Linear Tube Audio- Any feedback on their amps/ Preamp?

Because the ZOTL circuit reveals the character of the tubes (and most components in the signal path) so strongly, now that we've made more ZOTL40s and heard them in different systems, we've decided to find some new tube options, as the Tung-sol EL34s don't seem to be the ideal match. Mark is currently deep in a pile of NOS, various new stock, and tube equivalents that we'll be auditioning to find a ZOTL40 tube that can really complement the 40's nature. 

-Will
LTA

Will,

i am listening to the ZOTL40 with a quad of Shuguang Treasure 6CA7-Z. These tubes take an agonizingly long time to break-in. I put them in another amp I have and let them play for almost 2 weeks straight. The ZOTL is very easy on tubes and I think it adds to the long break-in. I think the tubes are almost there now, yes, sounding pretty damn good. Warmer, more liquid and very good bass.

lance

ZOTL40 - EL34 shootout

The shootout was a lot of fun. For those of you who haven't met Mark, he's a great guy and a dedicated audiophile. I like his business model too. Start with a fantastic design and employ local people to manufacture great products HERE, not by slave labor in XYZ foreign country to maximize profits.

OK, the results are in, the EL34 Tung Sols that come stock with the amp sound very good, but there are a few other tubes that sound even better. Here are my Picks for the top tubes in the ZOTL40 in order, no. 1 being the best:

  1. NOS Mullard EL34 XF2
  2. Genelex Gold Lion KT77
  3. Shugaung Black Bottle 6CA7 (very long break-in)
  4. NOS Sovtek EL34 Winged C
  5. psvane EL34PH
  6. Tung Sol EL34
  7. Mullard EL34 reissues

The Gold Lion KT77s are killer in this amp and are manufactured currently.
The very expensive Chinese 6CA7 black bottle tubes and the Phillips knock offs also sound very good but are costly. Equally as good as the Gold Lion KT77s are the NOS Sovtek winged C EL34's and maybe better, but I'm still listening to them. They're getting better with break-in, and I keep going back and forth on that one. I didn't get enough time with the KT77, but my first impression puts it near the top.

If you can get your hands on them, the NOS Mullards in this amp..... I can't explain it.... is the most incredible sound I have ever experienced. Yes, the Mullards are legendary and the ZOTL 40 takes advantage of these vintage tubes in a spectacular way. I bought a set of used NOS Mullards for a fairly reasonable price. Because the ZOTL is so easy on tubes, I expect them to last a long time.

I'm not really good at describing the sound differences in audiophile terms but it was all there, the sound stage, airy highs and tight lows. The top of the list giving the best of these attributes.

The upgraded tubes put the ZOTL40 a notch above the ZH230 in my humble opinion. Maybe that's why David Berning has decided to drop that amp from his line. I did hear that Berning is going to stick to his top of the line amps that he builds himself. The Berning 211/845 monoblock amps were reviewed this month in TAS and I think they used the term "best amp in the world." Oh well, $75K is out of my reach but I've got a ZOTL40.

If you ever wanted to own a $50k amp for a fraction of the price, this is it. I really can't say I've heard anything this good at any audio show. Although I've never heard the 211/845.

Associated gear:
Janszen zA2.1 hybrid eltrostats
JL Audio E110 subs (pair)
PS Audio Direct Stream DAC networked
PS Audio P10 regenerator
Micro ZOTL as preamp with linear power supply
Morrow and Cerious Tech Cables

Lance, thanks for hosting that shootout! We had another with Mark's system and we've decided to go full Genalex Gold Lion for both the ZOTL40 and the ZOTL10. KT77, 12AU7, and 12AX7 for the 40 and EL84, 12AT7, and 12AU7 for the 10.

These Gold Lions are really excellent current production tubes, and unless you want to pay significantly more for some of the boutique current productions, they seem like the way to go. Now they just need to make a 6SN7!

So given that the Gold Lions are the new stock tube, are the NOS Mullards worth the additional cost?