PR,

The claim of "ultra low noise and hum" is not the same as a "complete lack of noise or hum."

Hope your TORIIs have a "complete lack of noise or hum," when you start listening.

Will,

I tried to talk to Steve, but they were out. Sent him an email.

Since I've never had any hum with the other amps I've tried in my system, the Torii is the culprit. I have dedicated 20 amp outlets
in my listening room. I use Runnings Springs Duke and Haley power conditioners.

The only time I've had a computer connected to my DAC was through
an ART Legato USB converter which isolates the USB power and ground. It was dead quiet.

My goal is a "complete lack of noise or hum." Hopefully, I can find a solution.

I should have known that Steve had already addressed the hum issue:
http://www.decware.com/paper41.htm

I'm good. Now, it's just a question of power/headroom.

PR,

I didn't do the meter test.

I decided to stop treating the Torii as the culprit, and accept that it might be more sensitive to grounding than my other amps. After I found that it likes to be plugged into the same outlet as my DAC, all was well.

Listened to Bonnie Raitt’s “The Lost Broadcast” last night.

The TORII time warped me back to 1972, and a 23 year blues singer was in my listening room.

kana, that's great to hear.

Will be packing up my TORII for the trip back to Decware.

Mahalo to everyone on this great forum for all your assistance.

Aloha

Good luck kana!

As regards these tubes. . . I've gone through all the OA3, OB3 and OC3 tube types again, letting them sit in the amp for quite some time. . . and I keep coming back to the RCA OA3 straight shoulder type as my choice. (Interestingly I always seem to find the coke bottle type to be dryer and tarter than the other type, and I don't prefer them).

I think that the OB3 type is promising, but the only brand I have these in is GE coke bottle type (two pair) and they just don't do it for me. All the other choices are RCA, and I just love the sound of RCA rectifiers and regulators, there's something they did back then that really nails the sound for me. I'll look for a pair of RCA OB3 straight shoulder type to try in the future. For now, I'm just putting the other tubes I'm not using away, maybe for sale. The RCA OA3 straight shoulder is really giving me great sound in conjunction with my other tubes.

Lon, Interesting that you came back to the straight shoulder RCA. I guess since you have made a lot of system choices with them in place and have liked your sound along and along, this is not surprising.

Interested in your finding the RCA OA3-ST (coke bottle) tart and dry, I put in some eastern block straight OA3s Gopher had gotten. I had found these tubes open and bright in the extreme, but liked them with some tube sets. In context though, my original OA3s are RCA-ST and I rarely used them finding them a bit warm/dark in the low mid down and a bit in my face mids up (which might be what you called tart and dry). So even thought the straight OA3s I have are likely quite different than your RCAs, my reference was not at all the same as yours and I have adapted my system with ST shaped VRs which I would have described generally as notably warmer than the straight OA3 from Gopher. I usually use Sylvania OB3-ST or Sylvania OC3W. Warm and textural without being in my face.

Anyway, I listened to the straight OA3s and with the warm JJ 6CA7s  I am burning in, and the open and sassy National 7DJ8s. They sounded quite good. Then I put in my original RCA OA3-STs and after what in my conditioning could be an extreme openness of the straights, the ST midrange did sound a bit "tart and dry" and the bass and low mids darker and veiled by comparison.

I need to try to find some RCAs like yours to try. But what I am finding as we all flesh out tube preferences for the Torii is that no one tube can really be fairly taken out of the context of the tube set in the amp, unless it is directly compared to others of the same type. And even then, with the preferred set you or I use (aside from the VRs), and one someone else uses, it is hard to get clear on the whole story since each tube changes the sound of all the rest.

I recall that I kept looking for opener and brighter sound in my system as you kept preferring warmer sound. The difference is of course the context of the many things that make systems and tastes, but within this, it is very possible that our different sounding RCA OA3s and how they make all the other tubes sound is a big player in this. Now, your explorations point our that an RCA OA3 is not the same as an RCA OA3. And a straight might sound better in some setups while a coke bottle might sound better in others depending on the rest of the tubes.

Just points to the power tubes have toward influencing the sound of the Torii. Not surprising really since it is such a simple and revealing circuit that each tube set makes a big difference as the signal passes through each until it gets to the speaker wire.