Below are some of my favorite components and my reasoning behind choosing them. It’s not meant to be an exhaustive list, but more of a place where you can read what I would’ve suggested if you were to ask me directly :). As always, YMMV.
- Signal leads: for critical runs that are sensitive to noise (longer leads in a guitar, input lead in a pedal or amplifier, etc) I prefer shielded #24 AWG stranded teflon wire. It’s not easy to strip and is a bit tough to bend, but it’s very sturdy and it will not melt while being soldered or if you accidentally touch it while soldering other components. For non critical runs I like #22 AWG teflon or PVC stranded wire for amplifiers and thinner #24 AWG teflon or PVC stranded for pedals. For pedals and small builds I also use 10×0.5mm flat ribbon cable that can be very convenient to use. You can tear away as many leads as you need and it’s possible to do nice tight builds with clean lead dress when you keep leads together. For example, the 3 leads that go to the same pot can be together. It’s thin and easier to break and also a lot easier to melt, so keep that in mind.
- Tube heater leads: for heaters I mostly use twisted pairs of solid core #22 AWG teflon wire. Tightly twisted pair helps cancel out AC noise from and solid core wire stays put however you set it. That can come in handy because we want AC heater leads as far away from the signal leads as possible. Stability is great, but avoid solid core wire for places where there’s a chance that the lead will be moved around a lot, as it’s much easier to break solid core wire than stranded of the same thickness.
- High voltage coupling, guitar wiring: Mallory 150s and Orange Drops are always great choices. I like using NOS Russian military paper-in-oil capacitors as well as Vishay Roederstein MKT tubular caps. Another good cost-effective alternative are no-name tubular and drop-shaped capacitors from justradios.com. There are many decent options here, pretty much all poly film capacitors are decent. Unlike electrolytics, it’s hard to go wrong.
- High voltage filtering: I try to avoid electrolytics wherever I can, but sometimes there’s no practical way to avoid them. If you can afford the extra space, motor run capacitors are basically polyester film capacitors rated for high voltage and they will do great job without ever deteriorating. I used them in few tube preamps with success. Another reason to use them is the fact that they are readily available in most local stores and don’t cost a lot. After all, they are general purpose motor capacitors and there’s plenty of motors around! Finally, many of them have mounting screw that makes it easier to install them. If you cannot afford the extra space for motor run caps, I had great experience using German F+T electrolytics for board mounting and JJ can capacitors for chassis mounting. Electrolytic capacitors are where quality matters and cheap capacitors can cost you hours of debugging later (learned that the hard way). Using good quality capacitors is a good way to ensure reliable operation for years to come.
- Low voltage coupling: Wima has some really nice box-style radial capacitors like MKS2 (5mm spacing) and MKS02 (2.5mm spacing). I often use MKS2 1uF-2.2uF capacitors for cathode bypass as well.
- Low voltage filtering: in pedals and similar builds I like using Panasonic FM, Nichicon FW and Elna Silmic radial capacitors. There’s plenty other brands that are reputable, but I haven’t tried them yet. I generally don’t bother buying axial electrolytic capacitors for low voltage applications, as they are more expensive and there’s much less choice. I just use radial everywhere and mount them horizontally when a layout calls for an axial capacitor, as shown below. If I really must get axial, Sprague makes some good ones.
- Bypass, smaller values: whenever I can, I try to use Silver Mica capacitors in the pF value range. I try to avoid ceramics and use multi-layer when I have to. Polystyrene are supposedly good, but I haven’t tried them yet.
Besides those, I sometimes use oddball/vintage capacitors I find on eBay, but those are not always easy to find, so I won’t bother mentioning them.
- Pedals: I almost exclusively use Alpha 16mm. They are cheap and decent.
- Amps: for some I use Alpha, either 16mm or 24mm. For special occasions I splurge on those very nice CTS pots (some with plastic, some with metal shafts). They are 3x the price of Alphas, but also 3x the quality.
- Guitars: getting the right (subjective) smooth taper, noise free operation, low friction and longevity are the most important factors when buying guitar pots. My favorite pots are the awesome, but pricey Bourns plastic element pots. They are sealed, so dust can’t get in and they tick all my boxes. Very smooth, gradual taper, great for volume swells and durable, noise free plastic element. The other brand of pots I like are CTS/DiMarzio.
I hate noise and that’s the main factor that drives my choice of resistors.
- Signal path: 1/2W (for amps) and 1/4W (for pedals) metal film resistors are my to-go choice. Sometimes I use fancier brands, like those nice brown Vishay/Dale resistors or Xicon 1/2W resistors which are noticeably larger than most 1/2W types (larger should mean less noise). Other times I use generic metal film resistors that work just fine.
- Plate resistors: 1/2W metal film will work just fine. For even lower noise, using 2W metal film (Koa Speer has nice ones, but any will do) resistors can be a good idea. Carbon comp resistors are one of those magical mojo components often advertised as a big upgrade, but can introduce noise and that can become a problem in a higher gain amplifier. Used strategically, carbon comp resistors can add a touch of their character without introducing too much noise. Plate resistor is the one of the very few places in an amplifier that could benefit from carbon comp resistors as there’s the highest voltage swing across it. To maximize the effect of the resistor, use the smallest wattage rating possible taking the voltage and current into account. For most amps, 1/4W-1/2W should do.
- Power supply: My favorites are 2W KOA Speer Metal Oxide, but in a pinch, I don’t mind using 2W carbon film resistors.
- Jack sockets: either Neutrik and Switchcraft open-style jacks or Cliff plastic enclosed jacks. Cliffs are isolated which means they require a slightly wider mounting hole, but they give you more control over grounding as it’s up to you to decide where you want to ground the jack.
- Jack plugs: I like those hefty Neutrik straight and angled jacks, but for patch cables where I need more compact jacks, German Hicon pancake right angle jacks are good choice.
- Toggle switches: generic mini blue switches are just dreadful and melt easily, so I try to stay clear from them. NKK makes some really nice toggle switches and they have wide variety of models (I like those with a tiny LED integrated in the toggle bat). For larger toggle switches, as used in most amps, Carling makes some really nice switches.
- Guitar switches: in Strat-style guitars I prefer OAK Grigsby or CRL lever switches. In humbucker guitars I like using their “super-switch” aka “multi-pole” switches that have 4 poles instead of the usual two and can be used to achieve some very interesting wiring combinations. In LP style guitars, Switchcraft switches are very well made.
Obviously, there’s so many different semi-conductors and certain circuits call for certain types, but there are a few of them I like using in my own design or as replacements in existing circuits.
- Supertex LND150 can be used as a drop-in replacement for a typical ECC83 triode in tube amplifiers. Sure, it doesn’t sound the same as a triode when overdriven, so you can’t replace all triodes in an amp and expect it to sound the same. But when used strategically, they are very convenient way of adding another gain stage at the front of an amp (hot rod), or recovering gain after an FX loop or similar applications.
- Supertex LR8 adjustable high voltage regularor capable of working with voltages up to 450V and currents up to 20mA. Can be used to regulate even high voltage for tube preamps.
- IRF820 is another MOSFET transistor than can be used in tube circuits, as described in this cool geofex article. As with LND150, make sure that it doesn’t get overdriven. I tried it in a hot-rodded JCM800 design as cathode follower replacement and it didn’t sound particularly great, but used as the first gain stage or in the FX loop could save you a tube triode that can be used for something else.
- Russian germanium transistors are generally cheaper and more consistent than what’s left from the Western world stocks of Ge transistors. They are also much less prone to current leakage. GT308V/1T308V (ГТ308В/1308В) is a good example of higher gain transistor that works well in fuzz (Bonamassa Fuzz Face uses those). MP39B (МП39Б) are also good lower gain transistors.
- Preamp: I really like modern JJ ECC83 in most cases. They are consistent and warm sounding. For those who like experimenting, Russian tubes can be good cheap alternative but require rewiring heaters. 6N2P (6Н2П) and 6N2P-EV (6Н2П-ЕВ, higher quality military version) sound great and can have lower noise levels due to the internal shield. They seem to have a tad lower gain than the ECC83/12AX7 though, so keep that in mind.
- Power-amp: I’m a huge fan of low powered (<10W) amps and I'm always searching for cool tubes that can be used to build a good sounding amps that won't make your ears bleed. It's hard to find current production low-power pentodes, but NOS from the 50s and 60s can still be found if you look hard enough and in most cases they are not as nearly as expensive as the mainstream NOS tubes. 6AK6 are miniature B7G-base nephews of the 6V6 power pentode and can make a good sounding low power amp with around 1W for single-ended and 3W for push-pull configuration. EL91 are similar miniature B7G-base pentodes from the ELxx family. They can produce around 1.5W in single-ended and 4W in push-pull configuration. EL95 are slightly more powerful miniature B7G-base pentodes and can produce around 2.5W in single-ended or 7W in push-pull configuration. ECC81/12AU7 double triodes are normally preamp tubes, but can sound surprisingly well in push pull output stage and produce less than 1W of power. Two 6SN7 triodes can be used in push-pull configuration for around 2W of power and sound really nice. In the big league, Russians have some NOS tubes that are decent and cheap alternatives. 6P6S (6Π6С) can work as a drop in replacement instead of 6V6 and they sound really good, but I’ve heard that maximum anode voltage of 350V should be honored if we want them to last. Another Russian big boy is the 6P3S (6Π3С) which is their version of 6L6.
- Submini tubes: these are really cool – very small with flexible leads intended to be soldered directly to the board and built to last longer and endure higher Ge-forces than conventional tubes. They are more than capable of living in guitar rigs and stompboxes. Unfortunately, nobody produces them anymore, but some old stock can still be found as there were a bunch of them made for the military. Relatively recently, some manufacturers started using them in their pedals and amps which drove the demand (and price) up, but persistent eBay-ers can still find them. 6021 is a medium gain dual triode that can be very versatile. Seymour Duncan uses them in some of their preamps, Zvex Nano Amp uses them for both preamp and power amp. 6112 are higher gain dual triodes and they are really nice but also harder to find and more expensive. 5744 are single triodes with higher gain, similar to one half of the 6112. There are also sumbini power pentodes available, such as 5902.
As a general advice, when you are building an amp from scratch for your own use, sometimes it may be worth looking into oddball tubes that are not often used in modern amplifiers. That way you can find some nice NOS tubes very cheap. For example, I bought some NOS Raytheon 12SN7 tubes cheaply and they are identical to the 6SN7 except they need 12V heaters instead of 6V. Most people will go for the 6SN7, but not us, we’re smarter 🙂 . It’s also possible to find some cool triode/pentode combo tubes that are very rarely usedthese days. For example ECL86 is similar to a half of ECC83 and EL84 stuffed in the same tube. ECL82 is relatively similar. And it’s even easier to find PCL versions of the tubes cheaply which use 13.3V for heaters, but are otherwise identical to the EL cousins. Those tubes can either be used to build simple single ended amplifiers (e.g., LND150 gain stage -> triode gain stage -> pentode output stage) or use two of them in push-pull with the two triodes wired as phase-inverters.