great kit. I just popped these in and they sound amazing. Huge improvement. Its like I have a whole new amp. Incredible upgrade. Warmer, fuller, deeper, a 100% improvement!

I also bought the tube set for my new hybrid amp from Monoprice. First let me say the standard tubes were very good. I rolled the new tube keeping the old tubes in the tubestore boxes. At first I could not sense any real difference, but after a week of burning in the new tubes (I always wait until the tubes have 20 hours of use) I could definitely sense a cleaner response. I highly recommend the tube set.

The original tubes work well, but the new tube package gives more detail. The soundstage is very wide, and I noticed something I wasn't expecting, and that's the artificial electronic additives so many recordings have (Adel, Sia, etc.). The separation is absolute, and individual instruments amazes me. Yes, I recommend rolling the tubes to the upgrade.

This amp before sounded, in comparison, to an NYNEX operator, it was narrow, shallow, and overly bright, pinched. Although, it was better than its little brother the 25W Hybrid. These new tubes, however, are game-changers. The sound is bigger and warmer. It's spatially wide open and there's separation between the instruments. It's now far cheaper competition, in cost and quality, to Avery Fisher's 500.