Soundminded -
You're shooting fish in a barrel here. I would like to see a discussion of SOTA speakers based on the AR-9 vs the work of Lynn Olsen or Earl Geddes. I have friends who still swear by stacked large Advents and it's refreshing to see someone willing to take on the challenge of now vs. then.
You're shooting fish in a barrel here. I would like to see a discussion of SOTA speakers based on the AR-9 vs the work of Lynn Olsen or Earl Geddes. I have friends who still swear by stacked large Advents and it's refreshing to see someone willing to take on the challenge of now vs. then.
I will reveal just one of the ideas incorporated in this redesign. I'll tell you what but not how. It is the best that can be done with a speaker system of this type which has much in common with about 99%+ of all commercially available speakers, meaning it is a multiway direct firing speaker (except for its side firing woofers.) At it's best, after re-engineering it remains seriously flawed compared to the ideal model I've created for this type of "they are here" sound system. Nevertheless, it is a considerable improvement.
One goal in a sense is the same as Geddes, flat acoustic FR transfer from the speaker to the listener. Geddes tries to achieve this by restricting high frequency dispersion making it more uniform as a function of angle. He wants to eliminate the room where he can, ignore it where he can't. He rationalizes this by stating a cutoff frequency below which he says it doesn't matter. My design achieves flat power transfer by making all of the reflected sound flat when it arrives at the listener. It corrects what I call spectral reflection distortion. And further adjustments make it flat all the way back to the recording microphone by adjusting for each recording individually, it's the only way to make it work. The speaker isn't just tuned to the room, the room is an indespensible part of the sound system itself. If you fight the listening room, you will inevitably lose, it's a battle that can't be won.
Kudos to you - nobody's perception can be proven, its a subjective phenomenon. Your detractors appear to be following the maxim 'Don't accept any fact until it is proven by theory'.
I'm buying the components to build it myself.
However, RFI filter at the input of the isolation transformer doesn't exclude the benefit of quality power cord.
The one I'm about to build is reported to be beneficial. Anyhow, there will be a switch to bypass it. I'll see (actually, hear) what works best.
Kudos to you - nobody's perception can be proven, its a subjective phenomenon. Your detractors appear to be following the maxim 'Don't accept any fact until it is proven by theory'.
When you choose loudspeakers for your sound system, do you choose by how the speakers measure, or by how they sound to you?
Especially to the people in the business of making and selling them. How about a filter on the output of the PS?
For you this is just hypothetical but I had a situation where there really was RF interference. A contractor installed some smoke detectors in an existing system in a laboratory building and there were a lot of nuissance alarms. As best as I could figure out, the problem arose because the contractor spliced solid and stranded wire with wirenuts in an unshielded raceway. In all likelihood, the point at which they met formed a detector diode. There were a lot of RF sources in that building. Perhaps our resident expert in the quantum mechanics of electrical conductivity could explain how that happened. In any case the solution was simple. I shunted all of the affected zone alarm module inputs with 0.47 uf capacitors. That was the last of the problem.
What I like about you audiophile guys is that you deal in hypothetical abstractions with no data, no numbers and the only way to fix a theoretical problem is the most expensive and arcane way anyone can think of. After all, that's where the profits are. You won't make the kind of money on a 3 cent ceramic disc capacitor that you will on a $200 power cord.
Funny, in all the years I've designed power distribution systems for the most exotic laboratory and data processing equipment, nobody ever mentioned special power cords in their requests for a project. If they had, I'd have recommended a UPS instead. You won't get better isolation than that.
Comment of the week. This has been my observation over many years.
I also have a soft spot for the AR9 even though it had it's faults.
Before things get completely random, I might point out the history of power line filtering, at least from what I know.
About 1980, our local electronic surplus houses started stocking lots of RFI filters, brand new and some military grade. I bought several, and put a military grade one in Dave Wilson's Ultramaster 30 ips analog recorder. In 1984, Dave gave it back to me, finding that it did not sound quite right. Of course, I went to work to determine what this filter could possibly do wrong, and I think it was parts quality, rather than the actual filter, itself.
About 1990 a couple of engineers split from Corcom, a noted RFI filter manufacturer, to make an audiophile AC box with 3 separate isolation transformers, bandwidth limited, and some extra components as well. I have one in my lab. It works great, and I used it in my hi fi system for several years.
However, for whatever reason, they went broke, because Bybee had released his Quantum device AC outlet box, with my AC and lightning protection added. Yes, we got a lot of the business for awhile, then PS audio trumped us with a COMPLETE reclock of the AC with a special amplifier and an oscillator. Then, they got all the business, no kidding. Finally, Jack Bybee started working with another engineer, who formally worked at HP, and they came out with an ACTIVE AC filter that knocked my socks off, when I first heard it. This unit is produced elsewhere, at this time, and I have no contact with the principals. I think that Jack and the engineer sold the rights to produce the design to someone else.
Finally, Jack and mostly the other engineer have come up with a MODULE that works between the DC out on most power supplies and the amp or preamp. I just heard an A-B of this, 2 weeks ago. We will have it on display at 'The Show', wherever Brian Cheney of VMPS does his live vs recorded demo at the Flamingo Hilton. That's the latest.
About 1980, our local electronic surplus houses started stocking lots of RFI filters, brand new and some military grade. I bought several, and put a military grade one in Dave Wilson's Ultramaster 30 ips analog recorder. In 1984, Dave gave it back to me, finding that it did not sound quite right. Of course, I went to work to determine what this filter could possibly do wrong, and I think it was parts quality, rather than the actual filter, itself.
About 1990 a couple of engineers split from Corcom, a noted RFI filter manufacturer, to make an audiophile AC box with 3 separate isolation transformers, bandwidth limited, and some extra components as well. I have one in my lab. It works great, and I used it in my hi fi system for several years.
However, for whatever reason, they went broke, because Bybee had released his Quantum device AC outlet box, with my AC and lightning protection added. Yes, we got a lot of the business for awhile, then PS audio trumped us with a COMPLETE reclock of the AC with a special amplifier and an oscillator. Then, they got all the business, no kidding. Finally, Jack Bybee started working with another engineer, who formally worked at HP, and they came out with an ACTIVE AC filter that knocked my socks off, when I first heard it. This unit is produced elsewhere, at this time, and I have no contact with the principals. I think that Jack and the engineer sold the rights to produce the design to someone else.
Finally, Jack and mostly the other engineer have come up with a MODULE that works between the DC out on most power supplies and the amp or preamp. I just heard an A-B of this, 2 weeks ago. We will have it on display at 'The Show', wherever Brian Cheney of VMPS does his live vs recorded demo at the Flamingo Hilton. That's the latest.
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If RF is such an important problem the only way to get rid of it is to use a UPS in an RF shielded room. Is this going to be another of those hokey stories like where the best cable you found had minus 135 db of noise on the 7th harmonic of 5 khz and the cheapest Radio Shack cable had noise of only minus 120 db? BTW, that dispelled any lingering doubt in my mind that RS cables were more than adequate for any home audio system.
One of the best ways to remove the power line and perhaps the line cord from serious listening compromises, is to avoid toroid transformers, and to use common mode chokes in the power supply. I use either E-I transformers or D core to reduce inter-coupling capacitance from the power line to the equipment ground return.
This was used in the Blowtorch power supply and we did NOT use a commercial RFI filter, for the reasons previously discussed. Works for us.
This was used in the Blowtorch power supply and we did NOT use a commercial RFI filter, for the reasons previously discussed. Works for us.
What I enjoy is how some of you engineering types show the empirical curiosity of a turnip. Its far easier to posit mind experiments and solve their hypothetical issues with a wave of their hand. The good Lord, in her infinite wisdom has given us 4pdt switches with which one can subjectively compare power filters in situ. Then again, it would just make them flummoxed to credit anything they actually hear.
A ceramic X2 cap? You must be kidding, or have a really **** poor audio system.
John - The current iteration of the Bybee/Curl conditioner is far better than anything PSAudio currently offers.....
I wonder why audiophile curiosity usually covers things that can be easily changed without going inside the equipment, things like cables, powerline-conditioners, expensive feet or dampers .
It is of course a nice way of keeping yourself occupied while saving up for the next upgrade, also clearly visible for a visitor.
Also it doesn't require extensive knowledge of audio-electronics.
It is of course a nice way of keeping yourself occupied while saving up for the next upgrade, also clearly visible for a visitor.
Also it doesn't require extensive knowledge of audio-electronics.
FYI I have a United States Patent on a novel type of sound system. I've been experimenting with the most recent prototype for 8 years. Now what are your actual projects you've created yourself and built?
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