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tube rolling first-timer

So I bought some NOS tubes to try in my preamp. It is my first piece of tubed equipment, and this is my first time switching out the tubes for something different. The pre is a Nagra PL-L. It comes with some Sovtek tubes. The tube complement is two 12AX7's and one 12AT7.

So, I've done a fair amount of reading about different tubes, and decided to start with some Telefunkens. I found a good deal on a matched pair of Telefunken smooth plate 12AX7's and a Telefunken 12AT7.

Here are my questions:

(1) when you are first learning about tube characteristics and your preferences in your system, is it best to stick with all one kind of tube and swap them all out, or should I first switch out the AX7's (leaving in the Sovtek AT7)... I'm just curious if people think there is a "right" way to go about it.

(2) Does one generally switch to all of the same brand tube, or do people tend to mix and match brands to their preference? Of course I recognize you need to use the same brand (and closely matched) tubes for the L/R channels, so I would stick with the same brand for the AX7's.

(3) Do folks have particular preferences or combinations of tubes that they have like for the Nagra PL-L and would recommend?

Thanks for your advice and recommendations.
dgaylin
blindjim
3,092 posts
 
usually #2... for me.

Closely matched tubes are needs for a non self biasing unit.

Be a purist or suit yourself with the tonality NOS tubes offer. 'spensive. Frustrating. time consuming. In the end, I've found it rewarding though.

Look up substitutions for your tubes. It will either open new doors for you or outright confuse you altogether.

Number one deal with tubes though, especially if you don't get a tube tester for yourself, is to get a very reliable and knowledgeable tube vendor. Andy B at Vintage Tubes has always done right by me and I highly recommend him.

My pre uses both 12AT7 & 12AX7. I use RCA on the AT side, and Amperex Bugle Boys on the AX side. tele's would also be fine by me on the AT side too.

it's all a mix however, front to back, it's all about the mix and synergy and your preffs of course in the end. you may find too that it's not always just the tubes, but the design in which this tube or that is employed.

Roll 'em Roll 'em Roll 'em Keep them doggies rollin'...

Enjoy.
dgaylin OP
255 posts
 
Thanks Jim. Very helpful. I am going to try some Mullards at some point. Just doing this gradually.
lenny_zwik
259 posts
 
Given that Nagra is extremely diligent about component choice, sound, precision, why mess with it at all? I'm sure that if there were better sounding alternatives out there with commensurate reliability, Nagra would have chosen them.
dgaylin OP
255 posts
 
Lenny -- that's a quite reasonable thought, and where I was initially. I guess from what I've seen the Sovtek tubes aren't that highly regarded, but also, to get new ones Nagra charges quite a bit (they specially select them) Then there's curiosity at play too. But I am half expecting to swap in new tubes and decide that things sounded better with the stock tubes.
tbg
5,263 posts
 
I am sure that Nagra has to live with tubes that are readily available and make their best choice among them. I my opinion, 50s-70s tubes are far superior to what you can buy today.

I know my Reimyo 300B amp came with new production Westrex 300Bs that were made with the same equipment as my 1960s WE 300Bs, but in the amp the60s tubes were quite superior.

All that I can really tell you is to experiment. Telefunken 12AX7s are still sought.
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