|
Audio Asylum Thread Printer Get a view of an entire thread on one page |
For Sale Ads |
184.6.67.222
In Reply to: RE: Mesh 2A3 posted by craig-jackson on May 10, 2012 at 09:50:25
I know for sure, Dennis Fraker of Serious Stereo has regularly used BOTH types, in the same amp circuit over many years and many hours, and if you telephone him, he will usually comment over the phone.
Jeff Medwin
Follow Ups:
Hello 2A3 fans. I am forever indebted to JAC (Jacmusic.com) for steering me honestly and correctly about that GOOD batch of those AVVT true-mesh 2A3s.
To this day, they set a very high standard as far as honestly reproducing ALL of music's parameters go.
Nothing is totally perfect however, and there are differences. Since I do other things besides electronics for a living, I don't care at all about cost cutting, so that makes these tubes very attractive to me.... their price is not a consideration.
I have used most all 2A3s-- and have run them in different ways at different voltage, current, and drive levels.
Since I never would, and never will tolerate anything that fails, changes characteristics, or ever needs any kinds of adjustments-- for any reasons whatsoever, and I never cared about amplifier power ratings-- I just wanted the speaker to be perfectly driven under all musical challanges, I ran those tubes at very conservative continuous currents-- and as JAC has intimated-- never even had ONE failure-- ever.
The RCA-Cunningham Single Plate 2A3 was very good. It had a reliable mid-range presentation, presented decent highs, and kept pace, rhythm, and timing relatively intact-- something no Bi-Plate tube ever even hinted at. It even had SOME bass! (not a lot!). The Single Plate was OK-- not great. The BiPlate was ridiculous and basically massacred music, as do most all common 2A3 types..
The AVVT true-mesh tubes that I had were from an unusually excellent batch. These ran the entire musical range with great gusto, precise imaging, terrific dynamics and a very linear bandwidth-- not to mention an amazing introspective look into the inner details of recorded music.
The "bottom-End" of this tube was, however, good, but not great. It was clean, well delineated, but didn't go really deep and down there-- with real power. That was this tubes only limitation, so I still use it at audio shows-- where it still amazes and pleases. Its overall musical accuracy is simply stunning, there's no other word for it.
Today, we have the EML, and also the JJ Solid-Plate 2A3. The EML is as JAC describes it-- later batches are reliable, and it is a mesh with a small frame holding the mesh screen into place.
This tube-- sonically-- is a compromise. It had decent overall linear musicality, it has better bottom end than the AVVT, but can't compete with the AVVT's absolutely stunning feeling of absolutely real presence and total musical believability. Is it better than any other 2A3 out there? It certainly is, and I strongly recommend it over any other 2A3 today-- in fact, over any output tube made today of any kind-- and that in spades.. Run it conservatively, for sure, but it will take more plate current than the AVVT mesh would.
The JJ Solid-Plate is really a 300B carcass (tube body, base, bulb and plate) sporting a 2A3 filament structure, and appropriate 2A3 grid spacing and biasing.
This is a tube with a rated 40 watts of plate dissipation-- I would never run it there. It will stand more plate current than the other 2A3 tubes-- something which does not interest me.... as I have learned how to move speaker diaphragms with far more physical power on far less watts.
The JJ Solid-Plate 2A3 is extremely rugged, lasts almost forever, is ridiculously cheap to buy, and has terrific bass drive and power-- easily equal to some very powerful solid-state amps-- in fact, even better! It also has a nice, clean, undistorted sonic presentation, and really extended highs. For every day listening, and those very punchy Blu-Rays and DVDs that you play in your home theatre, this tube is a monster killer! POWER, POWER, POWER! LOW distortion of all kinds is another bonus!.
So, why not just use this? Well, sorry, but good as it is-- there are cues and clues in music that this device never even sees! At all. But what it does do is spectacular.
Ah, such fun! There you are-- the best 2A3s out there. Any others? Any "better" tube types? Some people may think so, but what if you want to play ALL of the music?
HMMMM--MMMM!
---Dennis---
Hello, I had 4 pairs of those AVVT 2A3M some years back. The first 2 pairs failed, and I was not willing to use the last two pair so I eneded up basically giving them away, and lost interest in the 2A3 after that. Not too long ago, I purchased an amp you built, from a guy in California. It's the "best" amp I have ever heard .....period. I'm Not trying to "toot a whistle about your amps to the public", nor stir up some debate, cause many of your past post kinda sounded way out to me but this amp is well........... the one. And I won't speak again in public about this amp you built, cause I dont want to get into THAT debate.That being said, I was curious about your impression on the AVVT2A3. And having actually heard something you built, your post carry a little more weight to my ears today. Thanks for the reply.
I think the first question from me would be-- what 2A3 are you now running?You can re-read the last post and get most of what's in a good 2A3, but today I use 3 kinds of them.
The best overall was the LATER AVVT 2A3M-- and I still use this today at audio shows. These are no longer made. This tube is NOT a high power tube, must be run at 11 watts plate dissipation or below, and has decent, but not great Bottom-End. Overall, sonically, NO tube in the world today can beat it. You might get 2 watts out of it-- I wouldn't push it that far. Reliability is total IF you run 245 volts across it, and run it at below 45 milliamperes plate current, and don't overdrive its grid with too much signal input.. If handled correctly, it will deliver terrific dynamics in spades and last almost forever.
The EML that is made today can be run at higher plate currents-- up to 55 milliamperes, and still likes around 245-255 volts across it. It has better Bottom-End, a linear, clean midrange, decent introspection into musical layers (not as good as AVVT 2A3M), and more power. Reliability is total if it's run right. This is today's best tube sonically.
The JJ 2A3-40 will stand plate currents up to 65 milliamperes, will stand at least 260 volts across it, but runs best at the parameters for the AVVT 2A3M!
There will be argument here, but that is just plain wrong-- what we're after is the best sound and the best reliability-- not winning arguments!
The lower plate current allows the tube to better respond to input signal, since that input signal will have less standing plate current as a barrier to overcome.
Response to signal is more immediate, more powerful and much more linear with the lower standing plate current. I'm NOT here referring to the so-called linear plate current curves you see published in tube data.
Instead, I refer to musical response-to-signal input-- a factor that is commonly ignored and is never published with regard to actual musical reproduction. It is a VERY important factor that I choose to pay strict attention to. Standing grid bias ALSO presents impediments to incoming signal for obvious and similar reasons, and must also be very carefully assessed.
The JJ 2A3-40 is, then, simply doing what one would expect it to do-- it also prefers less standing barriers to incoming signal. Just because it is a larger, more powerful tube-- doesn't mean we should ASSUME that it should be run as a larger tube. Actually, it runs just great in the parameters set up for the AVVT 2A3M. And now you know why. Cool!
It does, in fact, like the smaller parameters better. The JJ should be used where you are simply doing non-critical listening and enjoy huge rock-solid bass, power and authority, love a linear presentation, like extended, clean highs, but are not too fussy about musical cues & details that are almost hidden in Studio Mixes. For those, the AVVT 2A3M remains King.
Those amps of yours can run any 2A3, so you can play all you want.
Don't expect NOS biplates to do much-- they're semi-musical, but are not reliable and have a habit of mixing-- or homogenizing music. NOT World Class!
---Dennis---
Edits: 05/25/12
Thanks for sharing. Your comments speak a little above the drone often heard here, given your frame of reference and context.
Interesting the relative silence in response...
Cheers.
"The perception of sound is a highly personal experience. It is neither an art nor science, but our own private view through one of the windows of the senses."
The Mind has No Firewall~ U.S. Army War College.
It is what I have always reported on Dennis' amps after hearing them multiple times in different venues, public and private. I wish I owned a pair.
And of course RC Daniel, NONE of the nay sayers have ever lived with them, and MOST have never even heard them.
IMHO, NO ONE doing vacuum tube audio comes close to Dennis' amps' performance level, and particularly IMHO, amps Dennis has done the last couple of years.
I am not trying to be disrespectful to my many triode amp building friends. Not at all, lotsa truly great guys I respect fully !! But I am sure of my statement. The proof of the pudding is in the eating.
Jeff Medwin
~!
The Mind has No Firewall~ U.S. Army War College.
Sorry to burst your bubble.
I know enough about audio, and THAT amp's design, and the designer, to tell you nothing will come close to it in that power range.
Your "reasoning" is valid, but my vision is very excellent, and that is how I see and hear it.
It is just MY opinion, you are free to have your own.
Jeff Medwin
I never call anything 'best' Jeff.
Am merely more open minded than you. The amplifier surely sounds good, perhaps excellent, in the right room, with the right speaker.
The Mind has No Firewall~ U.S. Army War College.
I came across this thread and I would like to make a comment. I own a pair of Dennis's 2a3 amps using the EML meshplates. I also own a pair of his Altec 604 speakers. I am not an audio engineer but am a long time audiophile who has owned gear from Lamm, Shindo, Wytech etc. The Serious Stereo amps are by far the best sounding amps I have ever had in any system. These very low watt amps along with the Altec 604 provides incredible slam, mid-range magic, and high end extension with volumes that will drive you out of the room if you care to listen that loud. It never sounds stressed but produces music effortlessly. Many people think that this is not possible but those making that claim have never heard these amps. I suggest that any doubters look up Dennis at RMAF if attending to hear what his amps can do.
give me the schematic and I will weigh in myself. I build all my own amps to a level of quality far beyond over 95 percent of high end audio. Using overbuilt power supplies/No electrolytics, choke loaded etc.
The only 'new' circuit I have seen these last couple of years was The late Allen Wright's preamp design.
The Mind has No Firewall~ U.S. Army War College.
No Cleantimestream,I know the schematic. I have been designing and building DHTs since 1982. I believe you would NEVER in a million years be able to judge it from a schematic, or even duplicate the amp. I certainly can't build it, and I've been "inside" multiple examples of Dennis' amps over many years.
Dennis' work and thought goes WAY beyond what you THINK you might know about audio building and design. Dennis' latest amp, in particular, is the best. I don't precisely know who the above poster is who offered such a stellar review, but I "hear" the 2A3 amp at shows and home venues, so my comments are the result of much direct listening experience.
Cheers.
Jeff Medwin
Edits: 06/04/12
To say the schematic has almost nothing to do with how it sounds,
Sounds,
Well,
Rather absurd to me, Jeff.
I would call it in thirds.
1/3 implementation/layout
1/3 Schematic
1/3 Parts {obviously if feedback is used the parts would not carry so much weight}
The Mind has No Firewall~ U.S. Army War College.
I liked your response, at least the thirds analysis, good thinking.
Jeff Medwin
enjoy the same same aspects of a (live or reproduced) musical performance; not all people like the same type of musical presentation.
Prescribing a One True Path, or single best, or only is about as far from a true path as one can get.
Cheers.
Hello Guys!This question just BEGS for an honest explanation-- so here goes:
(1) Most recording studios strive to "lay down" a track that they enjoy and want you to enjoy. This is the art form of making music-- that's only part of it as the musicians are doing the same thing.
(2) If a person involved in audio playback CHANGES this in some way-- to fit a certain taste, then it is no longer the same recording.... it has been perverted.
(3) In fact, the only audio equipment that has any merit is that which reproduces what the musicians did and what the Studio recorded, keeps musician attitudes, dynamics and musical flows intact, and leaves absolutely nothing out. I'll repeat that: LEAVES NOTHING OUT.
(4) Sometimes, I have been accused of being a one-way guy-- "do it my way", so to speak. Incorrect.
My way-- or your way is not relevant. What the Studio recorded IS relevant.
(5) I apply no personal taste-- so please get over it! I use the best parts and methods that I can find or invent in order to reproduce the STUDIO RECORDING accurately. When I need help, I look for the best there is-- and I listen and learn-- and APPLY.
I never consider the source. The only thing I consider is what is true. Truth-- on any subject-- can and will stand on its own. One DOES have to look for, and recognize it!
I much prefer people who KNOW THAT THEY ARE THE BEST-- and ACT LIKE IT. I'm not interested in my own ego or in any of my own tastes-- or in any other egos or tastes.. I learn from the best primarily because I don't shoot the messenger-- instead, I like him because he is relating valuable information to me.
I want to hear those music recordings reproduced RIGHT... regardless of what they are, with total repeatable, no-fuss/no adjustments, and long term reliability designed in. Period-- that's all I want.
That's the minimum required!
(6) Of course, there are methods to do this, and there are methods that don't get it right-- or worse, some very popular methods that many people use and like (for want of better equipment, ideas and execution)--that will please some people-- but will leave out very important parts of the recorded experience-- or the equipment will change-- or need an---ahem!!-- er, uh--- ah--- adjustment! WHY!!!!! JUNK!!!!!!!!!!!!!!!!!!!!!
"What they don't know won't hurt them"-- or something like that--"Never had it, so therefore it doesn't exist"? "Never had any, so don't want any"?
"Each guy to his own tastes"? BULLSHIT. Each guy should try to reproduce it RIGHT-- or get someone who CAN!
This shouldn't be about your tastes or my tastes-- it's about accurate musical reproduction. All of it, please!
(7) Merely pointing out which methods do what-- does not constitute a personal verbatim or personal taste any more than observing that gravity pulls downward does.
(8) One can observe what is in a musical product-- and then, if he is honest, should cast his personal prejudices aside, and adopt only those electronic methods that result in accurately reproducing that music!
---Dennis---
Edits: 06/01/12
"This shouldn't be about your tastes or my tastes-- it's about accurate musical reproduction . . ."
Fully agree, that is what "Hi-Fi" means. It used to be the avowed intention of most audio manufacturers (who also provided tone conrols to add a bit of flavor to cater for individual tastes and/or to correct for deficiencies in the source).
When listening to live music, people will be unaware of their personal preferences, which will lead them to experience music differently to the person sitting beside them. By extension - and in my experience - this extends to the types of systems people use to play back music.
In a group of people, each having the same audio ideal, each will have a different personal understanding of a practical definition and methods for achieving said ideal.
Cheers.
“As long as we have any intention to be right… we should be wary. So long as words have the slightest ego attachment, they are dishonest.” Charlotte Joko Beck
I think you're right. There's no doubt that personal tastes do exist-- they do.
Should the designer of good audio equipment, then, build equipment that is inaccurate in order to sell to a certain group of personal tastes?
One could venture to say that most equipment IS built that way-- and quite a bit of it also sells.
The problem arises when you play recording "A"-- and the piece of equipment embellishes it-- "sounds good", you say.
Then, you play recording "B" and that same piece of equipment trashes it! Well, now what? Play only "A" recordings and learn to hate recordings like "B"?
Isn't that kind of stupid? You COULD HAVE had a GOOD piece of equipment, and then you would know what each recording really sounds like. Isn't that better than not knowing what ANY recording really sounds like because your equipment is always changing it on you?
---Dennis---
Hi Dennis,I am glad you interpreted my comments as I intended - sometimes I am less than clear. Sometimes in my efforts to tell people what I don't like I fail to let them know what I do like.
I agree with much you say, applaud the path you have taken and thank you for your willingness to question and share, even if I don't agree with everything you claim. I agree with much of your post, though I don't think someone is stupid for choosing equipment – consciously or not – different or inferior to what you have described.
It is understandable for someone who likes a certain type of music, to try to maximise their enjoyment of it, possibly to the detriment of other genres (often without realising it). When they listen to those other genres they might think them uninteresting, overly bombastic, crude, poorly recorded... indeed, it could be the fault of their system. And/or they may just not like that type of music. So they miss out, in a way. Or not. But, is it really missing out if they are enjoying their preferred music more? Their experiences would be limited, but I would not judge their choice as stupid. All of us are limited in our experiences. All of us make decisions that we feel are based on sound reasoning that are apparently daft to others. We all have blind spots. We are all at the mercy of our own BS.
There is much more I could say. But I will end here because I now wonder whether anything I say is relevant. My relationship with music and its reproduction seems different to most here. It is likely based in Zen practice (though I am not an active practitioner) and seems more about simply experiencing music, in 'most any form, via 'most any system... anything else is an addition that disconnects one from reality, including concepts of more perfect or enhanced reproduction. I also recognise that such is a vague ideal, that I am attached to certain presentations, and that certain systems that help bring me closer to simple experience or enjoyment. One such system would likely be the type you have described.
I would very much like to hear one of your systems one day.
Cheers.
“As long as we have any intention to be right… we should be wary. So long as words have the slightest ego attachment, they are dishonest.” Charlotte Joko Beck
Edits: 06/06/12
"The perception of sound is a highly personal experience. It is neither an art nor science, but our own private view through one of the windows of the senses." -Richard C. Heyser
Richard has ALSO just stated there is no such thing as objective.
Just as Chaos theory shows there is no such thing as 'objective':
Everything is subject to time and space with all coherent variables, known and UN-known. Your observations of the recording venue are turned inside out by WHAT room said recreated music is played, always an unknown variable that exerts by far the most influence, the speaker, second {2nd} in direct proportion to the room. I accept and respect any one whom likes what is reproduced for their enjoyment. I could say Criterion speakers sound exactly like my Quad ESL 63's. Others can rightly say, "To YOU, Ken they may sound the same but everyone else in the cosmos can hear a difference"
And yet from a scientific point of view I am Correct
Because,
Any scientific test must be free from all interfering variables, and it is incontrovertible that the test procedure itself can be a serious interfering variable when it comes to listening tests.
Acceptance is the answer to ALL my problems, regardless of topic.
The Mind has No Firewall~ U.S. Army War College.
I'd like to commend you on arguing your points well.
I certainly agree that the listening room makes a difference-- that's huge-- as you imply.
I would state that if we do the best we can-- up to keeping all of the music intact as it's coming out of the amplifier-- then we can apply a speaker system that is also accurate musically and, by having remained honest so far-- we can reap the benefits of having not left something out of our music in order to get it to sound "good"..
Now, as you're saying, the room becomes what's left. I wouldn't want to recommend that anyone use the source components, the amplifier, the speaker or any wiring in order to get a given system to work in a given room.
Rather, I'd approach that by keeping all of it as close to reality as possible-- right up to the room-- and then try to change that room and bring it into musical reality also.
I don't mean to imply that all rooms can be easily changed to accommodate an otherwise excellent system. Some rooms just have built-in limitations, and certainly challenge the best of us..
What to do? I would still use the most accurate amplifiers, speakers and wiring. If the room could not go beyond a certain point, I would be forced to use something at the source components-- maybe I would HAVE to make some source curve changes-- that's what people had tone controls for, and is why we now have digital room E.Q.
But please understand what's up here-- you need to get it as good as you can, keeping all of it honest and neutral, and work on the room seriously before you make that final decision to alter something in the electronic mix..
If you'll try to follow these guidelines, the end result-- even if it's not perfect-- will be better than if you had chosen an amp, speaker, or wire in order to compensate for a fault in a room-- by being in itself pleasantly inaccurate.
All I'm saying is you'll get better results by staying with an honest system overall.
---Dennis---
"If a person involved in audio playback CHANGES this in some way-- to fit a certain taste, then it is no longer the same recording.... it has been perverted."
I agree. I also agree with much of what you say in this post like, "reproduce the STUDIO RECORDING accurately", etc.
So why do you use a driver tube that can't fully drive the Miller, causing high frequency roll off?
Why do you use a power supply filter that causes instability of the B+ voltage?
Why are your cathode bypass caps (both driver stage and output stage) undersized to the point of changing the frequency response?
I think you are the one who is building to "to fit a certain taste".
If you can't (or won't) explain this in a normal, technical way I will go on believing that you are the one building to suit a certain perverted taste.
I tried to ask you about this on the phone but you got weird about it and wouldn't talk sense with me.
You talk a lot about truth. Truth does not fear examination but every time I try to examine your claims you start with the mumbo jumbo instead of talking sense in a normal technical way.
It's a shame.
Tre'
Have Fun and Enjoy the Music
"Still Working the Problem"
OH! My Gosh! DARN it!
I've gone and done it again! Designed a totally new Linear Power Supply for Music Servers.
Terrible! Horrible! THREE (3) of them in ONE BOX! It looks nice and professional too!
AND it hasn't failed in over 1200 hours of testing, and neither have its cousins. It runs cool.
It's much worse than that! It makes Music Servers sound MUCH more honest, dynamic and real than the same computers run on ANY other Power Supply!
As you can see, I don't know what I'm doing! Not only that, I can't even handle telephone calls from telemarketers, crackpots, intimidators, and fools! After about 1/2 hour, I hang up on them!
Sometimes even sooner!
Gosh! Maybe I better invent something else real quick! Oh, No! I forgot! I don't know what I'm doing and it's much worse than that! I can't explain it to TRE either!
Oh well! At least the music seems real around here....
---Dennis---
I was talking about your 2a3 amplifier and you go off with mombo jumbo talking about your PS for digital.In light of your statements,
"I use the best parts and methods that I can find or invent in order to reproduce the STUDIO RECORDING accurately"
"I would state that if we do the best we can-- up to keeping all of the music intact as it's coming out of the amplifier"
"What to do? I would still use the most accurate amplifiers"
Defend you use of undersized cathode bypass caps.
Defend your use of a driver with high output impedance.
Defend your use of a PS filter that is unstable.
Why won't you do this? What are you afraid of?
Tre'
Have Fun and Enjoy the Music
"Still Working the Problem"
Edits: 06/02/12 06/02/12 06/02/12
One should be able to understand the following:
(1) Conventional tube amplifier technique chooses cathode bypass caps by their Micro-Farad values. I choose them according to measured and listened performance under actual musically driven conditions.
(2) A high impedance driver is not a problem in this design because the HI-MU driver chosen is far more than capable of driving any good 2A3 vacuum tube way beyond the levels that this design requires.
The high-gain/fast response capability of a good HI-MU driver is exactly what I want-- fast, ultra-dynamic response to signal change. I also want the gain factor designed into TWO amplification stages, not three or more.
The reasons for this are self-evident-- there are too many parts involved in any 3-stage amplifier. The musical information losses in all 3-stage tube amplifiers renders their performance musically boring to me.
If you doubt this, simply compare the best 3-stage tube amp you can find out there to a good Solid-State amp. If you want pace, rhythm, and musical timing to come out correctly, the difference will at once be obvious.
A tube amp CAN be designed to perform with the best Solid-State. It requires a MAXIMUM of TWO amplification stages that are directly connected together, and are powered in such a way so that the two tubes operate as a SINGLE gain device.
Ideally, the "gain architecture"-- that is, overall amplifier gain-- will be in the 18-to-21 db area.
Such a gain figure will ideally match up to industry standard source outputs which ideally range from about 3.3 volts to about 5.6 volts single-ended, or double those figures for balanced.
A Digital source such as a good D/A converter, or a good CD player, etc., will have those output levels, and will prefer to see a constant load across its output of about 10K ohms-- in that range-- allowing proper output loading for the source.
These signal voltage levels (above) allow the inclusion in the system of a
passive preamp of about 10K loading continuously (A Ladder or L-Pad type attenuator), which eliminates the need for any musical-signal losing un-needed preamp amplification stages.
A further advantage of this kind of system is that interconnect cables are DRIVEN at voltages that actually allow such interconnects to work properly.
The amplifier's HI-MU driver stage is a necessary part of this overall "best possible" system approach-- it is very sensitive to interconnect cable output, and picks up musical details that lower-mu stages cannot respond to as well.
(3) The ENTIRE AMPLIFIER is designed as a modulated, distributed audio signal power supply.
To single out SOME OF the individual parts in that system and then claim that only those parts are the "power supply"-- and to further claim that it can't work is an incomplete assessment.
If one can envision an ENTIRE AMPLIFIER as a TOTAL ENTITY-- as I must do in order to get the performance that I require-- then it could be discussed intelligently by people who can see that it is an ENTIRE OPERATING SYSTEM.
I don't think that one can selectively pull parts out of an operating system, ASSUME that they're the only parts involved, and then make claims as to what one ASSUMES will happen in that SYSTEM.
In any case, it's easy to check out-- simply use the system and observe what it actually IS doing! What could be simpler than that?
---Dennis---
"(1) Conventional tube amplifier technique chooses cathode bypass caps by their Micro-Farad values. I choose them according to measured and listened performance under actual musically driven conditions."
The value necessary to fully bypass the cathode is a matter of math. The value you have chosen does not fully bypass the cathode. This make your amplifier, to use your word, "perverted". Not only will the frequency response be "off", the phase response will be off as well.
(2) A high impedance driver is not a problem in this design because the HI-MU driver chosen is far more than capable of driving any good 2A3 vacuum tube way beyond the levels that this design requires."
The high impedance driver is, by your own admission, a problem. You said it "starts to roll off at 15kHz". This makes your amplifier, to use your own word, "perverted". Not only will the frequency response be "off", the phase response will be off as well.
I didn't say anything about a three stage amplifier. Most of the rest of your post is a good example of you not addressing the questions and going off talking about other things.
You have done it again.
I didn't/don't assume anything. If the driver is not/can not fully drive the Miller that's a problem no matter what the rest of the circuit looks like.
If the cathodes are not fully bypassed that's a problem no matter what the rest of the circuit looks like.
Tre'
Have Fun and Enjoy the Music
"Still Working the Problem"
Too many "IFs"!
---Dennis---
Those are not "Ifs".
Your driver can not fully drive the Miller by your own admission.
The cathodes of both the driver tube and the output tube are not fully bypassed.
No IFs.
You are doing the very thing you argue against. Making designing an amplifier that is perverted.
Tre'
Have Fun and Enjoy the Music
"Still Working the Problem"
This message has been moved to a more appropriate venue .
Disagreed.
---Dennis---
Too many bases not covered in your design.Tre'
Have Fun and Enjoy the Music
"Still Working the Problem"
Edits: 06/02/12
I fully and completely disagree.
---Dennis---
You disagree with yourself?
You said that your amp starts rolling off at 15kHz.
The cathodes are not fully bypassed. That's just a fact.
If you disagree, show the numbers, show me wrong.
Tre'
Have Fun and Enjoy the Music
"Still Working the Problem"
All the amps I've owned before my SET have been flat from 20-20K with distortion well below 1%. None sounded nearly as good as the SET which doesn't have "the numbers".
If Dennis just said that his amps sound good I wouldn't say a thing.
But instead look at his response to your post,
"OH! But it DOES have numbers. It's been at University E.E. labs where it astounded their engineers."
With undersized bypass caps and a driver that even Dennis admits does not fully drive the Miller capacitance of the output tube, how can his amp have good numbers?
Tre'
Have Fun and Enjoy the Music
"Still Working the Problem"
Dennis,
Very nice answer. Best of all, your ending comment :
" In any case, it's easy to check out-- simply use the system and observe what it actually IS doing! What could be simpler than that? "
Any good listener understands this totally.
Jeff Medwin
"I have learned how to move speaker diaphragms with far more physical power on far less watts."
Care to explain that one?
I don't mean to be obtuse.
In terms of electromagnetism, one watt is the rate at which work is done when one ampere (A) of current flows through an electrical potential difference of one volt (V). Voltage times amps = watts.
Moving speaker diaphragms requires physical power and that power is normally expressed in terms of watts.
If it takes "X" amount of watts to move a speaker diaphragm the amount that you require, then that's what it takes.
There is no separating physical power and watts. They are one and the same.
Tre'
Have Fun and Enjoy the Music
"Still Working the Problem"
Is a watt of power delivered too little, too late-- the same PHYSICALLY-- as a watt delivered precisely on time, and in total relevance to the speaker's characteristics-- under the CHANGING, driven conditions?
In short-- does a watt that cannot relate to changing musical conditions have the same physical forces as a watt that can?
---Dennis---
First you talked about getting more actual, physical work out of less watts and now you are talking about the watts being different.You could have said a "clean" watt will "sound" (be perceived as) more powerful than a "dirty" watt.
But your original statement went well beyond that.
"does a watt that cannot relate to changing musical conditions have the same physical forces as a watt that can?"
Yes. It will displace the voice coil by the same amount as any other watt.
If it's inability to relate to the changing musical conditions are preventing it from following the waveform to it's peaks then it's not a watt.
It would be something less than one full watt unless the input was increased to compensate. But now we are talking about distortion when I thought we we talking about watts?
The problem (in this conversation) is your mis-understand of what a watt is.
Tre'
Have Fun and Enjoy the Music
"Still Working the Problem"
Edits: 05/23/12 05/23/12
"Perfect" audio involves instantaneous transitions between the high and low levels in the signal. The times taken for the signal to rise from the low level to the high level and back again are called the rise time and the fall time respectively.
If the system is overdamped, then the waveform may never actually reach the theoretical high and low levels, and if the system is underdamped, it will oscillate about the high and low levels before settling down. In these cases, the rise and fall times are measured between specified intermediate levels, such as 5% and 95%, or 10% and 90%. Formulas exist that can determine the approximate bandwidth of a system given the rise and fall times of the waveform.
So, yes, an amplifier that is optimized for damping with fast rise and fall times will subjectively perform audio replication better with one watt than an amp that is not as well optimized. It will not be more "powerful" in terms of average sound pressure level.
"If the system is overdamped, then the waveform may never actually reach the theoretical high and low levels"I agree with your point, but if the system is overdamped and the waveform is never reaching the theoretical high and low levels (and the theoretical high and low levels would be 1 watt) then the system is never outputting 1 watt.
So if we assume that Dennis is saying that his system (that does reach 1 watt) is more powerful than a system that never reaches 1 watt, he'd be right.
This is not the same as Dennis saying that he is getting more physical work done from 1 watt.
The rate at which work is done defines the amount of watts.
If there isn't 1 watt's worth of work being done then there isn't 1 watt present.
Tre'
Have Fun and Enjoy the Music
"Still Working the Problem"
Edits: 05/23/12
Correct. There exist plenty of high-power amps that WILL deliver 300 watts or more into a specified load. In that case, only on that load, only under that amp-drive condition-- sure-- a watt is a watt.
The problem arises when MUSIC changes both the amplifier's -and- the load's characteristics-- and keeps changing both continually throughout a musical performance.
Believe me, there are 300 watt amps that can light up a 400 watt light bulb, but CANNOT deliver even 1/400 of a watt of useful acoustical energy into a speaker voice coil under SOME combinations of frequency, frequency shift timing, and amplifier loading-- all of which are changing as music plays.
Enter an amp that can deliver one watt-- or whatever-- into any condition that music imposes on both the amp and the speaker-- and all wiring as well, and you will still have only one watt-- from the amp-- agreed.
What you're not addressing is that one watt is a LOT of power if it's working right all of the time under all musically driven conditions..
My JBL Paragon is a 3-way system using JBL 15" woofer in a Tunnel Port, a 2" midrange driver- spread-horn short-loaded, and JBL's Ring Tweeter.
Each channel has two crossover networks. The second network borrows power from the first network's output! Now, this thing is hard to drive! (more so than operating the same drivers and crossover networks in two separate cabinets would be-- the Paragon uses an integrator panel to combine and spread energy all over an entire room).
This means that all of the drivers must be driven harder to arrive at the same SPL's that are easier to achieve with the same parts-- operating only in stereo-- not as an integrated stereo/mono whole. (The Stereo Paragon is ONE stereo speaker).
There is a lot of wiring in this system, and that means substantial wire losses as well.
This system will not do anything even remotely impressive on solid state amps of less than about 500 watts/channel, and it has the same problems with almost all tube amplifiers, requiring a really good 150-200 watts of power per channel from them.
However, I am running all of this on a MAXIMUM of 1/12 watt per channel-- from a very carefully engineered S.E. direct-coupled tube amp.
Since the amp easily puts out over one watt, this system has tremendous bottom-end, outstanding wide-range dynamics, and tons of reserve power.
Measurements made of heat buildup INSIDE the woofer, mid-range, and tweeter voice coils tell the story: other amps are making a lot of HEAT-- this one is NOT.
The heat buildup from other amplifiers is because they cannot deliver MOST OF the musical signals ON TIME-- to the speaker driver voice coil. The physical motion is mostly fibrillation-- not music, and although the speaker may sound loud enough and sound pretty good, (because not ALL of said amp's power is causing fibrillation-- SOME is actually getting through on-time)--the heat buildup still tells the truth for anyone to see.
Also, woofer-cone motion is almost undetectable with the one watt D.C. amp-- indicating near ideal amp control over speaker diaphragm behavior.
1/12 watt MAX-- per channel-- that's all the listening room can take-- yet low-end output of this system is outstanding. The midrange is solid and full, and the highs are extended-- but coherent to the music-- they're part of the performance, not added "sizzle". Highs in this system, driven in this way-- are spookily real, sublime, pristine, powerful, solidly fleshed-out, multi-layered, and not a layer out-of-time or place.
The old Paragon is a great speaker-- I think easily the best ever built- but you'll never hear it on almost all available amplifiers-- it will sound bland.
Another interesting thing is that the system sounds exactly the same-- musically-- at all usable volume levels-- on the one watt D.C. amp..
This speaker will not do that on any other amplifier.
There you have it. Take it or leave it-- what exists-- is!
---Dennis---
I wish you would stop using these forums as advertising platforms. That is not their intended function.
In my opinion, AA is not an advertising platform for Dennis. And Serious Stereo is not even mentioned in his posts so web search engines will not find these posts.
Thanks tube wrangler. you gave me some insight about the AVVT 2A3 mesh, simply because I asked. All these threads behind my question and very little from anyone else about "my question". You guys have issue with the Wrangler, fine with me. Challenge the guy when you don't agree.Keep it up !!! I have to admit it's somewhat amusing. He obviously is going to keep doing his thing, and like it or not.... good for him. Anyway the truth is, those of us who are just lovers of how a SET reproduces the music , don't really know what he is talking about half of the time. And those who do, are going to build amps, or have them built their own way anyhow.
Very accurate post!
Hey! I stayed out of this feedlot for almost 2 years-- I liked the Grass-Fed world better!
This just got started because a guy asked about some 2A3 tubes that I have a lot of experience with. 300B's and 45's also! All I said was about tubes-- not anything else unless it was necessary in order to understand how the tube was, and should be-- used. I think any thinking person would want that important info., as it is CRUCIAL to getting the best out of said tubes!
But whatever! Perhaps forum guys could take a vote-- shall we outlaw all commercial posters so we can all go back to not learning anything important?
I'm not staying around for the inevitable mud-fest-- you can go back to standard whatever now!
---Dennis---
Dennis,Your contributions are needed and appreciated by all of us "modern" SE tube amplifier builders.
Please stay with us so we can benefit from your knowledge and wisdom.
dt 667
Edits: 05/29/12
Grassfed??? Well, that explains the tough hide. Been battling conventional wisdom on that since '99. About the same time I found tubes.
Put me down as a "NO" vote...I want to hear what the designers of good amps have to say...even if it is considered mumbo-jumbo by some!
I see you said you want to hear what these designers have to say....at least you didn't say you want to learn something from what they have to say....which is the point....no one minds Manufacturers participating in this forum. Gordon Rankin jumps in and his comments are sound and rational and you can learn something from him.....there is nothing unconventional about tubes....BTW. Dennis and his mini-me alter ego DLM view is that there is only one way to do something....their way....Dennis just went on to say that a speaker will only sound good with his amp....that is how far out their mumbo jumbo is....you have to have his amp, his wiring scheme and his speaker.....one stop shopping.
Mumbo mixed with my Gumbo .... Gives it a nice Flavor...!
Have fun
Willie
Yes, more from people who build and sell these instruments.
Willie
"I am running all of this on a MAXIMUM of 1/12 watt per channel"That would be .084 watts.
Your speakers are no better than 95db, 1 watt.
With 1/8 of a watt you get 86db. Recorded music has peaks that are at least 10db above the average level.
"1/12 watt MAX-- per channel-- that's all the listening room can take"
So are you saying you listen at less than 79db (less than 76db from each of the two speakers)?
Have you measured this and is that really all your listening room can take?
Your listening room must have very poor acoustics. That's too bad. :-(
BTW I believe very little of what you say.
Tre'
Have Fun and Enjoy the Music
"Still Working the Problem"
Edits: 05/24/12
"I believe very little of what you say." -Tre'
Who does this matter to other than you???
Dennis is demonstrably not believable. (examples given on request)
I would think that would matter to anyone who reads his posts.
On the other hand, anyone who reads his posts will see that this is true.
I state this to him so that he knows that I'm not buying into his BS.
Let me ask you a question, why does any of this matter to you?
Tre'
Have Fun and Enjoy the Music
"Still Working the Problem"
On the other hand, Mr. Fraker builds very good amps for sell to the public.
"It's the "best" amp I have ever heard .....period." - unsolicited opinion from this thread
I would think he knows something about building good amps and is willing to let the marketplace decide. I want to read what he has to say and I want to decide what its worth is.
It matters to me that I don't want you running him off the forum.
If Dennis would talk sense and discuss his claims in a reasonable, technical manner there wouldn't be a problem.Instead he makes nonsensical technical claims that he doesn't back up.
He can't get 110db from a 97db speaker with his amp that he rates at 1 watt. 8 watts won't even do that.
"The system that I build from the Great Plains Audio 604/704 series
is more efficient-- it hits about 96-97 db/watt.
Doesn't matter. Either system can be driven to over 110 db cleanly by the same amp."http://www.audioasylum.com/forums/set/messages/7/70810.html
lakerfan says his amps sound great, I'm not disputing that. But when Dennis says things, like the above, I will not let them go UN-challenged.
I don't care if you want me to.
Again, if Dennis would just discuss these thing in a normal, grownup manner there would be no problem.
Here's another example of Dennis' nonsense.
"Believe me, there are 300 watt amps that can light up a 400 watt light bulb, but CANNOT deliver even 1/400 of a watt of useful acoustical energy into a speaker voice coil..... "
To start with, an amplifier does not deliver acoustical energy into a speaker voice coil. An amplifier delivers electrical energy to the voice coil and then the speaker delivers acoustical energy into the room.
And if I questioned him about this he would go off into a different subject containing more BS.
From any rational point of view it's just maddening to try to reason with Dennis.
The misinformation he gives, for the sake of honesty, can not be left to stand UN-challenged.
I don't know why that should be hard to appreciate or understand.
Tre'
Have Fun and Enjoy the Music
"Still Working the Problem"
Edits: 05/25/12
I have no problem with post being challenged, but I think it more benefitual when done in an educational manner, not a condescending manner.
I appreciate the industry professionals here and look to them for education.
Tre has been posting in an educational manner over the past few years.....where have you been? Dennis and Jeff are all mumbo jumbo. no one is arguing what the amps sound like.....it is about technical mumbo jumbo, which you may not care about....if the amps sound good to you.....
Here 'ya go! As usual, I learn things from other things......
So, quite naturally, I got curious, and found this! (picture).
Since I haven't read it yet-- I offer no opinion....
---Dennis---
Thanks. Good luck with your business.
The iPod is a great accomplishment of electrical engineering.
I still want to hear from the designers of great sounding amps.
Well again, no one is arguing about the sound of the amps.....in case you missed that....no one is arguing about the sound of the amps.....this is an ongoing debate about the "Modern Tube Circuit Design" ..."Transfer Efficiency" and other terms made up by Dennis and Jeff....again, no one is arguing about what the amps sound like......I hope you captured that....now, I bet the the engineers that develope the Ipod can answer in a straightforward manner, basic engineering questions. also, please don't mention Dennis Fraker and Steve Jobs in the same breath. That is just foolish.
Edits: 05/27/12 05/27/12
No one is arguing about the sound of the amps.....
Hey Husky !!!!!!! I'm doing the analog thing for the first time since college.Tubes+Vinyl........ magical. Seems the 2A3 plus vinyl is my ticket to forgetting about the world these days.
Have a safe Connecticut Holiday.
No problem....How is life in the Windy City???? Thinking of a 2A3 myself actually! You into Jazz? I may have some LPs for ..... ps...I am sure those amps sound good. All of these argument have little to do with sound and a lot to do with technical credibility.......similar to the John Hogan debates, actually! (I miss John)...He was a terrific guy.
Edits: 05/27/12
Jazz ??? Most definitely. I grew up in a Rollins, Trane, post bop kinda home.
shoot me an email. I m lightening my LP load..
I once saw a JBL advert rating the Paragon system at 88db/watt.
The system that I build from the Great Plains Audio 604/704 series
is more efficient-- it hits about 96-97 db/watt.
Doesn't matter. Either system can be driven to over 110 db cleanly by the same amp.
Listening room is 13 ft. wide by about 24 ft., with a nice cathedral-peaked ceiling. The room averages about 8 ft. height.
The Paragon sits atop its own stage. This is 35 inches front-to-back, and is 120 inches long. A JBL Paragon is 104 inches wide (long).
The Paragon sits atop a stage that is 13 inches high. The top surface of my stage is made up of two layers of 1 1/8 inch marine plywood, glued and screwed together.. 2 x 12 rough-cut (full dimension, not planed)douglas fir timbers are used at 10 inch center-to-center spacing along the entire front width. These go front-to back, and are cut into the floor wood 1" deep. This is all screwed and glue-locked together.
The front of the stage is a 2 x 12 timber running the entire front of the stage, also cut into the floor, and screwed and glue-locked into the front-to-back timbers and to the top plates.
In our test lab, we have a replica of a room at RMAF, which is also 13 feet wide inside-- but the Hotel room is usually about 18 ft. long. In those setups, we run the Great Plains cabinets which we build across the narrow end of the room, firing into the riim's 18 ft. length. A bit of toe-in is used, and center to center spacing of driver center line varies in different rooms-- but about 57 inches will usually work OK.
Those cabinets have about 9 5/8 cu. ft. internal volume, and have found their way into quite a few homes. They work well on many different amps-- they are not anywhere near as fussy as the Paragon is-- because the Paragon is mixing right and left and doing stereo simultaneously. It is a SEVERE test of amp quality and power delivery.
It is hoped that this helps some of you out a bit with some of your own systems, and is the last of this series of posts.
---Dennis---
"I once saw a JBL advert rating the Paragon system at 88db/watt.
The system that I build from the Great Plains Audio 604/704 series
is more efficient-- it hits about 96-97 db/watt.
Doesn't matter. Either system can be driven to over 110 db cleanly by the same amp."
I thought you said your amp is rated at 1 watt?
How could it ever drive the Paragon or the Great Plains Audio system to 110db?
Like I said, I believe very little of what you say.
Tre'
Have Fun and Enjoy the Music
"Still Working the Problem"
Tre', I have to agree with you. I find many of Dennis's claims and "explanations" to be far-fetched and, in some cases, nonsensical. This is not to criticize his products at all, since I've never seen or heard them, but only to question his knowledge and understanding as demonstrated in his posts.
Edits: 05/25/12
Is the object of audio to make sense to theory, or to make the very best performing products possible, with no explaining needed at all?
Are you interested more in hearing the result, true to the musicians, or, knowing the theory?
Jeff Medwin
I seek the truth, as most of us do, I believe. Just trying to interpret/make sense of Dennis's long-winded ramblings -- or do you think that's a waste of time? Perhaps you're right.
Post a Followup:
FAQ |
Post a Message! |
Forgot Password? |
|
||||||||||||||
|
This post is made possible by the generous support of people like you and our sponsors: