EL34 & 6L6 characteristics

David, no matter what anyone claims, everyone gets the same tubes from the Shuguang factory. They do not release better or worse versions. When they pass QC, they're good tubes. Again, in my experience, Shuguang produces the most rugged and reliable tubes currently. As you noted, once they go off into the world, various entities screen their own names/logos on them.

If you decide you like the 6L6 sound best, go with it!

I'd still give the Shuguang EL34s a try, just to see how you like them. Normally, I need to listen to 2 or 3 variants before passing judgement on a tube type. EL34 should normally provide good detail.

By the way, I presume you own the Shuguang EL34B variant? You can tell by the fact that they have a reddish brown base. Their original, EL34 (EL34A) have a black base, and do not sound nearly as good.

I really like the Shuguang EL34B. That surprised me. I liked them better in my Coincident Dynamo 34SE than some NOS that shall remain nameless. I am really enjoying the Shuguang Black Treasure 6CA7 even more so.

As I said above they shall remain nameless.

I've owned the Psvane TII KT88 and 6CA7 tubes but only listened to the KT88s in the CAD 120S MkII. They sounded more dynamic but the midrange is not as sweet and pronounced as the Svetlana/SED Winged C EL34s which are biased at only 100mA with the pot maxed out. Cary Audio stated in the manual that it supports EL34 with 140mA bias but owners could not get that high.

Anyway the Psvane TII tubes are more expensive than the Shuguang black treasure and supposed to sound better. I also owned and listened to the new Tungsol KT120s in the same CAD 120S and they have bigger sound overall. I've also owned and listened to the Svetlana Winged C 6550s and they sound not much better than the KT88s. I've got the EH GP in the driver and TJ Full Music gold pin in the front end. The CAD 120S MkII is driven by the SLP-98P with Telefunken in the phono stage and two Sylvania JAN WGTA in the front end and the TJ Full Music gold pin as driver. I've not tried the acquired JAN CHS V231 Sylvania GTBs yet but for only a few listening hours with the more expensive MELZ 6SN7 in the CAD 120S, these cool looking ones sounded really wonderful.

The CAD 120S MkII is only a few months old with the Clarity factory upgrade but the Vcap CuTF have replaced them. The SLP-98P had the Mundorf S-G-O cap upgrade with better resistors. I also installed bypass capacitors in both.

Both are driving the new Maggies 3.7i speakers with AQ speaker cable and Columbia interconnects.

The REL sub is fast enough to keep up with the very fast ribbon drivers.

The result is breathtaking! The musical instrument clarity is just outstanding. So are the soundstage and image with better accuracy. For example the saxophone notes sounded so lively vibrant that they slightly annoyed my ears (you know that happened when getting near to a real saxophone playing).