Sun Valley vs Sun Audio 300b

I heard hashimoto are great, but the circuit is a lot more complicated and has NFB. Anyone can look at these two schematics and get a feeling for what would sound different? (Assuming similar components)

Sometimes simpler is better, and sometimes regulated, constant current source configurations, for example sound better. I wish I could help you more. Best of luck. 

@clustrocasual I am also interested in these 2 amps. Did you manage to find any more information which would help compare the two ?. 

@kdogsy I found a few things.

- YouTuber and DIYAudio poster Skunkie built the Sun Audio and found a lot of things she considered problems. Paraphrasing here - the input stage of how the twin triodes are wired is very very high gain and increases noise and distortion. She wired them in a different way for a much better and cleaner sound. It’s possible the original design was done this way intentionally, and I know OJAS is selling the "history" of the amp, but she questioned the original 6SN7 schematic and did not agree it sounds best. The design was thought to be from JC Morrison but someone else claimed it was a Japanese guy. I was interested in trying Skunkies schematic if I build it.

-I asked Brent Jesse and he considers both the 12AU7 and 6SN7 to be the best twin triodes for different reasons, and he said 12AU7 is lower noise and FAR more available. (Telefunken smoothplates, etc). A great 6SN7 is really hard to find right now and collectors bought them all up. If you plan on maxing out the amps, it’s something to consider.

- One think Skunkie did not like about the Sun Audio design is the 300b plate voltage is strangely low, around 300V. Her mod puts it near 400 which is the modern day common use.

- I asked Victor about removing the negative feedback on Sun Valley and he did not give a clear answer. It seems Sun Valley is designed for a "modern" 300b sound, more stable, a bit more circuitry. The Sun Audio with Skunkie’s mods may compete with it, but it also has a double starting price for the kit and you need to find good 6SN7’s.

- From what I read, Hashimoto transformers may give me the sound I prefer, which is a bit of Japanese Furutech sound, kind of OCC copper sound, very realistic and intimate.

I will likely buy the Sun Valley from Victor and try it with and without the GNF. I plan to upgrade all components to the best Audio Note, VCap and internal wiring, so I don’t think I will be disappointed. It’s impossible to know for sure, but gotta start somewhere. :)