Sun Valley vs Sun Audio 300b

@beattyomatic Great post. Thank you. 

@beattyomatic Sorry for the delayed response and thanks for the very informative post.

What speakers are you using with the Sunvalley?

My pleasure! Regarding speakers, I’m using open baffles made by Caintuck Audio. I chose the Lii Audio F12 full-range drivers, which are about 96dB sensitive. I also have two Caintuck subwoofers with Eminence Alpha 15’s in them.  

One thing I should add about these amplifiers. The Sunvalley, and I presume the Sun Audio, are Japanese appliances that are not grounded in the same way that that US appliances are grounded. They use 2-prong power inlets and power cords instead of our standard 3-prong power inlets and cords. So I understand it, it's because Japanese engineers approach safety measures differently, focusing more on preventing short circuits than ground issues.

However you feel about the relative safety of floating grounds, they can be noisy, susceptible to electromagnetic interference. And indeed my unit was, probably  because I set it in a spot in the house near all our wifi/router gear. Because the soft, static noise I was hearing didn't go away completely when I turned the volume all the way down, it was clear I had a grounding problem. After checking all my ground connections for cold solders and bad connections, I decided to earth-ground the unit, which was quite easy to do. 

Anyone who decides to build the Sunvalley will see in the build guide that all the ground wires connect to a central ground which is, not surprisingly, a through-the-case screw by the rectifier that holds down one of the terminal strips (it's marked "ground point" on page 8 of the illustrated wiring guide). That screw simply needs to be connected by wire to the third prong of a replacement US-style power inlet. Happily, those inlets very easy to acquire, indeed the product linked below is an exact duplicate of the two-prong inlet that comes with the Sunvalley. The screw holes even match up.

All you need to do is install the inlet, connect the internal power leads to the usual spots, then connect the inlet's third-prong ground to the ground point (the US version even includes wire and spades if you want.) The process takes about five minutes.

Anyway, earth-grounding the unit solved my noise problem, and I expect it would solve similar problems for other Japanese amplifiers. Plus in the end you have, at least IMO, a safer amp. Here is the product I mentioned:

Hi all. I am new to this group.

I've been addicted to DIY audio for many many years, but just recently decided to give tubes a try. I wanted to start out with a single-ended kit that could be modded rather than going full-on scratch-built as my first experience. I spent considerable time researching and I found myself in a similar situation that was the catalyst of this discussion thread - torn between the Sun Valley, Sun Audio, Elekit, and Audio Note. Not a lot of comparison reviews out there for these contenders. Buying an amp without hearing it or touching it can be stressful. I eventually decided on the Sun Valley 300B (SV-S1616D) with the Hashimotos. My decision factors were point-to-point construction, price, and footprint (aesthetics). I just ordered it from Victor last week and it should arrive this week. I will say Victor is great to work with and passionate about this stuff. In our numerous email exchanges he always responded quickly, never more than a couple hours. He gave me a great deal, with a combo discount for buying a tube set with the amp, and he threw in the silver solder for free. I have a few upgrades in mind as I build - better hookup wire, better capacitors and resistors, possibly upgrade the tube sockets, maybe repaint the chassis, etc. I bought the GZ34 rectifier tube so I can experiment with tube vs SS rectification.

@beattyomatic Thanks for your write ups, they are helpful as I get started on this project. Great point about using a grounded IEC. I am curious about your mention that the rectifier tube can barely handle the voltage. From the 5AR4 type tube spec sheets I have seen the plate voltage can go up to 550V, and as far as I know the SV 300B is running the B+ at around 400V. I would love more detail on this if you don't mind. I was feeling like I wanted to be all tubes and use the tube reification for that "sound" but not if it introduces reliability risks.

I will keep you all updated with my build.