I get great joy from building kits.
I've built various Dynaco ST70's with the Van Alstine Ultimate 70 being one of my favorites..I built their old 70i as well. A ST70 was my first DIY project. I've done two of the ANK EL84 but built as a straight power amp. Great amp. A no name el84 diy amp I was able make listenable by correcting the grounding scheme & a couple other small changes. Tubes4Hifj preamps & a couple of the Mellow Tone Kits preamps (the Universal & e80cc)..which I recommend for any first time builder. They offer low power amps & a new balanced pre I haven't tried yet. Recently built a very high quality (sounding) relay attenuator passive. Some Zaph ZRT Speakers & a TD1865 tube output non-oversampling dac. And an old Assemblage L1 preamp kit I rebuilt..& actually turned out pretty impressive. I did upgrades to my Icon Audio LA4 mkiii as well. Repairs & mods to old pieces as well. Reading up on John Broskies Aikidio circuits can give you ideas on how to change the tubes4hifi circuits or just build your own point to point. I built a Hypex Nilai stereo amp but that one is pretty simple. I really liked that amp compared to the earlier Hypex & Purifi modules. I think the Nilai is a really good class D module.
A lot of the fun for me is adding upgraded passive parts in important places. I like the pretty boutique pieces. Replacing voltage dropping resistors in power supplies with filter chokes. Adding quality stepped attenuators in place of the standard Alps pots found in most gear..even pricier stuff.
Upgrading electrolytic bias capacitors, adding or upgrading cathode bypass caps. Sometimes adding bypass caps to the last B+ electrolytic in preamps. Using film caps for smoothing after the rectifiers. Upgrading interstage & output caps or removing the interstage completely if possible. Grid stoppers, plate load resistors getting attention. Any input resistors in series with the signal.
Something like the Mellow Tone preamp kits which have simple line circuits have been fun to play with. Easily tuned to preference just by changing values to the first plate & cathode resistor while leaving everything else stock.. value wise. Because their circuits are short & sweet I went thru a phase where I bought a few of just the line stage PCB's are experimented with different brands of resistors & caps. I would just switch in & out the different populated boards to see if differences could truly be perceived by different brands/types in various positions.
I had no electrical or design background & just got into DIY maybe 4 or 5 years ago. Learning as I go as far as how tube designs work. It's all been a learning experience. Grounding techniques being the most complicated for me, more so when I first stated tinkering. Took me a little bit just learning to solder correctly without gobs of solder or making weak joints. Mellow Tone again is great for beginners because of their thorough build videos on YouTube..even giving temperature tips. I have no affiliation with those guys.
I almost forgot about Skunkie on YouTube, which is a great DIY channel. If you can handle getting the chassis her build videos are great..all point to point as well.
I certainly wish that there was more kits available out there. Not having pre-fabricated chassis hinders me personally. Im also to the point where I need a signal generator & oscilloscope. I've spent days & weeks trying to diagnose problems when a scope could have eased my pains.
I think that there is extreme value in DIY speakers. Lots of designs available using drivers you normally only see in the real high end stuff. My lack of tools keeps me from experimenting like I would want to with speakers. I have a local guy that makes good enclosures but it's certainly not as cheap as if I did it myself. My goal is to just keep adding tools as I see them come up cheap on my local 2nd hand market. I've done a couple crossover upgrades..same values though as I have no experience with crossover building.
So DIY has been a lot of fun for me. And when some pieces turn out to be legitimately great sounding there is a wonderful feeling of accomplishment & enjoyment. I'm still learning..but my confidence is growing. My paid version of A.I. has been extremely helpful. It has provided great insight into what I'm doing & why. Very helpful with upgrade suggestions while providing the information behind the suggestions.
I would love to see more DIY full kit options on the market. Though I'm at the point where if if I invested in certain tools I could try building more of the non-kit circuits out there. Great bang for the buck when it comes to DIY..components & speakers.
If getting involved with DIY has ever been an interest to anyone I truly recommend giving it a try. Find an "easy' kit. It can be as simple as paint by numbers in a way. Just learning how to solder is a big step..but not that hard if your hands still work well (I have a little arthritis). Realizing not everything is as delicate as you may think.. as long as you don't over cook parts with extreme heat. Start slow & easy, build some confidence, next thing you know you will be tinkering with everything.
