John Curl's Blowtorch preamplifier part II

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#63,021
RNMarsh said:
You try it. Not my game. mine is to explore the imperfections and see what it will take to make it more realistic. Why dont you try my idea?
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Because I'm all too aware of the limitations of "your idea" and do t care to wate time chasing my tail.

Most people here have read that I dont actually care half the time if I can hear it this way or that way or at all..... I enjoy circuitry, topologies, tests & measurements, music listening etc. Like John, I believe in what I have learned to hear. There are a lot of things that are very very hard to hear any differences. I could give examples. And, there are times like what I described which is not hard to hear the change (for the better IMO).
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And like John, you're in complete denial of your own humanity.

You pass yourselves off as individuals working to increase our knowledge and understanding. But really all you've done is just create a lot of confusion and misinformation. You're just a joke to be laughed at by those who actually do have a genuine interest in increasing our knowledge and understanding.

The problem is that you're completely oblivious to this fact and just continue to play numbers games and repeat the same nonsense over and over.

Remember, we arent doing anything so important as finding a cure for cancer.
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Credibility isn't the exclusive province of those finding a cure for cancer. This is nothing but a charlatan's cop out.

se
 
#63,022
fas42 said:
I was just reminded, again, what can be achieved by pulling out all the stops, and this, www.Basspig.com The Bass Pig's Lair, describes how to go about it, and what it delivers ... 😉
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My kind of guy! I use 4 each 15 inch cerwin vega for Bass and two 18 inch TC Sounds massive things for subs below 40Hz. Electrostatic mid-top. Some day stacked quad of them. Probably can produce high SPL at low freq but dont try to. Clean and accurate. AC line regulation (Elgar) for all except PA to woofers/subs, individual equip ac line filter isolated. No reflections before 15ms at the listening position.



THx-RNMarsh
 
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#63,023
Steve Eddy said:
Because I'm all too aware of the limitations of "your idea" and do t care to wate time chasing my tail.

se
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I dont let others define who I am. But, you are free to keep trying. I have yet to learn anything I didnt already know from you. From others, yes.

BTW - I have already discussed my thoughts on the need for DBLT and that it is needed at first cut but isnt enough and why. Not going back there dancing with you.... like it or not.

Decided to order a BenchMark ADC 1/USB to contribute to my educational project. Meanwhile, try to keep the noise level down around here.


-RM
 
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#63,024
Kindhornman said:
Richard,
You keep referring to not using a CDP to play back music, but unless you have all of your music stored on SSD I don't really see the advantage of a spinning hard drive reading with a magnetic pickup and a CD player? If you are indeed using only SSD drives then I would ask is that SSD internal to a computer or is it satnd alone in your configuration? I see so many problems with internal drives for music storage at a very high level, then you have to deal with all the electrical interferences that are inside every computer that I know of. Even with a NAS server it seems we still have to deal with many of the same issues.
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Most players load (buffer) either partially . or fully into RAM.
My FLAC's are listened to "right off the stick". Even my magnetic HDD's will read once and play fully from the DDR3 ram.
Network music , too - read it fully into ram !
PC's are "dirty". RAM - software(dsp) - spdif (optical) -DAC- 200W amp- speakers ... "clean route" !!

OS
 
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#63,028
RNMarsh said:
BTW - I have already discussed my thoughts on the need for DBLT and that it is needed at first cut but isnt enough and why. Not going back there dancing with you.... like it or not.
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Well until you can adequately control for the well known and well established human weaknesses (hint: vanity and ego are not adequate controls) then you're just ******* into the wind and should simply not be taken seriously by any thinking individual.

se
 
#63,030
davym said:
I can usually tell a 320kbs MP3 file from the WAV i converted it from but i have to admit it takes decent material to do so. 24/96 is much harder and to be honest, in a proper double blind test i would probably fail. That is my honest take on this based on listening to the dozen or so real high resolution files i have.
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😎🙂 pretty much mine as well. 24/96 is very very good.

Contrary to se assertions, I have done such tests from about 1975 (DBLT) to recently here at DIYAudio when I did a listening comparison while in Thailand.


THx-RNMarsh
 
#63,031
Kindhornman --- I have an external system. I agree that is the best way. Check the many brands available at modest cost -- E-MU is a popular one and mods have been done to them by DIYAUDIO members on other forums.
Some external brands are being used as test equipment to measure distortion down to about -100dB with them. I have been on those forums mostly. I compared' sound cards' - external units with my Audio Precision 2722 and other analyzers for their accuracy. I found the low cost 24b external sound cards not to be accurate below -100dB even though you can read data below that level.... it is worthless data for analysis but may sound very good. Get the best external converter(s) you can afford.


THx-RNMarsh
 
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#63,033
Kindhornman said:
OS,
I would assume that those using their PC for music storage also have a sound card inside that PC and are using that to convert to analog. I don't expect many have external systems such sa you just mentioned.
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Well , they better upgrade !

The S/PDIF coming out of my lowly realtek onboard is the same digital stream
that comes out of "fancy pants" asus/e-mu from a software driver.

Plug it in to your Ebay 24-bit kit or your TV , the digital stream has the same info.
SQ is the DAC/analog at the other end , whether it's an optical/electrical (or USB)
route.
PS - on better sound card , some of the DSP/multichannel features are hardware based and DO get sent out the S/PDIF
My onboard S/Pdif supports 8 channel HDMI - I only want 2 !!
Edit - the analog of my onboard is only -102db , my amp is 15db quieter !!
OS
 
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#63,035
#63,036
To reduce playback distortion requires the proper tip geometry of the needle for mono vs stereo grooves. Shure did a lot of development on its stereo V15 and produced many research papers.

Back when I had my first phono system, I loved listening to Tubular Bells and many well recorded DG records. But ultimately the very high distortion, surface noise etc got to me; Distortion of several percent is common --- The actual technical merits:

High Fidelity Phonograph Cartridge - Technical Seminar See Section 4 for distortion.


http://shure.custhelp.com/app/answe...idge---technical-seminar#DesignConsiderations See section 3.

The totals of the harmonic distortion and IM distortion shown would be quite a bit higher! What.... 5-10% ?

THx-RNMarsh
 
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#63,038
RNMarsh said:
...but the good news is that we thought to try a differential comparator (subtraction) between a pure analog sine wave(s) and its digital R/P in parallel path. Look to see what differences there are at various levels. Could even compare different types of converter architecture etc. But then there ought not be any differences by some accounts.

Who is up for that?

THx-RNMarsh
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Richard, what's the purpose of such test? Do you want to quantify the damage that's being done by inserting AD/DA in the signal chain? There are so many variables in the hypothetical AD/DA box that, in my opinion, without targeting any _specific_variable_, such test is destined to end in failure.

Some variables I'm talking about are:

1. Analog parts in front of A/D chip:
a) op-amps? discrete? what topology? (distortion, slew rate, output stage design etc.)
b) capacitors, filters (material, design)
c) capacitors, psu
d) resistors
e) what power supply? +5V? +/-5V? +/-15? How well designed?
2. Modulator design of A/D chip (architecture, number of bits - 1, 4, 6? order? resolution?)
3. Decimator of A/D chip (what resolution? output dithered? rounded? DC HP filter, if present, activated?)
4. Master clock (jitter induced artifacts, vibration)
5. Transmission to DAC , transmission induced jitter artifacts.
6. Receiver device:
a) is it 'transparent' or contains SRC?
b) if SRC'ed, how 'good' is that SRC? (what resolution? output dithered? rounded?)
c) how 'clean' is recovered clock (VCO induced jitter artifacts) or how 'clean' is clock driving the output of SRC ?
7. Oversampling filter in front of or inside the D/A chip (what resolution? output dithered? rounded?)
8. D/A chip (architecture, resolution? jitter sensitivity? does it contain SRC?)
9. Analog parts after the D/A chip:
a) op-amps? discrete? what topology? (distortion, slew rate, output stage design etc.)
b) capacitors, filters (material, design)
c) capacitors, psu
d) resistors
e) what power supply? +5V? +/-5V? +/-15? How well designed?

As you can see, before your precious test signal gets to the output it runs through a whole bunch of analog parts and, additionally, undergoes 2 -4 manipulations in digital domain.

Best,
 
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#63,039

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#63,040
Kindhornman said:
Richard,
I assumed that you had an external system. I don't think that many outside of this forum and a few audiophiles would understand the difference that would make in noise reduction.
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I run external USB soundcard connected to my netbook as a matter of course.

That said, the measured performance figures for modern desktop higher end internal soundcards are spectacularly good.
The Xonar_Essence_ST/specifications/ claims 124 dB SNR, Output THD+N at 1kHz:0.0003% (-110dB), and audiophile goodies like Nichicon "Fine Gold" capacitors and
Op-amp swap kit content:
1 x Needle-nose pliers
2 x LME49720
1 x MUSES8820

Dan.
 
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