The only tubes I can compare these to are the Tungsol... 6550 tube type that my Jolida 502CRC came with. I've only had them in for a few weeks and they still have a long way to go before break-in, although the quality of sound has changed from bright and crisp (Tungsols) to smooth and silky (Treasures). Bass response has increased and vocals are slightly more dimensional. There a bit more pricey than the Russian brands but I did'nt want to purchase a pile of lesser price brands and then find out these were the ones I should have picked in the first place.
Verified purchase: Yes
Compared to the Tung-Sol KT120, these run on quite... a different bias. I believe it's matched, but the problem I have is 2 of the tubes have serious microphonics. When using in power-amp, this will change tone sometimes if certain note is played. The only way you can "eliminate" this is to put the amp in a different sound-proof room - which in most cases not practical. For the sound, I think these sounds "sweeter" than the Tung-Sol, especially it has a milder bass and very smooth mid-range.
Verified purchase: Yes
These tubes are installed in each of two MC275LEs. Their... performance is excellent but not a huge difference from the original Macintosh KT88s. The build quality of the Canada Fuller is outstanding and the packaging is excellent. For me the jury is out on price/performance as other manufacturers of KT 88s are very competitive. I haven't had them long enough to get an opinion on their life expectancy. As to the value of these tubes, it is up to the listener. I recommend their consideration if you are looking for above average build quality and they sound good enough to warrant a listen.
Verified purchase: Yes
I switched out my KT120 tungsols for these and didn't ...expect an improvement. Well I was wrong. Can't say they're better I just like the sound better. I prefer a more vocal forward presentation which I wasn't getting with the tungsols. May have been the synergy with the preamp tubes which where special red 5693s. But I'm very happy with these and the 5693s. Running then on a Musical Paradise MP-501 V4, which I highly recommend also!
Verified purchase: Yes
EXCELLENT QUALITY TUBES, DEFINITELY HIGH END, CONSTR...UCTION & SOUND WISE. COMPLETELY TRANSFORMED MY SYSTEM FOR THE BETTER... EASY LISTENING, NO FATIGUE AT ALL, VERY MUSICAL, LOVE THEM... IF YOU CAN HANDLE THE EXTRA COST GO FOR THEM!!!
Verified purchase: Yes