Thanks will. It's because of you, LS, Lon and others that I came up with my tube rolling plan. While I'd be very happy with things the way they are.......as this amp is the real deal.....but rolling tubes is just too much fun.
Thankfully I sought Steve's advice when building my dedicated listening room so that I don't have room acoustics to worry about, but I was cursing him while half way into building the quadratic diffusers.....over 1000 wood cuts!!!.....I'm praising him now though. Decwares power cords, interconnects and the zcd240 sure helped improve my system also. It's safe to say I'm a Decware fanatic now.

Not quite 300 hours on my mkIV and its sounding so good it's hard to imagine  it sounding any better, yet I trust everyone here and know it will. After putting in the Gold Lion KT66's for the last 150 hours I put the RCA 6L6GC black plates back in ......and they are staying in. Had I never heard the black plates I would have been very happy with the Gold Lions but that NOS magic shows up in spades in the black plates and there's no turning back for me now. My NOS rectifiers ( 60's RCA 5U4's) and input tubes ( Mullard and the Siemens that Steve recommended) will be here tomorrow......so more fun tube rolling is on the way.

Mark, the tube Steve recommended is the Siemens PCC88/7DJ8. Not sure if those designations indicate the year they're from or not. I'm told they are very detailed with a gorgeous airy high end, silky vocals and tight bass. Steve mentioned getting long bottles but Andy at Vintage Tube Services had no idea what that was........and that's a first for him! I constantly floored by his knowledge of tubes and vintage gear. I also ordered a pair of Mullard input tubes, supposedly the antithesis of the Siemens. I want to see which input tube works best in my system.

Output tube question. I'm told the RCA 6L6GC black plates should last about 20,000 hours in the Torii. That seems high. Many seem to replace theirs yearly. Will the tubes actually last 20,000 hours but lose their fidelity much sooner?

Mine always ate tubes pretty quickly. I settled on the KT77's as my favs. I wouldn't go NOS for output tubes. I doubt you'll get any additional  mileage out of them.

I have a Mk III, not a IV, but they seem to use the same tubes.

My favorite budget tube is:

http://www.cryoset.com/catalog/product_info.php?cPath=22_80&products_id=335&osCs...

Especially if you like midrange.

Then I do like KT66 . . . my favorite that I have tried of new production are the TAD (second favorite are Gold Lion, then JJ, least favorite I have tried are the Tung-Sol).

The TAD:

http://www.cryoset.com/catalog/product_info.php?cPath=22_84&products_id=394&osCs...

I like cryo'd power tubes. Not only do I think there's some sonic advantage, the process that cryoset uses seems to weed out most duds.

Right, I mentioned them in my post above. Nice! Cheap!

I have used KT66, KT77 and El34 in my Blue. I have not used the 6L6 types Lon and Archie are recommending in that torii, but have in my MKIII and MkIV. It might work fine in the Blue Torii too. If this tube interests you, ask Steve if someone else does not answer that one here.

I agree with RW, the KT77 is an interesting choice. If you want to stay similar electronically as EL34s (supposed to be a direct replacement), and punch things up some, the JJ KT77 is cheap, and will tend to a more linear and dynamic sound with tighter bass, while having open spaciousness, really good inner and complex detail, nice textures....

If you want to stay with the EL34 sound, and want to buy some burnt in, but not much more, I have a bunch of them I could sell inexpensively. PM if interested. New or used, if you told us the tube you are using, and how you would like to change the sound, we may be able to guide you in the right direction.

I can send you a pair of those Chinese 6N1P type that some are talking about and up here. PM me your address if you wish.

They are very good tubes, and as you say a great value. Glad you are digging them Paul.

Hey guys!  i'm spending my evening ROLLING tubes.  I'm starting off with the cryoset Sovtek 5ar4's.  Right off the bat i feel like i'm getting more detail.  I'm pairing them with my Gold Lion kt66's right now, but plan to roll in some other power tubes throughout the night.  Any thoughts?

roggae,

Sounds fun. The KT66 Valve Arts look just like Lon's favored TAD KT66 to me. The companies may well have different screening methods...don't know the details, but I am guessing they are the same basic tube. Like the KT66 Gold Lion, it is another attempt at a remake of the famous early KT66s. I have posted here and there about the VAs as has Lon about the TADs, so I think if you search the Forum with those tube names you will get some ideas.

There are also posts around on the Tungsol KT66. I suspect Steve still ships these with the the Mystery and MKIV (KT66 option). Without putting them in to double check, I recall that Tungsols are likely the cleanest, most open and linear of the new KT66, the Gold Lion probably the darkest/warmest, and the Valve Art sort of in between...each having their own personality (and being highly influenced by the rest of the tubes used).

The 5AR4/GZ34 types are interesting. Compared to 5U4G-ST types, generally, they tend to be more dynamic, tighter bass, more clear and defined, more focused...doing this musically if they fit in with the rest....the combination likely coming off as more detailed and defined in your experiments. The Sovteks are attempts at old Mullards I think, and a pretty nice tube. If you get seduced further by it, you will pay much more, but also get more refinement in every aspect from NOS Phillips/Mullard types, expensive because they are so well liked. But there are deals that come up now and then, especially with off brand labels and/or if they are a little used.

I use Phillips/Mullard GZ32 types, a very similar sound, but a bit less powerful than a GZ34, so tending to more open, less big/dynamic, less deep and dark, less obvious. Not better or worse, but a nice choice for fine-tuning if the general GZ tube qualities are what works, but GZ34 tend to be a little strong. I loved RCA 5U4G-STs for years, but finally this GZ32 type has become a standard here. There are a bunch of variations of that basic Euro type too, all sounding a little different....Then there are American designated 5V4Gs, pretty close equivalents, but having a discernible difference in feel from the GZ32s, and each of them also sounding different. I find these can be quite good in the right company too, and much less expensive in general, but not generally as sophisticated in balance and refinement to me. Also, in my system, they tend to be a little less linear...often (though not always) a bit more open on top, and a bit darker/denser below in the general balance.

But if the balance of the Sovtek GZ34 works, the GZ32 or 5V4Gs could be too open/lean, and/or a little lacking in punch and power.

Mark I wish I had information about those Amperex I could contribute.

Will, I have actually today done what I undid a month or so ago: put the Sylvania bottle-type 5U4G back in the Torii that I had taken out to replace with my trusty RCA 5V4G rectifiers. I noticed this weekend that one channel was about 15 percent "weaker" in sound than the other and traced it to the rectifiers. Though I have another pair of RCA 5V4G to pop in I thought I'd give the Sylvanias another time to shine and they are doing so, I think those English 75C1 have given them a nice face lift. Really enjoying the sound: lots of texture and detail but no harshness.

These Decware amps are like having a dozen amps in one!

I agree Lon. I also find that 75C1 does wonders for refined friendliness without loss of fine detail and texture, creating even more Torii flexibility. I am using some late 40s Sylvania 5U4G-ST types in my MKIII at the moment, the ones with the wires running up between the plates...really refined and balanced/open tubes! I agree also, that with the flexibility of the Torii settings, and its many tube types, once we get  used to it, the possibilities for great mixing and matching of various tubes toward different flavors of beauty are amazing.

Well, I couldn't leave well enough alone. I was missing just a bit of bass and warmth and though the Duelund resisters may break in a bit more and deliver just that I put my other matched pair of old RCA 5V4G bottle type rectifiers in and there was that body that I was missing with attendant a bit of bass and warmth. So they'll stay in for these output tubes and when I switch out output tubes again I'll try the Sylvania 5U4 bottle-types--they may be perfect for the JJ6CA7.

I'll try GZ32s one day. 5V4s just seem to hit the right marks for my system. I'm trying not to roll tubes. . . but with these machines it's almost impossible to resist!

so i've been enjoying this little experiment so much.  i've found all kinds of combinations that have reinvigorated my love for this amp!  anyway with the combo i've got in the amp now i'm hearing a substantial amount of line level noise.  it doesnt change when i increase or decrease the volume pot, but it's present in the silences.  is it possible it's the tube combo or is it something else entirely?  i'm using stock tubes with the excpetion of the 5ar4 cryo'd sovteks and the jj kt77's.  interested to hear your thoughts...

I think the inputs are probably a good place to look, but if it is in both channels, that seems possible, but is weird for tubes in my experience...for two to go at once. If it is mainly in one channel, you can switch tubes side to side, one by one, to find out. If the noise moves, that's your tube.

I have had noisier rectifiers than others. If you have your original rectifiers, it could be good to trade them out with the sovteks just to see.

When power tubes have gone on me, they start distorting first, but these are early failures...I personally don't know what happens with too much age. I roll tubes too much for that so far!

Also, some power tubes are noisier than others. If you can't find it elsewhere, I would try the stock power tubes briefly too.

I guess you have looked at your cables, made sure the signal cables are distant from and cross the power cables rather than running with them, and signal cables away from noisy things, like power supplies.

If the noise is uniform, both channels, it could be a lot of things...Is it?

As to replacing input tubes, that would depend on what you want your sound to do...how you would like it to change?

roggae,
For the bass tightening try some OB3 rather than input tubes is my suggestion, if you haven't yet. May not "tighten" per se but will change the presentation in that sort of direction. . . .

where does one find an OB 3 tube?

i have a pair of OA3a's - any help?  i'm really wondering if my input tubes are the source of the line level noise?  it's really quiet but if i get right up to the monitor i hear it.  maybe thats normal.  i dunno...

thanks forthe help guys!

right on.  thanks for the offer, Lon.  i'll look around.  what is the OB 3 exactly?

Lon!  We think alike.  i bought some 0B3s from tubedepot and some OD3s.  Also bought some input tubes!  now, hopefully i'll be good for a while.  did you ever send off those tubes you'd planned for me to demo?

right on, lon.  no biggie.  where are you located?

Ha!  i live in rural WI.  I know your struggle!

first impression with the 0b3's installed: the bass is generally less boomy.  everything else sounds good.  with the new input tubes i am hearing less of the white noise i was hearing.  perhaps this is what is often referred to as the "noise floor"?