Charles Hansen said:
True confessions: I was a spec junkie for years. I can't even say that it was so much that I had an open mind. There were people telling me that I was on the wrong track, but I pretty much blew them off. The thing that kicked in my doors was the Linn Sondek LP12. No way that ugly thing can sound good--mediocre specs. Just..no way...sorry...get outta here and take that stupid POS with you.
Waitammit...uh...what was that? No, not that...that! Play that again. Shut up, will ya, I'm trying to listen here. Stop laughin' at me, dammit! I can't hear when you do that.
That one confounded piece of machinery pretty much laid waste to all my preconceived notions of what numbers meant.
I still own one. It's a bit battered, but it still works, still sounds pretty good, and it gives my secondary system a touch of class.
john curl said:
Speaking of Nelson and power supplies...I had a pair of Threshold S-500s and a cardboard box full of caps. Being an enterprising young lad, I felt that in the name of world peace, free love, and research into weapons of mass destruction that I should combine the two. After all, the caps were just sitting there, looking lonely. Can't have that, you know. Wasteful.
So I tagged together a quarter-Farad of extra capacitance for each amp and whipped up a slow start circuit to keep the transformer on the power pole from melting down at turn-on. Didn't even do CRC or CLC or anything like that. Just C major. (Ahem)
Needless to say, the amps got more dynamic and the bass got way deeper. Very useful, given that one of them was running my subs and the other was pushing the woofer panels on my Tympani IVs. But did they measure any better? How could they? They were already flat down to a fraction of a cycle. Distortion wasn't a problem. The amps THD was quite respectable. But the added capacitance was readily audible, even to my ex-wife, who thought all those caps sitting off to one side were very ugly, but she liked the sound.
Fortunately, I wasn't selling this as a modification of Nelson's amps, so I didn't have a conflict there. The stock S-500s had over 120,000uF in them and enough transformer to break your back, so they were far from puny in the power supply department. But, trust me, they reacted nicely to the addition.
I took it all apart when I moved and the caps scattered to the four winds. I still think about that system, though.
I still have those two amps. You never know, I might put that stuff back together someday.
Grey
I LOVE my LP12. I lost 2 of them in the fire, and I went out and got another one, after suffering two other turntables.
rdf said:
Depends what you want to get. On a really good equipment, some experienced listener hear 2H at 1kHz, more of them hear 3H, everyone hear 4H and higher. I speak about 1%.
On the other hand, almost no one can tell the difference of 20% THD at 10kHz. It reveals as volume change only.
BUT - try narrow band noise. THEN the distortion threshold is much lower, and you easily hear something like -60dB to -70dB of 3rd harmonic.
GRollins said:
Hello Grey,
This points to another interesting phenomenon: once your reputation has been firmly planted in people's minds, the impact of published reviews becomes rather marginal, and at any rate will ALWAYS be seen to reinforce the conviction. I've seen it with quality European cars also. Most reviews and tests are read with the unconsious and unstated purpose to confirm what one already knows: that this is a GREAT amp (or car). In the case you pointed out it was such an unconcious reaction of the sales man, that he tried to persuade you with a review even when that review had the same criticism as you had! He not only conveniently 'forgot' the negative point, he even assumed (again unconsiously) that you would not pick it up.
Don't you LOVE people...
Jan Didden
lumanauw said:
David,
You made your point, but in fairness, the second situation will never arise in any practical amp. So it is a bit moot.
OTOH, you may take the first graph and shift the phase of the distortion products around, that also can give you a completely different picture. Not sure what that would mean, though.
Jan Didden
Hi, Janneman,
Yes, a rising high order is not typical of power amp. Maybe it's a product of signal generator, can be seen in the paper pointed by KSTR. That paper is interesting (but difficult for me to understand). It seems the author directed the difference in sonic in clipping area, instead of normal linear area.
Hi, Grey,
About a week ago, I conducted A-B test between Linn Sondek, Kuzma, and Brinkman. Kuzma and Brinkman give clean sound. Linn Sondek give coloured sound. Analogy to amps, Brinkman and Kuzma is like Pass X, while Linn Sondek is like DartZeel.
If it is OK to have a turntable sounding like Linn Sondek, why a power amp cannot sound like DartZeel (have colouration)?
Yes, a rising high order is not typical of power amp. Maybe it's a product of signal generator, can be seen in the paper pointed by KSTR. That paper is interesting (but difficult for me to understand). It seems the author directed the difference in sonic in clipping area, instead of normal linear area.
Hi, Grey,
About a week ago, I conducted A-B test between Linn Sondek, Kuzma, and Brinkman. Kuzma and Brinkman give clean sound. Linn Sondek give coloured sound. Analogy to amps, Brinkman and Kuzma is like Pass X, while Linn Sondek is like DartZeel.
If it is OK to have a turntable sounding like Linn Sondek, why a power amp cannot sound like DartZeel (have colouration)?
There are cleaner turntables than the Linn Sondek LP12, but they are usually very fussy or they make the records more prone to noise.
lumanauw said:
I think it all depends on your preference. If you want clean sound, without any coloration, you would want your amps as well as your sources to be clean. If you like a bit of coloration, you can mix-and-match with components that provide some coloration like the Dartzeel and the Sondek.
It is your own decision what you like in a system; we may discuss at great length the transparancy or not of a specific component, but if somebody really likes a particular sound, he/she should buy that of course.
Jan Didden
This seems to back my results in these matters. I found narrowband, 1/3rd octave filtered noise to be very revealing (to the ear) to any kind of artifacts and distortion, better that steady state sine or multitone. With this test signal (see FFT per attachment) I could easily nail down the "biting quality" of my small coaxial tannoy's horn, at the start of its transducing range. It really gives an broadband intermodulation/distortion floor that sticks out, sonically. I wish I had that test signal when I bought the speaker (then I would have bought them no more).PMA said:
To my knowledge pulsed/modulated band limited noise is also a known good test signal in the measurement camp ;-)
- Klaus
Attachments
This is to be expected. The first harmonic is already at 20 kHz, already at the verge of what most mature people can hear.
All the best, Hannes
rdf said:
I'm not sure if this is exactly what you're looking for, but Keith Howard provides a utility that processes a WAV file through a nonlinear transfer curve. The curve is computed based on user-specified distortion components of a full-scale sine wave. The utility, AddDistortion, can be found here. He wrote this utility as part of a Stereophile article called Euphonic Distortion: Naughty but Nice?.
lumanauw said:
I believe that if you'll take a moment and read what I wrote, you'll find that I said the Sondek is in my secondary system. This system sits in the living room and is comprised of a bunch of random whatnots like the LP12, an Audio Research SP9 (rather thin sounding, but nearly free so I can't complain), a slightly modified Hafler DH-200 (darkish, tends to act as a counterbalance to the SP9), my first DVD player--a Sony DVP-S530D--serving as a CD player (horrible sounding, ghastly, a train wreck, choose any adjective you like, but it's really bad), all into a pair of Braun L810s (nowhere near as sizzle/boom as the ADS L810s that came later). The system makes noise, which is all I ask it to do. Background music, music to sing along to, music to broaden the kids' minds (my daughter already requests Miles Davis and St. Saens 3rd), and my wife's stuff, which ranges from classical to some of the more modern Celtic variants. In that context, the LP12 adds a touch of class, as I said. On occasion I take the poor thing downstairs and use it on the big system as a second turntable.
Everything changes the signal to some degree--there's no getting around that. The trick is to keep the coloration as low as possible. Once you've done that you get into the art of system building, wherein you try to balance strengths and weaknesses the way I'm using the old DH-200 to mitigate the sins of the SP9. I'd prefer that both pieces were more neutral, but I'm not going to spend a bunch of money on my secondary system and even if I were, the first thing I'd change would be that stupid Sony. The thing's an abomination. I picked up an old Panasonic DVD player that sounds simply marvelous--even more so when you consider that I only paid $10 for it--but it won't play SACDs. Well, you can't have everything.
Some people would probably consider this system to be high end. To me it doesn't rate. It's mid-fi. It plays loud enough that I can listen when I'm in the kitchen cooking or making sausage and it plays well enough that I can listen to music when I'm eating without getting disgusted. When I want something that sounds decent, I go downstairs and light up the big system.
Grey
GRollins said:
GRollins said:
One hears what one expects to hear. I’ve experimented in both directions and found, when more capacitance makes a difference it’s due to a bottleneck in either the power supplied to or the return path from the circuitry. I have also noted that in amplifiers, when applying large amounts of capacitance, you do gain the impact and weight in the low end but at the expense of speed and air.
My experiences with preamps are: overkill on capacitance creates incredibly long break-in times and a prevalent low level congestion. If your supply is stable enough, running with no filter on the supply output is also an ear opener (another generalization you made).
I don’t expect anyone to agree here, I’m just throwing it out as counterpoint, primarily for the silent followers as food for thought or to experiment with; this is DIY Audio.
Or entertainment, whatever.
Grey, what is your reference turntable, and what arm and cartridge are you using on the LINN? This question is also for Lumanauw. Also, what turntable mat?
john curl said:
The only break in test I do these days is noticing how much better the music sounds after a couple of beers. 😱
KSTR said:
Hi Klaus. How did you generate that signal?
andy_c said:
No, but slick anyway. Thx Andy. What I really keep hoping to find is recent perceptual research on masking and thresholds. Most of the 'everyone knows' stuff is decades old. Certainly the manic research into lossy compression unearthed a potential goldmine of insights into it, is it all locked in IP?
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