John Curl's Blowtorch preamplifier part III

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#6,882
Hi phase,
Have you compared performance between current output and voltage outputs when the DAC allows a choice between them?

Differences between how the designer treats the audio signal from the converter on forward makes a massive difference in how it sounds. That's why machines using the same DAC can sound so different.

-Chris
 
#6,883
If we have a fall Diyaudio get together in Toronto the dac will likely be there and Chris can listen. It’s not an ideal listening environment to judge critically, a noiser, bigger, and more reflective room than a typical home environment with an unfamiliar and changing electronics system, along with somewhat overbearing monitor speakers.
 
#6,884
What do you mean by "if"??? I'm counting on it.

I was looking forward to seeing your DAC. Maybe I can listen to it at my place ... or maybe I can build one for myself. That's what I was thinking right after I saw your post. My personal preferred analogue stage is the diamond buffer or derivatives of that design.

Knowing how diamond buffers perform, I'm reasonably certain that I would like to build one of my own. I'm not big into external DAC stages, but this one really interests me. I'm actually motivated to build one, and that isn't that common when I have so much to do.

-Chris
 
#6,885
john curl said:
Ticknpop, I like your approach. It is also what I am trying to do, over time. I too think that virtually EVERYTHING is important, and it is best to do it 'right' rather than rationalize that parts that cheaper or easier to get, but considered less 'ideal' for the purpose of just getting something to work or measure OK. A good example might be: Mylar vs polystyrene. Mylar can measure pretty well with standard tests like harmonic, or IM. But when you measure DA, there is a world of difference. It's best to put the highest quality parts in, because you never know what might show up in actual listening quality.
Click to expand...

Reflection... at the time SS came out for audio, it was not as good sounding as tubes.... some was due to poor quality circuitry which relied on poor quality polar coupling caps. The tube gear all used lower DA mylar type. This one difference was a large reason SS was not liked as much. When the SS circuit coupling substituted PP or direct coupled, the sound got a lot better. Other characteristics like slew induced distortion was there in many SS amplifying circuits. But it was the change in caps and to servo dc which turned the tide for SS more and more with direct-coupled SS designs. Now the norm. After that point, attention was to power supplies and what is needed there besides ripple smoothing/hum. Low Zo over the amps BW was determined to make the sound more realistic and accurate. First by noticing the effect of film bypassing in the PS. Then towards electronic means. Further refinements of these two basic fundamental issues still proceed.... in parts and circuitry. It got us to listen more critically to the sound and what accuracy means.... a discussion which still continues today.

-Richard
 
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#6,886
The next 'frontier' in the process towards higher accuracy was from work on ac power. The study of noise on the ac lines and where it originates started the next round of improvements. From isolation filters, introduced to the consumer thru Monster branded products became the basis for a whole new category and industry. From there into better psrr and dc isolation filtering and understanding the ground issues better for the products as a system.

The 'fine tuning' has been in more advanced topologies for SS designs. Notably the current-mode feedback operation of amplifier designs applied to audio. Now with CAD and combining all the known best elements, we have arrived where amplifiers are highly effective in creating truly blameless amplifiers of high precision and accuracy. Capable of extraordinary musical realism/accuracy.

Meanwhile, the source have developed ... CD and players. 24/96+. HD masters downloaded from the internet. Loudspeaker modelling and driver refinements have progressed with application of waveguide theory and controlled directivity. More needs to be done, however.

Its been a nice run. Where will the next gen take us? A further development of 'surround' or muliti-channel sound is VR and 3D sound is here (hear) to be enjoyed as a future staple in the home theater/music system. beyond that? Sound sent directly to the brain, bypassing the ear. Its here already and being used on the deaf. Think about that..... extended freq range, no losses due to aging. No room interference/influence, 3D inside the mind without VR head-gear. Hmmm. Where will that take us and how will it be controlled and used? By whom?


-- Richard aka RNMarsh
 
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#6,887
RNMarsh said:
.......beyond that? Sound sent directly to the brain, bypassing the ear. Its here already and being used on the deaf. Think about that..... extended freq range, no losses due to aging. No room interference/influence, 3D inside the mind without VR head-gear. Hmmm. Where will that take us and how will it be controlled and used? By whom?
Click to expand...
Hmmmm, this last step relies on RF/magnetic coupling.
Do we really understand what man made RF does to the body/mind/consiousness ?.
By modifying antennas I am able to change sound of BT or WiFi transmitted digital audio, go figure.
I am also able to change the sound of drivers by treating magnets, go figure.
There is more to magnetics and RF than meets the eye.

Dan.
 
#6,889
Max Headroom said:
Hmmmm, this last step relies on RF/magnetic coupling.
Do we really understand what man made RF does to the body/mind/consiousness ?.

Dan.
Click to expand...

I have a friend who has been deaf since birth. A couple Years ago he had a system installed on his head (like a coil maybe) that transmits audible mic signal into his brain and he hears. It is about the size of a quarter (american). His hair covers it. I will see him again Sept 4 when he visits me. Yeah. Its real alright.


-RNM
 
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