John Curl's Blowtorch preamplifier part III

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It even surprises me as to how much we did, on the side, back 40 years ago. Of course, we wrote some articles for the AES, IEEE, Audio, and even The Audio Amateur, but we had to make a living also. At this time I designed, amps, preamps, xovers, studio boards, and new electronics for master recorders. It kept me fairly busy, but it was not a very good living.
 
I've been eyeing these:
Why?

I keep expecting to find a Sabre DAC with a basic opamp I/V converter but for some reason they don't seem to exist commercially except for huge markup.

You might find an ES9028Q2M dac board with I/V and differential summing, but so what? The lowest price ones need I2S input, similar to AKM boards (which tends to add cost). And there are lots of other things that need fixing besides having an I/V output stage. Hardly makes much difference if the rest of the implementation is junk. :confused:
 
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Letters?

Not an article?

Jn

we had no intention to write an article from the beginning. Most of the time, I was just an invited participant. Peter Moncrieff is the writer and has a periodical. What ever is documented were informal conversations and inquiry. More or less, because we all want to do better and learn more and all live in same general area --- the Bay area of California. I had full time job at LLNL.

See IAR/P.Moncrieff for such info you ask about.


THx-RNMarsh
 
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It even surprises me as to how much we did, on the side, back 40 years ago. Of course, we wrote some articles for the AES, IEEE, Audio, and even The Audio Amateur, but we had to make a living also. .

yeah, me too. So much of what we learned and put out there is now in everything and all the DIY projects as well apply them. That is very satisfying. It was a very creative and productive time. We didnt invent something important to the world... like the transistor. But we opened doors into whole new subject areas not considered before or in the same way. Everything became suspect. All was opened to inquiry and inquire we certainly did. Take a bow, JC etal.

It was/is a passionate hobby interest. Much time and money has been wasted on it :)

Its Only Rock and Roll. But, I like it. I like it.


-Richard
 
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For measuring. Getting low noise and distortion from a ES9018 board is simple enough: Chinese ES9018K2M I2S DAC By all means, share what is the correct purchase to make for a low cost ADC/DAC.
Thanks KT, I have a capable playback USB DAC already - CM6631A which lives in my hi-fi system. What I need is outboard Sound Card ie ADC/DAC and usb interface. I do have a Tascam USB ext SC but it is dated in terms of sample rate and internal noise. I was hoping for a cheap Chinese pcb with fixed level ins and outs suitable for mounting in a case and better performance than what I have now, iow I am looking to build the likes of AP, Prism etc measuring interface on the cheap. Dan.
 
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... I was hoping for a cheap Chinese pcb with fixed level ins and outs suitable for mounting in a case and better performance than what I have now, iow I am looking to build the likes of AP, Prism etc measuring interface on the cheap.


Dan.

It really depends on your def. of "better" and "cheap".
Me, I chose to buy a Focurite Solo, ready to go for about $100 (actually got it used for $50 :)). With the line input, the floor is about -100dB, pretty consistent with ARTA and DiAna.
 

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It really depends on your def. of "better" and "cheap".
Me, I chose to buy a Focurite Solo, ready to go for about $100 (actually got it used for $50 :)). With the line input, the floor is about -100dB, pretty consistent with ARTA and DiAna.
Thanks Z, that's 20dB better than what I have and good enough except that I need identical input stages.
These things retail here new for $125 or so.....case, knobs, packaging, distribution, dealer markup, taxes etc.....so just how much does such a complete board cost ?.
Are there ASIO capable Ebay populated pcb versions that will do the same job ?.


Dan.
 
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What I need is outboard Sound Card ie ADC/DAC and usb interface.
I do have a Tascam USB ext SC but it is dated in terms of sample rate and internal noise.
I was hoping for a cheap Chinese pcb with fixed level ins and outs suitable for mounting in a case and better performance than what I have now, iow I am looking to build the likes of AP, Prism etc measuring interface on the cheap.

We want the same thing. Ebay kits are generally focused on DACs, there aren't many ADC kits and I don't think I ever found a single one that had a good ADC and a good DAC on the same board. It is nice to have the DAC and ADC on the same clock source.
 
For measuring.
By all means, share what is the correct purchase to make for a low cost ADC/DAC.

Ah, if measurement is the only issue, and you aren't too picky re how it sounds, Khadas Tone Board dac measures quite well for $99.

The reason I stipulate about sound quality vs typical measurements we use is reasonably well described in the following post: https://www.diyaudio.com/forums/dig...8-modding-topping-dx3-pro-11.html#post5726922

I should stop here, as no need to restart the never ending debate.
 
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Ah, if measurement is the only issue, and you aren't too picky re how it sounds, Khadas Tone Board dac measures quite well for $99.
That's only a DAC?


The reason I stipulate about sound quality vs typical measurements we use is reasonably well described in the following post: https://www.diyaudio.com/forums/dig...8-modding-topping-dx3-pro-11.html#post5726922

I should stop here, as no need to restart the never ending debate.


No need at all, but please remember that the plural of anecdote is not data, nor is it proof.
 
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