I have been an owner of Don Sachs gear since he began, and he modified all my HK Citation gear before he came out with his own creations. I bought a Willsenton 300b integrated amp and was smitten with the sound of it, inexpensive as it is. Don told me that he was designing a 300b amp with the legendary Lynn Olson and lo and behold, I got one of his early pair of pre-production mono-blocks recently, driving Spatial Audio M5 Triode Masters.
Now with a week on the amp, I am eager to say that these 300b amps are simply sensational, creating a sound that brings the musicians right into my listening room with a palpable presence. They create the most open vidid presentation to the music -- they are neither warm nor cool, just uncannily true to the source of the music. They replace his excellent Kootai KT88 which I was dubious about being bettered by anything, but these amps are just outstanding. Don is nearing production of a successor to his highly regard DS2 preamp, which also will have a unique circuitry to mate with his 300b monos via XLR connections. Don explained the sonic benefits of this design and it went over my head, but clearly these designs are well though out.. my ears confirm it.
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. Of course, 300b amps favor efficient speakers so carefully component matching is paramount.
Don is working out a business arrangement to have his electronics built by an American audio firm so they will soon be more widely available to the public. Don will be attending the Seattle Audio Show in June in the Spatial Audio room where the speakers will be driven by his 300b monos and his preamp, with digital conversion with the outstanding Lampizator Pacific tube DAC. I will be there to hear what I expect to be an outstanding sonic presentation.
To allay any questions about the cost of Don's 300b mono, I do not have an answer.
No, I am not going to do kits... I am retiring and letting a partner build the 300b project and matching preamp. That should be going before the end of the year. If you make kits you have no control over how they are built and you get LOTs of questions so customer service is a big issue. Just because most folks are competent and can build a kit, even if only 5-10% of people are in over their heads you get a support problem. It is far easier to build a product, test it, and then warrant it. Plus, these amps use multiple regulated supplies per amp, and it took a while to work it out and get it right. They are very stable when built correctly, but not trivial to do the build. They are designed to be easy to service as well, but kits... no. The amps need about 1.5 volts for full output so any preamp can do that. They also feature XLR inputs, which are very easy to drive.
I a quite smitten with this design and think they sound great, and of course I have not heard all the other great amps discussed in this thread. Hopefully someone who comes to Seattle has and can tell me their opinion!
The approach you described is used in DIY world for DHT SET, particularly 300B SET. There is a group who prefers this approach and there is a group who prefers the more simple way - using half or the 6SN7 in parallel as one triode and interstage coupled with the next stage, or alternatively using a more capable driver, including a DHT such as 300B itself, 4P1L, 10y, 801, EML’s 20 or 30, etc.
Evidently more use this splendid octal tube than I was aware of. There are lots of ways to get to sonic splendor and Don advocates one particular approach that is clearly favorable to my ears. Owners of Ralph or Rogers' gear might say the very same thing and they would be right. SQ is such a a subjective notion that there are plenty of paths to pure listening pleasure for all of us music lovers, because the gear is just that which yields the SQ with which our ears most happy.
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.
Don is licensing the production of his Valhalla integrated amp that owners on this forum have praised. I recall that the Valhalla amp is one of several that Clayton Shaw uses to demonstrate the best aspects of his speakers.
I am the least knowledgeable guy on this forum about electronics. I clearly admit it. I remember listening to Roger Modjeski explaining the design of one of his preamps at Burning Amp a few years ago where an attendee asked about worthy driver tubes. RM's minced no words in responding that 6SN7 tubes were a very poor choice of tubes -- "better employed in old TV's", because of their inherent high noise levels. Well, I had had Don's first preamp with 6SN7 tubes (derivative of the Roy Mottram's SP14 design and with Roy's full approval), and his Kootenai amp with the same driver tubes, and wondered how to square away RM's comment with the dead quiet sound from my system. When I shared RM's comment with Don after the show, oh boy, it was an interesting conversation. It is true that few audio designers use this tube in their designs (Modwright and Supratek come to mind), but Don does and is doing so with his new 300b monos and my ears tell me that Don is correct in his use of the octal tubes in all of his designs. Hearing in believing.
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.
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?
@charles1dadThe issue is always how much voltage swing will drive the tube to full output and how much grid capacitance is there. The more grid capacitance, the harder the tube is to drive.
You can get a 6SN7 to drive a single 300b no sweat. But doing it the way is traditionally done in SETs will likely but the tube at a disadvantage.
The 6EM7 does have one section that is considerably more gutsy than a 6SN7 has. But you will always be looking on the collector's market for replacements.
The way to get a 6SN7 to really do the job is to have it wired as a cathode follower direct-coupled to the grid of the power tube. In this way the coupling cap used in the amp stays rather small since its driving the 6SN7 rather than the output tube. Smaller caps are more transparent...
This is the technique we've used in our OTLs for several decades now. Its very reliable. One 6SN7 section is thus able to drive a number of highly capacitive triode grids with the voltage swing needed. 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. But from what I've seen, SET users are not particularly worried about cost if the amp gets the job done for them.
Great news - I own a fully tricked out one of Dons SP14 builds. Fantastic preamp.
Will this new 300b push-pull require that much gain from a preamp (6SN7), or will it have normal input sensitivity?
I'd also be very interested in an integrated version... don't know if that's on the cards.
Could it even be a DIY kit (Elekit style 😁)... unlikely perhaps, but at least Don wouldn't need to build them anymore. VK Music seems to do well enough from this business model.
@charles1dadNot sure what speakers yet. While my new amp is AD1 based, I think its strong points are more the design and power supply than the tubes used. I'm sure it would sound great in 300b too.
Wish you were going to be there. I will be there several days and plan to fully appreciate Don's stuff.
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.
I like the Viva Solista too. I own a very odd ball Viva 300b component. It is the Viva Fono phonostage that utilizes two 300b tubes as RECTIFIERS. The power supply to this component is massive in size (about the size and shape of the Solista).
@charles1dad@donsachsI will be at the Pacific Audio Fest Thurs thru Sunday. While I am currently listening to an Italian 300b with Sophia mesh tubes, my new custom AD1 based amp will be on display there before I bring it home.
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.
The Nenuphar is an interesting speaker. The Nenuphar Basis is a great speaker (full range driver plus powered woofer). The Basis has more weight and midbass fulness than the Nenuphar that makes the speaker very good with large scale classical music. The Nenuphar is, like many full-range speakers, is slightly rough and peaky sounding while the Basis is smoother sounding (full-range drivers used in multi-way system often sound smoother).
One of the best single driver system I’ve heard are the Charney Companion with the AER driver option. I heard this speaker, which is about 100 db/watt efficient, driven by a 300b SET. I also liked a Songer fullrange system that utilized a field coil driver. I believe it is quite high in efficiency. These two single driver systems are rare in that they sound smooth while retaining the liveliness of such systems.
I understand. One of the most intriguing systems I have ever heard was powered by the Viva. Oddly a set of Millennium electrostatic. A ridiculous combination. But, it’s incredible emotional connection brought tears to my eyes. I never forgot it.
Nearly thirty years later I have a 300B headphone system and an all ARC Reference main system that captures the magic and emotional connection that the Viva did, but with warm and realistic details. Wow, it took so long to get here.
My first tube amp was a Viva Solista Lt - a 845 SET with 6SN7 driver. The Viva Solista Lt produces more than 8 watts that many 300B amps advertise for, but only marginally more.
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!
My friend in Italy got the Nenuphars and has been been overwhelmed with the sound of them. I got their little brothers, the Jazzon, after hearing them at Axpona.
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.
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.
As I mentioned, I am going to attend the Seattle Audio show to hear Don and Clayton's latest gear and will be booking a room at the venue on Saturday night, June 24. If anyone of you AGer's are interesting in attending solo, I'd be up for sharing the room and splitting the cost between us, about $100 each. I did the same with a long-time internet audio pal at Axpona and we had a great time together, during and after the show, comparing our recollection of what heard at the show. Let me know if you are interested.
I did the same when I bought the inexpensive Willsenton 300b integrated amp, having never heard a 300b amp, but was aware of their sonic attributes and it opened my ears to the joy of this tube type. I have the Willsenton amp in my bedroom system, driving my Gallo Stradas and it is just a joy. A properly built 300b amp like Don's, is in a different realm, but the inherent magic of these tubes is revealed even with the modest Willsenton amp. I was a gateway amp that lead me to Don's creations.
I took a leap of faith and had a 300b built without ever hearing one. It has none of the “cons” often associated with generic descriptions of the tube type.
No mushy lows, rolled off highs. It all has to do with the design and parts used.. I can’t count how many times I have been surprised at the information I was missing with other amps that pours out of this amp. The detail and holographic image is spooky. Using WE 300b. produced in Dec 2021. , hopefully I get the kind of life that Charles Dad got out of his 300b
Good gosh, were I to get 11 years out of 300b tubes, I'd be extremely happy as would my pocketbook. ;-) I added some fans in my audio rack to ally some of the heat generated by the tubes. As I say, I am willing to play to play for this degree of sonic splendor. How Don got 27 wpc out of these monos is a mystery to me, but they sure drive my Spatials with alacrity and I am sure they'll do the same with my new Cube Audio speakers.
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.
Thanks as always for your positive comments; you set the high mark for thoughtful and erudite comments on this forum, once and always the most generous and civil gentleman on all audio matters. It would be a delight to meet you one day.
I got a quad of the Linlai 300b tubes recommended by Don from his Chinese supplier for $800, which is ~40% of the cost of the Emission Labs quads, yet Don admits that your tubes are even more revealing than the Linlai tubes. You have to pay to play with these tubes, but if Don is using these Linlai tubes in his own 300b monos, that is good enough for me. I sure hope they are long lived. ;-)
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.
The sound of these amps continues to blossom by the day, providing the most realistic sound presentation I have ever heard in my room. The images are palpably real with a pure tonal correctness to the music. I forgot what Don sourced for the stock tubes, but he recommended much better, but yet still afforable, 300b Linlai tubes, which is tells me will be even more revealing. I have rolled a boatload of input tubes in gear over the years, but will be happy to rely on Don's recommendations for affordable 300b tubes. By all accounts, Emission Labs also makes excellent 300b tubes, but they are nearly twice the cost of the Linlai tubes I ordered. Honestly, I could easily live with these stock 300b tubes, but Don assures me the Linlai WE300b tubes will provide a significant SQ improvement.
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.
I have had a DIY 300B integrated stereo amplifier since 2006 built by one guy.
But in all this long period of time I did dozents upgrade myself.
The amplifier has 6sn7 input, 6f6 (in triode mode) driver and 300B. Cathode bias and C coupling between stages.
I upgraded: output transformers, power supply choke, interstage capacitors, power supply capacitors, resistors, driver and input tube idle current...
My experience shows that big value power supply capacitors (after the choke), big value cathode capacitors, correct driver idle current gave me much better improvement versus change of output transformer from James Audio to Hashimoto H30 3.5 (3 times more expensive!).
Coupling capacitor quality and sound signature are very important too and cathode resistors as well. Also the quality of power supply capacitors is very important. To get big values and quality without spending too much I use a mix of electrolytic, polypropylene film and vintage German oil capacitors.
I don’t understand why producers put such small capacitors after a choke in 300B amplifiers (typically 100-200uF per channel). My experience shows x10 value gives huge improvement in bass control, transparency, focus, soundstage.
I don't have as much experience as @atmasphere@donsachs have. I also don't understand how audio designers make decisions. Probably a much cheaper change of schematics can lead to great sound improvement without spending too much on parts and size of amplifier.
The 6SN7 will barely drive a 300b, which is a very difficult load. I have not worked with 845 tubes nor will I given the high voltages and heat involved, but I did look at the data sheet. Yes, it takes more negative grid voltage to bias one than a 300b, but I have no idea of how capacitive a load an 845 is, and I really don't have time to research it. Ralph is right in that a 6SN7 is adequate to drive many tubes. It makes a wonderful driver for any of the usual octal pentodes like kt88 or el34, or a 6V6 or 6L6. Works great. But a 300b taxes a 6SN7. It works as in the original Reichert amp, but if you want to unlock the unlimited dynamics of the 300b you need a much better driver setup. The reason the original Dynaco ST70 was a marignal amp was it had a wimpy driver section that would clip before the output tubes, or about the same time, plus it had a very mediocre power supply. It was a pleasant amp and a zillion of them sold. But if the driver and power supply were better it would have been a much better amp. The output transformers are not world class, but they are quite good and capable of more than the rest of the amp could provide.
You can also improve the performance of any driver tube by changing the way it is loaded. For example, a CCS will give far better drive capability than just typical RC coupling. But CCS circuits do have some coloration. Not so bad in a pentode amp, but very noticeable in a DHT amp. The other ways are to add inductance to the plate of the driver with either LC (choke cap) coupling or full on interstage transformer coupling. The inductance the driver tube plate sees "helps" it out to drive the 300b. There are differences in the way all of these approaches sound, but all are better than just a plate load resistor and coupling cap. I have explored all of them thoroughly for a year with the 300b project and found a solution that Lynn and I like and sounds the most musical.
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.
@antigrunge2 Glad you have an amp you love. 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. As for the SET vs PP on musicality and soundstaging, well I would submit you've never heard a push pull 300b amp designed like the one Lynn and I have been working on. You might be surprised...
Thanks for highlighting the dependence of power tubes on driver tubes as well as on power supplies and transformers. My Wavac EC300B depending on whether I use EAT300bs with their preferred Tungsols 6L6 Coke bottles or Takatsukis with their preferred Svetlana Winged ‘C’s have quite different characteristics (bold and powerful vs. subtle and detailed). When you change the driver tubes in either case a significant bit of the magic is lost. At the top end SETs are simply unbeatable in terms of musicality and soundstaging.
Absolutely. I read a great quote somewhere about a million years ago, that a great tube amp was the sum of three things. How good is the circuit? How good is the power supply? How good are the transformers? If you take care of all three of those things you get a great amp with most any tubes. Most commercial designs that are built to low price points make serious compromises in one or more of those areas. If you take care of business, you generally get a great amp.
Most people think a 300b is a fuzzy rolled off tube. That is because they heard it in a single ended amp with a mediocre power supply, and most likely an inadequate driver section, and possibly mediocre output transformers.
@donsachs I made this point on another thread just a day or two ago. People get so hung up on the tube, whether a plus or minus, while the circuit design, which is far more important, gets ignored.
The post from @pindac above is spot on. Most people think a 300b is a fuzzy rolled off tube. That is because they heard it in a single ended amp with a mediocre power supply, and most likely an inadequate driver section, and possibly mediocre output transformers. Such as all the entry level Chinese 300b amps. They still are pleasant to listen to, but if you use a really good driver section that never clips before the 300b tubes do and is capable of driving the capacitive load of the 300b, a really killer power supply, actually multiple ones, and really good transformers, the 300b will walk all over any of the normal output tubes such as kt88, el34, etc.... That is what @whitestix heard.... A PP 300b amp done right is very special. I really had no idea how good they were until I spent a year working on one. See some of you in Seattle.
Iam 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.
Not to tread on any designers toes in any way, more a testimonial to the impression a well thought out 300b design can have.
I have heard 300b Valve Amp's over the years, mainly SET with low Watt Output.
I have liked the vocal and simple acoustic music when replayed through them, but in general have not got too attached to these types of design.
Recently I have been auditioned a Tim De Paravicini design PP 300b that was in production 30ish years ago.
A friend has purchased it, who has a system I know very well and have been used to hearting Neurochrome SS Amplification and VAC Valve Amplification. The Amp' was given a pre-heat prior to my arrival, the impact the the TDP design 300b Amp has made on the presentation was quite instant. I was aware something quite special was being used and become very contented with hearing a 300b Amp' in use that were really worth making a reference to, hence I am producing this post.
The Amp's owner has informed me the Neurochrome and VAC Amp were now most likely to be sold, as they do not foresee the need for them any longer.
There is in my opinion a a new satisfaction in place. This is so far achieved without a Tube Roll, or a swap out of some very old Cap's.
A PP 300b Amp can really work for those who have struggled with the Tubes used as a SET dsign.
I will be there Friday and Saturday in the Spatial Audio Labs room. I will leave by mid day on Sunday because it is an 8 hour drive home for me. Of course I will tour the show, but I will spend a good deal of time in the Spatial Room on Friday and Saturday.
@donsachsI 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.
If you truly want a true reference quality SET 300 B amplifier
Radu Tarta Shiny eyes products are way under the radar and No commercial
brands are even remotely close to his expertise . In Europe Thomas Meyer is his equal . What most miss is the sheer quality and engineering expertise on all levels
inside and out . Look at U.S Audio Mart he has a absolutely fantastic 2 box 300B amp that I have heard is stunningly good with premium tubes and choices of input tubes you can use for tastes of all music types it’s $10k+ , But if this were made by a big commercial company this would be with ease$25k,it’s that good, check it out !
It is really not my intent to get into detail here for something that is in prototyping. Yes, there have been many balanced tube preamp and amplifier circuits around for years, and I have absolutely no doubt you build an excellent balanced preamp as I know you guys build really good amps as well! This is a slightly different approach to a traditional tube circuit, and yes the transformer coupling is part of it.
Also, as you well know, the quality of whatever attenuator you use is critical, and of course the power supply. Anyway, I think I am going to bow out of this thread because it was never my intent to do business here. That is inappropriate and there is nothing to sell yet anyway! Just was commenting to tell folks what I was up to in my semi-retirement. See anyone who wants to chat in Seattle!
You must have a verified phone number and physical address in order to post in the Audiogon Forums. Please return to Audiogon.com and complete this step. If you have any questions please contact Support.
