John Curl's Blowtorch preamplifier part III

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How many listen on headphones for pleasure?

Rarely use headphones here, but rarely listen at 90dB SPL either. In fact, personally I happen to prefer to listen at a low enough levels that I can easily hear the difference between DAC-3 and Katana from half-way across the room. For classical music, some can be rather low level at times, and rather loud at other times, so perception of differences might vary over time.
 
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The answer that I am interested in is: WHY the DAC-3 sounds better than the OPPO 105?
We know that they both contain IC's, and pretty good ones too. Maybe it is somewhere else in the design that makes the big difference.

Interestingly, I did an audio show locally about a year ago. There is a guy here locally ‘hot rodding’ 105’s and charging about $2000 over the base price and positioning the final result as a giant killer.

They plugged into my system and it hummed badly - naturally the finger was pointed in my direction and I felt I’d really screwed up. We swapped it out for a regular CD player and everything was ok, but I still worried I had a cross channel ground loop that I had missed. We plugged the player into another system and same thing - it hummed even worse so one of the techs opened it up.

The guy had replaced some of the 105’s PSU with one using small EI transformers on a board mounted near the Output connectors and some other small bds that looked like discrete regulators.

Moral of the story - don’t mod gear unless you know what you are doing.

For the money the Oppo players are very good IMV (except ones that are modded of course). Funny how suddenly amongst some they’ve are now below par simply because ESS has a new chip out. They measure well and they sound good out the box (but I still prefer my Michel!)
 
Funny how suddenly amongst some they’ve are now below par simply because ESS has a new chip out.

That has nothing to do with it in my view. Allo Katana uses the mobile ES9038Q2M chip, which isn't new or even a PRO chip. What has changed is that when Sabre was new virtually nobody knew how to get any better sound quality than the eval boards do in a reasonably priced package. After some time has passed, now more people are learning how to out-perform the standard eval board designs by making digital and clocking improvements. Up until more recently most of the improvement efforts were done by analog designers focusing on output stages and power supplies. Those things can matter too, but they are not enough without understanding how to improve the digital and clocking end of things.
 
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I stand by my original claim. Oppo's were recognized as great players for the money and are still great.

Linn Sondek's and Michel's are still great T/T's. The fact that there are better ones out there now (for more money) does not negate their position as a quality, performance products depite that fact that they are both decades old designs. Ditto Oppo.

And its no good throwing up Benchmark DAC's or some other recent high performance DAC - those are specifically aimed at the streaming market and its a relatively new thing on the market, so I expect in a straight performance shoot-out, they will probably perform better (progress).
 
I stand by my original claim. Oppo's were recognized as great players for the money and are still great.

They may be great for the money, no argument on that. They may still be great for the money, if that's what you mean. Don't know that they are great in an absolute sense. That sounds more like an expression of preference or opinion, rather than indisputable fact. Some people still seem to think TDA1541A is the once and forever standard of greatness in dacs. I can't agree with that either.
 
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We are back to what is 'bad','good' and 'great'. Which is again preference as there are several audio professionals happy with DACs that are 'bad' on the Mark scale.



TBH some of this is expected. There are various things that some are raptuous about that will sent others running from the room. Certain horns, NS10s etc. I view this as sensitivity to certain things. But trying to home in on what is 'accurate' still intrigues me, esp as regards filter changes.
 
Bill, one can't avoid filters. I think I pointed out an article critical of DAC-3 by a fellow that purchased recording master tapes and the machines they were recorded on in an effort to find out what CDs were supposed to sound like. By such means, he concluded there are no dacs that get it exactly right (maybe no ADCs either). However, all I have is DAC-3, no master tapes, etc., so I will shoot for the DAC-3 sound, but with reverb tails intact if possible (the lack of which in DAC-3 being the main complaint against it).
 
That would be nice. By the time I have a working filter I think the time will have come where that will be a necessary next step.

EDIT: As it stands now for my own purposes, I don't need measurements to tell me there are certain areas where I still have more work to do. I also have a short list of things I haven't tried that I think I should try. After that, I will probably want to see some measurements to help me meet my goals for the project. As it stands now it is the curious onlookers who most want to see measurements (I'm not complaining, happy to see there is some interest. I am working my own way with what I have on hand is all. In part I want to show diy'ers its possible for them to do a lot without being test equipment wealthy or more mathematical/theoretical than would likely be accessible for some). To the curious, then, I say, fine, join me in building dacs and you can measure your own copy. That would be fine anytime. :)
 
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The family of those who listen to the opinions of others with kindness, especially when they are based on a life of passion in their area of ​​expertise.
Kindness, like the one quoted below?

No comment, my deaf friend. You are free to listen with your eyes, looking at response curves and distortion numbers.


PS: I apologize for being so aggressive, but this constant aggression coming from a bunch of bounded so calling objectivists must stop, because it is boring, disrespectful and unproductive.
So you want to silence those whom you disagree with. :rolleyes:
 
Scott,

Can we discuss the circuit shown in post 15413 by Dadod and how it differs from what is best done in discrete parts and what is best done in integrated circuitry.

I see current sources, complementary compound transistors, with regulators and an IC output stage among other bits.

Can we start with a discussion of the current sources and the strengths and weaknesses of his approach? I.E. NPN and PNP versions, matching etc.
 
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