Rebbi,
You really began what's become a very good and interesting thread. It does raise real world purchasing issues. Buying components when it isn't possible to audition prior to paying for them. This was my situation over 5 years ago before buying the Frankensteins brand new. My very first post on this site in 2009 was seeking out owners of this amplifier. I was so inspired by their response and enthusiasm(some via private email) I took the chance. To say it worked out fine is an understatement. I realize it doesn't always turn out that way. I can relate to your position and that's why I try to contribute in some fashion.
Charles, |
Rebbi,
The AN decision isn't unusual, just basic quality tubes for stock use (these "plain jane" tubes can sound pretty good). It saves money as the premium 300b tubes aren't cheap. Well I think the Audio Nirvana represents an excellent value if it sounds as Mdemaio described. Audion Audio SET like sound for 1550.00 would be a significant achievement. I'm an open advocate for quality SET amplifiers. If one comes along and delivers good sound for this cost, that's a good thing for music lovers. |
Rebbi,
Regarding David's comments, it isn't surprising. He may believe his carefully chosen parts yield the best sound and he may be right. Builders vary in their opinion on "upgrade" parts. He seems to suggest that aspect has been covered via listening/testing process. Speculation is all you have until you can personally listen. Mdemaio was certainly impressed and that's all we have to go by at this point. The 1000.00 cost difference(AN vs Audio Nirvana) represents established vs the new upstar factor. I get the sense David's amp "might" be more of an all out assault than the Bottlehead (only a gut feeling, nothing more). |
Rebbi,
I meant Bottlehead. You had mentioned them earlier and pricewise they compete with the Audio Nirvana. I realize I did just pop them into my last post. I'm curious to see what you select from this strong list of contenders. |
Rebbi,
Roxy54 gave you excellent advice regarding the volume control. This is an overlooked but important part affecting sound quality. Please get the best you can comfortably afford,you'd be surprised by the difference they make. Are you getting the Mundorf silver/gold oil caps or the Audio Note copper foil? I'm in no way telling you what to do, but if you get the good stuff/parts there's no looking back! You'll have a first rate 300b SET for just a few more dollars.
Again, congratulations.
Charles, |
Roxy54,
I googled the Khozmo attenuator and I suspect it's much better than the standard Alps volume control. |
Hi Roxy54,
No question that just those two changes(capacitors and volume control) improved your already fine SET amplifier. It's refreshing that Brian is open to the idea of using higher quality parts for his amplifiers. Roxy I'm certain that your amp sounds terrific.
Happy Thanksgiving to all of you.
Charles, |
Rebbi,
I thought everyone loved football LOL(part of my early culture).
Mikirob, the Eagles are good and explosive. I'm a big believer in good offensive lines and running the ball, thus Dallas for me. Rebbi Grant Fidelity is good and I have purchased from them without problems. The upper level line of Pavane tubes they sell are very good quality. Back to the football game, go Lions!
Charles, |
Mikirob,
Good call, the Eagle defense was dominant and set the tone for this game. |
Mikirob,
Yes, nice call on all 3 games yesterday. Green Bay vs New England this sunday, I'm going New England. Aaron Rogers has been on fire but Brady is as good and the Patriots are a better team overall. Yes I know the Packers are the home team. I hope Rebbi does a blog also. |
Smctique1, I wouldn't be surprised if the Decware's disappointing performance is output transformer related. What you described can be traced to that and a less than robust power supply. Brownsfan didn't have this problem with the Dynamo driving the very same speaker. There's no substitute for good iron in a tube amplifier. |
Smctique1 say at 80 db the Decware began to have problems. Brownsfan said the Dynamo was good up to about 90-92 db, that's quite a difference using the same speaker. Anyway both of these amplifiers will certainly have their loyal supporters. The Dynamo has gotten very positive professional reviews and favorable show reports (if that matters to anyone). I 'm less impressed by what engineers have to say based on specs and visual inspection. Bottom line for an audio component is how does it sound ? If that falls short then you won't listen to it much at all. A direct comparison would be a niceplace to start. They are both reasonably priced. |
Nice read Rebbi, I look forward to seeing the transformers. You're on your way with this fun project. |
So much depends on the speaker when judging an amplifier, particularly SET/SEP types. It seems Tim Smith of 6 Moons may have use more compatible speakers as he notes numerous fine matches. System synergy is such a key factor for success . |
Hi Al,
Yes the output transformer is a logical culprit. Except in this case two things counter that assumption to some degree.
1) Israel places much emphasis on the importance of transformer quality and is consistent in that stance.
2)6 Moons and Enjoy The Music reviewers as well as Mikirob and Brownsfan attest to the very high quality sound from the Dynamo. These different users cover a variety of speakers as well.
These factors would suggest that the output transformers must be pretty darn good at a minimum. I suppose it's possible to have good quality transformers that suffer unusually high output impedance. |
My advice for people interested in tube amps and specifically the Dynamo is to spend the money required to obtain high quality tubes. I've seen enough feedback regarding this amplifier to belive it is very good and an exceptional value.It has a good simple circuit,good transformers and is well built.If It comes with average quality stock tubes, upgrade them. A well designed tube amp certainly responds to better tubes. The entire point is to achieve good sound that enhances music listening enjoyment. I understand why most manufactuers use cheap tubes as stock. Consumers can easily improve this variable and tailor the sound to their preference. It begins with a solid foundation(good quality amplifier) then the use of superior tubes to take it further.
I followed this principle with each tube amp I've owned over a span 20 years. With my current SET amplifier it's near amazing how it reflects the different 300b tubes I've owned and borrowed(generous loans). You can very easily hear the subtle and not so subtle characteristics of every single one of them. This is one of the great attributes of tube amps and makes owning them such a joy and rewarding experience. After well over 5 years of pure satisfaction with SETs I can't imagine using any other type of amplifier. Rebbi, I hope you have the same thrilling outcome with your Audio Note Kit 300b SET. |
I wonder what accounts for such a high output impedance of the Dynamo. The Frankenstein has an output impedance of 1.8 ohms, quite a difference. Tim Smith found good speaker matches in his review despite this seemingly obvious limitation of the Dynamo. |
Hey Brownsfan,
Once you're settled in, just think about all the mountain trails and adventurous hikes in store for you.
Best Regards,
Charles, |
Grannyring,
Yes we all here would agree on the importance of synergy/compatibility. For this reason a reviewer should rationally use an appropriate speaker for the amplifier under review. Otherwise what good is the reviewer's results if the match isn't properly sorted out? SETs need easy to drive speakers with reasonable efficiency. As Mikirob pointed out, he has no limitation of music genres with his Tekton speakers. An excellent 300b SET will sound woeful if asked to drive a Magical or a Thiel. Get the match "right" and the amp will shine. |
Hi Mikirob,
What a wife you have. Not only does she appreciate SET sound, she wants to build one. She obviously is a music lover with superb taste. You must feel fortunate. She is attracted to a natural sound it seems. |
Rebbi,
I've developed much respect for Paul Joppa based on his contributions and demeanor on the Audio Asylum SET forum. I also appreciate the input of Gordon Rankin(Wavelength Audio) who posts there sometimes. I believe Dennis Fraker is talented and has much to offer but he's certainly a polarizing person on that site. Joppa seems to avoid the "drama queen" behavior that appears there at times. I'm not surprised that his Bottlehead kits are well done. |
I heard the Electra Fidelity 300b amp driving Cessaro horns at CES last year, simply terrific sound. It just needs the right speaker match in order to sing. |
Jet,
From what I understand a direct coupled 300b is difficult to execute for the reasons you mentioned. As far as capacitor vs interstage transformer it comes down to part quality and implementation. A good quality cap beats an average quality transformer. If both are of high quality it becomes a matter of design and preference. Companies that offer both such as Audio Note select interstage transformers for their upper tier products. Good transformers don't come cheap. I know excellent results are obtainable with eirher choice. Engineneer Andy Grove of Audio Note has written interesting articles on this topic. Strong arguments can be presented for either approach.
Charles, |
Hi Bill,
I didn't know that your speakers were that efficient for these types of low power amplifiers. I was under the impression that they require more power to be driven optimally. I believe that a DC 300b SET amplifier would be a challenging but doable project for you. I say have the fun and go for it!
Charles, |
Bill,
You should be OK given your listening parameters, and with normal hearing ability, 85 db is pretty darn loud enough. I know some on this site like to listen on average at 90-100 db. Too loud for me regardless of the components or system in place(and risky for one's hearing IMO). To each their own as they say. I thought the Manley Neo-Classic 300b allowed switching between SET and push pull. Not sure if the output transformer needed for that is ideal for either topology as there are different requirements. I heard that amp long ago at CES one year. Transformers best suited for SET are 'air gapped' to my understanding, PP doesn't require this feature. It makes me wonder if this amplifier is better in PP than SET mode. The right output transformer is critical to optimal SET performance. Interesting concept but how much compromise is involved?
Charles, |
Roxy,
Just a detour until Rebbi has something to report. |
Grannyring,
That sounds like a very intriguing and interesting amplifier. I have a question for you, is your speaker efficient enough for a 10 W amplifier to display its beauty or does your speaker require more power? Bill, I am very interested to read your impressions on this amplifier speaker combination. My gut feeling is that this amplifier with this type of circuit and power supply attention should sound marvelous if the speaker load is compatible and benign.
Charles, |
Thanks Bill,
I look forward to reading about your listening experiences with these different amplifiers. My average listening levels are 75-80db C weighted. So I realize my amplifier is only providing 1/10 to 1/4 of a watt. Most likely I'm using less then one watt of power probably 90 to 95% of the time I listen to music. I sit about ten feet from my speakers. Bill, on paper your new amp looks quite special and should sound exceptionally natural and realistic.
Charles, |
I have a very soft hum that is heard with ears within about six inches. The irony is this, my push push amplifiers have no sound within 6 inches of the speaker yet when music is played, the SET reproduces tiny nuances and details that are totally missed my the other amplifiers. Ambiance is preserved better than any other amp I have tried. Audio results are fascinating to observe. |
Hi Bill,
I googled your amplifier and found some very interesting information regarding it on Black Swamp audio and also found a review on Posiitive Feedback Online issue number 32. Bill I really like the concept and design of this amplfier, I like the decision to use a lower voltage on the plate and also the decision to go with a lower heat dissipation. I am really curious to see how this amplifier mates with your speaker. I get the feeling that this amplifier will be very pure and organic in character, yet also dynamic and lively. It should be much fun experimenting with this amplifier in your system. |
Larry,
At those prices I don't blame you. Israel Blume the builder of my amplifier believes in running tubes conservatively. He runs the 300b at 25 watt dissipation, max for this tube is about 40 watts. He says tube lifespan increases and tubes run conservatively sound better. Larry I suspect you'll get many years of use/pleasure from your tubes.
Charles, |
Rebbi,
Based on your continued highly positive and enthusiastic comments it seems quite apparent that your Audio Note kit amplifier is an excellent match with your current speaker. There is no reason for you to rush into another pair speakers at this point, you are enjoying your music in the highest form and this is commendable. That Omega speaker does seem to be very intriguing and definitely something to consider further down the road.
Charles, |
