|
Audio Asylum Thread Printer Get a view of an entire thread on one page |
For Sale Ads |
108.213.216.95
In Reply to: RE: Me too... posted by drlowmu on November 17, 2014 at 10:54:57
"foolishly THINK its representaive of a Dennis Fraker build, and have ass/u/me/d that for five plus years. It gets awfully old, the non-truth."
This is getting closer to the Real question. Thanks Jeff.
Question: How likely, and to what degree will 2 amps built with the same circuit, nearly identical operating points (coached, remember), many parts exactly the same on advise, sound different from each other?
We know what Jeff thinks, which is, there's no comparison.
Of course the "foolishly" built amp has nothing to do with advisors /proponents of it, there couldn't any foolishness there, right?
What has been claimed many times is that my choice of wire(s) is the prime cause of the "no comparison" status. So tell me, now that y'all
can see them both, how likely is this true? Examine the actual amount
of wire on either example. BTW, I did use solid silver wire from plate to grid, and stranded silver on the OPT, which has a partial silver secondary as well. My large gauge copper less than 6" long ground bus, has been named as a huge problem. It's the white wire in the pic posted by Tre. It goes from the center tap of the LOWER DCR PT (than the Hammond in the other amp) to a point near the input. In DF's build the stock red/yellow CT wire of the Hammond is present and connects to the "very special" silver wire under one of the two wires with the blue heat shrink. This is what Jeff is talking about. No guessing anymore.
Next is the obvious absence of multiple bypass caps, but I did at least get a decent one of the correct value, as coached, a Dynamicap, and bypassed it with another 0.01uf Dynamicap too. According to Jeff, I FOOLISHLY assumed there couldn't be a BIG difference. What do you think?
Next, it has been stated by both JM and DF that "a Dennis Fraker build"
is something so special that us morons just can't get it. Now that you can SEE what's been talked about, you can make up your own mind.
The 3 main reasons that are claimed to be the difference between junk and gold, are now here for inspection.
Follow Ups:
I don't have time to go point for point here. What you need to learn is one INCH of bad wire, in the wrong place, can easily ruin the musical experience !!!
I screwed myself for three years and three amp builds with using that ACME ( ? ) wire as an AC cord ONLY only, it sounds harsh and hashy, ugh.
How do you think I felt when I learned how bad that wire was ?? I had to eat humble pie, built three amps using it, never heard their potential, but I learned from my error.
You wanna dust your errors off into the corner and forget it or excuse it.... minimize it - HA !!
An INCH Grant, an INCH.
That is the truth.
Jeff Medwin
The perfect excuse to mask poor design 'you had an inch of wire in the wrong place'. It also conveniently negates any possible comeback from the builder.
Face reality Jeff - if an inch of wire can totally make or break an amp, the design is inherently unstable and fundamentaly flawed. Certainly not one a prudent individual would implement or recommend (let alone spend $15k on).
"What you need to learn is one INCH of bad wire, in the wrong place, can easily ruin the musical experience !!! "
Just imagine how many inches of "bad" wire must have been used in the entire chain of amplification and processing between the microphones in the recording studio and the output from the home CD player or record deck. Not to mention quite a few coupling capacitors that most certainly will not have been "boutique" varieties. And power supplies built using unmutilated transformers. And huge amounts of negative feedback along the path too.
How can you seriously imagine after all those stages of unspeakable degradations to the signal that one inch of wire carrying low-level signals in the home audio amplifier is going to make a critical difference?
Chris
GSH,
"What has been claimed many times is that my choice of wire(s) is the prime cause of the "no comparison" status. So tell me, now that y'all
can see them both, how likely is this true? Examine the actual amount
of wire on either example. BTW, I did use solid silver wire from plate to grid, and stranded silver on the OPT, which has a partial silver secondary as well. My large gauge copper less than 6" long ground bus, has been named as a huge problem. It's the white wire in the pic posted by Tre. It goes from the center tap of the LOWER DCR PT (than the Hammond in the other amp) to a point near the input. In DF's build the stock red/yellow CT wire of the Hammond is present and connects to the "very special" silver wire under one of the two wires with the blue heat shrink. This is what Jeff is talking about. No guessing anymore."
Grant, if you maxxed out this amp with all the parts and paid retail, how much do you think it would cost? Give it enough thought to come up with a good honest number.
Thanks,
Jamie
Big speakers and little amps blew my mind!
You are asking the wrong person. Grant and his mind set produced a NON-high-performance amp from a proven design.
I just went on line and looked up the caps, got all but one value covered.
You have to realize that all caps play narrow band in energy release ( my words...not bad Dowdylama ?? ) and so, ONLY the best caps are any good at all, and none of them are good enough, and it takes multiples to cover the audio spectrum.
Missing a value, the bypassing caps would seem to run from $97.00 a position ( minimum quality ) to $131 a position, NOT counting the main FILM cap.
There are about six positions I would currently bypass in a monoblock. That means, per monoblock, $485 to $665 for bypassing each monoblock, PLUS the main film caps.
If you do stereo, take $665 times two, or $1310 dollars as bypassing costs. An audio amp usually sells for four times parts cost, so we are up to $5,240 a pair, just to cover the bypassing caps ONLY, which I guarantee you from my listening experiements, are necessary for high performance.
You can always "dreck" stuff, Grant did, I sometimes do. But you are FOOLING yourself on caps, and in audio, unless you compare the cheap ones from Russia - surplus military, to the best made today, you won't really KNOW what you have. It takes money, AND a good system, to make such evaluations. None of the caps are perfect, and only the very best are usable, and THEY play narrow band energy-relase-wise, so, it takes MultiCaps or multiple caps to get it right. Dennis KNOWS all of that very well, Grant didn't understand !!!
Jeff Medwin
Damage control at its finest, or at least the Loudest, Horray! Horray!
Tenacity means you're right, have you noticed? Of course you have.
Hmmmm... You know Jeff, you might be able to program your computer or get some "app" that automatically fires your opinion, multiple times, in opposition to anyone's post that disagrees with your views. Thus silencing the opposing view by sheer repetition and redundancy. We have this (or the attempt) already, but it must be time consuming, and hey, you've got better things to do, than spank morons around who will never "get it". Or can't afford to "get it".
Funny, I was thinking about just that this afternoon after learning that I was wrong about the $5K each situation, it's actually $15K/pair which is $7500 each.
I figured the parts for a PAIR even with EML 2A3s would be somewhere between $3300 and $3800, with a $600 allowance for capacitors EACH. Could be less at OEM pricing and quantity discounts. Since I don't know exactly what caps are used, it's a blurry zone, but $600 is generous, could be less, could be a little more (exchange rates shipping etc..)
Here's my ballpark math:
2 x Hammond PT 350
2 x MQ OPT 400
2 x EML 2A3 630
4 x chokes (those) 100
6 sockets, fuses, switch, jacks, hdware 200 (could be more or Less)
2 x chassis 400 (steel powder coated) seems high
2 Filament trans 60
2 x 5U4GB + 2 x 7B4 50
pile o caps 1200 crazy but probably is
thermistor, RF chokes, "special wire" 150 ? Seems high
Misc + shipping taxes what? 200
Total $3740/2 = $1870 each
I believe it could be done for $100's less depending on a variety of things, not that I'd bother. Even if I believed in this concept, there
are various areas where quality could be improved for LESS $. I understand that in a new manufacturing world you need to be able to source all the parts, usually meaning "in current production". But considering the low numbers of these produced, it could be done with some
superior grade surplus stuff, in limited quantities, of course.
They don't make 7B4's anymore, but there's 1000's of them out there NOS for peanuts. Same with 5U4's. JJ 2A3's would save $100'S too.
Hours go into a build like this, drilling, installing and then soldering.
But if you've done it before even once, and it's just a repeat, then it's MUCH faster. Most of the time in one off DIY builds is decision making!
> I figured the parts for a PAIR even with EML 2A3s would be
> somewhere between $3300 and $3800
Hi, GSH,
You can be on budget if you build 4P1L based SET with filament bias and no cathode bypass capacitor whatsoever.
Look at the links below. Andy Jevans is professional musician, and Ale Moglia - really skilled engineer, so you can trust them. Its a matter of your personal taste if you like such amp or not, but at least you won't have to replicate and waste time and effort on flawed amateur design.
http://www.diyaudio.com/forums/tubes-valves/183329-one-more-4p1l-se-25.html
http://www.bartola.co.uk/valves/tag/4p1l-pse/
The success of your build would not be critically dependent on the placement of 1" of wire or the use of $1.5ks worth of bypass caps.
Sounds surprisingly like competent engineering to me.
Hi LG,
I like Andy's amp design, never heard it, I've made similar before with other tubes. I haven't tried filament bias yet, but perhaps will sometime.
I love the way he routes the AC power ground, and the b+ filter ground, the yellow wires, right back through the input circuit and tube! Those have to be the two nosiest wire in any amp. Why not run them around the back side where there is far less change causing of EMI.Poor engineering practice in my book.
Ahh, but wait. Dennis did claim in a past post that a little amount of hum is good. Something along the lines that it per-energizes the speaker so it can respond faster. This must be how he gets just the right amount of hum into the signal path.
Edits: 11/17/14
Don't forget the perfect amount of reverb achieved by the use of matched microphonic driver tubes. Saves you buying one of those spring based thingies.
Those amps were designed to drive movie theatre speakers.
The 60 cycle hum would annoy audience members into making frequent trips to the snack bar, thus driving up profit $$$ margins.
Brilliant concept and engineering, IMO.
Also added to the hum to the subliminal images spliced in just to make it doubly sure.
"Ahh, but wait. Dennis did claim in a past post that a little amount of hum is good. Something along the lines that it per-energizes the speaker so it can respond faster. This must be how he gets just the right amount of hum into the signal path."
There's no arguing with Dennis.
No matter what you say (or how technically right you are) he will come up with some crazy idea to makes him right and you (and all of the audio electronic knowledge of mankind that precedes him) wrong.
It's pointless to argue with crazy people.
Tre'
Have Fun and Enjoy the Music
"Still Working the Problem"
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: