Vibration, isolation and electronics...
- Thread starter Phelonious Ponk
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Sorry, terry, life gets in the way; I got caught up in things to be done while answering your longish post. We met at your factory some years ago, my memory wouldn't be able to pick how many; you showed off a new speaker you were putting together at the end of the day, to demonstrate what you were aiming at, etc.
As regards the earlier post,:
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Dear, oh, dear, what a twist. I acknowledged that capacitance changes may not be the primary cause, but suggested other second order effects could do the trick. In terms of measurements, like most people here I rely on my ears: if something sounds or works better because I address some issue related to vibration transmission then I use it: I don't reject it because I can't point at the precise technical explanation for what may be occurring.
Why I use the words "can be", etc is that I am not a black and white person: everything in life is always shades of gray. For example, there will always be at least one system where vibration has been sufficiently addressed so it causes no audible problems. But it still may have audible deficiencies because of other issues. So I will never use the language of "every system has this or that problem" because life guarantes there will always be an exception! I may appear to disparage expensive systems at times, but I have also heard quite brilliant sound from ambitious setups. There are no "nevers" and "always" in audio when you're talking about SQ ...
So if you have audible problems then the "true cause" may not be understand.
In this case, the language of saying that one can achieve very high levels of imaging and soundstaging if you approach system optimising in a certain way. As a coincidence, there is a very active thread on Audiokarma thrashing out this very subject at the moment ...
Finally, for all those who are happy to take a shot at the sub-quality of the HT: I'm the one looking inside the thing, and, sorry, electronics are electronics. It looks the bloody same as the insides of a NAD, Yamaha, Perreaux and Krell, the main differences are how whopping big the transformer and main filter cap's are, I'm afraid. If the engineer in me grimaces at anything, it's the photos of the insides of very highly regarded, vintage equipment like reel to reel, and marvel at how it managed to get good sound . Just chucking a few mega-expensive designer parts in a few spots doesn't do it for me, I'm afraid ...
Frank
devert, I appreciate what you're asking but it it wouldn't make sense. First of all, it looks a complete mess because I've butchered things fairly badly trying various ideas, and I use whatever's at hand that does the job. So it looks mighty ugly, and it would be hard to understand what I've done.
But the main thing is that there are several things that are original, and I am not yet ready to give these ideas away. It's the old IP problem, I'm afraid.
It most definitely is NOT simple repacement of cap's and suchlike with designer parts, and throwing in ferrite bits here and there. It's a lot to do with getting rid of every critical connection which just relies on physical insertion to do the job, doing major surgery on how the power supply is stabilised (that's mostly IP), stopping vibration affecting crucial cabling (hmmm, where did I read something about that ...), and filtering out garbage from the mains (also IP) and radio frequency devices like cellphones. As an example of what's possible, my test technique for mains filtering is to wind the volume to max, plug a high power globe cable into an extension cord and wriggle the connection so it just makes and breaks. You get a fantastic spluttering and sparking happening at 240V, normal gear sends the speaker off into an impressive sound show: I aim for complete silence from the drivers.
But thanks very much for asking! I would be happy to make some suggestions about what you can try with your own gear if you would care to mention what you have ...
Frank
So I'm talking now to someone who does understand the language! SMPS is something I've never dealt with, I would have to go quite some yards to understand what was required there. It makes sense that you would need to worry quite a bit about EMI factors in this situation ...
Yes, damping using viscoelastic materials is a key strategy, but so far I haven't needed to worry about capacitors and diodes per se, there are bigger influences elsewhere in the particular piece of kit I'm playing with. I imagine I would be able to get some further refinement, for want of a particular word, of sound trying that technique: if I were to say there was any lacking in the sound then it is that it would be a bit "coarse" until the soundstage fully expanded. So thanks for the tip!
I know it's a "length of a piece of string" question, but how much improvement would you say you got doing those TacT mod's?
Frank
Well, we agree on this much, Frank. And I'd add that there is no good reason to believe that putting a transformer in a system that is much bigger than that system requires will have a sonic benefit. This is why, of course, that driving a load well within their limits, the NAD will sound so much like the Krell that they will be very hard to differentiate when listening blind. Nevertheless, audiophiles manage to hear dramatic differences sighted, which is where you join the fold.
It's when you begin to talk about your methods that you lose me...
...and the results you imagine you get from them. The elimination of noise so small that most audiophiles and recording pros never hear it has, in your system, resulted in expanding the off-axis frequency response of your speakers beyond what is credible, in imaging that simply cannot happen - in any room at any cost - in dynamic range that is inconceivable from a system the size of yours. I don't doubt that you have some understanding of electronics that exceeds my own, which is very limited. What you clearly don't understand is how, and how much, those electronics can impact audio reproduction. In that area, you've transcended engineering, even science. You're firmly in the realm of science fiction. The methods you're employing - even if they were dramatically more effective than they've ever been for anyone else - are simply not capable of yielding the results you're reporting. They are, in fact, barely related.
Tim
Terryj-The reason why we let things go with Frank is that we have found out over time that when you try and drill down into his core to get answers, it's like pushing down on jello. It just gushes out the side and you never get the answers to the questions you ask or you just get more hocus-pocus. Frank was just asked to provide a picture of the inside of his wonder machine and he won't do it. Why? Because either he has done nothing, or it is so butchered up he would be embarrassed for anyone to see what he has done (which is pretty much what he said).
Imagine going to a digital photography forum and telling the membership that you soldered your USB cable to your computer to get a better connection, and added some physical damping around the motherboard to isolate it from vibration, and, as a result, your greens and blues are more accurate, and your landscapes are both sharper and wider.
That's the kind of thing we hear from the the internet audiophile community every day. That the responses are so often gentle and not consistently dismissive is remarkable.
Tim
That's the kind of thing we hear from the the internet audiophile community every day. That the responses are so often gentle and not consistently dismissive is remarkable.
Tim
Tim,
I think that except during the first minutes, when a cold Krell just powered on can sound terrible, in an appropriate system every one will easily distinguish it from a NAD.
It was an usual trick from the late 80's I remember well - driving small speakers such a Rogers LS3-5A or Cellestion 700's with a big and hot Krell - even at low volumes the speakers sounded full and poweful. When we went back to the NAD or Quad amplifier it was a disappointment. BTW, this was done really blind - the idea was fooling friends!
BTW, do you agree that a Krell amplifier sounds much better after one hour playback than after two minutes of being powered on?
It was about vibration .. Now it is about ampifier thermal behavior ... SS behavior is affected by heat. Actually cicuits components specifications are temperature -dependent. Negative Feedback and the likes makes these variations less problematic in the amplifer or circuit but within a temperature range
When testing an amplifer it is usuallysubjected to some signal to brings it to a certain temperature , usually above that of the room where the test is performed but it is known that the specidications will vary with temperature.
Cold, many amps do not sound right especially Class A and B. Left to run for a certain amount of time, they do sound better. Be they SS or Tubes. This can easily be repeated. meaurements of amps according to the IHF-202 standards require the amps to be driven with signals for a certain time before final meaurements (IIRC 30 mins) ...
Where is DonH50 where one needs him ?
back to vibrations ...
When testing an amplifer it is usuallysubjected to some signal to brings it to a certain temperature , usually above that of the room where the test is performed but it is known that the specidications will vary with temperature.
Cold, many amps do not sound right especially Class A and B. Left to run for a certain amount of time, they do sound better. Be they SS or Tubes. This can easily be repeated. meaurements of amps according to the IHF-202 standards require the amps to be driven with signals for a certain time before final meaurements (IIRC 30 mins) ...
Where is DonH50 where one needs him ?
back to vibrations ...
I think all amplifiers change a bit once they're warmed up, but an hour? Tubes don't even need an hour.
Tim
Tim
Tim-I don't think you are going to find anyone who will agree with your last statement that tubes don't even need an hour to warm up. It's not that a tube amp doesn't sound *good* after 15 minutes, it's just that it sounds better after an hour or so. One of the nice things about SS is that unless you are running Class A amps, you never have to turn the gear off. My Counterpoint SA-5.1 comes up to temp fairly quickly because the filaments are always on unless you unplug the preamp from the wall.
Well, thank you, microstrip, case dismissed!!! Of course, it is not politically correct to continue with the "charade", so for normal listening you must now throw away the weedy speakers and attach an appropriate manly one to the Krell ...
Of course, the thought for doing the reverse now occurs to me: why not get a miserable, zero cred amplifier, doctor it a bit and then attach it to mega expensive, impressive speakers and see if you can fool those same friends. Gee, there could be something in that ...
Holy dooley, I've just got a great idea! Why not get weedy speakers, doctor a miserable amp and get really impressive sound!! Hey, I hope no-one else has thought of that yet!
Frank
Steve williams
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Another thing I would note, by the way, is that in my experience with tube guitar amps, while they did sound better when they were running hot, it was not the kind of "better" one would look for in hifi. It was the kind of "better" that would compress and distort under hard attack, where you could go from clean to crunch with just the strength of your pick attack on the strings, and to creamy, liquid sustain by pushing the guitar's volume knob up.
You get a whole different view of the response characteristics of tubes when you logged a few hundred hours as the source.
Tim
You get a whole different view of the response characteristics of tubes when you logged a few hundred hours as the source.
Tim
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