300b lovers

@whitestix 

When we are treated to a master class in tube design philosophy, freely given, participants clearly appreciate the generous sharing of information by the masters: Don, Lynn and Ralph.  It has been a real education for me

Very well put.👍

This thread you initiated has miraculously avoided the all too prevalent trolling and disruptive deterioration. Bravo!!!

Charles

@donsachs 

It is undoubtedly a different topology than ours and I wish them well.  I am sure they will get their version to where they want it to be as we have with ours.  They will sound different of course due to the preferences of the designers.

Hi Don, I just want to say that I appreciate your decorum and professionalism.   No doubt that the two 300b push pull amplifies will sound differently precisely for the reasons you mentioned. I’ve greatly enjoyed the many insightful and educational contributions from you and Lynn Olsen in this terrific thread.

I wish you and Lynn the best. Also Atma-Sphere with their endeavor as well.

Charles 

@fthompson251 

I understand, retubing 8 300bs can certainly add up. I hope your VAC REN 70/70 finds a wonderful new home. I can also understand the desire to simplify one’s audio system.

Charles

@fthompson251 

Is the Coda amplifier replacing your iconic VAC Renaissance 70/70. amplifier? I have no doubt that the Raven preamplifier would work marvelously with either.

Charles

@jaytor 

Very nice system you have there!

Charles

@lynn_olson 

What they appreciate is artisan audio made to the highest standards, by artisans of superb taste. Not 1" thick anodized-aluminum front panels with a giant meter in the middle. That only impresses naive Americans who have never worked in manufacturing

I wonder how these Japanese engineers/designers view the products manufactured by Robert Koch (Robert Koda Audio). His approach seems to be a blend of Japanese aesthetic/philosophy and heirloom visual appeal for the North American and European markets. I don’t know how well received his components are in Japan.

Charles

@lynn_olson 

Gaining entry into Japan is nearly impossible. It can take decades. Even Wal-Mart has barely cracked it, and think of the massive resources they can bring to bear. Tourists are always welcome, but good luck immigrating to Japan, or cracking the local market

Some could arguably  accuse Japan as being a closed homogeneous society but out of control illegal immigration will never be a concern for them. Absolutely no way they’d allow such a debacle.

As always good insight Lynn.

Charles

@lynn_olson

The unusual thing about the US market is that it is really easy to sell into ... tariff rates are some of the lowest in the world, technical safety requirements are not too severe, and the market is huge and easy to serve. Markets everywhere else are different ... more fragmented, higher tariff barriers, multiple languages, many different technical standards, and other obstacles

What a very good synopsis of what manufacturers face if deciding to officially enter international markets. Good grief!! This is not a cavalier undertaking by any stretch of the imagination. A  multitude of serious issues  to contend with.

Charles

@lynn_olson

I expected all SETs to be terrible, but those two were the best sound ever on the Ariels (which are 92 dB/meter efficient). After hearing several other SETs, I was struck how variable they were. A few were superlative,

Lynn,

What do you attribute to this wide spectrum of SET performance from superlative to terrible amongst them? Given their relatively simple circuit, is it primarily part quality (Output transformer?) or power supply quality and design?

Charles 

@donsachs 

If you build a vintage amp with the sort of power supply you are using in your SET that vintage amp would sound much better.

+1 

Charles

@atmasphere 

perhaps this thread might have convinced you there is more than one way to reach audio Nirvana 😉 I’m sure the Blackbird is well worth hearing

Different pathways to audio nirvana is something I’ve acknowledged long ago. It’s an undeniable individual journey with numerous successful outcomes. What I have found to be most pleasing and satisfying for me certainly may not be the choice for another.

I don’t believe my comments above contradict this perspective. I was merely comparing two earnest efforts to build amplifiers that are vastly different in concept, design and implementation.

Charles

@atmasphere 

our class D, which has less bandwidth owing to the output filter, nevertheless has a very similar 10KHz waveform, despite (well, actually because of) running 37dB of feedback; 

This GaN  class D balanced amplifier with copious utilization of NFB  is literally at the opposite end of the audio design spectrum from the DHT (300b) balanced class A  zero NFB Blackbird under discussion on this thread. Talk about traveling different roads toward the destination of Rome.

The in depth information presented here concerning the Black bird amplifier has me exceedingly curious to hopefully hear it one day. Its development is a fascinating story.

Charles

@whitestix 

Amazing to watch the arc of the development and completion of these stellar monobock amps.  Just wonderful

Agreed! 
I wish them the upmost success. It been marvelous following this exceptionally interesting and educational thread.

Charles

@lynn_olson 

It’s a dumb truism in audio, but simpler usually does sound better. Not that I’m a fan of 2-stage amplifiers or full-range drivers ... there’s such a thing as too simple. Every designer has to find the balance point between simplicity and complexity.

No doubt a painstaking balancing act to conquer.

Charles

@tuckia08 

EML 300b XLS - Pretty good. Not as nuanced as the best. Depth and width OK, but not the best. Good low end drive. Much better than everything listed above.

Takatsuki - Excellent tube. Best bass drive. Good Detail. Depth and inner resolution good, but not the best

In my experience I’ve found that the preference for a particular upper echelon 300b is very dependent upon the specific amplifier in use. Some of these top quality tubes are simply better fits in certain amplifier/systems than our others. It’s very difficult to draw an all encompassing generalization.

Charles

@lynn_olson

I’m really pleased about this. In an era of superb all-digital, all-solid-state 4K HDR video, tube amps continue to make new friends because they sound so good, on all types of music.

Agreed!!!

I believe that class D GaN amplifiers will definitely continue to grow market share and popularity. This seems undeniable. Yet I also believe that there will remain a certain number of music listeners who find that nothing satisfies their musical/listening desires as well as high quality tube products. The two will peacefully coexist.

Both can be excellent while simultaneously being distinctly different. I do not share the gloomy “demise of tubes “ forecast . Time will certainly tell.

Charles

@lynn_olson 

Thanks for the exceptionally educational and interesting posts. ! Very much appreciated. Your summation of the simplicity of the DHT tubes really explains their longevity, continued desirability and enduring superb sound quality. Talk about withstanding the test of time.

Charles

Unlike the 845, which relies on voltage to deliver more power, the super tubes provide more current thanks to higher emission, and plates are more

Thank you Lynn for your reply.

The EML tubes are a bit larger and heavier compared to my other 300b tubes. The glass envelope is thicker as well. It does possess a heavy duty aura and appearance.

Charles

@lynn_olson 

400 mA might not sound like much until you realize it’s at 480 volts, and the output transformer multiplies the current

To give context to these stated  parameters is the Blackbird easy, average or hard on the 300b tube? How is tube longevity affected by the circuit’s operational points?

Charles

@lynn_olson 

The Mark I Karna's thrived on a matched quad of Emission Labs 320B-XLS, but that was also a serious investment. The European super tubes are something else

Agreed.

I had early production Elrog 300b tubes that sounded wonderful but had reliability issues. Fortunately that has all been sorted out with the current production Elrogs under the ownership of Thomas Mayer.

I have used the EML XLS 300b tubes over a 9-10 year period and they are utterly rugged reliable workhorse tubes that sound absolutely splendid. Expensive but worth every dime.

Charles

@lynn_olson 

I met Thomas Meyer at the 2004 European Triode Festival (I was the invited keynote speaker). He’s a lot of fun, and super knowledgeable about tube history. He, too, is a transformer enthusiast, particularly with modern transformers

Spot on! Definitely transformers in addition to tubes. I’ve learned much reading his site over the years. I bet that he’d admire the Blackbird amplifier effort and result.

Charles 

@invalid 

I really like Thomas Mayer's 300B amplifiers

I have long admired Thomas Mayer audio products (Particularly his power amplifiers). Given what I have learned regarding the Blackbird 300b PSET mono block amplifiers it’d be most interesting and informative to hear a comparison. Two very different approaches. I have no doubt that both are genuinely sublime products.

Charles

Quite attractive with an understated elegant aesthetic.

Charles 

Mark,

Thank you for your very kind comments.

Charles

@whitestix 

If you have followed this thread, Don and Lynn have made significant enhancements to the performance of the pre-pro mono's I have, yet I just can't imagine how much better the SQ will be after Don gets them back and updates them to the final production version

I eagerly await your listening impressions of the updated mono blocks. You certainly have terrific speakers to judge what you hear.

Charles 

@donsachs

I can build an amp with entirely different parts and wire and have it be exactly the same from an engineering standpoint, but have a very different sonic presentation. I believe that is what Lynn is alluding to.

 

Exactly my take away from Lynn. Most of the builders of Japanese tube amplifiers are degreed electrical engiineers from their native universities. European educated electrical engineers with Nagra, Gryphon, CH Precision etc. No question that although their products are at opposite ends of the audio spectrum, they all adhere and practice engineering principles they were taught.

You can certainly follow sound engineering practices and yet have vastly different sounding audio products. I’m sure that Porsche and Ferrari are built adhering to engineering principles and yet drive/feel very differently. A product’s performance can be tailored to achieve a desired goal.

Charles

@ffzz 

I don’t think DC, IF well done, is any inferior to AC in DHT though. But there are many ways to get DC done. So it gets down to implementation at the end.

The commercially available 300b amplifiers seem to bear this out. By a wide margin they are DC heated rather than AC heated. AC is utilized by the DIY crowd more (Relatively speaking)  than commercial manufacturers.

Charles

@donsachs 

I value blackness between notes:)

Understood!!!

I learn much when reading the rationale of opposing positions. AC versus DC filament heating is one of the classic topics when discussing tube amplifier circuits .

Charles

@donsachs 

The preamp and amps use regulated DC filament supplies in all positions

I know there are some DHT amplifier (Particularly with regard to SET) purists who insist that AC heating is sonically superior to DC heating.I have to say though that some of the very best DHT amplifiers I have heard utilize DC heating.

No doubt that either can work fine with excellent implementation.

Charles

@donsachs ​​​​@lynn_olson ,

Your detailed (And well written) explanations are greatly appreciated. It heightens one’s admiration for the decision making, knowledge, skill and simply hard work required to design and build very high quality excellent sounding amplifiers.
 

This thread could legitimately be separately filed/classified as a teaching course. No doubt that many following this thread have learned a lot and expanded their knowledge base.

Charles

@donsachs 

It also has 6 dB of negative feedback.  That isn't necessarily bad, but our amp project has zero feedback and you can tell.  So again, they have made a nice compromise with good tubes, obviously good parts and a bit of feedback

Don I’m convinced of the merits of zero NFB tube circuit amplifiers implemented appropriately. Is this harder to pull off successfully? Does utilizing some degree of NFB confer a bit of a safety net? I inquire because its use is nearly universal with power amplifiers. Zero NFB  amplifiers are a small niche.

Charles

@donsachs

I thoroughly understand your rationale with preference for current production tubes. The 6EM7 is inexpensive and lasts me 10-12 years with heavy usage. As mentioned before, I was just picking the brains of you and Lynn. I have zero doubt that the new  300b push-pull amplifier you two have developed sounds magnificent!

Charles

Thanks @lynn_olson

Here is a bit of information/listening impressions of the Roger Modjeski 6EM7 amplifier from a past Audio Circle thread.

https://www.audiocircle.com/index.php?topic=29587.0
Charles

Hi @alexberger 

Understood for certain. Given the extensive backgrounds of Don and Lynn I was just curious if they had any hands on experience with the 6EM7, that’s all.

Charles

@alexberger

Thanks for the information. I know that the late Roger Modjeski though highly of the 6EM7 and actually built a 2 watt SEP amplifier using it as the output power tube. No doubt that there are a variety of options to very sufficiently drive the 300b tube. The 6EM7 seems to be one of them.

Charles

Any opinion on the 6EM7 as a driver tube for a 300b? I use a zero feedback 300b SET that has this configuration. I’m not an electrical engineer but can attest that it sounds splendid! 😊

Charles

@whitestix 

Thanks for providing an in depth assessment of your experience at this show. I would have loved to listen to the Raven and Blackbird pairing.

Charles

@lynn_olson

Tube amps, by contrast ... the tech never becomes obsolete. For that matter, all of the tubes used in the Blackbird, and the basic circuit, were first designed in the 1930’s! Talk about not going obsolete

I sincerely believe that this is true. No question that class D has come a long way sonically and will continue to do so. I acknowledge that many listeners are ecstatic about their GAN latest generation iterations. Yet, there is something Intrinsically musically right and natural with properly implemented tubes.

I believe that there are certain listeners who hear and recognize this unique and innate sound character and presentation. It would be illuminating to directly compare the Blackbird 300b amplifier with the state of the art highly praised class D amplifier offerings.

Charles

@jaytor 

Thanks for your listening impression feedback. Very encouraging to say the least. I hope that others chime in.

Charles

@larryi 

The 300b is not the only contender in the low-power weight class.

True and I don’t believe that anyone on this thread is disputing this. However, Don and Lynn have stated the very compelling reasons why their amplifier was built utilizing the 300b tube. Excellent decision and execution it certainly seems. I’m excited to hear from those who’ll listen to it at the audio show very soon.

Charles

@lewinskih01 

BTW, I'm running 45-type SET on my tweeters above 1 2kHz and absolutely love them. I realize 300b gets more love, though :-) 

Lovely thread. I wish it weren't the exception arou d here!

I believe that both the 45 and 2A3 tubes get much respect and admiration. For a lot of folks the higher power output of the 300b provides more flexibility in choosing matching speakers. I do quite well with the 8 watt 300b Whereas 1 to 3 watt may be a bit shy for my particular speakers.

I certainly don’t think any less of the 45 or the 2A3 tubes. However, they do narrow speaker choices. The 300b push pull amplifier under discussion here has the “potential “ to be an outstanding success given its design and higher power output.

Charles

@wig 

I currently do my listening after 8 PM for a few hours and typically my listening sessions never exceed 75 db and I don't feel like I'm missing anything; excellent imaging, sound staging, low level detail, clarity and tight tuneful bass based upon the type of music I typically listen to

Yep! As we all can acknowledge this is purely an individual choice. My listening levels align with you, Don and Thom. @whitestix prefers a higher volume and I understand. Whatever results in more listening enjoyment, go for it.

Charles

@thom_at_galibier_design

I completely understand the example of your wife’s vocal power/control. At one time I played and studied the trumpet. As with any instrument you have much control over the volume you wish to provide. If I wanted to I could blow people out of a decent size room with just that single trumpet. The thing is that horn sounded just beautiful played at moderate and lower levels.

As you mentioned, audio system resolution seems to be the key factor. As this aspect of my system improved over the years I discovered I could immensely enjoy music at lower SPL levels. I’d say a very good parameter for a system is how satisfying is it to listen to at low and moderate volume?

No question however, to each their own choices. I know that some like to listen regularly at SPL of 90db and above. Their ears and enjoyment be served. It just isn’t for me.

Charles

@carlsbad2 

Good observation. Over the years I have attended my fair share of high end audio shows. For the most part I have enjoyed these experiences quite a bit. I do get annoyed with the high volume level demonstrations. Personally I do not fine these displays impressive. Even with the very high powered amplifiers driving difficult to drive speakers.

Good quality music sounds better on a good system played at what I consider reasonable listening levels. I do not understand the attraction of the “crank it up”  approach.

@atmasphere 

So the cap is not as efficient at the new voltage when new. It takes time for the cap to 'form' to the new voltage. Its important to understand that electrolytic caps have some properties in common with batteries and so are fundamentally different from film caps in this regard. Charging them and polarity are two examples of this similarity. Forming is one way they are unique.

Anyway, when the cap forms up to the new voltage used inside the amp or preamp it will be a more efficient bypass. Its my theory this is what people hear during break-in. I've found it measurable too- the voltage once the caps are formed is every so slightly higher and the supply is less noisy.

Ralph, this is believable and logical.

I recently had a DAC built and delivered to me from Ukraine. The builder (Abbas Esoteric Audio) told me that it will require roughly 200 hours minimum of burn-in time to sound its best. He specifically cited the Blackgate capacitors utilization as the reason. He explained to me that it takes time for these excellent electrolytic capacitors (His opinion) to form.

Sounds right to me based upon my experience with his DAC.

Charles

@lynn_olson 

This is why the notion of an Absolute Sound is inherently absurd. That’s like saying an Absolute Dream, or Absolute Taste

Hmm, Well if that’s the case how do you determine or judge the sound quality of reproduced or recorded music via electronic audio components?

How did you reach the conclusion that your amplifier sounds “right “?

A reference point is needed to evaluate and judge against. In my opinion the late Harry Pearson was right when he strongly advocated listening to live acoustic instruments and human voice. 
 

What is a more thorough/better assessment of an audio component than a comparison with an authentic instrument (Un-amplified)? Are you exclusively reliant on your test measurements and dismissive of actual listening?

How do you determine your products mimic or come close to the sound of a real cello, saxophone, piano or human vocalist? I’m genuinely curious as to your approach striving for sonic realism (If you believe that it even exists).

Charles

@whitestix 

A friend has owned the Cube Audio Nenuphars for over 4 years and simply loves them. They’ve taken full range single driver speakers to a very high standard of performance.

Charles 

@whitestix 

Now, with another 100 hours on the amps, I will amplify the comments I made in my OP--- these amps are the most stunning addition to my 50 year quest for more accurate and pleasant sound in my system

I believe you. These amplifiers with your Cube Audio Jazzon is going to be a sublime pairing.

Charles

Ralph,

I understand that you are referring to the approach you use with judicious application of negative feedback. I was referring to Lynn’s comparison to the “golden age “ PP amplifier which typically used 20db of NFB. Your current class D amplifiers do not fit this description.

Charles

That’s why I am agreeing with what Lynn wrote. Zero NFB seems to uncover a masking effect. The subtleties and nuance of virtually everything is revealed as noted.

Charles