I'm finally going to prototype some designs I've had rattling around my noggin for years. I've done some baseline circuit simulations for most of them, so it's time to grab a breadboard and a pile of parts (probably from Mouser). I'm mainly curious as to what relatively new/current-production transistors and ICs are popular among you folks and why. Most of my plans are in the realm of preamps, compressors, equalizers, and assorted instrument effects where I have the luxury of not necessarily needing to optimize for linearity, power consumption/dissipation, cost effectiveness, or other real world design problems. Noise is really my greatest concern, and if we want to get into the intangibles of audio design I do care about things like "warmth" and "musicality", but I know those generally have more to do with the design as a whole (not to mention the listener 😉).
I don't need the cheapest parts and don't want the most expensive. I'm a through-hole guy through and through (ha ha). As for the specific recommendations I'm after:
I don't need the cheapest parts and don't want the most expensive. I'm a through-hole guy through and through (ha ha). As for the specific recommendations I'm after:
- Complementary small signal, high gain BJTs - I used to use 2n5088 and 2n5087 all the time, and have used ZTX1053 and ZTX953 a lot in my simulations. I would use the ZTXes now but it would be nice to get 50~100 NPN transistors for less than $50 (less concerned about the PNP price since I will probably only need 10 for now).
- Complementary low-to-medium power, low gain BJTs - Again, I've used a number of parts along these lines but never had a strong preference.
- Complementary small signal (or suitable power) MOSFETs - I've been digging but haven't settled on anything yet. Low and relatively consistent gate-source threshold and low gate charge are priorities, excessive gate capacitance won't fly. They don't strictly need to be complementary, in all honesty comparable would suffice for my needs. Realistically I would only need 10 N channel and a couple P channel devices so spending up to a couple bucks a pop wouldn't be too bad.
- N-channel depletion MOSFETs - There are a few more parts available since the last time I looked. I have little practical experience with these and just intend to experiment with one or two models. Any strong contenders?
- Opamps - I've mostly used a range of NJM, TI, and AD devices, and have a shortlist of parts to grab (plenty of 072, NJM3404 and NJM2068 have been staples as well). I don't really need any recommendations here, but I'm always interested in what folks are rolling. Don't really want to spend more than a couple bucks on one chip, and only really want dual opamps.
- Buck/boost converters - anything "better" or as good but cheaper than an LT1054? My main uses are boosting and/or inverting standard 9V supplies. I like the 1054 because it would allow me to use up to a 15V supply (18V would be better, but it's not a big deal). I'm terrible at navigating these, every time I think I've found an interesting one there's a gotcha like unexpected circuit complexity or limited flexibility. I've found some neat little guys that accept 5V and provide +/-15V (etc) but the input limit is a bit of a dealbreaker.
- Not a semiconductor, but bonus round - any particular audio signal friendly, center-tapped, 1:1 (or close enough) compact transformers in Mouser's catalog you might recommend? It won't need to deliver significant power, but if it happens to suit, say, a headphone amp, that would be nice. Just another part to play with.
Maybe more likely to get some suggestions if you post a schematic. IOW, there are many transistors and context can matter.
I'm worried that my design and design choices will derail the conversation (questions about what I'm smoking, helpful design feedback, et cetera) but I see your point! Might be worth noting that I've worked on many variations of my designs tweaked for different parts. I've also made an effort to use a relatively small range of component values across all my designs (with some variation depending on age), which simplifies a great many things for me. Ergo, I would really like general purpose recommendations where possible, as I will be using any given part in a number of not necessarily optimized ways. An easy example is what I've put the 2N5088 and ZTX1053 through - output devices in a low power AB amp, gyrators, current mirrors, and simple amplifiers in circuits comparable to classics like the Big Muff Pi.
I should really tidy these up some more, but here are a couple quick examples of what I'll be playing around with. In some cases my schematics are greatly simplified, for example eschewing protection diodes, or are meant as more of a proof of concept than a finished design.
I should really tidy these up some more, but here are a couple quick examples of what I'll be playing around with. In some cases my schematics are greatly simplified, for example eschewing protection diodes, or are meant as more of a proof of concept than a finished design.
Attachments
You might take a look at some parts for which updated Spice models are available: https://www.cordellaudio.com/book/spice_models.shtml
I keep this list of modern-ish small sig/mediums on-hand, most bought from mouser. most are ECB pinout.
https://docs.google.com/spreadsheets/d/1-HTbilBn2ijWhBfK1KLDUHM4NhryRN7ylwL1duREcnY/edit
https://docs.google.com/spreadsheets/d/1-HTbilBn2ijWhBfK1KLDUHM4NhryRN7ylwL1duREcnY/edit
Ultra low noise JFET that recently came out is the JFE150, but you'd need a break out board for it (new components are not through hole).
Once you've got a break-out board any surface mount component can be through hole!
Low noise bipolar opamp the NE5532 and NE5534A still give a run for the money in the 1k to 20k impedance range, and of course are available THT. Many many opamps out there, quite a few still THT.
For higher voltage circuits (power amps) the KSA992 / KSC1845 are popular, no reason not to use them at lower voltage I know of.
For low impedance low noise transistors the ZTX951 / ZTC851 are notable devices.
Once you've got a break-out board any surface mount component can be through hole!
Low noise bipolar opamp the NE5532 and NE5534A still give a run for the money in the 1k to 20k impedance range, and of course are available THT. Many many opamps out there, quite a few still THT.
For higher voltage circuits (power amps) the KSA992 / KSC1845 are popular, no reason not to use them at lower voltage I know of.
For low impedance low noise transistors the ZTX951 / ZTC851 are notable devices.