This is the third valve I've bought for my Bhringer analogue monster stomp box.
1. A hugh improvement. So much so I use it a lot now.
2. The eq pots really work well now and with the drive at 1/2 setting it gives a very convincing 60s overdrive sound.
3. Cranked up you can just about get any overdrive/fuzz you like.
4. With compression/sustain up before, into the monster, and a touch of delay, into wah, you can have your very own Isle of Wight (I was there in 1970) festival..
It's cheap, buy it, try it..lots of good things come out of Russia..