@lynn_olson
Another factor is sensitivity to parts quality. An amp with 20 dB of feedback (which is nearly all Golden Age amps) tends to wash out differences in the sonics of different parts. This is exactly what feedback is meant to do ... 20 dB of feedback is a 10:1 reduction of all sources of coloration. A zero-feedback amp, by contrast, reveals the sonics of every single part, particularly at critical nodes in the circuit. This raises costs compared to the PP KT88 equivalent.
I do not have the resources to confirm this via test bench measurements as you do. I can only rely upon listening experiences with my own audio system. When I placed my 300bSET zero NFB amplifier in my system the first time (2009) the immediate difference/improvement was the sense of naturalness. Very stark and unequivocal. In my system realism and authenticity took a step (Or two) forward.
Charles
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@donsachs
+1.
Exceedingly absurd and silly.
Charles
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@cloudsessions1
Are you guys going to be at the pacific audio fest? I’d love to come hear your Class D amps and hear how it compares to the 300b statement monos
That would be terrific!! Even if not heard in the same system. Still worthwhile to hear the GAN class D amplifiers and how they compare with the new 300b push-pull amplifiers. My sense is that Don and Lynn’s amplifier is something quite special.
Charles
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@cloudsessions1
I have a purifi amp and it couldn’t hold a candle to the original 300b statement prototype. I love new class D as when you get the synergy right I find it to top any SS class AB I’ve heard. But the 300b just makes everything right
That is quite a tribute and observation.
Charles
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@donsachs
I wouldn’t own an inefficient speaker because I would be doomed to SS amps, and I hate the sound of solid state devices
It seems that the latest generation class D/GAN may be addressing this. Time will tell.
Charles
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@donsachs
I would stick to speakers that are 88+ dB and very well behaved. The spatial audio X4 current model is 88 dB 4 ohm (and very well behaved) and the amps will happily drive them to ear splitting levels in reasonable room
As @atmasphere has made the point eloquently on past occasions, easy load impedance (Higher ohms and less fluctuations ) speakers are less stressful on amplifiers. In addition he has pointed out that they are lower in distortion compared with low impedance speakers.
Charles
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@lynn_olson
Surprisingly, the 300B survives this gross abuse with no apparent damage, not something I expected.
Well as you said earlier,
Bell Laboratory and Western Electric knew what they were doing.
90 years later and it's still very much admired, appreciated and enjoyed by discerning music lovers. Quite the testament.
Charles
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@lynn_olson
IT-coupled PP DHT’s have a power and majesty unlike anything else in audio. Bell Labs and Western Electric knew what they were doing back in 1935.
A compelling point. I do believe that if implemented properly the DHT tubes are difficult to equal or surpass in terms of music reproduction purity. Nothing is perfect but they have considerable intrinsic sonic value and ability.
Charles
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@whitestix
He clearly knows the sonic splendor of 300b gear.
Sonic splendor is true. 300b SET mono blocks owned since 2009 and as happy with them as I’ve ever been. Listening to the great jazz guitarist Barney Kessel as I write. Reading the comments from Lynn and Don on the how and why of their PP 300b amplifier convinces me your description of its sound is dead on the mark. I have no doubt that it is sublime.
Charles
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@jeff_ss
I don’t mind.😊
I am interested in your listening impressions of this amplifier at the upcoming Pacific audio show.
Charles
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@whitestix
I am very happy for you. What you wrote expresses genuine joy and satisfaction listening to music. Isn’t this the ultimate objective? You are fortunate to have received this early opportunity. I know you are very grateful.👍
It’s been so much fun and interesting reading about the development of this new 300b push-pull amplifier and what it took to get here.
Charles
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@lynn_olson
The original Karna had twointerstages, which was frankly over-the-top. Requirements for the first one bordered on impossible, since impedance from the first tube was much higher than the driver. When I switched over to the 6SN7, I decided enough was enough, and went with simpler inductor loading instead.
I love the candor.
Charles
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@donsachs
So many paths to audio nirvana. So many tubes, so little time:)
+1
Charles
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@atmasphere
I’ve said it many times in the past. The greatest limitation SETs have is getting bandwidth as the design is scaled for more power. The OPT is the defining issue.
Yes you have and with clear explanation. I was specifically asking @alexberger because he was quite emphatic. A thread with this caliber of participants stimulates further inquiries from posters. Informed commentary is valued. 😀
Charles
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@alexberger
A well designed 845 SET will always be inferior to a well designed 300B SET in sound quality
I am a thoroughly happy long term 300b SET owner. However, I do know that there are excellent sounding high voltage transmission tube SET amplifiers. Do you believe that the output transformers in these amplifiers is the overwhelming factor that informs your opinion?
Charles
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@lynn_olson
The usage of 845,211,805,GM 70 and other high voltage transmission tubes have been manufactured and sold by very reputable and established brands for quite awhile now. They’ve been enjoyed by owners for years without reliability or hazard issues. So it appears they’ve addressed the real world problems you logically cautioned about.
I will say however that this new approach/design of utilizing 300b tubes in push-pull is highly interesting and frankly exciting. Certainly in terms of acquiring higher tube power (Thus expanding speaker choice flexibility). I’m really looking forward to reading listener feedback from those attending the Pacific Audio show.
Charles
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@donsachs
I didn't tell him to start a thread and certainly had no idea it would go on this long!
Understood. If a thread topic generates quality insight, information and perspectives from genuinely knowledgeable and earnest contributors then this is what happens. People can discern quality discourse from intentional agitating trolling.
Charles
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The most recent "coincidence" occurred last Friday (literally within hours of each other, according to Lynn), where we made parallel revisions to our 300B cathode's circuit.
... Thom @ Galibier
Long live the 300b! 😊
Charles
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@donsachs
So if done right, there are lots of advantages to a transformer coupled preamp. I can say that I don't miss coupling caps at all, note even the really good ones I was using previously. So again, for me it is about seeing what was possible and then refining it.
This has been a topic of long standing discourse. Premium grade coupling capacitor versus high quality interstage transformer.
Charles
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This degree of insight is so interesting and appreciated. I do recall the introduction of the Galibier 300b SET a few years back. Three highly regarded audio veterans sharing thoughts, ideas and concepts. This is precisely why I believe that there will always be a place for high quality well implemented tube audio components. If done right, sublime sound is the successful result.
Charles
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It’s my understanding that KR audio is now manufacturing a 101D tube in the Czech Republic. But yes, in the big picture a relatively rare tube. I use the Psvane W.E.Replica 101D in my preamplifier. It’s very good sounding and fortunately has proven to be very reliable.
Charles
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@lynn_olson
Part of amp design is deciding what "tone" you want. Because it’s going to have a sound, no matter what technology is there ... Class D, MOSFETs, bipolar transistors, pentode, triode, or DHT. No matter what you design, it will have a sound, no matter what you do, or how clever you are. The perfect component does not exist. It is the responsibility of the designer to steer that small residue of coloration in a desirable direction.
Yep!!!
Tubes and transistors both present some degree of colouration but with different signatures.
Charles
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@lynn_olson
It’s a fully balanced circuit, with 6SN7 input, 6V6 driver, and 300B output. It’s a high current, high speed design.
Thanks for taking the time to post on this thread. I have appreciated various articles written by you over the years. Quite some very insightful participation presented here on this topic. This amplifier from you and Don is genuinely exciting and intriguing. I wish you both a terrific audio show presentation.
Charles
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@ffzz @donsachs
Thanks for your very informed feedback and perspectives. The builder of my 300b (Israel Blume) Coincident SET mono blocks decided to go with an interstage transformer and 6EM7 driver tube. As has been openly acknowledged, numerous paths to success. In my case I can happily say that the sonic outcome is superb.
Charles
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@ffzz
Based on your listening experiences have you found one approach to provide better sound quality or is it simply an implementation issue?
Charles
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@whitestix
I believe that the 6SN7 is actually a pretty popular tube for input/drivers of power amplifiers and In preamplifiers. I think that the degree of success is overwhelmingly dependent upon the talent, knowledge and skill of the particular designer/builder.For example, Atma-Sphere and VAC utilize them quite effectively.
Charles
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@atmasphere
I do not understand why this approach hasn't been used in SETs since the design consideration is similar. It might be because a negative power supply would be needed.
Ahh, I see. The usage of the 6SN7 with your preferred utilization mandates a negative power supply. Does this add noticeable complexity and cost to accomplish successfully? This could be the explanation for its lack of popular use.
Charles
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@carlsbad2
I hope that you have a wonderful time at the Pacific audio show. I’m interested in your listening impressions.
Charles
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@carlsbad2
No doubt that your AD1 amplifier will acquit itself well. What speakers will it be paired with? If I were attending that show I would make it a point to hear that system and the Don Sachs amplifier room for sure.
Charles
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@ffzz
RE: the Viva Solista 845 integrated amplifier,
I had the amp for 6-7 years. Out of curiosity, I tried tube push-pull amps from very reputable brands during those years and found that I much prefer Viva each time!
I completely understand. There are just certain audio components that can somehow get the listener emotionally deeper into the pure heart/soul of the music. It’s definitely an art to accomplish this.
Charles
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@whitestix
I don’t believe that you could possibly go wrong with either of those 2 speakers. I expect your pairing to be truly excellent!
Charles
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@ffzz
Just look at Viva, their flagship model uses 211 as driver of 845. Thomas Mayer does the same. It’s not a show and dealing with filament for 211 (845 too) is no fun - it’s simply because 211 can share the same B+ and drive 845 well.
Good examples . I really like the Viva 845 amplifiers I’ve heard. Here’s what is interesting to me. A friend owned the Absolare Passion PSET 845 mono blocks for several years. They sound simply fantastic! The 845 was driven by the 6SN7. How ever they accomplished this, it worked.
Charles
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@oddiofyl
I sincerely hope that you receive the same tube longevity from your new production Western Electric 300b as I’ve gotten from the EML.
Charles
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@whitestix
I didn’t know that you are getting Cube Audio speakers. Which model?
A good friend has had their Nenuphars for about 4 years and he absolutely loves them. He’s driven them with a Pass Labs XA 30.8 as well as a T+A amplifier to very good effect. However, his favorite choice and main amplifier is a custom built (Found Music) 2A3 SET mono blocks.
Cube Audio speakers will unequivocally sing with your 300b amplifier. Excellent move by you.
Charles
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@whitestix
Thank you for your very kind words. I don’t have any experience with the Lanlai but hope that they are durable and trouble free. Yes, the EMLs are pricey, but fortunately utterly robust and reliable. I got over 11 years with my first pair with very frequent (Many long listening sessions) amplifier usage.
Charles
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@whitestix
It is so good and refreshing to read how much you are enjoying your Don Sachs 300b amplifier. I’m on my 2nd pair of the EML XLS 300b tubes. They are superb! However, I’d trust the Lanlai 300b recommendation from Don. I am lucky in that I only need one pair of tubes for my SET amplifier. Your PP amplifier obviously requires 2 pair of 300b. Things can become expensive quickly.😊
If he said the sound quality further improves, I believe it based on my experience with various 300b tubes. Keep us posted.
Charles
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@alexberger
You make salient and pertinent points. This is why there’s such a price discrepancy/spectrum for 300b amplifiers. They range from 500.00 to 50,000.00 USD. Implementation and quality of the power supply/driver stage and output transformer has so much do with what you get and hear.
@donsachs
I wish you much success with your new 300b PP amplifier at the Seattle audio show. It sure seems it is a winner.
Charles
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@donsachs
What I meant above is the design of the driver section of the circuit. Your amp is using a 6L6 to drive a 300b, which is a good choice. I was referring to many 300b amps that are pushing tubes like a 6SN7 to the max and barely driving a 300b. The first rule of amp design is your driver section should never strain or clip before your output section does
It seems perfectly rational that the driver stage of a tube amplifier is of paramount importance. If the output tube isn’t adequately driven then how could optimal sonic performance be achieved? The builder of my 300b SET chose the 6EM7 as a very suitable driver for the 300b. His reasoning was the same as you mentioned.
I am not an electrical engineer but I wonder how much is it the particular driver tube versus the implementation of said tube. Ralph has written in the past that the 6SN7 is a sufficient driver tube “dependent “ on its implementation in a given circuit. I have been told that the 6EM7 provides much more current, power and drive capability compared with the 6SN7.
I will say that I’ve heard an excellent sounding PSET 845 amplifier that utilized the 6SN7. I could certainly be wrong, but isn’t the 845 a more difficult tube to drive than the 300b? Anyway, no question that driver stage rivals power supply and output transformers in getting it right for tube amplifiers. So it appears that there are alternative executions that can get one there successfully.
I very much appreciate the comments this thread has generated. The education never stops.
Charles
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@dz13
I am seriously thinking of coming to Seattle for the audio show in June. Are you going to be there every day? I’ve never been to one of these shows before. Meeting you in person (finally) and seeing your 300b mono blocks is a main motivator.
As someone who has done this on numerous occasions I strongly encourage you to do so. It’s worth the time and effort. You can speak directly with Don , gain valuable insights and actually see and hear his new 300b amplifier. This can be a very rewarding encounter. Meeting the folks behind the products has certainly worked out that way for me.
Charles
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@donsachs
The prototype amps along with their matching preamp will be demonstrated at the Spatial Audio Labs room
This sounds like a very exciting venture.
What is your preamplifier tube?
Do you prefer the LampiZator Pacific DAC with preamplifier or direct into the 300b mono blocks?
Best wishes for the upcoming audio show.
Charles
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@whitestix
I-have been an audiophile for nearly 50 years having had a boatload of electronics during that time, but I personally have never heard such a realistic presentation to my music as I am hearing with these 300b monos in my system. 300b tubes lend themselves to realistic music reproduction as my Willsenton 300b integrated amps informed me, but Don's 300b amps are in a entirely different realm
Congratulations!!!
I understand your genuine satisfaction and happiness. Don Sachs is very talented and possesses a good ear. No doubt that he can exploit the vast musical potential of the wonderful 300b tube. Realism and uncanny presence is what it is so capable of if implemented well. I believe that it will pair beautifully with the LampiZator Pacific DAC at the upcoming audio show.
Charles
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