Thanks Lon, that is interesting. I actually have two pair of 5U4GBs that look like exactly the same construction, tall bottle, the same black plates, micas the same, double top hallow getters....everything the same. Both tested similarly too. One has no writing and was sold as an RCA make, the other pair is labeled Sylvania, and though their sounds have characteristics that are obviously the same, one is cooler and the other more rich and textural. Go figure.

That's what I've noticed too Will.....all these old tubes sound different!

Hi All,

I've recently been "re-employed", so only able to view sporadically...nice to see some new names enjoying Steve's wonderful offerings.

I noticed some ways back that someone mentioned an RCA 0C2 tube...would you mind sharing your source? I'd love to try it!

And congrats on being re-employed. I haven't steeled up the nerve to begin job-hunting yet but I hope that happens to me before summer.

Hey Chris,

To me the input VRs (at least of the same type) are the most subtle shifters in the Torii. But if your tube set/system/room is on the revealing side, changing from Raytheon to RCA OC2s is a real choice (changing to an OB2 is a big shift BTW). I like both the RCA and Raytheon, but I use the RCA most of the time. Both tubes bring out good balance top to bottom.

Like Lon said, the Raytheon does seem to have a little more bloom...it is a warmer tube, a little low mid bump that blends the music slightly more but without masking detail ...all good if this is what you need. The RCA I have I would call transparent, which can be good or bad to me depending on the other tubes, system and room, especially the input tubes that these regs "filter". The RCA is more open and spacious, more differentiating, and pulls a bit more ambient information. This is what I hear comparing the two with the tube set I have in right now, and for my sound needs a meaningful choice.

I buy from Ebay when I can too, an exceptional place for inexpensive 5U4GBs these days BTW.

But I check regularly with Brendan at tubeworld, who seems to always have the more obscure stuff, and VRs are relatively inexpensive.

https://www.tubeworld.com/index_high.htm

The site is weird. Individual page links don't take you there, and the search does not necessarily work for O type tubes. Click Vacuum Tube Stock, then All Tubes from the links across the top...the top one is O. I got my RCAs here.

C.E. wrote:

Quote:


C.E., just to be clear, you are looking for RCA NOS versions of the 0C2, the tube that ships with the Torii? I found RCA, Sylvania, and Raytheon I believe on eBay. There is a listing there now.  Brendan at TubeWorld is also a good source.

That seems odd. I've had EH 6922s (just sent a pair off with my SE34 Monoblocks to the new owner) and didn't notice they were "hotter" than other tubes. I've had OTK 6N2P tubes which were muddy and lower in output but not 6N1Ps marked OTK.

I'm not sure there really is a consensus on the input tubes, two or three different tube types seem to have a following among users.

There are so so many variables that I really doubt even exactly replicating another's tube set would get the same or closlely similar results. (Especially telling are the speakers, room, personal tonal balance tastes, and dare I say it, interconnects and power cords and speaker cables!)

I'll bite though and list what I've been using. As I've mentioned just a bit upstream I'm a big fan of the 6N1P as the input tube, I've tried others with various other combinations of attending tubes, but the 6N1P has the sound that makes the music seem real to me. This is very apparent when I use my ultimate test: music I recorded of bands rehearsing or making demos in my then garage apartment during the late 'eighties. These are recordings that I know very well, I know the players, the characteristics of the mics and machine, the instruments, the sound of the room.

I am using the JJ6CA7 right now, I've warmed up to them, and I'm saving my last quad of Winged C EL34s right now. I use RCA 5U4GB "straight" rectifiers, I've found a few pairs that have a particular rich sound I like in this amp. I'm using the stock Raytheon OC2 tubes, and I'm using RCA "straight" OA3 tubes. This is the tube set that gives me the least "hifi" sound and imparts the right tonal balance and detail to most of my recordings, allowing me to revel in some that I haven't been able to before.