0 Members and 1 Guest are viewing this topic. Read 35452 times.
Hi Mark - very excited to see the Z40 integrated! Will there be an inboard phono option? Thanks
HelloI have had the pleasure of owning the Zotl 40 Mark II amp for about 6 months now. Best amp I have ever heard in my home. What I wanted to share with anyone that owns this amp, is to consider trying the Tung Sol 7581A reissue power tubes. I have compared it to almost every new production EL34 and GL Kt77. This Tung Sol 7581A power tube is also considered a KT66 variant, so not a EL34 tube. I believe it will lower the watts per channel to 35, but I have noticed I keep the volume knob the same as with the other tubes..so no issue for me. What I have found is this tube has a very well behaved manner without sounding boring. Sometimes I have found newer production tubes to inject a thin or glarey aggressive character at times. This 7581a has great dynamics with a natural smooth spacious sound.Compared to the GL KT77 reissue, I found from top to bottom, the 7581a are much better balanced. The bass was more articulate, punchier, mids are clear but with weight and great natural tone, that is never forward or too laid-back. It's just right. The highs have decent extension but is more refined and smoother compared to the KT77. Another great thing about these tubes are the price...you can find them for as little as $90 for a quad. The GL KT77 are a good tube, but overall in my system a little too bright and messy. Overall this 7581a tube sounds like the best aspects of a KT88 (Bass) and EL34 (Mids) mix together, but with great refinement. Dynamics and musicality.
Thanks for posting about this. The ZOTL40 runs its power tubes very near the max operating voltage of 800V for EL34/KT77 tubes. The 7581 has a significantly lower max voltage rating. Given the design of the amp circuit, this may not hurt the 7581, but it is not a tube we can recommend and we have not tested it in the amp. The ZOTL40 sounds incredible with the 7581a. This tube is NO JOKE!~ Nicholas @LTA
Hey NicholasI do recall talking on the phone with you before purchasing the 7581a to see if LTA gave the "Green Light" on this. If I remember correctly you asked Mark also Mr Berning (who was in the house at the time) and you said that it "should be ok", but I was warned that the watts per channel would decrease. If you feel this could now be a concern after about 3 months of daily use, please let me know. The last thing I want to do is potentially damage anyone's equipment or mine. Why can't LTA test these? The upside for LTA and customers are a less expensive tube with better sonics compared to the pricey less impressive GL KT77.RegardsTom
One more thing! I am currently testing a New Production EL34 tube that is sorely never mentioned. The price is ridiculous low. This tube might just be the best power tube I have heard on my ZOTL 40. I am continuing to test and will report back next week.
(Drum Roll) The new tube that is without question the best new production powertube for the ZOTL40 IMHO is the JJ EL34L. Most people shy away from this tube because of the price, which is crazy. These tubes on the ZOTL 40 are amazing.
Since I have a new Z40 Integrated, I am interested in possible alternative tubes to the GL KT77 that come with the Z40i. The amp sounds great but I have been looking at the Sophia Electric EL34ST as a good option. It would be helpful if anyone has any experience with this tube, especially compared to the GL KT77. Thanks
Hello again and happy fridaySo I wanted to mention something that I don't think is talked about regarding the LTA amps. That is...the Protection Circuitry. So the story goes like this. My friend just acquired a NEW quad of the Original Wing =C='s EL34. He lent them for me to try. (Can you say Guinea pig lol) The date is 2011...that year is very hit or miss with quality control . So I plugged them in, started the amp up and within a minute, I heard what sounding like a distorted explosion. When I heard this, I ran to the amp and saw a LED light blinking on the circuit board. The text underneath the light said "Left Channel Protection" or something like that. So I then quickly turned the amp off. As you could imagine, I am thinking how much is this going to cost to fix. Well I am happy to report..NOTHING! This tube had a major meltdown and did not take out even a fuse on my Zotl 40. So my hats off to the Team LTA for creating what I consider to be the ultimate modern tube audio equipment. Its not just the great sound they produce, but the advancement of great techniques to prevent issues. Thank You LTA!