You should explore DIY ways of getting there. There are a lot of interesting drivers that can provide magic if used correctly.You can wax poetic about these things, but at the end of the day, either you have heard something, or you have not. Very few systems can convey "presence" to the degree that some can, and when you experience it, you know it. You don't need to be an audiophile to recognize it (my girlfriend, and a few friends, who are not audiophiles, came to the same conclusion as me listening to the Altec 755A), and you certainly don't need to have a vast experience of live music either.
When you do hear it, it feels like the stars have aligned. Salvatore talks about it in a way which I feel is honest and I don't doubt he has experienced it with the Sadurni speakers (in his room, with his system).
The Altec 755A is quite unique, but it is an old, very fragile, speaker. There is a reason why those who have heard one (in good condition, with a good system) are so enamored with it. The degree of realism (though that term may be misleading) is uncanny, unlike anything I had heard before, irrespective of cost. The other Altec models (ex: 755C) do not have that same magic either. Unfortunately, it is very limited in other ways. The sound is addictive, and I ended up selling mine to free myself from its spellI will also add that hearing what this speaker can do has led me to realize that many costly speakers are simply not worth it to me - but that's a personal point of view.
Natural Sound
- Thread starter PeterA
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I could but the benefits vs time spend (including lots of trial and error) are really hard to evaluate. Not sure I have the skills and energy to get back into this.
I wish there was a simple way of experiencing the more "exotic" systems that everyone talks about here (including @PeterA 's). Audio shows only give us a very incomplete picture, and videos are so limited... Travelling and visiting people's systems is really the only way to understand what they are all about - as Bonzo, and some of you do.
If anything I could have underestimated the number of stages involved in a process of listening to music played through a system and then writing up thoughts on it.
Perhaps all the processes don’t involve clear sharp change points and there can be complex overlaps but you could just as easily identify it listen, evaluate, write with a chain of different operational functions and mix of brain regions being involved throughout.
It would help to do every function well but you could be less than perfect and display variable quality in some functions but I’d suggest It’s completely possible to be a strong writer with poor listening skills and vice versa… equally it’s possible to be adept at analysis in listening and then struggle with synthesis in listening and vice versa… so a capable listener in ways but not without individual constraints.
As far as I know no-one designs to produce only even orders- there's literally no way to do that sans DSP. You can design something where the prior harmonic is higher in amplitude than the next harmonic in the series.
The trick isn't to design for even orders. Instead, you want the open loop design to have an exponential drop off of succeeding (higher) harmonics. What isn't often understood is that the ear treats the 3rd in much the same way as it does the 2nd (and is likely a good reason that reel to reel tape has so many proponents as tape heads manifest a 3rd harmonic as their dominant distortion component). These facts give the designer greater access to reducing distortion, by choice of exponent for the aforementioned exponential curve. That curve can be based on a quadratic exponent (higher distortion, including even orders) or cubic (lower distortion and no even orders). Both can mask higher ordered harmonics quite well and since the 2nd and 3rd harmonics are musical to the ear and close to the fundamental tone, innocuous.
I'm sure you see where that bit is going; SETs produce the quadratic non-linearity; to do the cubic non-linearity the amp needs to be fully differential, not just PP at the output. IOW one or the other, but not both. Otherwise you get an enhanced 5th which is less musical (see Norman Crowhurst).
The idea in any event is the distortion must be innocuous. SETs do that- they can have quite a lot of distortion but since the 2nd and 3rd harmonics are so prodigious, higher orders are masked. In a fully differential design the 3rd can do that masking too; succeeding harmonics fall off at a faster rate and overall the distortion is quite a bit less; open loop might be 10x lower.
The problem of course is the more distortion you have, the more it obscures detail.
As far as I can tell keeping phase shift to a minimum at either end of the audible spectrum is important. If you have no feedback, this requires a lot of bandwidth, since phase shift components involved with a 6dB/octave slope can exist to 10x or 1/10th the cutoff frequency; IOW if in the bass, 10x the cutoff frequency, if in the highs, 1/10th the cutoff. The ear is terrible at detecting phase shift at a single frequency but over a spectrum it interprets it as a tonality. So if you cut off at 20Hz on a 6dB slope with no feedback, phase shift can go up to 200Hz and this can be interpreted as bass shy despite the 20Hz repsonse. BTW this does not seem to apply to speakers- its an electronics thing. It seems this is the reason Stewart Hegeman (designer of the early Citation gear from Harmon Kardon) was such a big advocate of bandwidth.
If you run enough feedback and the feedback itself is applied properly, you can get around this problem as the feedback will correct phase.
If the circuit is to employ feedback things get a lot more complex and if the rules of applying it properly are ignored, Bad Things happen. If applied correctly, the feedback will simply reduce the open loop (innate) distortion and preserve its exponential nature. If applied incorrectly it will add higher ordered harmonics of its own! If the circuit lacks gain and bandwidth, the distortion will rise at some frequency because the feedback is reduced at the frequency on a slope (20dB/decade). Its my theory that these two issues contribute to brightness and harshness.
These are just a few of the things I think any designer has to consider if they want to build a circuit that sounds musical.
Some posts have been removed on this thread. Most of them were way off topic and some got into useless name calling and pointing out other members of the WBF. We would like to remind you that sticking to the thread topic is part of the TOS of this forum. In this case, the thread topic has varied a bit over time but always seems to get back on track to Peter's system.
One further note - Disagreement is certainly allowed but not disparagement of the individual posting. With that said, the thread will now reopen.
Please, let's drop the back and forth bickering. It helps no one. Now, back to our regularly scheduled programming.
Tom
One further note - Disagreement is certainly allowed but not disparagement of the individual posting. With that said, the thread will now reopen.
Please, let's drop the back and forth bickering. It helps no one. Now, back to our regularly scheduled programming.
Tom
Here is a video I made last night after some additional refinements and fine tuning of the set up.
Great music Peter, would love to know the players involved if you get a moment… really lovely piece of music.
Very much enjoying how your system seems to get a really good balance on subtle flow and attack in this… I find that intimate chamber music exposes that balance in a system because these qualities can show as quite nuanced and finely variable and appear in a microdynamic level of shading in the individual dialogue of just a few instruments. I find that this is an area where less subtle amplification falls all over itself and differences in various performances then diminished and lost.
For me the enjoyment of all music hangs heavily in the ability of a system to allow the music to flow when it is supposed to but then also getting spirited and angular when the music expresses vitality and verve. I am very much drawn to a good GM70 setup because it has that dynamic spirit and full range of expression. A very nice video share thank you.
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I’ve been quietly following this thread, but I had to finally post to say I have to hand it to you, Peter. This sounds really wonderful.
Thank you, Tony. I appreciate the kind words. Sometimes it is better to follow threads quietly. This particular thread is not for the faint of heart.
I started this thread to share my excitement about this new system, and to document changes and what I am learning. This video represents the current system presentation in my room from my latest round of experiments. I continue to try things to gain experience and knowledge. After 2 1/2 years, I am still learning how to tune and improve the sound of my system and the resulting listening experience. I am glad you enjoyed this system video.
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Thank you very much, Graham. Here is an image of the record cover describing a musicians and the catalog number: BIS LP-62 STEREO.
I used to play the clarinet, so I am very fond of this music.
This is quite quite good, Peter. The opening chords (which almost sound like Rachmaninov, but aren't) tell the tale immediately.
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