In the middle of the night, after finishing my tube rectifier dual socket modification, I prepare some tube rectifier to test the new socket. I think it’s gonna be nice to evaluate the sonic of some rectifiers to 😉

Actually, I have known the winner, although I haven’t compared them one by one on same setup – like this time.

Let’s start with Telefunken RGN 1054 Mesh, the basic or entry level tube rectifier from Telefunken. With the price around US$ 100 or less, this tube is just fine to let you know the special of RGN families. It sounds musical, crisp, and detail. The vocal is nice, although slightly thin. The Mesh Anode version is better in terms of transparency and musicality than the Solid Anode one.

Let’s continue with his bigger brother, Telefunken RGN 2004 Mesh. This one could produce higher current (you can see the red triangle is doubled compared to the 1054). With the current cost nearly US$ 400, the RGN 2004 Mesh provides enough jump in terms of sound quality compared to the RGN 1054. RGN 2004 sounds even more musical, even sweeter vocal, very improved staging (depth/width), and impressive music separation. Don’t forget to mention the excellent details also. This is the rectifier that makes me enjoy the vocal of Stacey Kent and want to repeat it again and again.

Below is the Valvo G1064. The 1064 has similar specification with 1054, but I think the 1064 is newer. Instead of using the RGN prefix, Valvo uses the G prefix. So we are talking the same between RGN 1064 or G1064. When comparing with Telefunken, this Valvo sounds a little bit thicker in vocal, slightly less details, but still on the level of “more than enough”. They are very good as entry level tube rectifier, especially for you who want to “try” the RGN series.

The Solid Anode version of Valvo G1064. Less detail and less transparency. But at fraction of the cost compared with the Mesh version, this is quite nice as a spare tube rectifier.

Below is el-cheapo Russian Rectifier 5U4C. You can get it less than US$ 10 each, probably around US$ 5. At this cost, you can’t expect more, but this tube has good tonal balance. Not to thin vocal, adequate detail, and solid bass. Also this is a rock solid rectifier. Ever push it around 2A for several minutes (due to my stupidity putting 100R bleeder instead of 100K), but this tube still last until now. Really a nice tube rectifier for most of common usage.

Another Russian Rectifier, but this one is not really known due to its rarity. It has B4 socket, 4 Volts filament, and over 2A filament current. Probably around 100-150 mA Anode current, but seeing the 6 red triangles, I assume it may have current capacity over 200 mA (so probably on the level of 5U4/5AR4 series). As common Solid Anode rectifier, this tube rectifier doesn’t give impressive detail, but overall the tonal balance is very good and better compared to other Russian Rectifier which I’ve tested.

All these rectifier tubes are tested on my Aikido pre-amp, powered with oversize customer power transformer, VCap-Jensen4pole-ASC (choke loaded) on the power supply, combination of Riken, Shinkoh, Kiwame, and Vishay S102 on the resistor, DACT 100K Stepped Attenuator volume control, Duelund CAST Ag as output coupling, Jensen Copper Foil Aluminum Tube as final Anode supply bypass, 6N1P-6N6P tubes. DIY Speaker with Vifa XT25 and PL18 (Auricap/Alpha Core/Solen/Duelund CAST Resistor inside). Power amplifier IC-based in AB-Class. Duelund 2.0 Rev 2 interconnect, custom DIY interconnect, Synergistic Research speaker cable, Cardas RCA, Shark RCA. All WBT solder on the signal side and most of the supply side.