6922 Tubes!

I have a MAGI Phonomenal preamp; it's all handwired PTP and uses four 6DJ8 types; one pair for input buffering (I think) and the other for gain and output. The topology is evidently similar to the Manley steelhead, but without as many front panel configurations, and not nearly as expensive. 

I got it used with a pair of 6922 and a pair of Bugle Boy 6DJ8s. It was a bit noisy and I went on a quest to quiet it down. I got a second set of 6922s. It didn't really lower noise significantly while idling, but when the music came on the noise was unnoticeable and the music was very nice.

Then, to see if I could lower the noise I got a pair of NOS 7308s off eBay for around $25 each. I tried them in various positions, but didn't notice any real difference, but they were at least as good as the ones they replaced. 

Finally, since Marc Voigt, designer of the MAGI Phonomenal, recommends 6N1P tubes (an ultra-low noise 6922-type) for this setup, I researched and concluded that the sweet spot is the Voskhod NOS Soviet Military surplus 6N1P with the rocket logo, made in the '80s. A USA dealer will want around $16 each. I got four of them from a Russian dealer on eBay for $21.95 shipped. I got them this past June and they have occupied all four sockets ever since. Dead quiet, musical, *excellent* dynamic range. 

So before you pay hundreds for some NOS tubes, check w/Manley that 6N1Ps will be OK, and then order some Voskhod Rocket Logo military surplus 6N1Ps. Although I bought them through eBay, the sale and shipping was facilitated by Tubes-Store.com. Their prices may be even better now. Prices are so low that even if the shipping cost as much as the tubes, it's easily worth it.

I've had very good luck with Amperex Orange Globe 6DJ8's. IMHO close to Amperex 6922 PQ in sound quality, but a LOT more economical. In my system, while the Russian rocket logo 6N1P's were indeed very quiet, they're a bit sterile for my tastes. I think I have a quad of those in my accessory drawer somewhere. BTW, there's a quad of Orange Globe's (made in Holland) for sale on EBay ($75). Seller has excellent 100% feedback. Check out Joe's Tube Lore on Audio Asylum for the rundown. If I didn't already have a pretty good back-up stash, I'd be all over it. Of course, YMMV. Good luck and Happy Listening!

I had been having  issues with noisy tubes in my preamp, mostly NOS Amperex, and was getting sick of shelling out big bucks for NOS tubes. Went with some JJ 6922 Gold Pins from The Tubestore, an extra $5 for balanced triodes made them $29.95 each. Hands down the quietest 6922's I've ever used and they sound excellent.
http://www.thetubestore.com/Tubes/6922-E88CC-Tube-Types/JJ-E88CC-6922-Gold
A good current option especially if your preamp uses a lot of tubes, mine takes 6 6922's.

You would need to check with Manley for sure, but Kevin Deal at Upscale Audio turned me on to, several years ago, the National (Matsushita) 7DJ8 tubes. I have used these in dozens of different preamps, phono stages, DACs that use 6DJ8/6922/7308 tubes with never a problem. Plus they are KILLER sounding. One of favorite tubes.

The platinum version, (the best testing and sounding) are only $35 each.

http://www.upscaleaudio.com/6922-6dj8-7308-pcc88/matsushita-national-pcc88-7dj8/

Strateahed:

In my system, while the Russian rocket logo 6N1P’s were indeed very quiet, they’re a bit sterile for my tastes. I think I have a quad of those in my accessory drawer somewhere.

Well, yeah. I can see your point, but it can also be related to system matching. Not long after I got my 6N1Ps, I put in a Denon DL-160 I had lying around, and it suddenly sounded engaging and dynamic. Then I got a Shelter 201, and it wowed me with its transparent and fulsome midrange, and strong but not overwhelming bass. Now I’m using an AT150 with Shibata tip mounted to a cherry wood headshell, and the combination is marvelous. The 6N1Ps may sound a little sterile with your current setup, but maybe if you warm things up a little elsewhere (wood headshell, warmer mat, etc.) it may help you appreciate the lower noise floor and broader dynamic range that the 6N1Ps bring to the party.