Shootout of Nos 6sn7 tubes

i also had get delivery of 1578 from Russia this afternoon.

After I get it, I will give a try to compare with other two 1578 that I have.

Good luck to you!

The 6n8s made in 1978 that I had tried this week is real deal.

I ordered four more of them and two of them is staying in Freya.

About 2 hours ago, I got delivery of another 1678 Melz tube from Russia after one week from placing order.

Very fast shipping.

I had not got tubes from Ukraine that I ordered 5 weeks ago.

It was made in 1980 and looks clean as Nos tube.

After playing demagnetization track, I am listening to familiar music to me.

"Thriller" by MJ sounds spooky with deep and full bass, wide and deep soundstage.

Its bass, decay and soundstage is just beyond any other 6sn7 tubes.

But people may get the impression that it is bass heavy.

Now I have three pairs of 1587 Melz tubes and eight 6n8s tubes, I am going to stop shopping of 6sn7 tubes.

After being back from Kr vt231 this morning, I found that 1578 has more body and decay while KR give almost same amount of details as 1578.

First impression of the 1578 - wow! Looking forward to see how they sound after a little burn in. 

OP,  your amp uses one 6SL7 and two 6SN7s, yes? I believe the 6SN7 would be the phase inverters. Correct me if I'm wrong.
I assume you've tried rolling the 6SL7. What tube works for you in this position?

I used to use Mullard ECC35 for more than one year.

But about 3 weeks ago I switched to RCA 5691 red bass which give more details and deep bass than ECC35.