Matched vs. "close" matched vs. new junk tubes

[Corto Maltese]

Time to roll the tubes.
I have a small but very nice Synthesis Nimis, with the stock tubes still on it. It is time to get something better. I do not have an option to go with the matched NOS (too much $$$, I paid $350 for the amp, and you know how much NOS can be). I can go with slightly used, strong 80 to 90%, but not exactly matched OS (cheaper, sound should be still very, very good), or with matched new Mullard, JJ etc - basically same junk as it is the stock tube.
My amp has the fixed bias, so matching is a must, as per manufacturer. I contacted Tube Classics’ Karsten Schmidt, who tells me:
“If the tubes are really NOS and good, they should automatically be enough matched. EI or new “Mullard” are junk tubes.
My question is this:
Did anybody played on the field like this?
What is the consequence if the tubes are not matched – am I going to create the black hole, which is going to destroy…
What would you do:
4 used Valvo EL84 (power section) together with 2 used GE or Mullard ECC83 (pre)
or
4 new Mullard (matched) with 2 Ei ECC83 (matched)
Thank you for your help!

[Feanor]

Time to roll the tubes.
I have a small but very nice Synthesis Nimis, with the stock tubes still on it. It is time to get something better. I do not have an option to go with the matched NOS (too much $$$, I paid $350 for the amp, and you know how much NOS can be). I can go with slightly used, strong 80 to 90%, but not exactly matched OS (cheaper, sound should be still very, very good), or with matched new Mullard, JJ etc - basically same junk as it is the stock tube.
My amp has the fixed bias, so matching is a must, as per manufacturer. I contacted Tube Classics’ Karsten Schmidt, who tells me:
“If the tubes are really NOS and good, they should automatically be enough matched. EI or new “Mullard” are junk tubes.
My question is this:
Did anybody played on the field like this?
What is the consequence if the tubes are not matched – am I going to create the black hole, which is going to destroy…
What would you do:
4 used Valvo EL84 (power section) together with 2 used GE or Mullard ECC83 (pre)
or
4 new Mullard (matched) with 2 Ei ECC83 (matched)
Thank you for your help!

Hi, Corto,

I can't give you a definitive answer, but I can tell you that I'm glad I bought used, supposedly matched according to the vendor, tubes for my preamp. (My preamp doesn't allow for biasing but this might be less important in case of a pre(?)).

What I bought was these Amperex 'PQ' 6922 for US$86 on eBay, (picture below). They are very low noise and have be working perfectly for a couple of years. They are the best sounding of the half-dozen or so different tubes I've tried, some being new tubes. NOS would have several times more expensive; THESE supposedly NOS, matched, at Tube Depot are 4.5x the price.

[Corto Maltese]

Thanks, Feanor.
Unfortunately, vendor from Hamilton is in a hurry, I might be forced to tell him to go away. He sent me an e-mail saying he has an offer on those Valvo tubes US$140, and I do not like to rush. I am bit older than that... I don't know how to obtain something nice from Tecumseh, where I live, and because of the nature of my job, I cannot compete on e-bay...I'll see what I'm going to do, and when I have enough time, I'll jump on something used. Anyway - more to come, I already have a pair of new, and matched Ei ECC83. I should be able to pick up a matched quad of new Mullards / EH / GL soon, and that is not that much money to invest. Next step is to get something used, but nice and old. After the roll, I'll post the findings, most likely by the mid November. That could very well be the best answer on my own question, since the money invested will not be even half of what I could pay for the NOS matched tubes, packed and protected with the rare Gobi desert goat's beard hair...