I had the experience in my listening room to compare the VTL 6.5 and my Ref 3. I have to notice that my Ref 3 has 2800 hrs on the tubes and that I read on many threads this isn't right especially for the 6550 (Guidocorona thanks for your evaluation). To be honest I did not experience any downgrade in my listening...but I will keep you posted since i have decided to retube in the next month or so. Now on the listening...
The firt thing and most important to report is that the ref3 has very high acceptance in the input and does like input voltage of about 4 Volts better than 2 Volts. For the VTL is the exact opposite. Infact just switching from Ref 3 to VTL with High voltage CD made the vtl sounding very bad in comparison; Harsh sound, flat dinamics, flat soundstage... With High Voltage there is no comparison: Ref 3 is much much better.
Adjusting the voltage to 2 volts ( possible on the wadia 27) the situation has strongly improved and the Vtl started to sing. In this situation what we noticed has been a warmer sound on the VTL, the low frequency more extended and the piano more silky... In other words less stressing sound...especially for Piano. The ref.3 seems to have more definition but at the expense of being sometimes stressing.
Now the evaluation has been made with the input set at 2 volts...But ARC likes 4 volts and with this set-up it gains a lot of dynamic and lifelike sound. So with appropriate set-up I still prefer the Ref.3
I'm not sure I would trade my ref 3 for the 6.5. This is especially true for the Phono input. Infact my Ref Phono has high gain and I fear this would be not compatible with the vtleven I did not do this experiment. I sense the 7.5 is probably really superior. I will let you know if by changing the tubes to my ref 3 anything will shift toward a warmer sound.
The firt thing and most important to report is that the ref3 has very high acceptance in the input and does like input voltage of about 4 Volts better than 2 Volts. For the VTL is the exact opposite. Infact just switching from Ref 3 to VTL with High voltage CD made the vtl sounding very bad in comparison; Harsh sound, flat dinamics, flat soundstage... With High Voltage there is no comparison: Ref 3 is much much better.
Adjusting the voltage to 2 volts ( possible on the wadia 27) the situation has strongly improved and the Vtl started to sing. In this situation what we noticed has been a warmer sound on the VTL, the low frequency more extended and the piano more silky... In other words less stressing sound...especially for Piano. The ref.3 seems to have more definition but at the expense of being sometimes stressing.
Now the evaluation has been made with the input set at 2 volts...But ARC likes 4 volts and with this set-up it gains a lot of dynamic and lifelike sound. So with appropriate set-up I still prefer the Ref.3
I'm not sure I would trade my ref 3 for the 6.5. This is especially true for the Phono input. Infact my Ref Phono has high gain and I fear this would be not compatible with the vtleven I did not do this experiment. I sense the 7.5 is probably really superior. I will let you know if by changing the tubes to my ref 3 anything will shift toward a warmer sound.