Steve, I prefer a more euphoric sound. The ZROCK2 is at 12-2 o’clock for the euphoric and harmonic magic it brings. With the OA3 in the front and no ZROCK2, it seemed like the ZROCK2 was in and turned up a lot. Eight 15” drivers change the experience. With the OA3, it could be too much energy in the room. Over 78-80dB, things get out of control exponentially. Peaks of 75dB are exciting and immersive.
When I first had the UFO, I was using an OA3 in the front position. OC3 was better. This morning received a RCA OD3. This is significantly better than the OA3. The slow and syrupyness is gone. Which could be due to room overload even at lower volumes. With the bias switch towards the back, it is very similar to the Torii. Torii is still snappier. Torii has a bit more shimmering highs and the bass hits are tighter. The amount of control the UFO is now demonstrating is truly impressive!
Torii MKIV tubes:
EML 5u4g
Westing House OA3
RCA 0c2
GL KT-77
EH Gold Pin 6922
UFO25TH tubes:
Sophia Electric 274b
Westinghouse OA3
RCA OD3 Bias switch towards back
6P15P-EV
EH Gold Pin 6922
I am curious to try an EML 5u4g in the UFO25TH. Not wanting to run one of the matched EML 5u4g I’m using in the Torii, Maybe I’m a touch neurotic with this stuff. I wonder if some of the density differences are because of the rectifier differences. The UFO25TH has Jupiter caps while the Torii MKIV has Miflex caps. This could account for some differences as well.
First track: Michael E - Beauty & Seduction. 25 seconds in a bass hit comes in that continues throughout. The Torii feels like it’s trying to stop my heart! It’s so sudden and fast I’m concerned it’s hurting the speakers. UFO25TH does an excellent job keeping up. If I hadn’t experienced what it was like with the Torii MKIV, I wouldn’t question the tightness of the bass hit with the UFO25TH.
Second track: Martins Garden - Paladin’s coming. Both amps the room disappears, and it’s like floating in space surrounded by music. The UFO25TH doesn’t have the distinct texture on the bass like the Torii MKIV. The UFO25TH is smoother and creamy on the top. All the information is there. The Torii MKIV has a bit more separation between everything.
Third Track: Slenderbodies - Anemone. Both amps are very close. The UFO25TH has a bit more density than the Torii MKIV. Changing a cable or two may get them extremely close. This also could be the difference between the Jupiter and Miflex caps.
Fourth Track: Lhasa De Sela - My Name. The rumbling bass that rolls around the room is more defined with the Torii MKIV, more texture.
Fifth Track: Michael Nesmith - Cruisin’. Both amps rock! I’m having fun. UFO25TH 90+dB everything is tight and clear. The Torii will play louder…I have no desire to go any louder. (Sorry not available on Qobuz or Tidal I selected some songs from my library. I then created a streaming playlist.)
https://open.qobuz.com/playlist/9122596https://tidal.com/browse/playlist/f2112e8f-b0ee-44e2-9be4-a9024464b6efBoth amps sound very similar now. Steve say’s he voices all his amps to sound like the UFO and he has succeeded. Speaker choice and tube selection can radically change how the amps sound. Learning how the amps respond to tubes and the way you want to change the sound, you can take the amps from fast and clean to molasses syrup.
On another forum, I saw that someone had a Torii Jr. for less than a month before selling it off. He didn’t like the sound. This seems like a huge misstep, as he didn’t even give himself the chance to explore the possibilities.
I have much more experience with the Torii MKIV. Over the past year, I’ve tuned it to my system and the sound I enjoy. Having the UFO25TH for 2 weeks and getting them to sound almost the same is really rewarding and an excellent learning experience. I still find that I listen at a slightly lower volume (3-5dB) with the Torii MKIV.
I still prefer the Push-Pull sound over SET. The differences are so much closer than my last experience. The Torii has more options to fine tune the sound to exactly what one wants.