Let me start by saying that JJ continues to have quality issues. I thought a burned in, apex matched quad would filter out the bad tubes but 2 of my tubes had a rattle. Just turning the tube upside down I could hear something loose inside. Now I know rattles are rarely an issue for hifi amps so while waiting to hear back from the seller, I installed them to hear how they sound. Well, my rack is quite close to the side of one speaker and once or twice I heard effects of a tube rattle so there was no way I was going to hold on to them. From what I could tell, they sound great! Solid bass and mid-bass, a sweet smooth midband and a little rounded at the high end just the way I like it. This is a big bold sounding tube. The seller agreed to a return promptly but I had to pay for shipping both ways so I cannot recommend them to anyone. Stick with New Sensor brands, the EH 6CA7 is sturdy and reliable and a decent sounding tube as is the Tung-Sol EL34B.