 
|
Audio Asylum Thread Printer Get a view of an entire thread on one page |
For Sale Ads |
|
|
Audio Asylum Thread Printer Get a view of an entire thread on one page |
For Sale Ads |
71.0.211.193
Got three JJ 5U4GBs in the mail today, and finger tapped all three with the tubes right up to my ear, as I have seen Dennis do in shows. HEY, its easy to tell how they ring, higher or lower frequency, IF you do it !!! Got two that are close. Next, off to my TV-7.
Thanks Tube Wrangler, glad I tried !!
Jeff Medwin
Follow Ups:
Interesting. Ringing can come from looseness within mica sheets or even on power tubes especially from grid wire windings
Grid windings are only swaged on to support rods. Technique is to nick the rods and slip grid windings into notches wedging them tight mechanically. I suspect older tooling can lead to some loose grid wires (lots of maintenance manufacturing miniature precision parts)
Nothing wrong with looking at any possible avenue to better sound. For example, other industries have studied nature to improve designs such as bird wings and aircraft wings.When I find what I believe is a route to a superior amplifier, I will attempt to explain why the improvement comes forth or ask why. Perhaps my thoughts inspires others that may have more expertise to further explain it. That is why we visit various internet sites to further our knowledge.
To state it does not matter how a process gets there, it is enough that it performs does not go so well with engineering types. So, one cannot ignore that others have a legit compliant when implied they do not need to know why.
Edits: 12/10/14
One DOES need to know why.
And, when one finds out WHY through years of applied experience, applies it again and again. lab-tests it again and again and it always results in spectacular improvements, but all he gets when he explains it is "the world is flat because my engineering knowledge/texts calculates and adds up perfectly when it is used to re-create a flat world, so THERE-- all else is false because my training, no matter how obsolete it is-- proves it"-- then, the sources of the newer information will dry up, leaving Jeff with ideas but not the proofs.
Jeff knows that this attitude is what is going to prevail should he expound on the good times to be had with these new apps,, so he just has fun with teasing people because that is all he's going to get out of it anyhow!
There you are! Will people really ever know WHY? Not likely here on this FLAT EARTH.
And WHY is that? It is because no one can tell most "experts" anything new and get away with it-- the atmosphere becomes much too burdensome for the newer sources to explain things in, so they dry up-- you lose your sources of new and useful information because it clashes with the old training that calculates mathematically, but can no longer compete results-wise..
It's proving to be a FLAT EARTH after all. It isn't, but you can't mention that and go unscathed.., so go ahead people-- keep it flat for yourselves.
---Dennis---
Yup, just look at your PC. How far have we come since 1980 to today?
Yup, engineers are closed minded and lack the ability to explore new ideas!
And lets be clear on this: I use the term "engineer" in a dictionary sense, not a formal vs self taught manner. It's true that many innovations come from engineers with little to no formal education. Yet these people are still engineers nonetheless. And because of that their ideas are proven, duplicated, and become standard practice.
Now what you and Jeff claim to be new thinking is quite different. None of your ideas and theories have been quantified or proven. That's why they are ignored by the scientific community. It's not a matter of having an accredited background at all. You just need to build something that really works and that others can duplicate.
Most if not all the Fraker/Medwin audio theories fail in that regard.
We're both good guys. Jeff is the dreamer who loves people and interacts with them, he's not an engineer, but show him some ideas or theory and he'll go right to work on it-- he may accidentally lose a few details---.
It won't be perfect, in fact some of it will get left out, but none of us are perfect anyway.
I'm the engineer, but through experience I'm also able to cut through all of that RED TAPE when I want to or need to, so I can think or operate in either camp and that makes me a Maverick in BOTH religion's camps-- tweakers OR engineers-- neither is going to understand me.
I may choose to ignore some engineering theory that is true and dear to formally trained engineers who are religiously trained in that particular discipline. I may need something different or want something done better than what I can buy or build with their engineering.
Make no mistake-- if I can BUY something already engineered right for my job, I WILL NOT waste time building it, I'll save my time, buy it and go Swimming at the Hot Spring or drag out my MX bike and have a Ball. Maybe go Jet Skiing or whatever.
But I do love to listen to music-- I always have, and I know what it should sound like.
I don't listen formally. I listen indirectly-- like when doing dishes, etc. That gives me a realistic perspective on music. Either it's real or it's not-- either it talks to me or it doesn't. I don't study it or study the performance unless something is wrong. Then, I have to figure out what to do about it. Most equipment is always very wrong in many ways...
At this time my home system consists of a Pioneer BDP-09FD Blu-Ray transport (I use the SPDIF digital-out for audio), A P.C. using Windows 7 with a Berkeley Audio Designs Alpha-DAC2, which I use their external USB link for-- this actually makes USB Hi-Fi instead of just USB)-- my own 12 VDC 3 separate power supplies for the computer/MusicServer, one for the processor, one for the Motherboard, one for the SoundCard. Why did I build this? I needed it because my Turntable for L.P.'s sounds better if I don't build the "triple-12" P.S., for the computer so I had to build it. NOW, for the first time, the computer is better than the VINYL-- much better.
Then a VPI turntable, with an old GRADO "lab Standard" tone arm with a ClearAudio cartridge that is High_output because I prefer to leave out as many preamp stages as possible, since I am hooked on both big time dynamics and pristine audio details-- yes, I operate in both camps on those things also.
These components drive my 2A3 amps and those drive my MLTL GPA-604 speakers. 11+ cubic feet. Why so big? Music simply sounds better with them than without them. Why did I build them? I couldn't buy anything that was good enough for the amps...
Well, that's silly! What! Was I married to the little amps-- why not just get higher-powered amps?
Well, I studied that beforehand-- Amps.
Studying amps became a mental exercise into what it would take to get played back correctly everything that was on a commercial recording. What could do it all-- day-in and day-out, never need servicing or adjustment and be reliable-- and always sound great-- really right EVERYTIME?
The more I studied it, the more obvious it became that the number of amp stages had to be cut back, coupling caps had to be eliminated, and the power levels had to be cut back to what tubes can do better than solid-state-- operate primarily as voltage amps at low currents.
This translates into low-wattage, or why not just get into solid-state. So, I simply built what was best-- for tubes. Why not just buy a low-wattage tube amp? Nobody ever sold one that worked right for music-- they were all full of compromises and sounded wrong to me.
Would I do all of this over again? ONLY WHEN I HAVE TO.
There are two areas that I am interested in right now because they are potential improvements: (1) Better digital. This will be handled by Berkeley's New Alpha-DAC Reference series DAC. It's a 10-year thing-- get one and you won't need to replace It-- you'll have music and that is what it's for.
The other area is in the DHT tube's filament structures. (2A3, 300B etc.). DHT output stages sound more true-to-life when they are operated on balanced A.C.
The problem is the BALANCE. If the filament in one of these tubes is slightly off-center, we will get A.C. hum from that tube. We always do. EML is looking at this problem, and is marketing some DHT triodes that have the center-tap (of the filament) brought out so you can hook-up balanced, and get the cathode signal out without going thru the filament transformer. . Is this an advance? It is if they get the center-tap centered!
Then, there's the filament transformer itself. Is it's center-tap really centered? Physically, magnetically, and capacitatively? Let's see if someone will build one.... then you could use other tubes (than EML).
NO! I don't want to build it, but I WILL if I can't buy one!
I don't give out free schematics because I won't spend time on anything mediocre. I want anything I build to outperform and outlast the best that I can buy, so I go straight to the best thing possible that is out there--and try to buy it. ONLY if you have to, should you build it. If I build it, it's because it gets the job done better that way-- I'd much rather BUY it if I can.
Since I won't bother to build it unless it can outperform, I have to spend a lot of time researching, engineering, and then building it. Anything that can help out other builders out there I'll give them if I CAN, but I'm not going to give out the whole Farm for free-- but you do get some very useful advances that you can use..
Jeff is wonderful to me. He and some others talked me into posting. I would never do it for years for obvious reasons, but I did finally cave and started making technical posts, which caused a storm of super-religious engineers to laugh me out of town!
So what? It was all given honestly, and every word of it was very good engineering.
Then, there's the Tweaker camp where a Pin-Head, added to your Bedframe, will give you better music-- maybe. These people seriously need some formal engineering study.
But most engineers seriously need to do more than just calculate mathematics. After all, if you're going to design a superior DogHouse, where do you go?
To DogHouse Engineering? No, you go to the Dogs and Observe THEM. DOGS are your best source for DogHouse Engineering.
That way you can get a GOOD DogHouse.
---Dennis---
.
.
.
I would swear NJJOHN wrote this post.
Edits: 12/11/14
Lordy, even me.
Link below:
GEO,
I'm a big Harvey Rosenburg (Dr Gizmo) fan. Not because he was the end all of knowledge but because he had a great sense of humor and he had a great appreciation for the pursuit of "Musical Ecstasy"
What NJJohn seems to be describing is an accurate Music sound stage and maybe what we try to achieve with our systems "Musical Ecstasy"
Stuben
You are so uninformed.Dennis builds these days, the BEST SOUNDING tube amp "I" have ever heard.
It was written up as "best sound" at RMAF 2006 by 6Moons. Does THAT count for anything ??? I think so !!! Its improved since then, I know !!
Maybe you need to read the reviews. Attend a show, travel to Montana and HEAR it yourself.
Others have only partially duplicated Dennis' designs, myself included. I helped Barry Black in London last year build his first amp. A DC Type 45, which I have not heard. Barry replaced some Starchiefs he owned for a decade with his new amp, no comparison "STAGGERING" improvement he tells us.
Results speak for themselves. ONLY the results, the performance, is simply what matters at all !!
Jeff Medwin
Edits: 12/11/14 12/11/14 12/11/14
Slam them on your forehead and see if anyone notices. If not, try chatting to the chicks instead.
Jeff,
This might be an already worn out question...apologies if it is...
Have you determined a correlation between the frequency match and bias?
Interesting stuff..
Just keeping an open mind but I'm also being mindful of snake oil that separates one from the pack.. particularly in such a subjective business..
Stuben
There is no correlation.The best match will be when both tubes "ring" the same, measure the same, and hum the same, and LOOK the same internally..
Normally, you'll get about 2 pairs out of 11 or so-- any brand has this much variation.
Don't pay "extra" for tubes that are current-draw "matched". That's not enough. Buy your tubes in bunches (negotiate lowest price/tube) from the same batch and mix & match as you go along.
---Dennis---
Edits: 12/07/14
Dennis,
Thanks...I truly regret getting this wave of silliness (bad energy) started although Jeff was asking for report...
I don't necessary subscribe, but I do understand...only because our sound is so subjective...rest assured, you have many of our inmates tapping on their beautiful triodes... :> )
To tame all of this bickering, a good listening session for all of our players would be golden...maybe impossible....
Stuben
Hello,
You ask " Have you determined a correlation between the frequency match and bias? "
NO , I have not done that if I understand what you are asking me. I do run almost all my tubes at "Golden Ratio" (62%) of maximum plate dissipations, as I find there is a thermally STRESSED unpleasant sound when I push currents up on tubes. Being a voltage device, I maintain high P-K voltages, and just relax the currents through the tube. I LIKE doing this, sounds more relaxed and natural to me, and the tubes will perform that way for a MUCH longer lifespan.
There is NO snake oil with tapping tubes held against your ear, and listening to them respond. It tells you how loose or tight the elements are assembled, and if anything is rattling, etc. It sure seems intuitive to me that we can do EAR matching of the assembles, and get a uniform sound form the two closest resonating output tubes, in our SE amps !!
Jeff Medwin
I have just two pieces of JJ 2A3-40s at home, and they sound VERY different to me today when I Tap and Listen to them against my ear for the first time.
This means I need to order about four more JJs', and HOPE to get one great pair out of six of them, for my SE use. I WILL do this, especially after hearing this difference. If I lose $20 a tube, it will cost me $80.00 in a resale loss, but.... THINK of how nice the pair I keep will be.
Of course, I will test all in the TV-7 tester, but this "Tap and Listen " has become meaningful to me, very much so, now after gaining practical experience. I encourage others to do this !!! Makes sense now to me after HEARING it all !! I feel stupid giggling in my mind at Dennis when he used to do that at shows. Oh my !!
Jeff Medwin
Bankruptcy and OFD (obsessive Fraker disorder) . What a combination !
Al
Why not just send the defective tubes back. Tell the vendor they don't ring right when tapped. Surely any reputable vendor would not want bad tubes like that in the hands of customers.
How about you buy some 5U4's from Steve at Angela. Then call him to say the tubes are bad based on your tap test. See what he says. I would pay to hear that response!
" How about you buy some 5U4's from Steve at Angela. Then call him to say the tubes are bad based on your tap test. See what he says. I would pay to hear that response!"
I'd pay BIG money to be listening in on THAT call! ;-)
The proper way to plan an amplifier is to ingratiate the Gods. For this it is necessary to:
1. Build a pyramid with a flat area on top for sacrifices
2. Hire a suitable High Priest
3. Make some suitable masks for ceremonial dancing
4. Make sure the moon is in a suitable quarter and the planets are properly aligned
5. Sacrifice a cherished tube, e.g. a 5U4 with a deeply spiritual "ring" to it.
If this doesn't placate the Gods sufficiently you may have to sacrifice a 52 tube, or even a WE 300B.
Non productive comments are unnecessary.
I urge you to try some of these ideas before 'taking the piss' out of others.
I'm getting tired of reading these threads as they descend into playground bullying and don't know how Jeff can still remain an avid poster and a gentleman too.
getting back to the topic, though I can not confirm Tapping my tubes, I can tell you that the tube measurements do not relate to how tubes match up sound wise. So, could it be that structure within tubes is more important to sound quality. Think about filament design across various manufacturers.
Just wishing to have a happy Christmas and a normal conversation.
Smart
I'll give it some consideration for a signal path tube, especially in the lower level stages.
But a rectifier tube? Come on!
Its a shame I have to teach you this Gusser. Rectifier tubes , especially in amps that use high mu early stages, are totally audible as to paralleling them , or using a single plate. It can and does easily skew the input tubes and amp's overall sonics, when mis-matched rectifier tube sections are placed in parallel..
Now you know, and I never had to take one EE or science course to KNOW that !! Ye need to be reborn !!
Jeff Medwin
How about you cite some theory as to this "skewing" you drone on about.
How much delay are we talking here? And how does a filtered DC power supply using two rectifier tubes cause this skewing in the audio path? Even if there was significant skewing of the rectifier action, how does this get through the filter network?
And furthermore if there was skewing, let's call it phase shift, between the two rectifiers, wouldn't that actually be beneficial? Look at three phase DC power supplies. One of the chief benefits is the need for less filter capacitance. A power supply with more than one AC phase would be quieter using the same filter network as a single phase AC source.
So tell us how all this actually works since you seem to be the only person who understands it. You claim to easily hear it, but how do you know it's due to the causes you cite unless you have some understanding of the physics at work?
Honestly Gusser, I don't HAVE to understand why, the physics behind why something works or doesn't work. All I need to do is find out what does work - and doesn't work - to build the amp to my liking.
Even more perplexing to you will be the following details, the "skewed audio input stage is fully shunt regulated, drawing about 16 times more current in the shunt-to-ground, than the tube's idle current, yet it is HEARD as a skew, and certainly NOT just by me alone !! Ripple on the decoupled input stage, shunt regulated, is under 2 mVAC, sometimes under 1 mVAC. Bear in mind, I am discussing a single triode, mu of 100.
Jeff Medwin
You have said before using paralleled tubes causes a timing difference that is audible. So how do you know that?There are a plethora of legitimate technical reasons why paralleled tubes sound different. I too have heard it myself. But rather than research and intelligently discuss the phenomenon, you want to make up silly cowboy physics explanations for that you don't understand.
And extrapolating it to the rectifier tube is just more cowboy logic.
Edits: 12/09/14
I know its audible because I have a high mu driver in my input stage, and the power transformer and tube socket capability to run one to four rectifier tubes, in my DC SE amp.As I very clearly stated right above, I don't care what the reason is, nor do I know what the reason is.
Whats this cowboy stuff Gusser?? I grew up in Bucks County, PA and was a stockbroker for a few decades in Beverly Hills, CA. I have never fired one round from a gun.
Jeff Medwin
Edits: 12/09/14
"As I very clearly stated right above, I don't care what the reason is, nor do I know what the reason is."But that is precisely the problem. If you would just say it like that, it would be OK. But then you go on to make absurd claims, like "timing errors between paralleled tubes," or claiming that wires that you criticise for being too thin are OK "if they are in a magnetic field," or whatever, where it becomes completely obvious that you are trying to invoke pseudo-scientific "explanations" for things of which you have no basic understanding.
And then, to top it off, you throw in some entirely groundless attacks on people who do have an understanding of the basic physical principles that govern the workings of electronic devices.
As an amateur builder, you probably have some useful ideas that you could share with others. But please don't try to teach real electrical engineers about things that they understand far better than you do.
Chris
PS: Let me add that I am not an EE myself. But there are quite a few on this forum. And as a physicist, I think I can tell when someone is just BS-ing.
Edits: 12/09/14 12/09/14
You have to hear Jeff's amps to understand it. Being educated only means you are mis-informed.
Our old family room Motorola TV console, 1964-1970, had a 6AQ5 ,or perhaps it was a 6V6 SE output stage. (It's been over 40 years since I took it apart!) And it also had an 8in woofer with a 3in tweeter using a single capacitor crossover. Not bad for a TV.So yeah, I do know what JM's amps sound like!
Just the thing for his old Lawrence Welk collections!
Edits: 12/09/14
If you're getting tired of these threads , don't read them . Narcissists who spam one forum after another are the bullies and they fair game . What would you prefer : common sense , reason and logic or junk science and dogma ? I suspect tapping tubes is BS . How on earth does the sound a cold tube make when tapped relate to one that is hot or with music playing through it ? Especially if it has a filamentary cathode such as a 5U4G or a 2A3 . Remember these devices are hand-made
I think you'd better cancel your custom tube order with EML , you only bought two and one may sound different to the other :)
Al
Only two V4s plus two standard 4 pins. These are globes by the way and too late to canceI but hey ho just have to see what comes.
I also have a quad of standard pin, solid plate non globe and may just order a quad of standard shape V4s in the new year, it is a hobby after all and should make us all smile.
Offer is still open to both you and Andy to visit for a listen should you wish. I would appreciate another set of ears to hear my system and give comment. Perhaps I've gone down a solitary path of my own choosing and only hear what I want to hear.
Wish you all well.
Smart
Your neck of the woods is a major P.I.T.A to get to for me :( I'll try to head over at some point , hopefully with an amp under my arm to try ;)
Al
Your neck of the woods is a major P.I.T.A to get to for me :( I'll try to head over at some point , hopefully with an amp under my arm to try ;)"
Yeah - me and Al are degenerate West London chaps..... well, someone has to live there....
email EML and tell them to send over the ones that sound the same when they tap them...and tell EML to keep a log of the singles to find the ones that match otherwise its and endless game of 'concentration'!
Surely the audio revelation of the century (along with 12AWG 12AX7 anode load wiring with silver plating to avoid 'big-wire' sound) would be to invent a coating that makes all tubes sound the same when tapped . Then everyone could throw their tube testers away and would no longer need to do matching of any kind . I was thinking of wrapping Viton tape around the bottle then a 1" thick coating of concrete . Do you think that will work and help Jeff make all his 5U4G match/poing the same ?
Al
...for some folks here to abandon their self-proclaimed "common sense, reason and logic" in favour of banal piling on. So easily manipulated.
Cheers.
"In the beginner's mind there are many possibilities, in the expert's mind there are few." Shunryo Suzuki
+1 !! Pavlov....dogs! Unfortunately most of the dogs, squatting in their pens with drool dripping from their jowls waiting for the bell, think they are Pavlov!!Cheers,
Geary
Edits: 12/10/14
It may salivate at the sight of Pavlov.
8^)
Me thinks you are simply too old, and too rigid, to learn something new ( to you ) .
Dennis has done this now - for decades. You know, he had his own Radio Station in Billings, Montana when he was 16 years old...all tube.
If you tap a heated tube, you will burn the skin on your ear lobes Albert !
Jeff Medwin
Me thinks you are simply too old, and too rigid, to learn something new ( to you ) . > >
Al's a good friend and you couldn't be further from the truth here - he's not old at all and he's a real character with a great sense of humour.
But Al is an engineer, and a very good one. That's the origin of his views - nothing to do with personality.
Who is Albert ? Thanks to you I'm going to have to throw all my Osram PX4 away . I just went through 8 and all sound different when tapped . I think I'm going to have to listen in mono until I can find a pair . Never mind...
I also just tried this with 3C24 and the whole idea falls flat as tapping different parts of the glass produces different noises
The point I was making regarding hot tubes , you don't seem to understand :)
Al
So, unless all tubes tap exactly the same, a manufacturer can't have a consistent sound across a manufactured line of amps. I suppose Dennis will say he keeps a "control" tube as a reference. Everybody knows measurements don't always predict sound. Some measurements will and some won't. The old Smart 845 measured great but sounded bad untill you changed the coupling caps and reduced the negative feedback.....,,
We are exploring the interface between engineering, show business and lunacy. This is an asylum, you know......
I like that Andy
Cheers
The pyramid needs to be three sided, not the common / usual four sided ones, to reflect that these JJs are real triodes !!
You have enough 4P1Ls on hand to learn something from my post. Tell us how that goes for you. It was surprisingly easy for me, as the tube is held directly in contact with your ear.
Maybe even get matched pairs or quad 4P1Ls to parallel even better.
Have fun. I am. Tell Al, I am an amateur, don't work for Dennis, don't really have a business, and he is far too old to be worried about "me" spending $80. to get tubes that play similarly to each other.
Jeff
"The pyramid needs to be three sided, not the common / usual four sided ones, to reflect that these JJs are real triodes !!"
I hadn't thought of that!! You're absolutely right!!
Jeff, that statement about four sided pyramids reflects your narrow point of view. There are no three sided pyramids. You might be referring to a tetrahedron. A triangular pyramid with four sides.
You really need to study basic geometry and it's effect on audio before you make such rash claims.
Edits: 12/08/14
And you are right !!!
BTW, have you ever tapped a tube and listened to it ? Very interesting, informative, to hear several in a row, and get a match.
Jeff Medwin
Maybe, it's just me.
8^)
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:
Top of Page ]
[ Contact Us ]
[ Support/Wish List ]
[ Copyright © 2024, Audio Asylum, all rights reserved ]
