After giving a general overview of what stores are out there, it’s helpful to give an overview of parts sourcing from the component perspective—the best place to buy resistors, the best place to buy knobs, etc. Of all the knowledge I’m collecting in this document, this is probably the most practical.

Resistors

I use only ¼W metal film resistors in all my builds. They’re only marginally more expensive than carbon film these days.

Mouser is by far the cheapest place to buy resistors, and their Xicon brand is very good quality. However, in mid-2020, they stopped selling most values in individual quantities, so you have to order in bags of 200. The bags are only $3.00 each, so it’s still very affordable, but if you only want the parts for a single pedal then you’ll end up with a lot left over.

At Mouser, you can also find Yageo and KOA Speer brands of resistors, both of which are still sold in individual quantities. They are much more expensive than Xicon, so if you need more than 25 of a single value then you’re better off going with Xicon.

What to avoid

Avoid buying metal film resistors from eBay or Tayda Electronics. I’ve never gotten any that tested bad, but the leads are extremely thin and they feel flimsy. They also fit poorly in sockets and breadboards because of this. High-quality ones are not expensive at all, so don’t settle.

Capacitors

I use WIMA MKS2 box-film capacitors for all values 10nF through 2.2uF, and Kemet PHE426 series polystyrene caps for everything 1nF to 10nF. Both brands are readily available from Mouser.

For values less than 1nF / 1000pF, I use multilayer ceramic capacitors (MLCC), generally the TDK FG28 series.

Ceramics and MLCCs

A word about MLCCs (multilayer ceramic capacitors). These are very space-efficient, they look great, and they tend to have far better tolerances than the ceramic disc types (which are sometimes -20% / +80%). I use MLCCs exclusively instead of disc capacitors, but you have to be careful about which dielectric you use—some MLCCs are very good and some are very bad, with nothing really in between.^[1] Be very careful to pick MLCCs with a C0G or NP0 dielectric (those are zeroes, not O’s). These are considered Class 1 and have much better temperature coefficients and less distortIon.

The cheaper and more common Z5U, X5R and X7R (Class 2) are very nonlinear (the capacitance drifts with voltage and temperature) and higher in distortion. C0G/NP0 capacitors are only available in small sizes—so no matter how tempting it is to use a 1uF MLCC, the only 1uF MLCCs are the Class 2 dielectrics, so stay away! (On a practical note, I believe Tayda only sells Class 2—I’ve only found the Class 1 MLCCs at Mouser.)

Higher than 2.2uF

2.2uF is the largest practical size for film capacitors, so for anything higher than that, I’ll use electrolytic or sometimes tantalum.

Tantalums can be very expensive from places like Mouser, but Tayda Electronics has them for pennies and they are top quality.

For electrolytic capacitors, I prefer Nichicon from Mouser. A single value such as 22uF may be available in several different diameters such as 5mm, 6.3mm or 8mm depending on maximum voltage and other factors. Because of the wide variety of options, Aion FX PCBs are standardized around the following values and sizes:

• 1uF–47uF: 5mm
• 100uF–220uF: 6.3mm

What to avoid

Avoid buying electrolytics from Tayda. It’s important that electrolytic capacitors be high quality and theirs aren’t. Don’t stray too far from the “ons”: Lelon, Rubycon, Nichicon or Panasonic.

Also, avoid any old-stock electrolytic capacitors. Unlike most components, electrolytic capacitors have a shelf life, and the longer they go without being used, the more susceptible they are to failure. So if you don’t know where they came from or how long they’ve been there, don’t bother.

Potentiometers

Small Bear has the best selection anywhere. I use mostly Alpha 16mm right-angle PCB mount pots, especially in all of my DIY projects, but I’ve done some really cool things with their clear shaft illuminated 15mms (Small Bear also sells clear knobs to match). Their 9mm pots are great for tight or modular builds. All of their pots have the full range of linear and audio taper values, with most also having a 20k “W” taper available (used in the Tube Screamer tone control) and reverse audio (“C” taper).

Tayda Electronics has also been steadily improving their selection for the past few years. They have incredible prices on right-angle Alpha 16mms. And as a bonus, their 16mm pots all come with dust covers on the back. I use these dust covers on every build as insulation for the right-angle mounted pots which would otherwise short against the solder pads on the bottom side. Small Bear does sell these dust covers, but you have to buy them separately.

What to avoid

The only thing issue I’ve found with Tayda’s right-angle 16mm pots is that even though they’re Alpha, they seem to be made by a different factory and they feel very slightly lower quality. I am a stickler for quality and have no reservations about using them, but it’s pretty easy to tell apart Small Bear’s and Tayda’s, at least visually.

With Tayda, you also have to make sure to get the 6.35mm shaft diameter (they also sell 6mm in most values). It can be pretty daunting to wade through their list since they are only categorized by taper—all the values and sizes are in the same long list.

Diodes

For your standard clipping and reverse-polarity diodes (1N4148, 1N4001-7, LEDs, BAT41, BAT46), you can’t beat Tayda’s prices or selection. They even have a good selection of germaniums, though they are new production and not NOS and don’t tend to have the standard forward voltage of most of the old-stock types.

Transistors

For general-purpose silicon transistors, I get everything from Mouser. It may be temping to look at Tayda, but some of their components have been verified as fakes (such as their J201) or tend to be really far outside spec. The prevailing theory is that they sell a lot of factory reject parts, so while they’re sometimes name-brand, they are not the same quality as purchasing from an authorized reseller.

So with these, if it seems too good to be true, it probably is. Small Bear has a better variety of NOS stuff and you’re guaranteed to not get any fakes from them.

For germanium transistors, SBE is by far the best. They audit all of them ahead of time so you know you’re getting good ones. They do limit the quantity of audited transistors you can buy, so you won’t be able to make high volumes, but they do also sell unsorted ones with no quantity limit for builders.

ICs (integrated circuits)

For in-production ICs, check Tayda first. They have great prices on JRC4558, TL072/4, CA3130EZ, NE5532, OPA2134 and many more, and unlike their transistors and JFETs, they are almost always the real deal. I’ve only ever seen complaints about their PT2399 delay chip, which is frequently reported as noisy and may be factory seconds.

For obsolete ICs, you can find almost anything at Small Bear Electronics. They have a huge selection of NOS op-amps and bucket-brigade delay chips. Prices are a little steep sometimes, but they are guaranteed to be genuine.

Some obsolete chips such as the CA3080E can be found cheaply via Asian eBay sellers, but make sure to check the seller reviews as there are a lot of fakes coming out of Asia.

Enclosures

For bare enclosures, Love My Switches has the best selection. They have great economy options as well as high-end stuff like GØRVA. Prices are fantastic and shipping is lightning-fast.

For finished enclosures, check out the Professional Enclosure Finishing article.

Knobs

Small Bear has a great variety, including many that you can’t find anywhere else, from your basic Davies knobs all the way to “hi-fi stereo” aluminum knobs.

Love My Switches also has an amazing selection and are typically a lot cheaper than Small Bear with more economy options.

¼" jacks

Aion FX kits use a custom-sourced PCB mount jack, but for almost everything else I use Switchcraft #111 (mono) and #112 (stereo) enclosed jacks. The open-frame jacks (#11 and #12A) hold the plug too tightly and can come unscrewed after a while as a result. I’ve found that onlinecomponents.com has the best prices on these, especially if you need more than 100, but if you only need a couple of them then just get them from Small Bear.

I also like the Neutrik NMJ series (such as the NMJ6HC-S) for certain applications. The chrome ferrule looks really nice, they’re electrically insulated from the enclosure, and they have 3 transfer circuits (e.g. break a connection when a jack is inserted) so you can do some interesting things with expression pedals or effects loops.

What to avoid

Honestly, I would avoid any jack that is not Switchcraft or Neutrik. Most of the parts suppliers have very economical unbranded jacks available, but I’ve had bad experiences with them. They’re fine for prototyping, but I don’t trust them for production builds. They’re flimsy and the metal often corrodes easily.

DC jacks

Aion FX kits use a PCB-mounted DC jack, but for normal builds I always use the switched Kobiconn jacks, SKU 0611 from Small Bear. The same thing is available from Mouser, part number 163-4302-E.

There are others from places like Tayda that look identical for much cheaper, but there is a notable difference in quality. The DC jack is so critical to a pedal’s reliability that I wouldn’t use anything but Kobiconn.

For tight builds, I recommend SKU 0611G from Small Bear. It’s much smaller and easier to fit into a miniature build. (It’s not switched like the other one, so it shouldn’t be used in builds with a battery.)

Stomp switches

Love My Switches has you covered on stomp switches. They have great-quality economy options (this one is around $2.50). If you want something a little higher-end, check out their GØRVA or Taiway options.

Toggle switches

Love My Switches has a huge selection, including SPDT, DPDT and 3PDT with a few other interesting ones. I prefer the short-toggle variety as they make for a cleaner looking pedal. I would stick with their Taiway options because I have had bad experiences with economy toggle switches, but they have a great selection and good prices.

The selection at Small Bear Electronics is also excellent and they carry almost all of the same ones as LMS.

LEDs

Get all your LEDs from Tayda Electronics. They have every color of the high-brightness water-clear LEDs as well as diffused red, green and yellow, and their prices are a great deal lower than anyone else.

Wire

Aion FX kits use wire assemblies, so I don’t do a lot of manual wiring these days, but the best wire by far is SKU 0507 from Small Bear Electronics. It’s pre-bonded, so very easy to solder, but still much more flexible than other pre-bonded wire I’ve tried from other suppliers. Stock up and buy a couple of spools in different colors and it’ll be a long time before you need more.

Notes & references

1. DIYStompboxes thread on MLCCs with explanations of the different dielectrics. Also see this thread from diyAudio and this article from EDN if you want to get technical. ↩