Elrog 300b's for sale. Your thoughts?

I noticed this morning an add for the new Elrogs.   I and many others on the forum ran the experiment when the Elrogs were initially launched.   We found the tubes to be superb sonically, but woefully unreliable.  In fact, the early failure rate on those tubes was apparently 100%.  I and others received replacements that were hand selected for suitability in our particular amps.  In fact one individual had 3 pairs fail.  In my case, I went so far as to purchase a PS audio power plant, having been assured that limiting incoming voltage to 115V would ensure reasonable lifetime for the Elrogs.  Two days ago, one of my replacements failed, after having been nursed along carefully.  Honestly, I doubt the tubes had 600 hours on them.  So the Psvane T1s went back in and I began the period of mourning for my deceased Elrogs.  This morning I awake to the siren song of an ad from a reputable dealer who is announcing availability of the new improved Elrogs with a 1 year warranty.   My initial reaction was, "I don't think so.  Someone else can run the $1200 experiment.  Burned once and lesson learned."  But here is the problem.  If all of Elrogs former customers take that approach, the new Elrog will also fail even if the tubes are good for 10000 hours, simply because no one will buy them.    The tubes are so good that it would be a tragedy if that happened.  So the question to all of you who have already been down this road is this?  What would it take for you to give these tubes a try again?
Elrog needs to re-establish goodwill.  I wouldn't want to be a $1200 beta tester with their history. Elrog should drop their price until their  reputation has been rehabilitated.  
Hi Bill,

The following article by the gentleman who founded the company that is producing the new Elrog tubes will be of interest:


I note the following statement in a response to someone's comment beneath the article:
These are tubes of the latest production with improvements which solved the reliability issue of the filaments in some amps. The tubes now carry a full 1 year warranty also on emission.
I suppose that a logical question would be if the improvements that are referred to can be expected to result in any changes in the sonics of the tube, compared to the original.

Best regards,
-- Al
Thanks Al.  I had previously read the information for which you provided a link.   Your question is a good one, and had occurred to me also.  I trust that information will be available to us shortly, provided that even 2-3 "beta testers" take the bait.   But brf's comment is spot on.  The two principals who were responsible for failure of the original company are deeply involved in the current effort.  Their reputation is less than stellar. Remember that there was a persistent denial that there was an issue with the tubes. The fault was this amp or that amp, never mind the fact that the tubes apparently failed in every amp they tried. Lots of us will be skeptical of their current claims without empirical substantiation, i.e, we find that people are getting 2-3 years of service out of these tubes.  If 90% of there potential customer base waits 3 years the new company will fail. The purpose of this thread is for the new company and the US distributor to gain an understanding of the magnitude of the public relations nightmare they are up against with these tubes.  They will need to explain to me why I should take this risk instead of buying, let's say, the excellent sounding and reliable EML 300b's at 60% of the price of the new Elrogs.   Sorry, but I can't justify $1200 a year for one pair of tubes no matter how good they sound.   I don't expect more than a 1 year warranty under normal circumstances, but this is not a normal circumstance. 
Hi Bill,
Well I did indeed have 3 failed attempts with the Elrog 300b and excellent support from George at tubesusa.com, the tube failures sure weren’t his fault. This is a classic example of superb sound vs product unreliability. No doubt about it, the Elrog was stellar in my amplifier.

Who wants to be a 1200.00 dollar beta tester? Good question bfr. It’s interesting how we are able to accommodate change over time. I returned to my EML XLS an excellent 300b that I truly enjoy listening to (this is an exceptionally robust and reliable tube). It’s only with direct comparison where I can say that the Elrog is a bit more nuanced and organic thus a bit more emotional. The gap between them is small but detectable. The EML XLS is as dynamic, perhaps more so. Honestly in my particular SET amplifier both tubes (along with the Takatsuki) are wonderful music conveyors.

I’d need to know precisely what has been done to improve the durability of the Elrog. A full year warranty for a tube does suggest a high degree of confidence from the manufacturer. Bill I’ll say that I am curious about this new and "improved " version. I’ll read the article posted by Al. I feel no sense of urgency to try the Elrog at the moment.
Charles, thanks for you comments.  I agree.  While a 1 year warranty may be more or less  standard, in view of the history of the tube, one might have expected a longer warranty as a statement of confidence.   I am also troubled by what I read in the material provided by Al, where the statement runs along the lines of correcting the issue that caused failure in some amps.  That sounds to me like they are still in denial.  The information that I have from my dealer is that the failure rate for his customers was 100% in a variety of amps.  He did not have a single customer that did not experience premature failure.  Unless I see more, I'm going to have to sit this one out and go with the EML tube.  I want the new Elrog to succeed, but I don't need any more weasel words, and I'm not placing a $1200 bet on something that looks like a long shot from my frame of reference.
I would jump on 4 pairs and pray really i would pass big time and get some real tubes.
Is the sound THAT much better than other brands?  I had issues with tube stuff and have been using s/s trouble free for many years.

November 2015 i purchased a pair of Elrog 300b’s for my Lampizator Golden Gate dac. i used them for 30 days on the 300b setting and loved how they sounded. then one of them got weak. i called Gary at tubes USA where i bought them and a week later he sent me a replacement pair. feedback to me from Gary who was told directly from Elrog, instructed me to use the 101d/45 setting on my Lampi GG going forward.

i installed the replacement Elrog 300b’s in mid-January of this year, 11 months ago and listen for 3-5 hours a day to them since then without any issue at all. still going strong.

I preferred them to Psvane 101d WE replicas, Psvane 300b WE replicas, and a number of NOS 45’s......all of which I still own but have not used since I installed the Elrogs. and yes, they are a cut above those others to my ears.

very happy with the outstanding performance and reliability since then and would highly recommend them assuming you get good advice on the context of how they are used.

Stringreen,  I can say that the Elrogs are substantially better than the Psvane Ts that came with my amps.  Well worth the price, provided they last.  I spent most of my life using SS equipment.  The Elrogs in my Coincident Frankensteins easily surpasses any other amp I have personally heard, either tube or SS, including some that are far more expensive.  Charles and others have much more extensive experience with a wide variety of different 300b tubes.
Mikelavigne, I had read of your experience with the Elrogs in your Lampi.  I am eager to hear of success stories with the Elrogs.  I'm just not sure how relevant use in your Lampi DAC using the 101D setting is to what is likely to be a more demanding power amp utilization.  BTW, I use the WE 101D replicas in my preamp.  The fact that the Elrogs bettered them and some NOS 45's is a testament to how good the Elrog sounds.

Mike, thanks for those inputs. But I’m puzzled by the fact that the three tube types you mentioned use different filament voltages, among various other differences in electrical parameters. The 45 has a 2.5 volt filament; the 101D has a 4.5 volt filament, and the 300B has a 5 volt filament. Not sure how the "101D/45" setting you referred to could work with all three tube types. Although I’d imagine that a setting intended for use just with a 101D, that applied 4.5 volts to the filament, could work with a 300B in a reasonable manner, at least in a line-level application such as a DAC. It definitely wouldn’t be healthy for a 45 though.

-- Al

I believe that Mike’s experience with the Elrog in his Lampizator DAC unfortunately has minimal relevance to its performance in a power amplifier,. I’d assume that far greater demands are placed on the tube tasked with driving speaker loads. It is as he describes sonically beautiful in character.

Stringreen, the Elrog sound quality has been discussed and compared with many other 300bs  in several different threads (I’ve been fortunate to have heard 11 different types in my amplifier over the years) . As I’ve said before the Elrog is the very best in sound quality "but" it doesn’t by any means embarrass other top tier 300bs. The gaps are subtle.

Stringreen if you have found a SS amplifier that pleases you as much or more than a tube amplifier, sincere congratulations to you. There’s no logical reason for you or others to own a tube amplifier. This hasn’t been my experience by any stretch. As Brownsfan stated, the SET tube power amplifier listening experience is above and beyond what I have heard with transistors. So this is simply a matter of our individual sonic objectives.

No intention of the tired tube vs transistors debate resurrection. My point is, only that these premium 300b tubes in the right amplifiers have taken my music listening to higher ground..
The cost of the tubes is not what worries me. I am much more concerned about the risks of any potential amplifier damage should they fail.

Hello Gary,
I'm relieved to report that the Elrog tube failures did not harm my amplifiers at all. I know that the magnificent Takatsuki 300bs  are serving you well 😊
It's been exactly one year since I have used my updated 'new production' tubes. No issues, no flaws.

Mind you I don't keep removing them for any A/B testing while they are warm, etc.

But I have changed them from one amp to another, while completely cool.

And needless today they have a wonderful SQ.

Hi All,

my name is Thomas Mayer and I am the founder and owner of Deutsche Elektronenröhren Manufaktur GmbH, which produces the Elrog tubes now. I’d like to share some more insight into the situation. Before I bought the machines of Elrog and started to produce tubes I was a distributor of Elrog tubes and I used them in amps I sell. I went through the same pain as other distributors with the failure of the 300Bs during the first year. Like George Lenz I made sure that each customer who experienced failed tubes either got replacements or his money back.

The company is under my sole management and I handle all customer interaction. You can rest assured that we will honour all warranty claims. In fact we are giving warranty on tubes produced by the old company as long as they are still in their original warranty period. Also be sure that if similar problems pop up again, there will be no denial.

I fully understand the reservations some of you have against Elrgo tubes after all you went through. It will take time until the reputation will return and I understand that people want to see others use the tubes for some significant time without reports of problems. We are prepared to go through this period. In fact the sales of the newly produced tubes has been quite good and we had trouble to keep up with the demand.

About the issues of the tubes. As has been reported, the tubes underwent numerous changes during last year. The most significant one was introduced in January this year, which involved a strengthening of the filaments. 95% of the failures were breaking of one or several of the filament segments. The filaments were very sensitive to overheating and especially inrush current at amplifier turn on.

The filament had been strengthened in January which was well before I bought the assets of the company. I am happy to report that I did not receive a single returned 300B tube which has that change. Also since the tubes are produced under the new company we did not experience a single 300b fault. In the new company we introduced several more changes, like different bases, better, more uniformly shaped glass and improved vacuum. Also much more improved quality control. Although the failure rate of the 300B is 0 so far of course it is unrealistic to expect absolutely 0 returns. A technical device can fail and at some point we will also see some failed 300b. But the experience so far indicates that the percentage will be very low and of course every fail will be handled under warranty. We continue the policy that every customer who experiences a fail has the choice of getting new tubes (with new warranty) or money back.

To show the confidence in the new tubes we extended the warranty from the previous 6 month to 1 year. Warranty will be handled graciously and we will not be fussy about tubes which fail shortly after the warranty expired.

Some more info about the problems of the 2015 tubes: There had been amps in which the failure rate was 100% and amps in which the failure rate even of the early tubes was negligible. For example I have customers who use amps built by me and are still running Elrog 300bs produced in March 2015. The amp with the highest failure rate was the Frankenstein. Before releasing the tubes for the Frank I asked a beta tester to use the tubes in his Frank. This test has been going on for almost 6 month now and the tubes are going strong. Of course a longer time is needed to have statistical relevant data. But we are willing to supply tubes for Franks again and would be thankful for early customers to provide feedback. We are also supplying Lampizator DACs with tubes and they are running fine. No problems whatsoever reported from Lampizator users so far. We do have a list of certain amps which we do not recommend to use with Elrog tubes, but these are known to eat other 300B brands as well. When inquiring for Elrog tubes mentioned your amp and we will tell you if it is on the black list. This black list is very very short and wr do not want to mention the manufacturer publicly.

I was in close contact with George Lenz before I started the new company and he was the first distributor on bard after restart of production. George continues to be the exclusive distributor for Elrog tubes in the US and Canada. I am happy to have such an experienced and customer oriented in George to take care of this area.

I hope this gives some more insight. Don’t hesitate to email me or George if you have further questions

Best regards



The 211 and 845 did not have the issues the 300B had. They did however also suffer from poor quality control. This has been improved as with the 300B. The 845 and 211 also got new bases and better glass and the same improvement to the vacuum.


Hello Thomas,
I'm aware of your well established reputation for building very high quality custom amplifiers over many years.  I've read with much interest your detailed descriptions of the planing, design and construction process posted on your site. Knowing that you've taken over production of the Elrog tubes does inspire me and elevates my level of confidence. 

I'm the owner of the Coincident Frankenstein MK II amplifier and George Lenz did honorably replace my failed 300b on 3 separate occasions without any resistance on his part. I know that he was frustrated with the tube failures but he kept his word and never wavered,  I'll always remember the support provided by him. 

I will give the "new" Elrog 300b some consideration to try again. 
1. My experience with the tubes was obviously a poor one in terms of reliability. 
2. My listening experience with the tubes in my Frankenstein was truly fabulous.  The best I've had thus far in terms of musical realism and emotional involvement/engagement. 

Thomas thank you for the Elrog situation update and explanation. If the Elrog can approach the trouble free workhorse durability of the excellent EML XLS  this would be an amazingly good outcome. 
Thomas, is there a preferred operating point for the Elrog 300b tubes? For example an operating point of 350v across the plate @ 60mA would be considered a traditional operating point for the 300b. Some amps run the 300b at a much higher point for example 400v or even 450v across the plate @80 or 90mA. Thank you.

Thomas, Thanks so much for your response.  This dialogue with the company is what I hoped would happen when I opened the thread.  I am encouraged by your candor, attitude, and also by the information you have provided on the changes to the tubes and resulting gains in reliability.  As I have said, the Elrog 300b is a tube of stunning beauty.  I want Elrog to succeed and have the opportunity to add additional tubes to its catalogue as time goes on.   I would encourage you to drop by this thread on occasion to provide updates on tube reliability.
I also own Coincident Frankenstein amps.   As you know from my post, when I received my replacement tubes I bought a PS audio P10 so that I could limit the voltage.  In addition, the P10 provides for a soft start up where the initial inrush is limited to 1/2 current for the first 5 seconds.  I almost never listen for more than about 2.5 -3 hrs, so I had hoped to make the tubes work.  I had intended to go with the EML xls as a replacement, and may still go that route.  But I am going to put this decision off for a few months to see what transpires with your recent production tubes in the Coincident amps.   Can you share with us the number of customers currently running your new tubes in their Frankensteins?   I am personally willing to consider the Elrogs again based on your comments, but I would like some statistically significant data on the tube lifetime in the Franks.  I don't expect 0% failure, of course.


thanks a lot for the positive responses and good wishes. As mentioned in my post so far there was a single beta tester who used the tubes in a Frankenstein amp. He had them for almost half a year now. I wanted to have this test first before releasing the tubes for the Frankenstein. Since this release only happened now, there are no additional users of Frank amps yet who have the new Elrog tubes.

@jetrexpo: The choice of operating point depends more on the amp design than on the tube. As long as all max limits are not exceeded any op point which is preferred by the amp designer is ok. 450V/90mA would already be slightly over the limit and thus is not recommended. I personally use fairly traditional op points of about 350V/65-75mA

@brownsfan: The inrush current issue was solely relevant for the filament supplies. When the tube filaments are cold they are basically a short. If the filament supply uses brute force voltage regulation it will push a lot of initial current into them. An external softstart will probably not do much there. We also saw that some current regulated filament supply kits for DIY amps actually start with a current spike and initially put 7V across the filaments before settling to 5V. This is not healthy for any 300B, but it simply killed the early Elrog 300Bs. Also a tube rectified B+ supply doe snot have any affect on slowing the filament inrush current. But as mentioned the tubes are more robust now to be able to withstand some abuse at turn on. Yet a well designed amp with good filament supply and conservative op points will ensure a longer tube life. Not only for Elrog 300Bs but for any brand.

Best regards

Thomas, thanks very much for your excellent responses.  And I second the good wishes extended by the others.

450V/90mA would already be slightly over the limit and thus is not recommended.
I would add that neither number is in itself over the limit.   It is the combination of the two that would result in the tube's maximum power dissipation rating being slightly exceeded.

I say that based on the ratings indicated in this datasheet for the original version of the Elrog tube, as well as on the ratings specified in this 1939 datasheet for the original Western Electric tube.  Although this 1950 datasheet does indicate 400 volts as a "maximum rating, design center value" for the Western Electric tube.

-- Al  

Hi Al,

yes you are right, each parameter on it's own is within the allowed limits, but the combination of 450V/90mA results in a plate dissipation slightly above the maximum allowed 40W. 450V * 0.09A = 40.5W (40W max)

Best regards

vinylsavor - Thomas,

In purely general terms may I ask what one might expect in terms of hours of life for your "new" 845 tubes?  Some online forums suggested the prior manufacturing of those were problematic as well. Txs

As mentioned above the 211 and 845 did not have the issues which the 300B had. They suffered from the poor quality control as well. During the time I was distributor for Elrog I got only very few returns of 845 tubes.

Life time cannot be generally estimated since it depends a lot on the operating conditions. During the many problems with the 300B we learned that there are a lot of amps which push tubes too hard. This can shorten the life time. op point, usage pattern (on off cycling) and tube rolling all affect lifetime. Normally you should be able to expect 3000-4000 hrs from a thoriated tungsten power tube. This can drop significantly if the tube is abused. It can also extend well beyond that number if the tubes are handled well. The distribution is a kind of bell curve

We also do not make the 845 long enough under the new company to have significant statistical data. I do not expect any issues with the 845 though.

Like the 300B the 845 and 211 carry a full year warranty now.

Best regards


Is the website for the Elrog's up to date with prices and able to take orders or does one need to email you personally?

For the US and Canada please send inquiries to George Lenz of tubesusa.com.

I will update the elrog.com website in January with prices and order information. Until then drop me an email

Best regards

Facing one's critics and being honest and forthcoming is an excellent start in rehabilating one's reputation.  I wish only the best for Thomas and Elrog
Based upon the threads, even on Audiogon, relative to poor experiences with the prior 845 regardless of  whatever  the causes were and the apparent lack of current manufacturing empirical data , I'm having a hard time at this juncture to move forward at the  $1650/pair price tag
I have been considering the Elrog 300b's for my Lampizator Golden Gate Dac but have held off because of all the failures reported by the Lampizator community. Mikelavigne reported success using the 101d,45 setting instead of the proper 300b setting. I wonder what would be the proper setting to use with the new and improved Elrogs. 

We have several customers with Lampizator DACs who use the 300B after the major improvement in the filaments in January 2016. None of them have reported any issues. The tubes should be operated like any other 300B. Especially the 45 has a much lower filament voltage than a 300B. So use the 300B setting of your DAC

best regards

I have had Thomas's new 300b's in my Manley Neo Classic Pre for over a month now.  Within one day of listening to them I ordered another pair.  I can't say enough about Thomas's help and Mr/ Lenz's great customer service. I can also say these tubes don't need any real break in period compared to the others that I have used. I own many -both chinese we300b 1:1 models (psvane and shungyang), Gold Lion 300b, EML, Western Electric 300b (68), Takatsuki TA-300B.

I replaced my Takatsuki TA-300B's and I prefer the sound of the Elrog 300b by a . Now theTakatsuki is a great sounding tube and was my favorite until the Elrog ..yes including the original Western Electrics.  

IMO the Elrog is not yet another 300b clone.  This tube is very different and sounds more modern and defiantly less pillowy on the bottom end.  Transients are much faster and in genera the tube is a joy to listen to.

Thomas, thank you for acquiring Elrog and making the changes you have.  I hope to have you build me a new archiving pre for my turntables that bests the Manley Steelhead I am using now. Also, can you start making some Elrog t-shirts already? 

(yes I am now an Elrog fanboy)


Thanks a lot for your feedback and sound description. T-shirts will be made  :-)
We will have them for the High End show in Munich this May. Anybody who plans to visit the Munich show, you can visit us in room F231e

Best regards


I hope to have the website updated by end of the month. We are totally busy with production catching up with demand and development of a new tube type to be launched at the High End fair in Munich in May. So the web site had to wait. But there are regular updates on my blog and I will keep posting about the tubes and manufacturing process. See here:



I have interest in purchasing the Elrog 300Bs. Have there been any other experiences since the last glowing post by diminishing_returns who surprisingly has that one and only post on audiogon? Have the reliability issues been ironed out - any user experiences to share?
Interesting remarks from Thomas about 300b operational points, I remeber his amp showing 140mA at the milliamper meter (400V at voltage meter), is that a sum of current for two tubes?
I just passed the 1 year mark for my Elrog 300B tubes. I will admit that I have also been running the EML 300BXLS in my Art Audio Diavolo 300b SET Copper Reference amplifier as well. So I can say they have about 1000 hours on the Elrogs. Regarding sound quality, I enjoy both tubes equally and wouldn’t say one is particularly better, but the Elrog is a tad smoother, slightly more euphonic, and a tad less dynamic. EML 300bxls comes across as more dynamic and neutral sounding to my ears in comparison. I’m splitting hairs here as they both sound much more alike than different which surprises me as they are constructed differently. They are both superbly made tubes with excellent construction and looks, but the EML 300bxls are structurally built more robustly and are beefier in looks and stature whereas the Elrog feels a bit more delicate, but the Elrog probably would win a beauty content based on looks and that beautiful glow that you won’t get from the EML.

The real question is would I buy them again. Well, at their current prices ($1455), which is more than I paid a year ago, I will not be reinvesting in them because they have priced themselves out of the market imho. They simply aren’t worth the premium for that subtle of a difference. The EMLs have a much better warranty, proven reliability, and a much more affordable price point at around ~$900. More importantly, and correct me if I am wrong, but running a 300bxls at 8wpc should probably last significantly longer than a normal 300b as it’s designed to put out more wattage and they are basically loafing in my amp’s standard 350v/75ma voltage mode. If I flick a switch I installed into my amplifier it switches to the higher 450v voltage transformer windings. I then just tweak the auto-bias circuit pots from 75ma to 110ma & I get about 13wpc which is an added bonus and a very noticeable improvement in performance for certain types of large scale music that the higher wpc output setting does benefit from.

Hi jacarcopo,
I glad to hear that the current Elrogs are seemingly more durable compared to the earlier versions I had. Despite our different Amplifiers/audio systems I find our listening impressions virtually identical. Yes I’d say that the Elrog is just a little bit smoother, warmer and organic in presentation. The EML XLS is more dynamic and authoritative yet retains an organic character  and is by no means a "cool" sonic presentation IMO.

The XLS is as you note very robust and well built. There are reports that early versions of this tube are approaching 40,000 hours of use and yet still are able to test as new. By any standard this is impressive! I did enjoy the Elrog in my Coincident Frankenstein amplifier but honestly I don’t feel as though I’ve lost anything with the EML XLS (Just subtle differences and tradeoffs) . At this juncture I’m very pleased with them and don’t anticipate a tube change.

The XLS isn’t inexpensive itself but does offer excellent sound quality and apparently extraordinary lifespan/ reliability. After over 3 years of heavy near daily use mine tested exactly the same as the day I got them.
Jacarcopo,  Thanks for posting this report.  I've exercised considerable discipline in waiting things out for a year before making a decision on Elrog vs EML XLS to replace my Psvane Ts.   Much as I loved my Elrogs, I just can't get to a justification for taking that risk again, and even if the reliability issue has been solved, I'm not hearing either you or Charles reporting a huge separation in purely sonic terms.  Hopefully, I'll get around to this before a tariff on vacuum tubes is imposed. ;>)
Hi Bill,
It good see a post from you, it reminds me of the of the good old days on this forum 😊. To be fair you just might find the Elrog superior and may prefer it based on your own comparison. The Elrog certainly is a excellent sounding tube with its undeniable strengths. You could find the gap between the Elrog and EML XLS perhaps a bit wider than jcarcopo or myself.

As I wrote above when all is considered sonically across the full spectrum the XLS does acquit itself very well.Bill some say that the Psvane W.E Replica 300b is an excellent tube and probably a bit more organic and midrange centric relative to the EML XLS.

I don’t envision Elrog (or any tube manufacturer) producing a surplus of their tubes and dumping them here at ultra low cost, so I believe we’re safe from tariffs 😊😊.
Charles, I'm sure the EML is going to be just fine.  Its been a year since my 2nd set of Elrogs burned out.  That should be enough time that a comparison of the Elrogs and EMLs from me will be meaningless.   Over the years I've learned that we seem to hear the same things, and value the same things, so I have no inclination to run a very expensive experiment to ensure that that still holds true.   I do think that the Elrog design offers much to recommend itself, and I want them to succeed and continue to roll out new products.   But, they got off to a rough start, and I suspect they are going to have to offer something better than diminishing returns at premium prices to fully realize their potential as a company.   BTW, I am really enjoying the Franks in the downstairs system.   Nice having the luxury of a good SET system and a good OTL system based on the M-60's.  
Well you do have 2 very fine audio systems to enjoy when some struggle to develop just one. Of course you know how I value your listening impressions and perspectives. What are the essential differences (If any) you hear between the 2 systems playing the same music. I realize that one uses full range speakers (Super Victory) and the other monitors on stands (Triumph Extreme). If must be quite nice to have both a first rate SET mono blocks and OTL mono block amplifiers for enjoying your classical music library. Have you tried the M 60s with the Triumph Extremes?
@charles1dad   I'm ecstatic that people are getting such longevity out of the EML tubes.  I want to possibly try their 300B Meshplate, any thoughts?

@brownsfan You're quite welcome. Yeah I can't see spending that much on another pair for the subtle differences that I'm hearing, but I do like rolling between them and EML just for the change of pace.  It's nice to have choices.
@charles1dad  I guess I'll find out if the meshplates are an improvement.  I just ordered a pair from George at TubeUSA.
I tried the EML meshplate in my Frankenstein several years ago. The operating points(O.P.) in this amplifier are too demanding for this more delicate 300b and so durability is poor. If a 300b amplifier is gentle in terms of O.P. then the meshplate tube is a very viable option. I will tell you that the EML meshplate is absolutely beautiful sounding.

A bit less dynamic than the XLS but very airy with much finesse. A different sonic perspective from its EML sibbling. If I had the appropriate amplifier I could be exceptionally happy with both of these. The XLS is an ultra built, robust 300b that sounds superb. A wonderful fit with the my Frankenstein SET yielding a powerful, tactile and very natural sonic character.
George is is a honest and straightforward person.  I bough my EMLs and Elrogs from him. He firmly stood by me and provided excellent customer service during my Elrog failure episodes. 
You ask two great questions for which I have less than clear answers.  First of all, I have not evaluated the M-60's driving the TE II's.  Getting the SVIIs dialed in upstairs was a bit of a chore, and moving them in and out of the room is a considerable project.  Similarly, optimal positioning of the TEII's upstairs would likely require a fairly significant investment of effort, without which, a valid comparison could not be drawn.  Moving the M-60's downstairs is also not going to work.  There is just not enough room for them in the area in which the downstairs system electronics resides to accommodate them.  So that experiment is pretty involved and probably won't do more than satisfy curiosity.  As for the essential differences between the two systems playing the same music, it is pretty much what you might expect.  The TEII's are the best monitors I have heard (although I can't say I've auditioned scores of monitors), and they mate superbly with the Frankensteins.  I do not perceive that the Franks struggle at all to drive the TEIIs, based on the absence of objectionable levels of distortion.  While it must be stated that the source and preamp downstairs are not in the same class as the ModWright Sony HAPZ1 and Coincident Statement Line Stage present in the upstairs system, both source and pre are good enough to convey the essential strengths of a 300B DHT based system.  That dash of euphonic 2nd order distortion, absent in the M60's, can make for mighty sweet listening.  The TEIIs driven by the Frankensteins are going to be pretty hard to beat in my book for Schubert Lieder, violin sonatas, and the like.  It is a really good "sooth the savage beast" system perfect for decompression after a day of frustration.  As you might expect, the M-60/SVII pairing has a clear  edge with larger scale works, especially when there are large swings in the dynamics.  When it is time for Mahler or German Opera, it is time to move upstairs.  Upstairs has the advantage of dedicated circuits, room treatments, and superior ancillary equipment, so this is not entirely due to differences in the two amps.  As you know, I found the Franks to be not up to the task of driving the SVII's.  No amount of effort on my part could make this work.  So I've got two respectable systems that serve me well.  Don't ask for a Sophie's Choice here.  I love both systems, and won't give up either.  I suspect that if you had both amps as options in your room and your system, you might feel the same, but might have an easier time sticking with the Franks if you had to choose one. 
Hi Bill,
Thanks for the thoughtful and clear description of your 2 audio systems.
I can understand not wanting to move equipment around if it isn’t a simple task. Your summary of the 2 respective amplifiers is on the mark. I had an opportunity to hear the Frankenstein and Atma-sphere MA-1 head to head in a friend’s system who had easily driven speakers. Essentially it is 
2nd order harmonics(just a dash as you wrote) versus the 3rd order harmonics character of the MA-1.

The Frankenstein came off a bit fuller tone and harmonically richer.
The MA-1 a bit leaner and faster. Overall subtle destinations, both were exceptionally open,transparent and very lively. You have two excellent power amplifiers with their individual sonic signature.
Autospell strikes again,  in the final paragraph should be overall subtle "distinctions" not destinations.