What are some good tubes to use in a Thor phono

stage? I was recently Spring-cleaning some of my components and took the chrome anti-RF cover off without realizing that I had not muted the pre. Normally, this would be no big thing, but one of the output tubes became Very Upset as I approached its little crown with my fingertip. Starting at about 1 foot away, that channel started to roar!

These tubes are the original factory chosen: a pair of Gold Dragon 12AT7 and a .5db-matched quad of Sovtek 12AX7s. While it still sounds good at all sane listening levels, and the trick reversed itself when I swapped the output tubes, I believe the fault is in the tubes and that the preamp is sound, but I have not shopped for tubes personally in my life. I always had a dealer I trusted to make decisions like what tubes to buy, but I have not found any I can trust since Salon I Audio in Wisconsin closed. My biggest concern is about the integrity of the 12AX7 quad's verification. They will have to be matched as closely as possible. Does anyone out there know a tube supplier that can be trusted to honestly put together a high quality, closely-matched set? I do not have access to tube testing hardware and so must trust a vendor for this critical purchase. Also, can anyone recommend other better tubes to go with? These originals were not very expensive at the time they were new (1999), and only cost $150 from the factory for a replacement set.
I love Golden Dragons. Kind of a budget version of Mullard. There are so many killer 12at7s out there to play with such as RCA, Telefunken, Amperex all NOS. There are a thousand better 12ax7's out there that will crush your sovteks.
The 3 best dealers out there are upscaleaudio.com Not cheap but top quality. Thetubestore.com for a variety of good quality tubes and tubesandmore.com
No one out there should be able to complain about any of these three. For fun go to tubeworld.com but be sitting down when you look at the prices.
Jim McShane is another good tube vendor. But I am a bit confused because 12A?7 are small signal tubes not output tubes.
Hi McBuddah,

Which Thor preamp do you have? I had a TA-2000 for a few years - a very sweet sounding preamp, but not the quietest with MC cartridges.

For matching NOS 12AX7s, I would also recommend Brendan at Tubeworld. I loved the Mullard CV4004s with the Thor (in fact, I am using those tubes now with my Doshi), but the prices now might be on the high end. At a more reasonable rate, the Philips 7025 is not a bad choice, and won't be much more expensive than the factory replacement set.

Best of luck.

Jim McShane or Andy at Vintage Tube Services would both be good suppliers. I think Andy is the best for NOS tubes.
Thanks for the suggestions - especially for dealers who can be trusted. Based on the current price for the Sovtek tubes, about $12 each with maybe a $5/ tube charge to build a quad, I would imagine that there are a lot of them. The concern I have to have answered is more more one of not wanting to disturb the immaculate flat frequency response of this unit, which was achieved by shipping with and selling Sovtek 12AX7 tubes if I substitute similar but not quite identical replacements. The problem is that I have not taken the time yet to understand how RIAA decoding is accomplished in the first place, and what role the tubes play. It occurs to me that there are a lot of tube data and measurements when looking at the individual tube descriptions on the sites you all have suggested, and they vary a bit for different tube models. It would be good to know which values were the ones the designer focused on when choosing Sovteks. Then I would be able to look for similarity in the tube catalogs. Unfortunately, Thor seems to have folded their tent at the end of 2014, and their web site has no referral for support.

Sampwalker: My apologies for misusing terms. As I explained in this post, I am totally uneducated about how a phono-stage circuit works; I assume that the Sovteks are used in the decoding of the input signal and the 12AT7 tubes are used in the gain stage to bring the decoded signal up to line-level. I guess I've got some reading to do.

Rzado, I have an early TA-3000.It had been a dealer-owned store demo unit at the legendary Bruce Jacobs' Salon I Audio in 2000, listed at $7500 and I have no clue as to what I paid for it and never have. Bruce had store poilcies that were generous for trading up and I bought it as part of a deal where I traded in a Vendetta research phono stage and a VPI TNT table with a tricked out ET2 arm plus around $5k for the Thor and a gently used Versa Dynamics table. The table died shortly after both Salon I and Versa went out of business and I pouted for ten years and just listened to CDs because I couldn't afford another table that good until a couple of years ago when I bought another record player. So, the Thor was practically NOS in 2012 when I put her back in service. I had a Benz back when I first bought it; can't remember the model, but it was one of their top models. It had only about .25mv output, but the gain on this unit is 68db. I never had a problem with noise in that system (Atmasphere Music Amplifiers)and a DR6 used as a linestage only. I am currently using a Grado Statement 1 (.5 mv output) and the sound is glorious. With 90 db speakers, I reach the threshold of pain at only about 30% of volume control range, but when I run the Thor outputs directly into my headphone amp's pre-ins, I need to go nearly to full gain and it is almost as dead quiet as when throttled back in the main system. I think it's a match made in Heaven for the big Grado.