[audiomaniac]

Just curious what others have tried. I'm particularly interested in the Genalex Gold Lion EL84 reissues.

[rhing]

I don't have an RM-10, but I do have a matched quad of the Genelex Gold Lion EL84 reissues playing through my EL84 P-P stereo amp, and these tubes are awesome. They are richer and more balanced from the lows to highs compared to JJ Tesla EL84s. I haven't compared these to NOS EL84/6BQ5 tubes, but I'll be set on using these in the long term. I got a great deal through Parts Connexion when they had their year-end 20% off sale.

[audiomaniac]

That's what I've heard and read. That's great that you got a deal on them! I might have to try some out. Not the cheapest tubes, but not bad compared to some NOS I've seen. Thanks for the info!

I don't have an RM-10, but I do have a matched quad of the Genelex Gold Lion EL84 reissues playing through my EL84 P-P stereo amp, and these tubes are awesome. They are richer and more balanced from the lows to highs compared to JJ Tesla EL84s. I haven't compared these to NOS EL84/6BQ5 tubes, but I'll be set on using these in the long term. I got a great deal through Parts Connexion when they had their year-end 20% off sale.

[pubul57]

There are many of you out there that must have done some tube rolling, even if Roger's tubes last 10 years. Other impressions. I have Rogers Sovtek EL84Ms, but have no idea how they compare to others, inlcuding Roger's Yugo EL84s.  Can this circuit run 7159s as well? Is it compatible? While we're at it, how much tube rolling experience is there out there on the 12ax7 slots? Will a 5751 work without any problems?

[stereocilia]

I've tried the reissue mullard el84, and they are fine but sound a little bland for my taste; I actually prefer the cheaper jj el84.  Of the power tubes I've tried the RAM EL84M sound the best; they sound a little more refined and powerful than the others.  The differences are not night and day to my ears. They may be to yours. 

The nicest sounding 12ax7s I've heard for that amp are NOS Brimar -- they have a lively yet meaty sound which I like, and the electro-harmonix 12ax7 have a similar character only a little less less of it.

I haven't tried the Gold Lion.

edit:  this is in my rm10 mkii

[pubul57]

Well. My amp has Roger's Russian EL84Ms, so I might already have it as good as it gets.  Good to hear the JJs performed well as I think a quad cost $50! I have not heard Roger's Ei EL84s though.

Any reason you can't or shouldn't run a 5751 in the 12ax7 slot? Less gain, but I hardly need that with my source. I'm thinking RCA, Sylvanis, or GE versions of that tube.

[Clio09]

I'll be getting my RM-10 MkII in a couple of days. I'm going to start with the RAM tubes, but plan to roll a bit. I have a set of Telefunken and Russian (6H14) power tubes, as well as some GE 5751 and RCA 12AX7 tubes. I'll give them a try and see what happens.

[chadh]

I was checking out the notes Roger has on his site about his RM-10 design.  It's worth noting that he is kind of particular about some of the tubes that are used in order to minimize noise:

Since the total value of the first plate load is over 600 Kohms, it is virtually a current source. This allows the 12AX7 to operate in its most linear and highest gain mode. A neon lamp is used to conduct the large positive grid voltage and protect the second stage during warm-up. This often overlooked detail makes the 12AX7 much happier and extends its life markedly. Unlike the classic split load converters, the RM-10's runs at lower current to extend life. Drive is more than adequate, yet not so much to overload the output tubes. Note that V1 is a RAM grade AB (section 1 selected for low noise) and V2 is grade BA (section 2 low noise). It is essential to have a grade A section as the first amplifier to achieve the very low noise of which the RM-10 is capable.

Chad

[pubul57]

Hmmm. I see what you mean. Clio9, I'll let you experiment with those 5751s before I go hunting for some Sylvania, RCA, or GEs:)  Maybe there is no good reason for it, but just hate the idea of using RAM Sovtek 12ax7s, you just think there has to be something better (which doesn't mean there is).

[pubul57]

Oh, I see Roger actually has Yugo, Russian, and Chineese 12ax7 variants. Don't know much about the Tungsram, but he says it is the same plate structure as the Telefunken......so...

[Clio09]

I'll have to see which RAM tubes mine comes with. The seller said two sets were included. Roger's prices are pretty high for the SLN versions of the 12AX7, especially since we're talking Russian and Chinese tubes for the most part. I'm thinking Andy at VTR can source some phono stage quality tubes (his lowest noise rating) at the same price and they won't be Russian or Chinese.