Which 300b amplifier for Devore O/96


I am looking to upgrade (and simultaneously downsize) from Coincident Frankenstein Mk2 300b SET monoblock amps to one of these stereo amplifiers.

These are the four candidates so far: Nagra 300p, Luxman MQ-300, Wavac EC-300B, Air Tight ATM-300R, Shindo Cortese 300b

My preamp/dac is Bricasti M12 and my speakers are Devore O/96.

I am not looking nor interested in any other 300b amps at this point.

If anyone has compared one or more of these amps (esp on an Orangutan) do chime in.

Where I live I can probably demo the Nagra and the Air Tight but nothing else.

Thoughts?
essrand
Myself and several enthusiast friends did a shoot out of sorts between a number of amps on a pair of O/96s. The preamp used was a CAT SL-1, a modest Rega TT with the CAT phono stage and a decent digital system with a transport through a Thor Audio DAC.

The amps used were: old Mastersound 32B integrated, Audio Note 300B parallel SET, VAC Phi 200 and Atma-sphere M-60s. The clear winner by a significant margin were the Atma-spheres. When bypassing the Mastersound's internal preamp with the CAT this amp came in second followed by the VAC. Last place was the Audio Note. There was a 100% consensus.

When compared with the M-60s all other amps sounded restricted and confused. This was especially true of the SETs. When you got above low volumes the SETs had a very obvious tendency towards homogenization of the presentation. Only with the M-60s did the sound truly leave the surface of the speakers and these were the only amps to offer a truly balanced presentation.

I cant stress enough the need for power with these speakers and also how these speakers love to be driven by OTLs. Even though many may disagree, I dont think that 300B SET power is enough to let these speakers truly breathe. 
 


You stated you are interested in 4 amps, but you listed 5. Which ones are you interested in because I am not sure if it’s 4 or 5....and if 4 which ones??
@essrand  The O/96 is a great speaker; 2dB less efficient than my Classic Audio Loudspeakers. This is just my experience, but the power of a single 300b is simply insufficient on *my* speakers. Unless you're in a small room or never listen with volumes past 80dB, IMO 7 watts just isn't enough power.

I find about 30 watts is a good minimum, if its clean power. I have a type 45-based amplifier (which is push-pull); it makes the same power as a 300b SET. Its simply not enough power on my speakers for a satisfying volume. Now SETs are different from most amplifiers in the way they make distortion; that distortion interacts with the human ear/brain system to make you think they are louder than they really are. As you turn the volume up, this distortion (higher ordered harmonics) first tends to show up on transients. This is why SETs are often credited with being 'more dynamic than their power would suggest'; a common paraphrase you see in SET reviews.

So if I were you, and you want a 300b-based amplifier, I would go with a push-pull 300b amp. It will be making about 30-35 watts which will really help out a lot. There are plenty to choose from.
Yeah its 5 not 4 amplifiers.

@atmasphere @jsautter you guys have given me fodder for thought.

I feel like my Coincidents were powerful enough. But now you are making me doubt that. Will put those amps back in, listen more and get back.

So I am guessing out of my choices your vote would be for the Nagra 300p (its a push-pull 300b, 20W).


@essrand If I were you I'd be open to more than just the Nagra, but out of your list that would be the one. I personally don't think 20 watts would be enough power though. I see 30 watts as a minimum on my speakers and 60 watts is a lot nicer. I did recently move though and my new listening room is slightly smaller and I've still not sorted out all its differences, but for now its more lively so 30 watts has been enough for now. I think if I can tame the side walls I'll be able to play easier with more power though.


The trick is to really have more power than you're going to need! With SETs, because of how they make distortion, this really means that to hear what they do properly you really shouldn't need to run them past about 20% of full power (otherwise the higher ordered harmonics become more audible). That means to take advantage of many SETs you need speakers that are over 100dB...
I once had the integrated version of the Nagra 300b. It didn't sound like a 300b..it was pretty linear if a 300b can be called linear. With that being said, it had a solid state pre section and the speakers were Stenheims. It was nice and reasonably dynamic within its power band. I like the combo but I haven't had seller's remorse like I have every time I've ever sold a Leben. LOL
Atmasphere 5-15-2019
The O/96 is a great speaker; 2dB less efficient than my Classic Audio Loudspeakers.

Ralph, if I recall correctly your speakers are 98 db/1 watt/1 meter, and the O/96 is indeed spec’d 2 db less than that, at 96 db. However John Atkinson’s measurements in Stereophile showed the O/96 to have a sensitivity of only 91 db/2.83 volts/1 meter. For its 10 ohm nominal impedance that would correspond to about 92 db/1 watt/1 meter.

Which would seem to give further credence to your (and JSautter’s) advocacy of more power than most SETs can provide.

Essrand 5-15-2019
I feel like my Coincidents were powerful enough. But now you are making me doubt that. Will put those amps back in, listen more and get back.

To state a fairly obvious point, I would just suggest that you make a point of including recordings having particularly wide dynamic range in your assessment. Such as many recordings of classical symphonic music, if you listen to that type of music. For a given average volume, recordings of music having narrow dynamic range and/or recordings that have been engineered with a lot of dynamic compression are of course less likely to reveal the issues Ralph and JSautter have referred to.

Good luck. Regards,

-- Al


How about the Line Magnetic 508i or 805i. Both seem to have enough power, uses the 300 tubes and are a SET. Only reason I mention it is the fact I have the push/pull 216i and it is a stellar amp. Not in your 5 amp list, but seems you are exploring options...
My recommendation to OP.

Get the NOS Wes 300B (6k$ or more) made before 1960, then Coincident Frankenstein will be alive again.

Or you can get Line Magnetic 508 or 805, then you have lot of room for tube rolling.

After tube rolling, LM amp sounds very  close to Silbatone 300B SET which will blow up Nagra.
To state a fairly obvious point, I would just suggest that you make a point of including recordings having particularly wide dynamic range in your assessment. Such as many recordings of classical symphonic music, if you listen to that type of music. For a given average volume, recordings of music having narrow dynamic range and/or recordings that have been engineered with a lot of dynamic compression are of course less likely to reveal the issues Ralph and JSautter have referred to
:)  OK. These are all on LP.

Wagner Gutterdämmerung, London, Solti conducting, final scene (Immolation scene)Verdi Requiem Soria Series RCA, side 1 track 2 Dies Irae
Black Sabbath 'Paranoid' German white Vertigo press, side 1 track 1.Canto General America Insurrecta Atma-Sphere 3-001
Play any of these anywhere near a satisfying volume and that power problem is easily revealed.
ESSRAND,

Perhaps these previous posts supplied all the information you wanted.
If not, one other source you might want to engage in a mind-meld with Glen at Tubeaudio.com He sells Devore, Line Magnetic, Nagra, Shindo, Leben, Innous, Odin and many others. Ten minutes with Glen or Bill and
you can sh-t can most the above.
@essrand Just commenting so I can come along for the ride. Very curious how replacing the Franks goes, please report back over the months as you try various options.  

Can't remember if you commented on one of my amp threads, but damn I struggled to replace mine in driving my Coincident PREs.  Tried some quality class D, class A, and OTL amps but always preferred the Franks.  All those amps bettered my monoblocks in various ways, but it was never quite enough.  I am currently building a First Watt F4 to use as a "booster amp."  Everything I read suggests that putting it on my bass cabinets (driven directly by the outputs of the Franks) will greatly improve my low frequency control.  I'll also try running speakers full range from the F4, but fed from the Franks loaded by 8 or 16 ohm resistors.  6moons claims this gives you all the liquidity and dimensionality of a non-distorting set (because it simply sees a perfect, constant 8/16 ohms), but with the full current and bass control of a great class A SS amp. 
@firstnot  Damn, what a perfect situation...
I dont know Glen or Bill, but 10 minutes with either of these guys might result in a goldmine of information or it may result in ten minutes of competitive product bashing and only an attempt to sell you their products. I hope it is the former, but please be careful. 

I do know that in my conversations with John at DeVore he often shows with push pull designs which may or may not be entirely the result of sonics. With our group it seemed that we didnt know how much better the system could sound until we added more power and what I believe to be an inherently superior amplifier design (provided the speakers present a higher and stable impedance load). 

Seek advice first from those that have no dog in the fight.

 
Dear Op

We had exchanged opinions about Lyngdorf before.

Are you still located in India?

If so, even refutable dealer in US have limitation to help you.

Thomas
@shkong78  One of the amps I tried was a Lyngdorf TDAI 3400.  Unfortunately it was not an easy transition from the 300b Frankensteins... I much preferred my SETS.

@OP

each of your choices for amplifiers on its own merits are fine amps.

the issue I see is as has been said by Al & Ralph, they are likely not the 'optimum[' match in terms of power for your O96s.

a secondary aspect apart from power of an amp is the amp's 'voice[' given the build is on par with premium built amps.

Naturally there is some latitude for re-voicing' by rolling tubes but I've found its best to find amps whose voice as is is what you prefer, rather than to speculate on what other tubes 'may' later on bring to the table and in this thread I've read nothing about your sonic preffs, or musical interests which could point to something more specific regarding your short list of amps.

in amplifiers as with life i've found it is best to have it and not need it, rather than to not have it and need it.

amps whose power is seemingly too much is not nearly the possible issue that amps whose power is possibly enough though one is not certain of it.

I've heard glorius SET like sounding amps which ran EL34 PP w/Tformers pushing out only 30wpc into 6-8 ohm, 87db speakers.

as well with some NOS tube exchanges on those same speakers I've used 60wpc BAT vk60, and later 60wpc EL34 PP amps.

at modest listening levels things were fine enough.

exchanging the 87db units for reputedly 93db similar 6-8ohm speakers it was a completely different world!

speakers gotta have an appropriate amount of power or one has wasted a good bit of money and time regardless how well respected the amp may be rated.

then, again, there's the 'voice' of the amp to consider

there are a number of let's say lesser build and less costly amps around whose power ratings are better suited for the O96s you could bring in and later flip to prove or disprove what is being said here to your own ears in your own setting.

I'd definitely try that route if you do not lend much creedance to what Al & Ralph and others have input here before puting all my eggs into one pricey basket.

lastly, what does it say for a speaker maker to show a product with PP amps rather than with standard SET amps?

best luck to you going forward and as posted please drop back in and relate your final verdict..

You can definitely use Shindo/Audio Note amps with O'96s. Obviously they would work better with Avante Garde or other 100+db speakers BUT don't let anybody tell you they simply wont work well. The West Coast Shindo dealer has the O'96's as one of his Demo speakers to be used with the Shindo amps.  I have the O96's and a Audio Note Jinro....have had Shindo La FonGM70 Mono blocks previously.

excerpt from http://geekout.io/index_files/The_truth_about_AirPlay_audio_streams.html
AirPlay uses regular WiFi standards (802.11n) for transmission of audio and video content. Against initial speculation this process is not limited to Apples Airport station, third party routers equipped with this protocol can handle the streaming without complications. The only predisposition necessary is that all participating hardware is on the same WLAN network.

AudioMIDISetup
What is the audio quality for this type of transmission?

In contrast to Bluetooth connections, which sometimes lead to downsampling and loss of quality, AirPlay is transmitting “CD quality” audio (16bit / 44.1kHz). This can easily be verified with the Audio Midi Setup tool that is located in the Utilities folder in your app directory.

For streaming content Apple is using the in-house Apple Lossless Audio Codec (ALAC). Here data density is permitted for up to 120 megabit per second. No matter what format the audio originally coded, your Mac or iOS gadget will turn it into a lossless audio stream. Only so-called “Hi-Res” Audio formats used by pros and audiophiles with higher resolution (e.g. 24 Bit / 192kHz) will be down-sampled to 16 Bit / 44.1kHz.

Video playback with tricks

Video streaming is tricked out by Apple. Audio tracks in videos are generally sampled in 48kHz. The AirPlay specifications state that audio needs to be down-sampled to 44.1 kHz for remote playback. The subjective audio quality itself is only decreased minimally. Most of the video content available online is limited to 160 kBit/s transmission rate for audio. This also applies to movies and TV series on the iTunes Store. = = = = ==

given this input one can stream up to 16/44.1 from which ever service via Air Play... and now Air Play 2, into what ever is supported by license from apple, apps, hardware, etc.

check the audio midi app on your mac to see what is what in terms of available..

if the service however streams out at max MP3 levels or 320bits that will be what one realizes and no more.

I'm a bit at odds on things being upsample or rather converted into another format entirely to lossless as is said in the above article regardless if it comes from Apple or not.

despite the conversion, if any, one only gets what is there. no magical changes arise during conversion from lower bits of info via fidelity when one merely increases the size of the file from a condensed or compressed file.

only native rips into 16/44 will be unaffected if a format is converted, ala, WAV to AIF, or to FLAC and or ALAC. lossless to lossless.

this said, much depends on your ears and system as to wether or not you'll either detect some loss, or just enjoy what ever streaming rate you are receiving.

maybe its best to stay in the dark and just let your ears decide which service sounds better.

I've not connected up with TIDAL or 'boz but do have Apple Music and Spodofy. of these two the latter does often seem to present a more expansive stage. Yet fidelity seems to have little disparity between them, yay or nay. its IOW, a coin toss in terms of SQ between them.

even with my current feeble rig, listening to lossless vs lossy files is pretty readily realized, so opting for uncompressed streaming even with Air Play I or II ought to do well within its designed constraints.

Hope this helps.
Hi,

Wonder why you restricting yourself to 300b?

I currently have my O/96s hooked up to a Kondo Overture = Bliss

They were in my second setup before driven by a Tron Syren / Telstar (211 tubes) which also was fantastic.

As mentioned above, the O/96s shine when there is ample power behind them.

Cant imagine running them with 300b SETs.

Just my humble opinion.

Brgds
Try the unknown brand Canary Audio you will love them 
Of the list you provide, I would only choose the Nagra if you like a less traditional tube sound. My experience with Air Tight is similar to the Nagra. I cant comment on the Wavac due to limited experience. The Shindo gear is great for a more traditional tube sound and what Luxman I have heard errs to the pleasant. 

But, in my experience, both push pull and SET designs are inherently somewhat flawed and in somewhat opposite ways. With the right speaker I have yet to encounter a better design than an OTL especially if you really want to hear what is going on with your software.
 Coincident Frankenstein Mark two is probably one of the best 300 B amplifier available at any price. Dead silent with the most natural life like sound with midrange to actually die for. Extremely highly recommended 
My experience with 300B has been pretty good having used a number of them. My favorite would be the Sophie Electric. They have both mono blocks and integrated......highly refined and plenty of power for the Devore's. 
I was in the amp shootout mentioned earlier by jsautter and I also built the Audio Note Kit 300b interstage amps used in the comparison - I wanted them to win! In fact, prior to the shootout, the Devore's sounded terrific with the Audio Note amplifiers and I was quite confident they would win.

I'm not technically savvy like many on the forum, but from just a listeners perspective, with the Devore O96's, the Atma-spheres are magic, even against some very strong competition including the Audio Note's and the Vac. They were detailed yet smooth, and the bass response was amazing but not muddy. 

It's tough sometimes to know how certain combinations will sound. Most of the time you have to guess. I'm sure there are other amps, some worse some better with the Devore's. But I know the Atma-sphere's are a great match and not something a Devore owner would regret. 
Thanks everyone for your thoughtful inputs.

After reading @almarg @atmasphere and @jsautter I put my 300b Coincidents back on and played some music with a with great dynamic range. This song goes from 66dB to 98dB in 10 minutes and back down.
I thought my 8W amp was able to handle it quite well without running out of steam. I put my 200W SS (class D, Lyngdorf TDAI-3400), I liked the Coincidents better and it even had as good or better bass.
Perhaps like the cliche we always hear in mags, the quality of watts not quantity matter here.

@riaa, yes I remember Matt @ Pitch Perfect Audio used Shindo Cortese with O96, and Art Dudley used the Air Tight ATM-300R on the Devore O93 (lesser sensitivity that the O96s by 3).

Hence I rounded up these set of 300b amps as my final list.

Maybe they sound even better with PP tube amps, I have not tried that combo yet, so I will take that into account.

In the coming weeks I will try to get a home demo of the Nagra 300b and compare them with my Coincident 300b that should conclusively tell me if I need more watts.

@pah, wow! The Kondo Overture was in my shortlist as well. You are making me want to put it in the running as well.

@cal3713 , yes will keep this thread posted as developments occur. Think our journeys are quite similar.

@shkong78, I was considering getting Takatsuki 300b tubes, I heard with the Coincident Franks they are sublime. WE 300b for $6000 are simply insane, I won't even go there.


@essrand Thanks for providing the update. Assuming a listening distance of say 10 or 12 feet, and a medium sized room, and given that the speakers are not planars or line sources, and factoring in a few db of "room gain," according to my calculations the 8 watts that can be provided to each of the 92 db/1W/1m speakers (as indicated in my earlier post) by your Franks can produce a maximum SPL at a centered listening position of about 97 to 100 db.

So given those assumptions your findings don’t seem to me to be surprising. But given the distortion vs. power level characteristics of SETs, which Ralph (Atmasphere) has described and which from a technical standpoint make sense to me, the bottom line would seem to be that when playing recordings having the kind of dynamic range you described (about 32 db) you are not hearing the Franks at their best.

I’ll add that while a dynamic range of 32 db is no doubt a good deal greater than the dynamic range of a considerable majority of recordings among the various genres, there are some that greatly exceed that amount. I referred earlier to the wide dynamic range that can often be found on classical symphonic recordings. In a few such cases, on labels such as Sheffield Labs and Telarc, by examining waveforms of the recordings on a computer using a professional audio editing program I have found dynamic ranges of as much as 55 db! Correspondingly, at my 12 foot listening distance SPLs produced by those recordings cover a range from about 50 db to about 105 db. I would feel safe in saying that the combination of an 8 watt SET and 92 db/1W/1m speakers could not handle such recordings at reasonable average volume levels, say 75 db or so.

Just some food for thought. It has long been my belief that a major reason for the divergent opinions we often see about power requirements is differences in the dynamic range of the recordings different listeners listen to. As well, of course, as differences in individual volume preferences, listening distance, room size, etc.

Good luck, however you decide to proceed. Regards,

-- Al
If you find WE Nos 300B to be too expensive, then I recommend you try
Psavne Acme 300B.

https://www.hifi-amplifiers.com/en/psvane-acme-serie-300b-hiend-vacuum-tube-replace-we300b-matched-pair-p-5262.html

I had have sweet and natural sound with Line Magnetic 508 with Acme 300B for more than 400 hours running.

My Nos WE 300B had been running more than 10K hours with no problem.

If you account for its longevity, then it is not expensive.

The problem is that it is  hard to get good and genuine Nos 300B at reasonable price.
essrand

Well I am not surprised that you liked your 300Bs better than the Class D amps. Kind of an apples to oranges comparison. Take to heart what Ralph has said about how SETs sound when pushed. I truly believe that both P.P. and SETs are intrinsically inferior on the right speakers when compared with OTLs. Also, with respect, I couldnt disagree more with shkong78 reagrding his insistence on the influence that 300B tubes have on any SET design. In my experience the driver tubes have at least as much impact, somtimes more than the power tubes themselves. Tubes usually nudge, sometimes significantly, but they do not transform.
With SETs, the quality and specs seem to make quite a bit of difference as well.  
Hello essrand,
You have generated an interesting thread which has yielded informed responses. As the varied comments here demostrate, there are simply no absolutes in regard to High End audio and personal listening objectives. Your experience with the Coincident Frankenstein vs Lyngdorf mirrors that of cal3713 in preferring the Frankenstein. Yet there’s no doubt that some other listeners would prefer the Lyngdorf.

SET vs OTL, again this will result in another split decision. How could it be otherwise? So many variables/specific scenarios/ listener taste for there to be any other outcome. Any blanket statement that one particular topology is superior to all others regardless of circumstances is patently false. I’ve owned the Coincident Frankenstein for nearly 10 years and it’s a superb 300b SET. So I appreciate and agree with comments from drdavid. However I certainly recognize it won’t be the right choice for everyone.

Essrand the list of alternative 300b SETs you are considering is a formidable one. I’m pretty certain each will sound excellent and no doubt different than your Frankenstein. But better? Maybe or maybe not. I’m glad that you’ll be able to hear the Nagra and decide for yourself. I hope you can hear and compare all of the amplifiers on your list. They are all held in high esteem. I don’t see a bad choice no matter what you ultimately decide.

Essrand I bought the Takatsuki 300bs direct from Japan about 6 years ago and they are fabulous in the Frankenstein. For my needs/taste I prefer the EML XLS. I know that others will disagree but that’s okay. Just personal choice.
Best of luck,
Charles


Essrand,

If you have access to one then I highly recommend you try the Overture out, I am sure you will not regret it.

I am running mine with a GE-1 and refurbished TD-124/SPU combo along with a Swissonor step-up. All in all in a happy place.

If you are dead-set on 300b, don't forget the Tron Atlantic or for that matter the Allnic T-1500.

Brgds,

Peter


I am the importer and reseller for Art Audio.  Our Diavolo 300B is legendary and has been steadily improved over 20 years.  I would put it up against any of these and I am 100% certain the Diavolo will win.  It is available in stereo, mono-block and integrated.  We also offer a Harmony Silver version which eliminated PCBs and is point-to-point wired using silver wire.  

We have great reviews on older models and the amp is even better now.  And because I am consumer direct, you get a bit sharper of a price with no wholesaler margin.  I will also give you 30 days in-home with it.  And we offer upgrades to either KR or Sophia Tubes (for a price) and we have a bunch of other options available.  Your only risk is return shipping.  

Basically, I believe you should be able to get your amp, your way.  

I know you said your not interested in other options but I promise, you won’t regret considering us.

artaudio.us is our website.   
@pah 
I can't try it. I would have to buy it to try it. Will audition (sadly not on a O/96) when I am in NYC next month.

@jsautter 
Yes, I agree its apples to oranges comparison. Sorry, I was not clear, but what I meant was that the dynamic range seemed not different with 200W Class D vs the 9W 300b amp? I didn't feel like I needed any headroom, but then again I never go beyond 100dB since I live in an apartment complex.

@firstnot 
I have contacted tubeaudio.com, will let you know what he says.

@riaa 
I have contacted the west coast shindo dealer as well, lets see what he says.


the bottom line would seem to be that when playing recordings having the kind of dynamic range you described (about 32 db) you are not hearing the Franks at their best.
^^ This.

If you really want to hear what any SET does, to really do them justice, the speaker should be of efficiency such that about 20% of full power is *never* exceeded. With a speaker of only 92dB (and while I'm not a fan of Stereophile, in this regard JA's measurements can usually be trusted), that isn't going to happen unless your listening environment is very restricted.

Put another way, to really take advantage of most 300b SETs, speakers with +100dB is really the only way to do it in an average room in the US.


It is for this reason that out of the list presented initially I chose the Nagra.


But if you want to get more in depth about it, there isn't anything special or magic about the 300b. Its a good tube, but often SET advocates prefer the 2A3. That too is a good tube, but often SET advocates prefer the type 45. So 25 years or so ago, the 300b was the one that had the inside track, by 2003 or so the 2A3 was King, and now its the type 45 and its brethren (sub-1 watt-output).  What's happening here is not so much the tube, but the capabilities of the output transformer combined with that tube. Usually the plate current of the power tube is taken through the primary of the output transformer. The transformer can take a bit of DC, which causes a DC magnetic field (in a push pull transformer, the two aspects of current flow cause a DC cancellation so only an AC field exists). To minimize some of the effects of this (since the DC field leads to saturation of the transformer core), the core has a saw cut in it to vastly reduce the DC aspect. This however makes it less efficient for AC as well. So this leads to two practical aspects: bandwidth and distortion caused by saturation of the core.


In both cases, by simply using a tube that is lower power, this problem is reduced. Practically speaking, the upper limit of power on this account has been traditionally about 7 watts; above that the bandwidth and saturation issues really close in around the designer (not saying they can't be solved, but it gets prodigiously more expensive to turn out a transformer that actually has respectable 'hifi' bandwidth)! That's why the 2A3 sounds better and so on; get away from SET operation and you get away from this problem.


I've run plenty of SETs in my day. They all jive with what I mentioned above- a type 45 amp so far is the best I've heard. But it made so little power (0.75 watts) that for the most part it was impractical. I built a pair of type 45 amps that are push-pull; on the same speakers (which were 100dB; not nearly efficient enough for a 45 SET) they were able to reveal much more clarity in vocals and instrument details- bringing just a greater sense of musicality. The push pull version of the 45 makes about 6-7 watts.


In case it isn't clear at this point, SETs need efficient speakers! When you push them harder, the distortion not only obscures detail but it makes the amp seem 'loud' (hence their 'dynamic' quality so often mentioned). IME, in about 95% of audiophile conversation using the word 'dynamics' you can safely substitute the word 'distortion' without changing the meaning of the conversation, other than to make it more truthful.

By comparison, any push pull tube amp has a greater amount of usable power- instead of 20% or so you get about 90% or so; even though you are playing higher sound pressures, it doen't sound as 'loud'.



Ralph, thanks for the extremely informative post.  I hadn't previously realized how much the sonic characteristics that are commonly attributed to the various directly heated triodes, in SET applications, are the result of the requirements each tube type imposes on the design of the transformer.

Best regards,

-- Al

Charles and I have gone back and forth regarding individual 300b tubes. I prefer the Takatsuki; he prefers the EML XLS (and 213Cobra [Phil] prefers the KR Balloons). However, the number of 300b variants on the market is insane with price ranges from the reasonable to the ridiculous; and there are new ones being produced all the time. IMHO, the specific tube can have a greater impact on the overall sound in an 300b SET based system than one based on an SET using 2A3 or 45 tubes. Unfortunately, rolling 300b can be expensive; but it can be as worthwhile as searching for the best amplifier. And the longevity of a good 300b offsets the cost. . . somewhat. 

Gary
Post removed 
@firstnot I got in touch with tubeaudio.com, never heard back.

But I did hear back from the West Coast Shindo dealer who told me that although a lot of people do use Cortese with O/96, a little more power might be preferable.

I played my Coincident 300b at 90-100 dB and @almarg @atmasphere I need notice the need for headroom and distortion and congestion in the loud passages. It was quite noticeable after hearing the same music at a fellow audiophile who had a SS amp (400-600W Karan Acoustics on a 92dB Kaiser speakers), the previous day. I am learning a lot here thanks to you guys.

So I have to redo my list now and make sure I get at least 20-30W in my amps. The options are now limitless with PP tube amps. 

New List (as of now): Nagra 300p, Kondo Overture (used only, can't afford new), Shindo Haut-Brion (if I can find one).
I agree a 300b amp is a bad choice for those Devores.The Devore dealer near me Im thinking pairs them with Line Magnetic mostly.If me I would call a dealer of Devore
There was just a pair of Haut Brion's on Audiogon/Audio Mart in the past week or so...reasonably priced.
So I have to redo my list now and make sure I get at least 20-30W in my amps. The options are now limitless with PP tube amps.

New List (as of now): Nagra 300p, Kondo Overture (used only, can't afford new), Shindo Haut-Brion (if I can find one).
@essrand I'd go for a bit more power if I were you. The trick with any amplifier is you don't want to work it hard- its lower distortion and power tubes last longer. BTW as you may have surmised our M-60 works quite well on that speaker.
An update on this:

I am in NYC, probably the only city where I can demo almost all of the mentioned above amps.

Current candidates are:

Engstrom Arne
Shindo Cortese
Air Tight ATM-300R
Luxman MQ-300
Kondo Overture I

So far I have heard the first three (impressions to come soon).
Two more to go.

Esstrand,

I look forward to reading your listening impressions of this  list of very fine amplifiers.Any one of these amplifiers is capable of excellent sound quality/performance if paired with an appropriate speaker. I’m sure you’re enjoying this experience.

Charles