Who are your favorite custom amp builders for low powered triode amps?

I’m a huge fan of Oliver Sayes out of Brooklyn. He makes incredibly affordable DHT designs, cloning and building off Korneff 45 and Yamamoto designs, amongst many others. He can source top notch transformers and components, either ones he may recommend or ones you request. I sold my last one to a person here on Audiogon. It was a very special amp, but I no longer own high efficiency speakers. Feel free to PM me if you want me to put you in touch with him. 

I have really liked my Aric Audio Super 300B SET.  

https://aricaudio.com/products.php?product=SPR300BSET

I am also a big fan of Brandon Wade's amps.  I have a custom 2A3 amp from him that I really like.  He has been finalizing the design of an 811 amp that is higher power but still SET.  I heard the prototype and liked it too.

https://apolloaudiosystems.squarespace.com/

Decware offers the finest triode amps available at a reasonable price. The hitch is that you have to be on a long waiting list unless you buy used, which is a great option. 

The only drawback to buying these simple basic amplifiers from boutique companies is they do not stay in business very long, leaving you with an orphaned product that has poor resale value when you decide to upgrade.  Having said that, I have owned SETs from Sophia Electric for the past 20 years and recommend them.  They carry in house all the parts you might need to retube or modify your electronics and are available for personal consultation.  Great company!

You never know who will be around tomorrow…. Hopefully most builders and small companies  with a good following survived COVID.   That really hurt small companies that buy electronics in smaller quantities.   Plus a lot of businesses temporarily shut down losing skilled workers.