Are you SURE those emitter resistors are 5 ohms and not 0.5 ohms?? 5 ohms would be an unreasonably HIGH value, methinks.
I didn't know it is the Q-speed that you are using. I thought it is a super/hyper fast type that I have used before. The Q-speed is indeed very different than MUR680. And it's only 6A, which is a good sign, and the low Q is a schottky resemblance, which is the best compromised diodes IMO.
I don't think I could find that information. But what's wrong with an MKP coupling caps? I have never had serious problem with MKP coupling. They either sound similar or only slightly different but the most important thing is hard to know which is better.
What's wrong? You used 5R when it is supposed to be 0.5R??? Mills is a good brand and even the cheap ceramic is good enough. But some boutique R sound "terrible"...
I think Cumbb and Mooly had a point. What are you doing with trying to improve inferior amplifier? The diode I believe is too good for the amp hehe (with amp like this, I will never bothered with trying better parts).
Here is why ultra fast diodes that I have used are always sound terrible. Also why many people prefer Schottky diodes (and I guess tube rectifier too) which has very low Q.
This is also I believe why I have never preferred a power supply RC subber circuit.
Attachments
Search for quasimodo thread. In quasimodo, an RC at secondary winding transformer is used to flatten the ringing due to transformer inductance leakage.
Attachments
Often I prefer the switchposition "no R or no RL" at the psu (built a C-R-C-R-C with switching, as example). Not "better" without Rs, but more "merciful": not as clean, not as sturdy, not as hardy. The ear does love little "distortions", a little "un-damping" in my mind,-)
Eww... I didn't realize the typo.
We have similar preferences. But I disagree that the ears love "distortion". This has bothered me for a long time. Because it was hard to accept that I like distortion. But now I'm quite sure. It is not about the existence of distortion of "type A" but it is about the nonexistence of distortion "type B"...
"Type A" is not okay, but "type B" (that we get as a compromise for getting rid of type A) is even worse.
;-!
Very good verbalized,-!
We can not avoid "distortions" (EVERY alteration, influence, modulation...), but we can choose.
My preferred example: balanced - unbalanced. The less of influence of psu sounds - most much much - better than (the more of "distortions" of) two minimal different amps. And: (In this case) the harmonic distortions are not as important as the "cleanness", the "un-noisy" is. (The reason, not to use channel-separated, or many, psus, too,-)
An extract of my current experience.-)
Very good verbalized,-!
We can not avoid "distortions" (EVERY alteration, influence, modulation...), but we can choose.
My preferred example: balanced - unbalanced. The less of influence of psu sounds - most much much - better than (the more of "distortions" of) two minimal different amps. And: (In this case) the harmonic distortions are not as important as the "cleanness", the "un-noisy" is. (The reason, not to use channel-separated, or many, psus, too,-)
An extract of my current experience.-)
Many people find this hard to accept. I note that your chosen explanation involves the postulation of 'distortion B', which is undescribed, unmeasured, unexplained and probably non-existent.Jay said:
Interestingly, almost all systems which are sufficiently low in 'distortion A' to be indistinguishable from each other in ears-only tests seem to exhibit 'distortion B'. Indistinguishability is a consequence of 'good enough for faithful sound reproduction', yet some people find them 'boring' or 'unmusical' and assume this is a sign of the presence of 'B'. Occam's Razor tells us that it is the lack of 'A' which some people find boring, and hence 'B' does not exist.
It is not Occam's Razor. The reason I didn't describe what "distortion B" is, is because that statement applies to a lot of phenomena, so "distortion B" (and "distortion A") is different from cases to cases.
As a basic "introduction", it is sufficient to say that when you try to solve problem with the existence of "distortion A", you introduce something else to the system. Many people cannot hear this (but I can), that's why many people think "distortion B" doesn't exist.
There is logical fallacy there.
The logical reason why things can be "similar" and thus indistinguishable from each other is when these things follow exactly the same design "principle" or process.
In my case, I already know what "B" is.
One reason why people don't know about this, is because they cannot "hear" it, so they assume it doesn't exist (Is this an Occam's Razor?). My hypothesis was that even if people cannot "hear" it, they still can "feel" it (so it is equally important for them as it is for me).
If you mean by "principle" the idea that output should be merely a larger version of the input then yes. There are lots of different ways of achieving a good approximation to this, and they all lead to indistinguishability. If an amplifier sounds so much 'better' than others that it can be reliably picked out in an ears-only test, while all the others sound the same, then this means it suffers from 'distortion A' - but an 'A' which some people prefer.Jay said:
Bad amplifiers will all sound different from each other, as there are lots of ways to mangle a signal. If amplifiers all sound the same then it is likely that they are all good; people who don't like them are expressing a preference for certain types of bad amplifier. In most cases they will deny this because it is hard for them to accept that they like distortion, as you said.
So we agree on this.
I agree that most people should NOT be able to hear small differences in an ear-only test. But don't forget that people may have different taste. And about distortion, I have many times mention the dog and cat analogy (which one is more similar, male dog and male cat, or male dog and female dog). It is just about convention, not about truth.
Every single wines may have different taste (tho only a few select people are able to differentiate them). But if you add 5% H2O2 they all may taste the same, and still there is no reason to say that this is the good one.
Not always like that. I like the "seven blind men and an elephant" analogy. Each blind man can only see small incomplete part. Those who aren't blind can see the big picture. For those who can see the big picture, it is not anymore about right or wrong, it is subjective/relative (ask Cumbb about it hehe).
BTW, why worry about amplifiers. I have never been impressed with whatever amplifiers I have built or heard. It's different with speakers. IME in building speakers, for cost no object design, non-linear distortion of the drivers is the bottleneck. But then, nobody think anyone can hear non-linear distortion 🙂
That is precisely my point. The snag is that people confuse taste with truth.Jay said:
OK, if you want to call "convention" the aim of hi-fi, which is to reproduce sound. Now I realise that not everyone wants to merely reproduce sound; instead they want what seems to them to be a pleasant experience. Nothing at all wrong with that, provoded they don't think they are pursuing hi-fi and don't think that their chosen distortion is somehow higher fidelity than the much smaller distortions favoured by hi-fi people.
Once again you are confusing taste with truth. Wine is like music; the bottle/cork is like audio. If a given wine tastes the same with different bottle/corks, but then tastes different with one bottle/cork we can be reasonably certain that it is the latter one which damages the wine and the former ones which do not. This remains true even when someone prefers the damaged wine.
Taste is what makes us feel good and gives the fun.
Truth (look at the world around you) is ugly most of the time.
Wrt listening being a personal subjective affair this discussion is rather redundant.
Borders of taste: Cleanness or not-cleanness. Sometimes obvious for EVERYBODY,-) And nobody would/will choose the indistinct, curtained sound. I am sure. No doubt,-)
Please think about the "dog and cat" analogy. I think we can agree on what truth is. Which one is more similar: male dog to female dog OR male dog to male cat. Do you have the answer to this question?
Or let's limit this to a conventional model: 1kHz sinewave input and 1W output...
Option A:
0.2% HD2, 0.4% HD3, 0.1% HD4, 0.3% HD5, 0.1% HD6, 0.08% HD7, 0% others
Option B:
0.8% HD2, 0.3% HD3, 0.08% HD4, 0% others
Which one is it?
Given 3 amplifiers with 1 to 80ppm distortion, do you know HOW people will rate their preference? No, it has no correlation with the distortion. Do you know? I grade this preferences into 3 levels. Level1 is the 80% majority who cannot hear subtle differences. Level2 is the 19% more experience listeners and usually builders/designers. Level3? I think nobody has ever mentioned what it is yet.
You've either heard a faulty one or there was a problem with whatever it was connected too.
Read the reviews:
Cambridge Audio TOPAZ AM1 Black | Stereo Amplifier | Richer Sounds
Amazon.co.uk:Customer Reviews: Cambridge Topaz Am1 Blk
Sorry Andrew. Not sure how I missed your question.
The output resistor is in parallel with an inductor BUT I will have to check the emitter resistors. Hmmm, think I may have made a mistake 😕 I'll open it up and check later.
I bet I measured it with my multimeter, when I should have used the DATS 😱 Multimeter wont measure resistances that low.
- Status
- Not open for further replies.