What is the best 5U4G ?
- Thread starter Tango
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@Solotov I wouldn't recommend against it, or at least not the first version, but at the time I found the Telefunken AZ1 mesh to be far superior. I may have one to sell with an adapter no longer in use, but notice that you are across the world.
My lack of knowledge and fear prevent me from using any tube adapter haha. But I saw in multiple Lampizator threads that many users are using it with great result. Hmmm...
May I know what recti you would recommend?
Almost every non-adapting 5U4G variant I tried was objectively better than the Tak 274B for me simply because of its overly emphasized mids, and artificial tonality across the frequency spectrum that sacrifices transparency. If that's the sound you need based on the context of your current system then it might be worth a try. IMHO.
re: Sophia Aqua II 274B
I freely admit to being a newcomer to tubes. I have a Modwright KWH 225i hybrid integrated amp that came with a pair of JJ E88CC triodes (upgraded to 1960s-era Holland Amperex 6DJ8s) in the preamp section and a Modwright PH 9.0XT phono stage that employs a Russian 5AR4 rectifier in its separate power supply and a pair of 6C45s and a couple of 6DJ8s in the phono stage itself.
After the phono stage's 5AR4 died I replaced it with an identical new Russian tube. As I spent more time listening, however, I kept feeling that the tube might be holding the sound back a bit. Notably, there was a bit of upper midrange mud that I didn't hear when listening to my digital side, along with some soundstage constriction.
I decided to take a chance and replace the phono stage rectifier with a Sophia Electric Aqua II 274B. I'm an experienced and careful listener, but as a relative tube neophyte, I was uncomfortable taking my chances in the obscure world of tube vendors and the questionable provenances of many of their wares, particularly as I was only taking an educated guess that spending several hundred dollars on a phono stage power supply rectifier might make the difference I was looking for. But I decided that investing less than $300 (with tax and shipping) on a new Sophia was worth a shot.
As a brand new tube, I expected the Aqua II to take some time to get comfortable. Right out of the box, however, the upper midrange was significantly cleaner. It wasn't that the overall sound had become leaner; rather, it had eliminated the slightly muffled thickness that was there previously while leaving the overall weight and timbre intact.
I've continued to enjoy the Aqua II's performance, noting a wider and deeper soundstage as time goes on. I'm quite sure that the success of any tube is system-dependent, but the Sophia Electric Aqua II 274B rectifier works for me. Yes, I'd like to try a pinched-waist Valvo CCA, but that kind of money, that kind of wait, and that level of risk is not my personal style.
Anyone tried the new and more rugged 2025 version of the Kron / KR Audio 5U4G that's been re-designed to take a first filter capacitor of up to 50µF (compared to only up to 10F for the earlier versions, in contrast to NOS 5U4G)?
Greetings from Switzerland, David.
Greetings from Switzerland, David.
I can't comment on this specific question but I'm another fan of the RK 5U4G as being state of the art. I lean toward using vintage NOS and have tried several Marconi, Osram & Mullards but the RK tube is cleaner and more dynamic.
British or Italian Marconi? I have an early Italian one with top side square getter (looks pretty unique), sounds completely different from two Marconi-labeled 5U4Gs that belong to @morricab (and of which I seem to remember he said one is Canadian, but not sure). Interestingly enough, the romantic sounding wasn't the Italian, which instead is one of the cleanest and lowest distortion sounding 5U4Gs I've come across. Of the RK, I have a preference for the Riccardo Kron Anniversary Special Edition, but due to their specs I wouldn't dare use either in an amp with a 47µF filter capacitor, which is why I asked about the new 2025 version.
Greetings from Switzerland, David.
I have a bunch of NOS RCA 5U4G if you want to sample one for the cost of shipping.
I'm not sure now whether it was British or Itailian Marconi. My guess would be British, Mullard or Osram?
I have one Canadian and two Italian Marconis. The Canadian is slightly romantic and the Italian ones are very romantic sounding…one more do than the other despite them only being one year apart (1955 and 1956).
My Italian Marconi has a square getter, usually a feature of early builds, so probably older than either of yours I could try? Doesn't sound anything like other 5U4G I've tried, including yours (not romantic at all, but not in a negative sense either, just a very undistorted, clean, clear and solid sound). I really like both (incompatible) sound signatures.
Greetings from Switzerland, David.
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