12AX7 tubes for the phono stage of VAC Avatar SE integrated.

 wharfy,

12AD7 ? I'll take a look.

You may want to try the cryoed tubes from CryoTone. I have bought the 6SN7's. They are extremely quiet. And there's an extensive trial / return policy. They're not NOS, of course. 

@inna 

Your query got me to look through my signal tube stash. In a box labeled 12AX7 is a pair of NOS Matsushita, black plates, that were manufactured using Mullard tube tooling equipment. I bought these from Brent Jesse at his recommendation.

He also recommended Japanese manufactured 12AD7 because they are low noise tubes, used for recording. I didn't pursue it even though it had the same specs as 12AX7.

I read extensively on another forum where guys talk in details about tubes for their amps and it is now more or less clear to me. In my amp and for my taste it's Mullard. Amperex long plates and Raytheon black plates would be bright, regardless of their strong points, and RCA black plates would be a bit too thick. Sylvania long black plates have exceptional clarity and tonal balance but they can be microphonic and they lack the sophistication and depth of Mullards.

tomcy6, yes. Perhaps I could order a pair of Amperex from Brent and give them a try. I would have to burn them in for 100 hours, and if I don't like them enough send them back. That would cost me 20% of their price plus shipping both ways, which would be a little over$100 in worst case. Not a big problem if there is no other way.

wharfy, yes, I know, I bought tubes from Brent of Audio Tubes. He is very good, and pleasure to deal with. Replies to emails on Saturday and Sunday. I might talk to him about it later as well but first I would like to hear what audiophiles think. Besides, he is currently out of stock of reasonably priced Mullards. RCAs and Amperexes are available.

The Amperex will sound different from the Mullard and RCA tubes, but I can't say if they're what you're looking for.

Let's limit it to NOS only.

By the way, VAC's designer did recommend the original 12AX7 Chinese tubes that he put in there. He's got spares, you can get those tubes from VAC. I wouldn't listen.

However, for 12AU7 driver tubes he suggested I experiment a lot, though he said his preference was vintage Sylvania and Brimar, especially Sylvania. He said he was not a fan of RCA black plates because they might sound a little dark for his taste. They sound fine for my taste.

And for power tubes he said vintage Mullards, and that's exactly what I just got.

Today's Gold Lyons are very good, affordable, and available.

noromance, be nice, you are not the only one with ears.

I don't consider Telefunken because they are not recommended by the designer of the amp.

Shuguang Premium in the fancy box. I have a pair! 

@inna That’s a bummer. I’ve used scores of different ax7 tubes and these are the best to these ears. Anyhow, I’m not sure why you’re fizzling around with Mullards and their recessed highs and dull warmth, and RCA black plates with their constricted and strident upper mids when you can get Telefunkens which are neutral, open, transparent, and detailed.

@inna 

When I was looking for 12AU7 tubes and variants, I contacted these two- Brent Jesse and Andy at Vintage Tube Services. 

Well, there is a matched pair of NOS Mullards 10M with gold pins for $799 obo on ebay. He sells them here too for $999.

That would probably be fine but too expensive for me.

First, I don't do Chinese, and second - they are not available.

Shuguang Black Treasure 12AX7LS from Grant Fidelity

There is also NOS Raytheon long black plate for $500 for a matched pair, from a different dealer whose prices are often the double.

Amperex NOS, made in the Netherlands, is available from a very reputable dealer, from $200 to $450 for a matched pair. But would they be any better in my set up than Mullard or RCA ? That's the question.

Amperex are noted for their midrange. The ones made in the Heerlen, The Netherlands factory are what you might want. They can come with different labels, mostly Phillips, but also others.

There was also an Amperex factory in New Jersey. Good tubes but not the same as those from Heerlen.

Tubes for phono must be especially quiet and balanced. Similar to tonearm cable.

@inna 

If you want mids, NOS Mullards have the mid-range-to-die-for-reputation. I imagine older 12AX7 have higher-microphony issues. Thoughts?