Hi Howie,
You should have a look at the RTX-6001 and Virtins MI package developed by some of our members. Once the integration is complete you may be able to get something very useful for under $3K or somewhere close to that.
While you are looking at the AP, also consider the Keysight U8903B. It's in the same ballpark for price. Given a choice I would take one of each home for a week and compare them. Spending that much on an audio analyser demands some care in the process.
-Chris
Outstanding!!!
You should have a look at the RTX-6001 and Virtins MI package developed by some of our members. Once the integration is complete you may be able to get something very useful for under $3K or somewhere close to that.
While you are looking at the AP, also consider the Keysight U8903B. It's in the same ballpark for price. Given a choice I would take one of each home for a week and compare them. Spending that much on an audio analyser demands some care in the process.
-Chris
Here is another case of technical quibbling, without followup. When 'marketing literature' says: 'no loop feedback, no local feedback' or something similar, you guys will quibble that it is impossible to not have ANY local feedback, and so they must be lying about everything they say. Perhaps it would be slightly better if they said: 'No loop feedback, no heavy local feedback' to be most accurate, but a REAL CIRCUIT DESIGNER knows what they mean.
What they are saying that they do not add HEAVY LOCAL FEEDBACK to deliberately kill the gain, increase the open loop bandwidth, and finally reduce the actual measured distortion in the gain stages (usually first and second). This is what Richard Marsh put up a short time ago here as an an example of of 'zero open loop feedback amplifier'. He just greatly increased either emitter or source resistors in the first and second stages of one of his typical power amplifiers. It works, but it is not necessarily the best way to do it. It is better to actually use an inherently lower distortion topology that has less open loop gain, like the CTC Blowtorch uses, or Charley Hansen used in all his designs. This appears to be what MSB is referring to in regards to their power amp, etc.
These guys, completely separate from Charles and me, have found the optimum solution for them to be the same approach as we have put forth, i.e. that IC's, and even high loop feedback is not as good as open loop and quality passive devices as much as possible. Apparently, they have removed quality IC's from their output buffers for their best D-A converters as well, getting an audible improvement. What a concept! '-)
What they are saying that they do not add HEAVY LOCAL FEEDBACK to deliberately kill the gain, increase the open loop bandwidth, and finally reduce the actual measured distortion in the gain stages (usually first and second). This is what Richard Marsh put up a short time ago here as an an example of of 'zero open loop feedback amplifier'. He just greatly increased either emitter or source resistors in the first and second stages of one of his typical power amplifiers. It works, but it is not necessarily the best way to do it. It is better to actually use an inherently lower distortion topology that has less open loop gain, like the CTC Blowtorch uses, or Charley Hansen used in all his designs. This appears to be what MSB is referring to in regards to their power amp, etc.
These guys, completely separate from Charles and me, have found the optimum solution for them to be the same approach as we have put forth, i.e. that IC's, and even high loop feedback is not as good as open loop and quality passive devices as much as possible. Apparently, they have removed quality IC's from their output buffers for their best D-A converters as well, getting an audible improvement. What a concept! '-)
John, I'm sorry, everything you write screams something similar to confirmation bias, i.e. "I'm only paying attention to people who already think they way that I do and validate my opinions while ignoring anything contrary to that."
REAL CIRCUIT DESIGNER? Really John? That petty or do you want to just hit all the logical fallacies?
Obviously there must be local feedback and it's a case of "whatever", but even then their entire design is philosophy-first and design-for-performance last. Bruno Putzeys has a lovely little quip about that in his "G-word" article.
REAL CIRCUIT DESIGNER? Really John? That petty or do you want to just hit all the logical fallacies?
Obviously there must be local feedback and it's a case of "whatever", but even then their entire design is philosophy-first and design-for-performance last. Bruno Putzeys has a lovely little quip about that in his "G-word" article.
If anyone is lacking adequate audio RTA/metering, check out this suite of meters...I may deploy one or all on my TV to watch during playback...
Aurchitect Audio Software
Howie
[edit] crap, it only runs on MacOS...
Aurchitect Audio Software
Howie
[edit] crap, it only runs on MacOS...
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It's one of the few Zuccarelli encoded disks you can get. I was setting up a diffmaker for two consecutive plays on different RIAA stages and listened to right from play one and left from play two by accident. The effect was amazing way beyond the normal flanging you get.
Sorry John, but it seems you are stacked in the past, and those REAL CIRCUIT DESIGNER are just selling a fog as there say in my country.
Yes, this is very common today with all sorts of class-II devices with, notably those with switch-mode power supplies that don't have medical approvals. A standard SMPS typically has a 1nF EMC capacitor from primary to secondary, you'll find this cap in any standard SMPS schematic, and therefore a standard "floating" SMPS couples the primary voltage with respect to PE (which is rectified mains voltage) to the secondary via the quite large capacitance. Medical SMPS have very restricted coupling (much less than 100pF typically) so don't get the tickling sensation -- which btw is largest on the skin of the inner forearm. Good transformers with split bobbins (C-core) also have very low coupling capacitance but those are out of fashion today (don't have "universal mains" feature) and not even legal anymore for wall-warts.
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I used to flange with two vinyl copies playing simultaneously. Get the levels right, the null was total, even when I drifted them at a reasonable rate for effect.
Billshurv, that Russ Andrews grounding link was amazing.. Not quite sure how to think of it, total chaos, total dangerous, what... when he says 17th part, 2008, I assume he is talking about NECode? When I talk code, I use words like "bonding", "grounding"...lightning, that kinda stuff.. I couldn't figure out what he was trying to do. Ah, it's a subtle hint when they mention earthing to send all the bad emi and rf to go, as a sink...
ah, edit...he mentions connecting another grounding rod to the house ring (finally noticed the euro plug wall wart pic) as being outlawed, but then a few pages later, goes on to describe an earthing star ground and pipe burial to send all that bad rf to ground.
So, while outlawed, he shows how to do it anyway?? But instead of hard to grounding conductor, some wimpy spade lugs to the equipment external metal surfaces? There is so much wrong there, I had to call it out.. The setup screams unwanted grounding currents, total disaster should there be a nearby stroke, either cloud to cloud, or to earth. Nevermind what would happen should a powerline conductor break or fall and cause a earth gradient. If worms started jumping out of the earth near the rods, do NOT turn on the stereo or TV....
Jn
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Does not look like it is useful as an analytical math tool. Real programmers learn how to deal with the horrifying mess that Windows audio is.
Exactly. And, some devices still exhibit the touch effect event with a grounded interconnect - depends on the relative impedances etc.
It still feels like bad practice to me - and when you get it in audio devices, another potential noise injection source.
It's not that bad actually. The idea is to bond everthing together (for DC and LF/MF) with a lower-Z path than the mains connection of the devices as well as a lower-Z path than the interconnects. But it will work properly only if all devices have the jack gounds connected directly to their chassis, most don't. Also, the mains connection should really be higher impedance (long cables with high resistance and/or common.mode filters effective at audio-frequency). Anyway, it is still better that having all the balancing inter-device current flow through unbalanced interconnects grounds/shields where R*i and L*di/dt voltage drops will appear as signals.
I wasn't listening to the null but left1 and right2 drifting with respect to each other, the image did crazy things I assume due to the Holophonic encoding.
Does not look like it is useful as an analytical math tool. Real programmers learn how to deal with the horrifying mess that Windows audio is.
Like Bob Orban (or Matt Gonzales). I use his meter at WXYC and my home studio to analyze peak and average levels. It is the best PC tool I know for setting compression as well. I find it to be as accurate (within it's resolution) as the statistical analysis available in ProTools or Sound Forge. It is available for free:
METER — Orban
Howie
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...which is exactly "HEAVY LOCAL FEEDBACK". But of course, "REAL CIRCUIT DESIGNERS" do not accept emitter/source degeneration as local negative feedback.
Except the "Otala" amp was just this and three stages to boot with the associated lead/lag compensation nightmare.
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