most of what I know's already been posted but I'll add to get most capacitors rated at 100v or less for audio circuits.. otherwise they'll get big, fast

I like Mouser's search because once I find via the filters a resistor or capacitor that fits my needs, I can just reselect the capacitance or resistance value and a part with all the same characteristics. Saves lots of time when doing large part orders.

[paults]

If you want a good "point of reference", you should look over this 5U-centric DIY site. It has TONS of info about modules, parts, BOMs, and food recipies.

http://www.dragonflyalley.com/billAndWillMOTMSynth.htm

[decaying.sine]

Hey Adam,
What Matlab toolboxes you use? I use it for some end user type stuff and was just curious because we get sweet academic deals on it here ($50 a year for basically everything).

[frijitz]

No need to hunt (and pay!) for polystyrene caps any more. C0G and NP0 ceramics seem to work just as well. I've tested this carefully in hyper-accurate VCO designs.



Ian

[Adam-V]

That's great to hear Ian.

Cheers,
Adam-V

[paults]

But they are pretty and still are at Mouser. They are elegant and sleek.

[J3RK]

I try to keep a pile of styrene caps around, but I have noticed that other film are not bad, and I just started trying some c0g for a few things. I do love the way the styrene caps look.

I can't seem to buy enough 1N4148 diodes, 2N3904/2N2906 transistors, and I'm always out of 100K resistors. Every time I order I double it, but still run out nearly as fast. LM3900s seem to be in season right now for me too. I wish I could stock up on the SSM2220 and SSM2210s, but they're pretty expensive, so I've been using them sparingly.

[frozenkore]

Small Bear has resister kits here. As for the 1N4148 diodes and 2N3904/2N2906 transistors, I've gotten tons on ebay pretty cheap (like 100x 1N4148 for $2 something shipped).

[Paradigm X]

Cheers all for info, useful to me.

I just bought a huge load of components, mainly from the list of parts required in the Nicolas Collins Hacking book. £115!

But i bought 5% resistors, is this a major problem? I got them in a big grab bag of assorted sizes so it wasnt too expensive.

Are they worth playing with, or is it a case of leave them out of the equation?

Many thanks

Ben

[phono1337]

Cheers all for info, useful to me.

I just bought a huge load of components, mainly from the list of parts required in the Nicolas Collins Hacking book. £115!

But i bought 5% resistors, is this a major problem? I got them in a big grab bag of assorted sizes so it wasnt too expensive.

Are they worth playing with, or is it a case of leave them out of the equation?

Many thanks

Ben

5% resistors are fine, it just means they will be rated within +/- 5% and should you need more precision you can always meter and hand pick them.

[Paradigm X]

Nice one phono.

Im hardly doing anything precision at the mo, just going thru some of the basic projects in the book.

Cheers

[Luka]

while you at it find a metal shop and get a whole bunch of blank aluminium panels

[wenzel]

Just a quick note comparing 5% carbon and 1% metal film resistors. In synth making when a design specifies a 1% resistor it's much safer to use a metal film resistor, not a carbon resistor that you've measured to within 1% of the specified value. Metal film has a much lower temperature coefficient (the amount by which the resistance changes as the temperature changes). This is particularly important in VCO cores and CV summing stages where we want tuning to be independent of temperature. I always read 1% as shorthand for 1% metal film.

[Paradigm X]

Cool, thanks for the info.

My first projects are going to be filters/distortion boxes, simple things. So assume their fine. If i ever get a decent design together/make a synth, ill def get 1% MF resistors.

[Veqtor]

most caps are available at 35v, get that...

[ach_gott]

Didn't René assemble a text file of all the components required to build a complete set of Oakley, CGS, and MOTM modules? That would be a pretty good start.

I searched for it the other day but didn't find it.

[iopop]

http://www.teaser.fr/~amajorel/misc/sdiy-parts.txt have listed the parts for quite a few modules. Will at least give you an idea for which parts to keep on stock. Think most have been mentioned already though.

[ach_gott]

That's it! No wonder I couldn't find it... It was Andre.

[EATyourGUITAR]

I would disagree with people saying to buy 1% or people saying bad things about carbon comp resistors. its all true but I think you can spend less time and money and more time building if you buy the cheapest components and adopt a use what you got attitude. if your concerned about temperature drift, use tempco resistors. but only in the one or two spots where it actually causes an osc to drift. that way you save money. the great thing about a breadboard is that its so easy to try that resistor or whatever in the circuit while your waiting for the exact one you want to arrive in the mail. if you have a batch of %20 you'll have all kinds of cool stuff. like a 102k resistor that might come in useful.