I know you're aware that the sound will change a lot as your new amp
settles in. This can take some time, so while it's tempting to start tube swapping straightaway, what sounds " off " today may be much more
involving down the road.

I only use 6P15P-EV output tubes.

always go back to the tubes Mr. Deckert supplies, you might be surprised, and save a ton of money!!!

tesla 7dj8seems as good as 6n1p. Any thoughts on the large labeled 6p15ev as opposed to the small label of the same tube????

I have tried Mullard labeled but Philips(Canada) made EL84 but they sound muffled and rolled off. These valves(I am in the UK  :) ) are tested and known to be good. The amp was built last year so I assume current spec so just wondering if standard EL84 can work successfully or with any modifications.

I have had good success however with Philips and Ferrantti 5r4gy's.

Philip, thanks for the response. It sounds like a standard SE84CKC isn't ideal and I may need some modification if I want to use EL84's. Shame but I think its one of those comprises I have to face as Decware focused on getting the best out of well made but low cost SV83's.

Currently listening into Auditorium 23 Solovox which are 95db sensitivity and were a great 2nd hand bargain.

Curently have:  Amperex W. Ger nos 62' ECC88-6DJ8 -input,  6p15p-ev -output, and Philips 5R4GYS -rect...sound is excellent.

I used to have a pair of SE84C+ and I will be receiving a SE84UFO shortly.  My tube-rolling experience with Decware gear has always brought me back to the original input (6N1Ps or 6N2Ps) and output tubes.  Yet, the rectifiers have significantly contributed to the signature sound of the amps.  

On my SE84C+'s, I used 6N1P's and SV83's that came stock with the amps and a pair of NOS RCA 5U4GB's from 60's.  On my TORII mkII, I used a pair of 6N2P's and Mullard EL34's that came with the amp and a pair of NOS Mullard GZ32's.  With the TABOO, pretty much the same; yet a NOS RCA 5Y3GT at the rectifier slot.  Most probably, I will be just swapping the rectifier tube in my newly ordered SE84UFO and I won't look back!  

Best,

Alper

Ellsworth,  there are few rules, just use tubes compatible with the amp. I have a pair of Zen Signature Monoblocks (2.3 WPC) that are no longer made.  They are like each channel of your amp in two different units...they use the same tubes as your Amp.

Most here have not gone to the EL-84 but rather kept the Russian output tubes.  I did buy some NOS SV83's but the tubes Steve sends are military spec of the same tube...I'm not sure whether there's much of a sonic difference. I have not used EL-84s so can't comment on them.

For the Rectifier I tried a few and have settled on 50's RCA 5U4Gs.  They sound nice and are relatively inexpensive.

For inputs my favorites are the Amperex White labels 6DJ8, 6922 and 7308 tubes.  Recently I  tried a Mullard 6DJ8 which was very good but I was running it with an Amperex 6DJ8 in the other Amp so until I get another Mullard, I couldn't say that I preferred the Mullard over the Amperex.  I have found myself rolling the input tubes quite a bit so all the tubes will get time in the  Amps.

In regards to  which tubes are most important to the sound, for me, once I settled on a Rectifier, it is the inputs that I've concentrated on, leaving the SV83 in the outputs.  I'll leave the descriptions of the sound with each tube to others with better Audio Lingo than I.  My experience has been mainly with the Amperex family so others will have to comment on different brands.  Hope this helps,  Mark.

I think the tubes that are sent with the SE84UFO sound real good. But the setup I like with my speakers and the the acoustics of my listening room are a SED Wing-C 5U4G rectifier, a pair of tubestore Preferred Series 7189 power tubes and a Ediswan/Brimar CV2492/6922 signal tube. While the DecWare supplied tubes sound real good, my tube setup sounds magical in my listening room with my speakers.