Shootout of Nos 6sn7 tubes

I bought a pair of the Melz 1578 from the seller @shkong78 recommended for my Modwright LS 100.  I played them for a while last night and they sounded really good right out of the box (I had the LS 100 in HTBP mode for about an hour to get them warmed up, watching TV).

They are detailed, dynamic, and the bass is prominent with a texture that I have not heard in my system before.  Pithy might be a good description of the sound of the bass.  The soundstage was expanded and there seemed to be more separation between the instruments.  I can't wait for them to break in a little more. 

They were one of the best bang for the buck upgrades I've made to my system.  I've used Shuguang CV-181, the stock Tung-Sol tubes, Sylvania Chrome Domes, Sylvania 6SN7GTA "tall boys", and Sophia Electric clear and blue tubes.  The 1578s were the best by far.

Congratulation big_greg

But I have a problem with one of tube.

KR is dead quiet, but 1578 has hum and high frequency noise until 20 minutes warmup.

I am going to wait few more days before I contact the dealer.

I have three pairs of 1578.

Funny thing is that both pairs made in 1980 has some hum and high frequency noise

But one pair made in 1983 sounds fine and has filthy bass as described by "big_greg".

I am listening to "The Wall" .

I am happy that Line Magnetic 508 fitted with 1578 can drive my speaker Lansche 4.1 with such full force and control of bass.

It also give widest and deepest soundstage with holographic layering in my listening room so far.

If you are bass freak or soundstage mania, then you shall try 1578 Melz

I am back to Kenrad vt 231 playing "Autumn Leaves and Songbird" by Eva Cassidy.

Although 1578 Melz give best bass, decay, widest and deepest soundstage, it has two drawbacks.

The first one is slight hum and high frequency noise which is almost gone after 20 minutes warmup while KR is dead quiet without warmup.

The second one is that its treble can sound closed in slightly lacking air or sparkle.

KR vt 231 sounds very similar to 1578 but with slight more sparkle.

Thus I prefer KR to 1578 in playing lady vocal music like Eva Cassidy while I prefer 1578 in playing orchestral music.


I will take turns at tubes to taste different flavor depending on music genre and my mood.

But be sure to use socket saver if you roll tube often.

https://www.ebay.com/itm/CED-P-ST8-1000-VACUUM-TUBE-8-PIN-OCTAL-SOCKET-SAVER-for-6L6-6V6-6SN7-EL34/150688246271?ssPageName=STRK%3AMEBIDX%3AIT&_trksid=p2057872.m2749.l2649

Interesting thread!I recently found a seller on Esty and ordered a few GE,Tung Sol,RCA to try for the input tube in my amp.All short bottles, black plates,black bases.Those RCAs are really dynamic with excellent textured bass.A nice surprise:-)The TSs have a wonderful midrange but not much detail top or bottom.The GEs are both lush and detailed,really nice.These all averaged around $20 apiece so not too expensive to experiment with.

I needed to replace the Sofia Blue which I really liked for almost a year.They aren't noisy or anything,but somehow lost their tone and sounded flat.Just not worth the price if they have to be replaced often.