I'm working on a version of Nelson Pass' M2, JFET source follower feeding an interstage (600:15K) connected as an auto transformer feeding a power FET class A/B output (emphasis on the class A).
I'm looking to like this and be entertained.
Thanks guys,
We will have the best outcome possible.
Hi Richard,
What am I not working on? I have too many projects, most waiting on other things. The main project is getting my bench and parts back where they should be, then creating an office. In the mean time, I am designing a tube power amplifier (35 ~ 50 wpc) and a tube preamplifier. Of course these major projects spawn smaller projects - like high voltage regulators for example. After this will be solid state versions. I also have bench instrumentation to work on. A GPS disciplined 10 MHz frequency reference for the bench with 2 receivers, and a load centre for amplifier dummy loads and instrumentation that patches in to that.
We will have the best outcome possible.
Hi Richard,
What am I not working on? I have too many projects, most waiting on other things. The main project is getting my bench and parts back where they should be, then creating an office. In the mean time, I am designing a tube power amplifier (35 ~ 50 wpc) and a tube preamplifier. Of course these major projects spawn smaller projects - like high voltage regulators for example. After this will be solid state versions. I also have bench instrumentation to work on. A GPS disciplined 10 MHz frequency reference for the bench with 2 receivers, and a load centre for amplifier dummy loads and instrumentation that patches in to that.
Mission creep on the current phono amp. New features being added all the time*. Also having fun getting some one of a kind rebuilds done on cartridges by a Russian friend.
#2 daughters boyfriend has a 3D printer so planning on getting him to make a few bits for me.
And still need to finish the active speakers. Luckily littlest is getting better at sleeping.
* Each time it gets above 40 relays I start again as getting silly
#2 daughters boyfriend has a 3D printer so planning on getting him to make a few bits for me.
And still need to finish the active speakers. Luckily littlest is getting better at sleeping.
* Each time it gets above 40 relays I start again as getting silly
We just moved our laboratories to a new research building (RIP July/August for that), and as result, we're left with a lot of shipping/packaging materials. I had some leftover cheapo full range drivers that I'm using to make a simple USB-input powered speaker/sub combo for our lab area. Already purchased TPA3116 PBTL boards for the amps, and a 9018k2m+SA9027 (I think? Some USB-I2S receiver) board for the DAC. I'll veroboard out an I/V and feed the appropriate filters for splitting the speakers from the subs. If I go crazy, I'll rewire the 3116's for post-filter feedback, which will compensate for the cheapo output inductors.
Our new CNC mill at work will be featured prominently in the design of the panels to make some ridiculous steampunkish looking hardware. The whole thing is a whimsical project that gives me an excuse to get a whole lot better on the CNC for work-work (and get back into the wood shop), and my colleagues really like the ridiculousness of the whole project. Plus the lab is pretty sterile right now, so some character (and a means to play some tunes) is welcomed.
That said, they'll be coming with me when I move on to my next job. (Postdoc positions are intentionally temporary)
Our new CNC mill at work will be featured prominently in the design of the panels to make some ridiculous steampunkish looking hardware. The whole thing is a whimsical project that gives me an excuse to get a whole lot better on the CNC for work-work (and get back into the wood shop), and my colleagues really like the ridiculousness of the whole project. Plus the lab is pretty sterile right now, so some character (and a means to play some tunes) is welcomed.
That said, they'll be coming with me when I move on to my next job.
(Postdoc positions are intentionally temporary)
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> I take exception to your term "ridiculous spin".
I am sorry you took it that way.
What I am saying is that "music" has very little to do with fidelity.
( or "location " )
"Music" is more the arrangement of timing and tonalities.
Have you never listened and enjoyed a $5 xsistor radio or somesuch ?
Again sorry ...........
I am sorry you took it that way.
What I am saying is that "music" has very little to do with fidelity.
( or "location " )
"Music" is more the arrangement of timing and tonalities.
Have you never listened and enjoyed a $5 xsistor radio or somesuch ?
Again sorry ...........
^ dadod, I find that very strange as at least the posts that survive seem to be rather polite (quite unlike my own, hah).
Another fun topic is the crazy ideas floating in your head as of late. Like, it'd be really fun to do a line array with all the DSP front end needed to tame it and then drive the whole arrangement with a properly designed OTL (into something like a 300-400 ohm load by series wiring all the drivers).
Another fun topic is the crazy ideas floating in your head as of late. Like, it'd be really fun to do a line array with all the DSP front end needed to tame it and then drive the whole arrangement with a properly designed OTL (into something like a 300-400 ohm load by series wiring all the drivers).
Well one arena is scheduled to finish the end of this month, a supermax prison microphone system after that, then a mid size club. Of course the normal small stuff, repairs, church systems etc.
Today working on on furniture an interview desk. About $2,000.00 worth of wood and other materials and three man weeks of labor. CNC router cuts the parts then hand trimmed to pass very close inspection.
Doing relay tests also this week as all the samples are in.
But the I work on audio every day.
Today working on on furniture an interview desk. About $2,000.00 worth of wood and other materials and three man weeks of labor. CNC router cuts the parts then hand trimmed to pass very close inspection.
Doing relay tests also this week as all the samples are in.
But the I work on audio every day.
I admire your energy on that thread. At one point you claim discerning the difference between -120dB and -122dB low order THD. Considering I doubt you have earbuds, headphones, or speakers capable of better than -80dB THD at normal listening levels and the distortions add vectorially, that claim amounts to discerning hundredths or thousandths of dB's.
Yeah, I doubt I can do that too. I think it could be something else was going on too. I don't know what. IMD is something I find myself getting more sensitive to noticing. I don't think measuring THD at 1kHz at some fixed level has much to do with how those things sound. Too bad none of us have more comprehensive measuring equipment.
Also, been thinking about how to measure that transitory distortion Martin Mallinson talks about when there are transients in music and modulator state variables are settling. Sometimes people have used test signals where the levels are stepped up and down to capture dynamic effects such as with compressors. Maybe something like that with signal averaging could pick out something interesting or useful to look at from a measurement perspective for delta sigma dacs. Don't know.
EDIT: Recently I did have the experience of tweaking ESS dac harmonic distortion compensation, and only a very little bit. I think it changed the brightness of the sound much more than I would have expected, and strangely something audible does seem to change. Makes no sense at all to conclude it amounts to directly hearing a change in distortion of a fixed sine wave down at the level. I kind of expect there are some more complex mechanisms in the dacs that I certainly don't claim to understand. I would be very interested to study it. Also, I think it would help if we could get some skeptics in the same room for awhile and have them spend some time developing listening skills. Eventually, some people are going to hear the effects, and they don't sound at all like low level volume level changes sound. When the skeptics start to notice too, then we will probably at least be able to agree there is something more to study, whatever it is. All, IMHO, of course.
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Quite a few people DO have comprehensive measuring equipment. Richard has almost everything. Find someone nearby with an AP that does multitone (did I mention I like multitone testing). That gets you a much better picture of if anything is majorly wrong.
But I'm in the great unwashed who think that, if a 32 tone test shows nothing above -100 then jobs done at least for IMD type issues.
But I'm in the great unwashed who think that, if a 32 tone test shows nothing above -100 then jobs done at least for IMD type issues.
Richard does have some kind of AP, and once in a particularly trusting moment said I could even borrow it. But, it is a treasure of his and I don't like borrowing things of that nature. I don't like borrowing things at all, as far as that goes. Also, I think I would have to spend some time with the thing to get up to speed on it. And I don't think I could ask someone else to keep running tests for me as I keep changing this or that little thing in the dac. Not to mention the hassles of driving back and forth over the mountain. I am too old for that kind of commute. Don't know what the answer is. Maybe I should start reading the 500 or whatever page manual then see.
EDIT: However, as far as the guys over in the dac thread, they have different interests than the crowd over here. Most are not sound quality skeptics or experienced listeners either, although a few are the latter. Over here people are more interested to see if people are just nuts or what the story is when it comes to some of the things people claim to hear. I have a foot in both camps, and don't find some listening claims credible at all.
EDIT: However, as far as the guys over in the dac thread, they have different interests than the crowd over here. Most are not sound quality skeptics or experienced listeners either, although a few are the latter. Over here people are more interested to see if people are just nuts or what the story is when it comes to some of the things people claim to hear. I have a foot in both camps, and don't find some listening claims credible at all.
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Hi Bill,
I was in that boat. I had an HP 339A and a couple spectrum analysers on the bench. I was taking the THD residuals and feeding them to oscilloscopes and spectrum analysers. That helped a lot. But, I needed something like the RTX (which I was lucky enough to buy) to really see what was beyond my noise floor. Talk about frustrating when changes are made to the circuit and your measurements don't change one bit.
The RTX-6001 may or may not be the equal of an AP, but since I can't afford an AP anything, the RTX will be my version of an AP. The U8903B from Keysight is another dream I have for the bench. But at the core of things is the ability to take reproducible readings that cover the murky depths below the noise floor of the equipment I'm working on. That's without jumping through hoops to take those readings.
Improving audio equipment without the ability to see what effects you are having is like camping in the deep bush without a compass. And, just as silly.
-Chris
I was in that boat. I had an HP 339A and a couple spectrum analysers on the bench. I was taking the THD residuals and feeding them to oscilloscopes and spectrum analysers. That helped a lot. But, I needed something like the RTX (which I was lucky enough to buy) to really see what was beyond my noise floor. Talk about frustrating when changes are made to the circuit and your measurements don't change one bit.
The RTX-6001 may or may not be the equal of an AP, but since I can't afford an AP anything, the RTX will be my version of an AP. The U8903B from Keysight is another dream I have for the bench. But at the core of things is the ability to take reproducible readings that cover the murky depths below the noise floor of the equipment I'm working on. That's without jumping through hoops to take those readings.
Improving audio equipment without the ability to see what effects you are having is like camping in the deep bush without a compass. And, just as silly.
-Chris
Something like that anyway. What I do have here to keep me honest is a Benchmark DAC-3. If I can change my project dac to sound closer to DAC-3, I know it was probably a move in the right direction. It really does help to use it that way, and without something to serve as some kind of reference one way or another I would agree it would probably not be possible to avoid getting lost.
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