SUT - electrical theory and practical experience

Thought I share my perspective. In short, SUT’s are imo very cost effective and it easily gets forgotten. Some people have restrictions, for example room/placement and/or economical limits. Thats the case for me. 
Have Kenwood KD-990 (increased mass on tonearm) with Denon DL-103 for the past 25 years. Monitor audio speakers just as long. Standard gear all the way. 
Phono preamps have changed over the years though and also nowdays have a Denon DL-305. Started with cheapest Pro-ject stage and my last and to me most ”expensive” phono preamp was ASR Mini Basis. It was a nice sounding unit for sure, but there was constant noise from the speakers. Not too bad and didnt really notice it once the needle dropped but there was noise for sure. Decided to try a SUT instead, bought AU-340 and never looked back. I run the SUT to my Denon AVC-X8500 built in phono stage (I assume its crap!) still this is the best sound I had. Paid 350 USD for the AU-340, there is absolutely no way a phono preamp at that price would stand even the slightest chance against the SUT. So take this into consideration please. Also, maybe some people like fiddling around with dip switches and experimenting with loads etc etc, I did with my ASR but the whole thing just annoyed me at the end. 
I am about to buy a better MM phono preamp now. No silly money though, looking for something tops 500 USD. Any recomendations apreciated. 
Respect and thanks for a great forum that helped me a lot over the years.

Thanks o_holter. I believe your right I never got the settings right on the ASR. Didnt quite understand the loading/gain thing back then to be honest (still dont).
Finally got a new phono preamp though (schiit mani 2) and it was a great improvement using the AU340 SUT into the mani MM stage with 42 db gain. Everything kinda opened up and better punchy sound, better dynamics with zero noise/hum/buzz added. No coloration and that I also like a lot. 
I did try the Manis MC stage with 60db gain and 200ohm loading. Sounded nice but I no longer quite recognized the DL-103. The clean, dead silent, natural and organic sound Ive become used to with the SUT was gone. The Mani MC also picked up more vinyl noise (crackling etc etc) when compared to the AU-340 that seems to mask record imperfections really well. Maybe more engaging sound with the Mani, I think thats a matter of personal preference and the rest of the setup. This is really not a fair comparison at all (mani being very low budget) but it at least confirms my believe that you need to spend much more than 150 usd to beat a SUT.

Anyways, I asked myself before how much my ”new” receivers built in MM phono was holding the sound back? And how important is the MM stage when using a SUT? In my case it made huge difference even with a low budget preamp like the Mani. Know theres always room for improvement but this I can stick with for some time. 

Am soooo curious trying the Kenwood SH-305MC, anyone with experience?