@ charles1dad
So true and think my listening levels are contributed to my near field listening; 8 feet from my loudspeakers.
Wig😁
300b lovers
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.
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Undoubtedy individual preference is paramount regarding "best" listening volume. I wonder how certain speaker designs might affect that as well. I'm into DIY speakers and I'm missing the palpable feeling with my 18" open baffle midbasses than I had with smaller sealed midbasses, until I turn up the volume. Midbass definition is better with my OB, but missing some slam/palpability. I run sealed subs below, so slam down low is there. I noticed @whitestix uses Spatial Audio open baffles so wondering if there might be a correlation there. 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 |
45’s are wonderful tubes. By measurement with a spectrum analyzer, possibly the best tube of all time, with a beautifully clean harmonic structure. Which is why the Mark I Karna’s used them as drivers. But ... NOS examples are now very rare, so it’s down to a few vendors as a specialty item. I am hoping they become more broadly accepted, though. They really are something special, and are much easier to drive than a 300B or 2A3. |
Current production Chinese 45 tubes are about $350 per pair plus shipping. I may try a quad in my Lampi Pacific DAC. I quite like the 46 tube there with adapters. The current production European 45 tubes are twice that price. That said, if run at sane operating points they may well last 30,000+ hours. So if you like them, they are really not that expensive in the long-term. |
Yes, folks that try the 46 (a direct-heated pentode that is often connected in triode) really seem to like it. By general consent, it sounds very much like a 45. How different does a triode-connected 6V6 sound from a 45? Good question. The 6V6 was designed as a replacement for the 45 back in the mid-Thirties, and has very similar operating points (by design). |
I too am a fan of the 45 tube type. I also like the 2a3. But, it is not only triode tubes that I like. I am a big fan of the 349 pentode; I wish this were not so rare a tube. Other pentodes I like include the 350B, and thankfully not as rare 6L6. 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 |
I visited the Spatial Audio/Don Sachs room this morning and again this afternoon. This was the first room I visited today and I don't think I heard any rooms I liked better today, including some with systems that cost MANY times more. The friends I am with felt the same way, and we often don't agree on what sounds the best. Congrats Lynn and Don for building a killer amp and preamp. Very impressive. |
My 4+ hour drive to the hotel ended up being a grueling six-hour battle, but I did finally arrive unscathed. After checking in and transferring our luggage to our room, I kissed my wife farewell and went straight to the Spatial/Don Sachs room.
The amps and preamp are beautiful - and have that distinctive D Sachs look IMHO. [I listened to just four songs before getting into a conversation with Don, markusthenaimnut , and his good friend Bob.] How do I describe the music? The first song was a Jennifer Warnes song <not a top 40 song>, and I didn’t analyze it...I mean I so enjoyed the music and her voice without once thinking about the highs, lows, mids, etc. I just sat and enjoyed the moment. How often can you sit down in front of unfamiliar gear; listen to a song, and just enjoy it without analyzing it? And, yes, the songs that followed were excellent.
Once I’ve had a good night’s sleep, and <hopefully> forget about the 6-vehicle smash up on I-5 near Nisqually, I’ll return to this room first thing tomorrow morning and pester Don or whomever is in charge of the music to play my favorite songs, and listen for an hour or more.
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I attended the show yesterday (Friday) and spent significant time in the Spatial room listening and chatting with Don. I have been a repetitive customer of Don's over the years and was excited to hear the latest. Wow both the amps and pre did not disappoint! I'm calling Spatial on Monday to get on the list. . |
Thanks for the positive feedback from all so far. The room was a bit of a struggle to get things to sound good, but after a whole afternoon and evening of getting furniture moved out and putting acoustic treatment up we pretty much tamed it. We have very good image depth, and of course the ceilings and walls limit height and width, but it is a nice sound. Like every other team here, we work with what we have! Hope see a few more of you today! |
The older preamp is a nice, but conventional single ended tube SRPP circuit with Akido buffer (extra tube per channel). It uses dual regulated power supplies and dual regulated filament supplies and really good signal path parts, and the wonderful Khozmo attenuator. The Raven is a completely different approach and circuit. It is fully balanced and transformer coupled at both input and output with custom wound transformers from Dave Geren at Cinemag. It will take either xlr input or rca input, and will happily provide xlr or rca, or even headphone output, and will drive even a 10K power amp impedance. The Khozmo setup is dual mono because you have to control both halves of the xlr on each channel. The power supply uses two damper diodes, very high quality transformer and is a true C_- L - C (cap, choke, then cap) that feeds a much higher quality regulator that is used in the previous preamp and also feeds a pair of gas regulator tubes after that. It is dead quiet, fully balanced, and has very little sonic signature, but provides great drive for the power amp. I really like it, and those who have been to the show have heard it driving the 300b mono amps. |
The Raven was the surprise for me. You see, I’ve been listening to the Karna amps for 20 years, now reborn as the Blackbird. Yes, there are differences, but what’s at the show is very very close to what I know so well at home ... maybe a teensy bit better, with a couple more improvements Don and I are hiding up our sleeve. But the show amps are 95% to 98% of what the shipping amps will be (yes, the production Blackbirds will be even better, Don and I promise that). But I’ve never heard a Raven before. Hoo boy, is it good. Wow. I didn’t expect that. I knew what it does, of course, because I designed it more than twenty years ago, and Don refined it and took it a few steps further. But I never actually heard it, just other people’s impressions of it. I was quite surprised when I hear it for myself, in what is a very good room. I’m not all that good at writing puff pieces, but the initial impression is speed and power, followed by vividness, and depth of tone, an impression that grows over the course of a few minutes, and after listening to a few different selections. We keep telling visitors, no, there is no 200-watt subwoofer (or two) tucked away in a corner, and yes, the new Spatial speakers are entirely powered by ONE Blackbird per channel, with passive crossovers (sample on display at the entrance to the room), and no electronic EQ, no active crossovers, no multi-amping, and no DSP. What you see is what you get. As for source, Don and I are joking around about our favorite DACs. He’s all-in on the LampizatOr family, while I was dazzled by the Bruno Putzey-designed Mola Mola in a nearby room. I was expecting to be bowled over by the Holo May, but nah, it’s not for me. But there’s no way I’m going to cough up the $13,500 the Mola Mola costs, especially considering how fast DACs become obsolete ... five years or less. 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.
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The sonic differences between the old Akido circuit and the Raven are fairly dramatic. The Akido circuit sounds like one of the best darn traditional tube preamps I had ever heard, and that is why I built it for years and kept trying to squeeze another few percent out of it with every improvement. The Raven is part of the 300b project. Both the amps and the Raven will happily play with the rest of the world, either single ended RCA or XLR, but together they can form a complete balanced chain with a balanced source. The Raven can drive the input tube grids of the Blackbird amps directly via XLR because it has an output transformer. I would not do that with a solid state preamp or DAC output stage, only something with an output transformer or coupling cap to protect the amps from DC input. A solid state device would be fine for possibly many years until one instant that it isn’t, and then DC can come flooding into the amp. That would not destroy the Blackbird, but the input tube would be really unhappy, and some nasty noises could arise from the speakers. The Raven simply cannot do that because it is transformer coupled. The RCA input on the Blackbird amps is transformer coupled, so that is always safe, but the XLR inputs can bypass that input transformer. So the Raven is made to mate with the Blackbird. The sound of the Raven vs. the older Model 2...? Well, as much as I like that circuit and build, it sounds slightly slow and veiled compared to the Raven. The Model 2 is a great preamp and I have maybe 150+ of them out in the world in one form or another, but the Raven is a step up. There is just more resolution of fine detail, with what sounds like effortless and unlimited drive. It is not bright in any way at all, but it is highly detailed. The whole 300b system is like the iron fist in the velvet glove to my ear. It has all the subtle detail and shadings of a flea watt SET amp, but serious grunt and drive at the bottom and extension to 34KHz at the top end and a very subtle roll off after that. I suspect the final version of the amps may make it out to 50 KHz before the roll off begins. So HF is extended and airy, but again, never bright sounding. The Raven is definitely part of that experience because I built the amps first and used them with RCA inputs and my old preamp, and then I built the Raven. Like the amps, once I heard the Raven there was no going back. So then Lynn and I experimented with several power supply variations before deciding on the final topology. They all sounded quite good, but the final choice was clearly the best to my ear. At any rate, the Raven is a big part of the sound people heard at the show. My old preamp was good, but not in the same league. My 2 cents..... |
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 |
What. A. Show! Just got home ten minutes ago from Seattle. The most intense thing I've done since I went to the European Triode Festival in 2004. At least I didn't have to fly to Zurich this time ... only a 2.5 hour flight to SeaTac, and quick trip in the hotel bus. But man, the SIZE of the concourses in Denver ... combined with THREE gate changes. Lots of fun meeting people at the show, and there were three or four really outstanding rooms, including [blush] our own. The Spatial team are great people and thoroughly professional, and several pre-orders are coming in. I have a feeling several vendors will be using a flight of Ravens and Blackbirds in their rooms next year. |
Yes, it was fun! As Lynn said, there were 3 or 4 outstanding rooms and we had one of them. It was a scramble taming the room and the internet connection on setup day, well into the late evening. But we got it! I would say the system was very much on song except for image height and width and that was totally limited by the small room. But depth was very good and tonality was unaffected. Hope a few more folks that stopped by will give others an unbiased opinion on this thread as they get home. |
I stopped by, and it was the only room I was made to feel totally unwelcome. Someone on the way in basically told me to get out there's a reviewer. Inside there was one guy sitting down being lectured about how great blah blah blah. I was totally ignored. Asked if we could hear some music? Got a glare and a terse "in a minute" then back to being ignored. Another guy I trust managed somehow to hear it, said it was okay. Only room all weekend actually refused to play music and treat attendees rudely. You want my unbiased view on this thread? Never seen one so dedicated to shilling allowed to go on and on. Free advertising. Must be nice.
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Wow... It's really unfortunate that you had that experience and was certainly not how I was treated and I'm just a nobody. I stopped by 3 times across the day on Friday and while the room was quite full each time. However, I did introduce myself to Don and had a quite nice conversation. Shill, not really sure what that really means but I get the implication and at least for me incorrect. |
I’m truly sorry you had that experience. The staff in the (fairly small) room rotated between Don, myself, and the four younger people at Spatial. (Don and I were the obvious old farts.) The Spatial people were manning the room (with a nonstop 4-hour playlist+personal requests) and Don and I were there to explain the electronics, tell various origin stories, and provide comic relief. Reviewers popped in and out, and the famous Amir from ASR even showed up for a minute or two. Crowds came in surges, particularly on Saturday, when it was jam-packed. I was not aware that anyone had emptied the room for a reviewer, that’s certainly not what I saw when I was there. They had to take their chances like anyone else. There might have been special cases after 6PM, with private showings arranged in advance, but after-6 was mostly Social Hour for the exhibitors ... for example, I dragged all of the Spatial staff and Don to hear the Songer/Whammerdyne room, just down the hall from us. I’ve been old friends with Matt Kamna, the designer of the Whammerdyne 2A3 amplifier, so that was my after-hours excuse to get them to open the door ... "hey, here’s all my friends, can we listen for a while?" ... kind of thing. I don’t know who the Famous Name Reviewer was. I wasn’t aware of anyone dropping by, much less closing the room for them. Our plan is to build a customer base (that’s you, folks) before we let any product get formally reviewed by the magazine or YouTube reviewer. Speaking only for myself, we’d like the Big Guns to give us a little breathing room, while we get the production machine going. Don and I already have market identities ... we’ve been doing our respective things for thirty-plus years, with our names attached to what we do. We don’t need to build something that’s already there. So I’m not in a hurry ... at all ... to get in a review queue. People have heard about the Karna since 2003, well, here it is, in a room that’s about half the size of my living room, so please make allowances.
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There was a reviewer from Stereophile who came twice. I let him play what he wanted, but I certainly did not chase anyone out of the room, so maybe that was someone else in the rear. I assure you that Stereophile will not be getting the amps for review. There is no free advertising as the product is not even in production yet. Sorry you were not treated well, but it wasn't me.... |
Also, as Lynn said, the plan is to have Spatial Audio Lab build the preamp and matching 300b amps, which we all are currently calling the Raven pre and Blackbird amps. They may get a final name change before launch, or they may sing together with their current monikers. Reviews are way down the line. Direct sales to customers is the way this will go, just as with the Spatial speakers. There is absolutely no relationship with any publication. We are aiming for availability late this year or first thing next. It is our hope that a few people will have them playing in their homes for the holidays! |
First things first. I share Lynn's sorrow for Edisoncarter's perceptions of how he was treated in the room and honor his impressions, with the exception of this thread being a shrill for their gear. But personally being camped out in the room on Saturday, there were waves of folks coming and going which always can be confusing. Sorry for the bummer experience, Edisoncarter. The sound in the room with the new Spatials and Don and Lynn's front end with the phenomenal Lampi DAC all combined for a stunning sound. (I don't recall that they had a TT in the room.) Don played an unusual song with all bamboo instruments and the articulation of each note was brilliantly clear and suspended in air. Then Don played "Kind of Blue", the finest jazz recording in history, and the music simply bloomed in front and behind the speakers, with amazing imagining. I have had this recording for nearly 50 years and know it intimately. It was easy to pick out where the players were located in the sound field with lofty air around them all. Clayton was there and I am very happy to see that he has regained his robust health, and his new X4 Ultras brought to life the excellence of the the front end electronics, pure and simple. Don was not completely happy with the room dimensions, but I have always thought that Spatial speakers are the least room sensitive of any speakers I have owned. And so my ears told me in my extended listening of music in the room. Let me state the obvious: Don has much better ears than I have and is a hyper-critical objective listener or how else could he tune his gear to nth degree trying various caps, etc? A word or two about Lynn Olson. Very rarely have I met such an erudite person in the audio realm... he knows tube gear in a way that I suspect few people do. I think he has to be one of the unheralded geniuses in the hifi world and can expound with the same knowledge on economics, history, philosophy, religion, anthropology, climate change, psychology (his initial training), politics, and on and on. He is a true polymath and is among the most gentle men I have ever had the pleasure of meeting. I learned much of this at dinner after the show with him and Don, where I got an understanding of the full dimension of the collaborative effort that created these stellar electronics. The two of them are cut from a different bolts of cloth, so to speak, but they put their fertile ideas together to create this gear. Moving on, the Whammerdyne room with the Songer speakers was excellent as Lynn noted. The Von Schwiekert room with a panoply of VAC tube amps was outstanding. Jeff Wells' room with his electronics and the $13K TAD speakers was exceptional. The new Mofi 10's were a joy, kind of an old school sound, updated, and a real bargain. The new iteration of the JBL L100's did not move me at all. The Chapman speakers in the Kuzmo room sounded really fine. I got to visit with Gary Gill, a very affable guy, who put this show on as a region event, with no pretensions of it being an Axpona. The vibe was very relaxed, I sensed, with about 40 or so rooms that attendees didn't feel like they had to rush around to hear everything. The after-show musical entertainment was way beyond anything I have heard at Axpona or RMAF... hats off to Gary for that, a real swell guy who I pleasantly visited with about analogue vs digital music and it was delightful to share different opinions in a very pleasant and humorous matter. He is a great guy, very easy going. I had a wonderful time hearing Don and Lynn's new electronics and Clayton's new speakers and finally, after 15 years of having Don upgrade all my vintage Harmon Kardon gear and then getting his preamps and Kootenai amp... and now his 300b monos, to finally meet him in person was a purely joyous experience. He is a bundle of focused energy and as affable as you can imagine. Oh, I got to meet Miller Carbon, too, who was playing Tekton Moabs, probably 7' tall and they sounded quite good. It was a great show with many really fine exhibitors. It was a great event, no question about it. Cheers, Whitestix |
The day before, Don told me about Whitestix, his oldest customer, and said he was trained as an economist. (!) So as we sat down to a delicious dinner at the Thai restaurant across the street, I was curious and couldn’t help asking: "Chicago School or Keynesian? How do you feel about MMT? Freshwater or saltwater (terms of art to economists)?" Economists famously disagree with each other, even more than audio designers, and the stakes are far higher, since their assessments steer entire economies. Worse, there is a general consensus in the economic community that economists have probably wrecked more economies than they have helped. When economists get it really wrong, people starve, are sent to gulags, or revolutions start. By contrast, all that bad audio design does is make people a little unhappy. And things kind of went on from there. Not downhill, fortunately! |
I’ll third Don Sach’s opinion. I’ll go further and say the Songer speakers are the best full-range drivers I have ever heard, better than the Feastrex (which I have heard), and remarkably, free of the upper-mid roughness that usually plagues drivers with whizzer cones. I did not think that was possible. They sound more like a really good coax with an electrically perfect crossover. If money’s burning a hole in your pocket, get the dipole version. You didn’t really need that BMW, did you? Just drive the Lexus a couple more years. You’ll enjoy the Songers more. |
I want to share my thoughts about this equipment and about the show, and a little about my experience in the room. The opportunity to hear the Raven and Blackbirds and (hopefully) meet two people I’ve only "met" on the internet was a major reason I drove up from Portland to attend the show. So the Spatial/Sachs/Olson room was one of my first stops Friday afternoon. First visit... what can I say? Completely unlistenable, mind-crushing, thought-destroying, ear-splitting rave music or (what the hell, I don’t know what to call it but I could not think when I was in the room to come up with an alternative to listen to, though I was invited to do so)... I had to leave. Second visit a little later was a little better and my third attempt was much better. Oh - a comment about listening levels at the show. I carry a SPL meter with me and typically measured the SPL levels in every room I went into. Many rooms were playing with peaks well over 80dB. Some rooms were measuring 80dB outside, in the hallway. Since my buddy @jzzmusician has tinnitus we didn’t spend any time in rooms that were loud, ’cause loud music aggravates his condition, which is mostly bearable and controllable. Back to my account about Don’s room. On our third visit I asked a young woman who was managing the room whether Don was around and she said he was in the other room in the suite and would be out soon. They were switching amps from the Spatial integrated to the Raven/Blackbird combo and were having some trouble getting the streamer to connect or something, so when Don came into the room the female assistant let him know there were folks who wanted to talk to him, so we got to hear his thoughts about the Linlai 6SN7s which seemed to be in every piece of equipment in the room, and then the story about the evolution of the Raven & Blackbird. I found Don extremely likable and really enjoyed his off the cuff account of the project. I also really enjoyed hearing about how he came to own a Lampizator Pacific. Fun story. It’s hard for me to assess equipment in this kind of an environment. I think the Spatial integrated amp sounded really good, the Spatial speakers sounded great, and the combination of Pacific/Raven/Blackbird/Spatials sounded simply like music. Pure, unadulterated. Really, really good. Easily one of the best sounding rooms at the show. The Whammerdyne/Songer room was sounding typically top-notch. Oh my merciful heavens. It was also really good. I think the Songer speakers are perhaps my favorite speakers in the world. There were many rooms which, frankly, didn’t really do much for me. The was a ne-to-me brand of electrostatics that sounded okay, but I didn’t really agree with their stated premise that "we all know that electrostatics can’t do bass". Yeah, I don’t agree with that. My Quad 2805s do. They don’t do bass as well as my JBL monitors but they are a very livable compromise. The new electrostatics were something like $70,000/pair. On Saturday I was back in and out of Don’s room a couple of times and somehow, through a kind of a miracle, I thought I recognized @lynn_olson in the hallway and said "are you Lynn Olson?" He stopped, I introduced myself and he generously spent quite a bit of time talking about his experience, amps, design, the Raven, the Blackbird, scattering gems of knowledge right and left. I was far out of my technical depth but enjoyed it thoroughly. I agree with the comment above that he’s probably some kind of genius. (Lynn, I know you won’t let that go to your head.) Only after returning to Portland I learned from my good friend Harry that Lynn is a spiritually oriented person. Wish I’d known that - we could have gone off on that tangent which I really would have enjoyed. This post is getting too long. And it’s unfocused and I’m rambling. Oh well. Oh, one more amazing coincidence was that I got to meet another person I’d only previously met via Audiogon - Michael from Corvallis. Yeah! We’re going to be able to finally have that shootout we’d planned to do back in 2019/2020. Really was a pleasure to put a face to the name. Overall my experience of the show was that it was great. So many audiophiles seem to be real gentlemen and I enjoyed every conversation I got to have. |
Don’t get me started on the differences between Mahayana Buddhism and Vedanta Hinduism, and subtle (but fairly obvious) Buddhist influences in the Sermon on the Mount. Here’s one for you: when I was a little tyke in Japan, no more than ten years old, I was preoccupied with one burning question: "Where Do Thoughts Come From?" My parents deflected me, of course, because they had no clue, and probably thought it was a ridiculous question. But as an adult looking back to those days in midcentury Japan, it would have been pretty entertaining if this little brown-haired Western kid asked a Japanese monk that same question. Our family went to plenty of temples, after all, and English was fairly widely spoken at the time. The monks would have went bonkers to see a little Western boy ask, in all seriousness, a Buddhist koan. They’d be running around and shouting, "Proof of reincarnation! Bring the abbot! Take a photo!" Sometimes I think my Higher Self has quite a sense of humor. I may not get the joke, but it certainly does. P.S. So, sixty years later, where do thoughts come from? If I met him now, I’m not sure I could honestly answer the little boy. |
I heard, and liked very much the Songer fieldcoil speakers I heard at Capital Audiofest. I believe the dipole driver speaker and the more conventional box speaker were the same price, even though it appears that you get much more with the dipole version (two-way instead of a single driver). Both sounded quite good to me. It would be interesting to hear them more or less contemporaneously with my other show favorite--Charney Audio full range systems (higher efficiency than the Songers so even more low-powered SET friendly). |
I am glad I followed this, am in search of a new line-stage and the Raven looks like a good prospect. I have simple needs with only one RCA and 1 XLR input and same with outputs. I will pair it with my VAC Renaissance 70/70Signature amp and XLR into my Legacy Audio Focus XD’s. Saw the Raven design on a You tube show Video. |
Coming back to Earth, I heard the Purifi Class D amplifier at the show. Quite good, and free of the usual transistor Class AB metallic coloration. The Raven preamp would make an excellent match for the Purify, since it is very transparent, has plenty of drive current, and is also an ultra-quality ground and RFI isolator. It might seem like an odd pairing, but for somebody that needs cool-running Class D power, the combo would probably work really well. However ... the way the Raven is configured now, it can only drive one output at a time, either XLR or RCA. Well, technically it can drive both at once ... no harm is done to the circuit or any parts ... but the load is then unbalanced, with more cable capacitance on one side than the other. So the amp with the balanced inputs will receive a signal that doesn’t quite match at high frequencies. This is probably true of other preamps with XLR and RCA outputs ... unless the literature comes out and says it has independent and isolated output sections for each set of outputs, you should assume the RCA is simply connected to one side of the XLR output. If that is so, then the added capacitance of the RCA cabling, plus the input capacitance of the RCA power amp, will unbalance the XLR output. I should also mention when a transistor power amp is turned off, the input section of that amp is not isolated from the cabling, and the turned-off input transistors can create a nonlinear load for the preamp. Once it’s on again, feedback and power is restored, and the amp operates as specified. But when it’s off, best not to have another amp connected in parallel. This is an important difference between tube power amps and transistor power amps. The input grid of a turned-off tube amp just sits there with a few pF of capacitance from the tube socket. Nothing else happens. It would take hundreds of volts to arc-over the tube, or break something in the input section. By contrast, the base or gate of the bipolar or JFET transistor has a nonlinear input capacitance that remains when the power is off, and there is serious risk of damage if a 20 volt transient comes by ... this is a real hazard with conventional cap-coupled tube preamps and their associated turn-on thump. (The Raven is transformer-coupled and cannot pass DC transients, but there’s a small click when the VR tubes snap on, but small enough that even the most delicate Lowthers would not be harmed.) |
"However ... the way the Raven is configured now, it can only drive one output at a time, either XLR or RCA. Well, technically it can drive both at once ... no harm is done to the circuit or any parts ... but the load is then unbalanced, with more cable capacitance on one side than the other. So the amp with the balanced inputs will receive a signal that doesn’t quite match at high frequencies."
I wonder if this is an issue since the XLR’s are just driving the bass, however this happens with in the internal crossover in the speaker. I spoke with Don on the phone today, getting clarification from Legacy how this works with RCA and XLR together in bi-amp. |
Lynn makes note of hearing Purifi Class D amps at the show in a favorable way. I did hear Atma-Sphere's new GaN mono amps driving the the Tekton Moabs and I thought they sounded excellent. I could easily see a synergy between the Raven and Ralph's mono amps and I personally would require a tube preamp with any amp I might choose to use. That Ralph has made such a move to Class D technology after decades of being a tube designer/manufacturer ought to make the audio community sit up and take notice. What I heard of his $5500 amps was very impressive. Of course, let your ears be the judge. I am luxuriating with Don's DS2 preamp and his new 300b monos driving my now run-in Cube Audio Jazzon speakers. I am enjoying the sound in my room to a degree that I have never experienced before. From morning to night...
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The Raven is particularly well-suited to driving transistor amps because: 1) The transformers prohibit the transmission of DC pulses to RCA and XLR outputs, under all conditions, including total failure. 2) Unlike solid-state preamps, there are no DC servos to fail. There are no coupling caps on the output to store turn-on pulses, unlike cathode-follower designs. No muting relays are needed, or used, so the signal path is direct from transformer secondary to output. 3) All internal circuitry is fully balanced. The faint click when the VR tubes light up is only due to small residual imbalance (no more than 2%) in the 6SN7’s. Balanced operation alone reduces noise by 30 to 35 dB, then the VR tubes another 20 dB, and then 130 dB from the regulated power supply. 4) In addition to internal balanced operation, phase splitting at the input and output is entirely passive, not using discrete transistors, op-amp inverters, or split-load tube inverters. The custom transformers are precision balanced through 30 kHz, ensuring accurate phase balance for the power amplifier, whether it is solid-state or vacuum tube. 5) The input connections are floating, breaking any potential ground loops from the DAC or phono preamp. The transformers only respond to differences between signal pairs, with 80 dB or better common-mode noise rejection. The transformers also reject radio-frequency interference (RFI), passing only audio-band signals. |
My personal award show notes from PAF, including the room with the amp in this thread: *Most intensely rich yet detailed tubey midrange: LTA prototype DAC, LTA Pre, LTA Ultralinear+ monoblocks, and Daedalus Argos V3 speakers *Most delicate and intricately revealing top end with too much mid-bass: VAC components and Von Schweikert Ultra 7 speakers *Second place for best top end and also clear midrange but garbled bass: Songer + Whammerdyne *Most gossamer presentation: Don Sachs' Raven/Blackbird + Spatial Audio Lab X series speakers *Largest sounding very small, yet full range speakers: Gershman *Most humongously oversized images and stage and most impressive driver tech: Aavik/Ansus and Borreson M6 *Most resonant enclosures: Black Ocean Audio *Most disappointing tonality: Joseph Audio Pearl Graphene speakers *Biggest surprise: Vanatoo's little office stereo sized powered speakers *Friendliest exhibitor reps: Tie between Furutech and ASC *Most advantaged by vibration control: Millercarbon *Most classic solid state sounding room: Infigo Audio *Most inoffensive yet not all that unique sounding room: Bella Sound |
I wish I had heard the Dutch & Dutch 8C’s. The exact opposite approach of our room, but 100% valid: internally tri-amped with DSP for the side-firing drivers to create a near-perfect cardioid radiation pattern. Digital-in is limited to 48/24 PCM (higher-rez content is accepted but internally downsampled), and the triple internal amps are Class D with 400W each. I was reading Amir’s ASR show report (third section) and the Dutch & Dutch exhibitor was measuring 15 Hz during setup. This might be anathema for some readers, but I like the massive engineering effort that must have gone into this bookshelf speaker. DSP to shape the polar response with side-firing drivers is not trivial, and from the reviews, they actually tamed the hotel rooms that were driving the rest of us nuts. Of course, with DSP tailored for each driver, the speaker would be flat as a pancake, not a bad thing. For analog fans, the prospect of converting every precious LP on-the-fly to plain old 48/24 PCM is appalling, and for high-end DAC fans, the standard-issue ESS or AKM converters hidden inside the Dutch & Dutch are probably not acceptable. So you pick the approach that you like. Surprisingly, Amir, of all people, liked both Spatial rooms. Did not expect that. The real invective on ASR was reserved for the absurd cables in the ballrooms ... to be honest, have to agree there. The Anticables we were using worked just fine, and were unobtrusive, as a cable should be. |
The takeaway from your observations (quoted below) is that no system is universal, and we all latch on to different elements of the sonic illusion. Well done! ... Thom
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Wow. I’m just seeing this thread, and I just want to take just a moment to thank everyone for spending time with us over the weekend, and for sharing these lovely comments. We loved doing the show. @lynn_olson @donsachs Meeting you and the immense praise you’ve offered for the driver and loudspeakers... it really is indescribable. I won’t even bother attempting it here. I’m so grateful to you both. And, your room with Team Spatial was absolutely astonishing. Incredibly clean sound, unbelievably deep and wide soundstage, razor sharp imaging... Between the two of us, it's hard to say which I felt was subjectively better. |
Who is this @edisoncarter, whom feels they were overlooked when visiting a Room, that was on all accounts buzzing with excitable interest and inquiries. Most who arrive at such an atmospheric place, would humbly inquire about when music was to resume, maybe even ask, if I return a little later could I hear a track of choice. I don't know how the @edisoncarter made their approach, I was not their. The follow up communicating of their interpretation of their experience has been presented in my observation with a Forked Tongue, this is pretty much self evident by the content of the last comments made from @edisoncarter "You want my unbiased view on this thread? Never seen one so dedicated to shilling allowed to go on and on. Free advertising. Must be nice." If this is the case as a casual observer of this Thread and then becoming influenced enough to contribute through making posts, is suggesting I have been complicit in Shilling a Product presented by a few individuals I have never met, or never communicated with until this very Thread. Have the individuals behind the product got their correspondence absolutely honed to the point where they are able to compel others to do their bidding, either of the above are all BS, and not reality. You want my unbiased view, "well done to 'Cutting the Head of the Snake'. Fortunately it is only one's Pride hurt, @edisoncarter has engineered their 'What about me Moment'. It does look like the Reputation of those that put in the real Sweat, Blood and Tears remains intact, credit where it is due. Hopefully my 5 x referencing @edisoncarter in one Post has been a Band Aid for the Bruised Ego incurred. I'm feeling like this following experience, might be a description that is accused of being a Shill, for a Certain Brand of Stepped Attenuator, so I will tread carefully. A Certain Brand of Stepped Attenuator, referenced on the 25-06 @ 6.13 am, is a device I am quite familiar with. I have been demo'd it as a Upgrade VC in a few Pre-Amp's over the past 5 Years. Most recently a Pre-Amp' I get to sit in front of regularly had undergone exchanges of a few VC's over course of a Year, and the Pre Owner thought they had made a Good Choice with a DACT, which most who had heard it in use was in agreement. Not too long ago the itch was scratched and out with DACT an in with said VC. The difference the Part made was Night and Day, the new an impressive insight into the recordings was immediately perceived and as the session went on there was too many attractors detected and spoken about, to even consider the DACT might be worth a revisit. I am not poo pooing the DACT, I have heard them as a Mono Device used a Balance Control on a 300b Monoblock Power Amp and they have been superb, when used as a VC on this set up. I also own a Brand New unused Stereo DACT The said VC, has just shone out as belonging in this Particular Pre Amp's Circuit.
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Our egos are not too bruised. We have a pretty thick skin. No matter what you do, there will be a certain number of people who are unhappy. It cannot be helped. This thread has been a wonderful discussion of amp topologies, with all points of view respected and debated. Even a little philosophy and the nature of perception tossed in. As was stated early on, these are prototypes that were shown in Seattle. Most people seemed to have a favorable impression, and there are already tweaks afoot before the final versions start to be manufactured later this year. We had great fun in Seattle meeting many other audiophools:) We tried to accommodate most people and play tracks and volume levels they wished to hear. Things got crazy on Saturday in our and many other rooms. It was quite the turnout. Again, we tried to accommodate everyone. Friday and Sunday were much calmer. If one person felt mistreated so be it. We can only do the best we can, I have enjoyed the project with Lynn for over a year now, and we are close to making them available for sale. Like any audio product, some folks will really like them, and some folks not so much. This is always the expectation. The Pacific Audio Fest was a perfect example of how many different ways there are to build a stereo at different price points and levels of performance. Some things are well worth the asking price, and others are not. Let the customer decide. |
I am all in, 'in this thread', it has catapulted me back in time, to when I was involved in discussion with a EE, who was helping me achieve something quite unique as a Valve Power Amp'. A very enjoyable period and wonderful to be reminisced. The Bruised Ego is certainly not pointed at any regular contributor to this thread. It is specifically for @me! me! me! carter, who felt the need to declare two designers as ringleaders and many/all Thread contributors as accomplices to a 'Sting'. What a Bungalow this individual has shown themselves to be.
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Yes. That is what keeps any manufacturer in high end audio in business :)
@lynn_olson FWIW dept.: We've been using a direct-coupled output for our fully balanced tube preamps since their inception in 1989. To that end we've used a servo to sense and correct DC at the output. Here's the FWIW bit: a servo is (or should be) very reliable. We've not had a failure since their inception. |