stoolpigeon said:
I'm not sure what question you are asking. All of our digital products except for our least expensive (CX-7e CD player) uses a fully-discrete analog stage after the DAC chip.
But if you mean trying to build a fully discrete DAC, we have never tried that. There was an Accuphase CD player about 15 years ago that had a discrete DAC. They no longer make it, so I would assume that they have concluded that their discrete DAC doesn't perform as well as an IC-based DAC.
I'm sure it could be done, but I think the cost to do it well would be astronomical. Another problem would be the physical size of the beast. I think you would run into all kinds of problems with parasitics.
stoolpigeon said:
It's well past my bedtime, so that's where I'm going...
Charles Hansen said:
Interesting - what properties of the PCB material change due to "break-in"? What causes the change? How long is the break-in period?
I am involved in circuit design at frequencies from 1GHz and up, so any changes to the characteristics of the PCB are of interest as it will affect the performance of the circuit, and possibly therefore the entire product. Can you elaborate?
thanks.
MikeBettinger said:
I did exactly that. I wrote about this several times. Anyways:
After I took off all components after my DAC IC I installed Lundahl line level transformer.
Than I listened that and it sounded really, really good. Than I needed more output in order to drive my amp. I made output circuit consisted of OPA627 and BUF 634.
Listen to that and sounded fine. Compared that to the output with Lundahl only and it didn't sound as sophisticated and clean, but it has more gain and it sounded muddied.
Ok I went step further and I built complete discrete Mr. Pass's X Bosoz. I listen to that and that was day and night comparing to the opamps. I took off BUF634 from the opamp circuit to see if that will improve - using only opa627 in the signal path. That still didn't change much. Discrete output circuitry was clear winner.
If I didn't try on my own, listen and compare I wouldn't know. If I didn't compare I would say opamp output sounded quite fine. But compared to discrete - not even remotely close. Out of all them just Lundahl in the output circuit would be my preference if that would present enough gain for my amp. After that XBosoz is the next choice, and that what I am using.
Hello forum,
I would just like to take this opportunity to thank the contributors to this thread. Thank you very much to Mr. Hansen and Mr. Curl.
Catching up on this thread after a tough night at work was really something special.
How many of you have heard music that was so beautiful that it made you cry?
Isn't that what it's all about?
I have heard things so beautiful that there are no words.
I heard them all with a Harman/Kardon HD7450 (1-bit?) CD Player into a DH110 Pre into a DH XL-280 Amp into a pair of Magnepan 2.6/R. A fairly discrete, now 17 year old setup.
I never, ever had to look further for better sound. That is what has shaped my gut feeling on this issue.
Peace forum, it's bedtime for me too.
I would just like to take this opportunity to thank the contributors to this thread. Thank you very much to Mr. Hansen and Mr. Curl.
Catching up on this thread after a tough night at work was really something special.
How many of you have heard music that was so beautiful that it made you cry?
Isn't that what it's all about?
I have heard things so beautiful that there are no words.
I heard them all with a Harman/Kardon HD7450 (1-bit?) CD Player into a DH110 Pre into a DH XL-280 Amp into a pair of Magnepan 2.6/R. A fairly discrete, now 17 year old setup.
I never, ever had to look further for better sound. That is what has shaped my gut feeling on this issue.
Peace forum, it's bedtime for me too.
SY said:
That was not mudslinging on my part; it was a description of how I felt when Charles himself engaged in mudslinging when he described engineers who use ICs as mere "packagers". There are many very smart, good engineers out there who make wise, considered choices to use ICs in certain areas (not just the WalMart designers who are saving money and power) in very high performance gear, and they don't deserve to be slandered. Charles is entitled to his own opinions, which may be wrong, but he crosses the line when he maligns a whole segment of the audio engineering population of engineers. I was truly disgusted by his comment. Is that a better word?
Bob
Charles Hansen said:
You continue to use hyperbole and irrelevant, specious arguments to support your position.
Perhaps you should go to the seminar that National is putting on at the AES convention in NY one week from this Monday, and learn more about the devices and the technology they use, and their genuine interest in improving the technology available to audiophiles.
Bob
john curl said:I agree, MAYBE they have finally done it right! I have been waiting for 40 years for the perfect IC. Bob Cordell should go to the AES next week (or so) in NY and get National to sample him all that he wants. He can then tell us a thing or two.
Hi John,
I will be there. I will report back.
You and Charles should go as well.
Cheers,
Bob
Charles Hansen said:
Charles, here you go again with your hyperbole.
The IC-150 was built in the early '70's using 301 op amps, which everyone knows are early generation cr@p op amps for audio. 35 years have gone by and a lot has changed. True, as in many other areas, early-generation stuff gave some technologies and techniques a black eye.
If you have measured an IC-150 and think it measures darn near perfect, you don't know how to measure audio equipment. Newsflash: there is more to audio measurement than 1 kHz THD and frequency response, Charles. Go measure one and tell me what you find.
Bob
Charles Hansen said:
In all honesty, it would take some unique degree of engineering proficiency to design an amplifier so bad that its sonic performance was distinctly influenced by ferrite based filters in line with the ac mains input.
john curl said:
Oh please.
The non sequiturs, unsubstantiated claims and general baloney of the calibre that this thread is full drives away its fair share of meaningful contributors too.
And whose opinions you decide to laugh at or not is hardly of any relevance to anyone but yourself.
Putting the audio quackery presented here down to mere marketing hype would actually be of credit to those who propagate it – for then they would only be guilty of dishonesty.
I'll let you figure out what the alternative is.
Cheers,
Glen
Like whom? The thread topic is an interview that Charles gave. He's participating and defending his views vigorously. If you want to directly take on his ideas within the bounds of civility and courtesy, feel free to put forth your arguments. Merely dismissing his with a few insults is not persuasive. I'd say the same thing to Bob. And guys, this is coming from someone whose views are closer to yours, OK?
SY said:
Like the few that usually send me a PM every time I submit a post like this and/or prefer to discuss their more advanced designs elsewhere or via private correspondence instead. I’m not naming names here. In fact, I’ve probably blurted out more than what is wise in this thread already, but I am silly in that way.
I'll shut up now, OK?
Cheers,
Glen
PMA said:Just a personal taste of yours. To my ears, and not only mine, the Bosoz is not a good sounding preamp. Again, my personal taste and that of several of my colleagues
That is quite correct. I could not share someone else's experience but just mine. I am certainly not claming that my experience is the only good one, it is just pure description of how it sounded to me in my particular situation/system. I do not know if Bososz is generally good or bad sounding preamp, but in that particular situation that I tested it sounded to me much better than Burr Brown top of the line opamps.
From a different point XBosoz didn't sound as good as just Lundahl in the output and no preamp will ever do. I didn't compare it to the tube which I am sure would sound better or different.
I share my experience here hoping to add to a great amount of personal experiences and knowledge to this great place. The test I did was for my personal need and it happen to be almost exactly about what we are talking here.
If this discussion shall make any sense, you must define what you're comparing. So far people have compared just about anything from apples to oranges and strawberries 
To compare a BOSOZ to an opamp based standard output pre, and yet again maybe something like a high gain pre, makes no sense.
There are horses for courses......
Magura
To compare a BOSOZ to an opamp based standard output pre, and yet again maybe something like a high gain pre, makes no sense.
There are horses for courses......
Magura
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