John Curl's Blowtorch preamplifier part II - Page 1072

Steve Eddy · 6th March 2011, 09:18 PM

Quote:

Originally Posted by john curl

Steel! Let's measure the added distortion!

Well, we've got measurements of an interconnect with a copper clad steel core which actually has signal flowing through it rather than something that's just in the vicinity.

No distortion there. At least nothing that can be seen above -145dB.

se

Steve Eddy · 6th March 2011, 09:19 PM

Quote:

Originally Posted by john curl

Ultra caps can power flashlights, they can easily do a pilot led.

But the light doesn't look as good as it does when it's powered from a low impedance power supply.

Try it yourself.

se

SY · 6th March 2011, 09:22 PM

Quote:

Originally Posted by scott wurcer

In fact the AD745 is my own personal IC Blowtorch, probably a reasonable portion of them ended up as RIAA's.

Always good to know where the barber gets his hair cut.

john curl · 10:56 PM

Darn, can't even engineer something without people putting out lies and mis-information, such as low Z driving an LED. '-) This doesn't work, folks.

Steve Eddy · 6th March 2011, 11:16 PM

Quote:

Originally Posted by john curl

Darn, can't even engineer something without people putting out lies and mis-information, such as low Z driving an LED. '-) This doesn't work folks.

Well, suggesting charging a capacitor with one of these doesn't inspire much confidence.

se

john curl · 6th March 2011, 11:28 PM

Sorry everyone, I should have said PHOTOVOLTIC, rather than PHOTO (cell) in my original phrasing. I don't want to mislead anyone here, just convey a new idea. Gotcha, is a Steve Eddy trademark.

john curl · 6th March 2011, 11:29 PM

Next time when I say 'transistor' SE can easily say: Bipolar or unipolar? And so it goes.

jacco vermeulen · 6th March 2011, 11:36 PM

Quote:

Originally Posted by Steve Eddy

one of these doesn't inspire much confidence.

Okidoki, how about this :
http://www2.dupont.com/Photovoltaics...netsolar_1.jpg

(for joyriding, better steal the one in the top right corner : +45mph Italian aluminum boat, called Adler)

Steve Eddy · 7th March 2011, 12:02 AM

Quote:

Originally Posted by john curl

Next time when I say 'transistor' SE can easily say: Bipolar or unipolar? And so it goes.

No, because bipolars and FETs are all transistors. A photocell and a photovoltaic are two different animals.

se

john curl · 7th March 2011, 10:08 AM

Moving on, I hope, to a more appropriate input.
I would like to talk, once more, about 2 stage phono design vs single or 1 stage phono design.
We have discussed the 1 stage phono design in some detail, some months ago. It can be made very cheaply, and was the design standard from many decades. Marantz, Mac, and Dyna phono stages in the '50's and the '60's, used this approach. Later, the Audio Research and the Mark Levinson JC-2 also used this approach, in the 1970's.
However, by 1980, many other phono designers started to use 2 stage design. This included: Electrocompaniet, the JC-80, Vendetta Research, and certainly many others.
In most cases, the 2 stage approach, whether made with vacuum tubes, solid state discrete, or IC's, tend to sound better, all else being equal.
You will find a tube design here, on this website, by SY, an excellent example of this design technique. Perhaps if you reviewed his preamp and the write-up around it, you would gather most of what you need to know about the 2 stage approach. (More later, if possible.)

6th March 2011, 10:48 PM	#10714
john curl diyAudio Member Join Date: Jul 2003 Location: berkeley ca	Darn, can't even engineer something without people putting out lies and mis-information, such as low Z driving an LED. '-) This doesn't work, folks. Last edited by john curl; 6th March 2011 at 10:56 PM.

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6th March 2011, 11:28 PM	#10716
john curl diyAudio Member Join Date: Jul 2003 Location: berkeley ca	Sorry everyone, I should have said PHOTOVOLTIC, rather than PHOTO (cell) in my original phrasing. I don't want to mislead anyone here, just convey a new idea. Gotcha, is a Steve Eddy trademark.

6th March 2011, 11:29 PM	#10717
john curl diyAudio Member Join Date: Jul 2003 Location: berkeley ca	Next time when I say 'transistor' SE can easily say: Bipolar or unipolar? And so it goes.

7th March 2011, 10:08 AM	#10720
john curl diyAudio Member Join Date: Jul 2003 Location: berkeley ca	Moving on, I hope, to a more appropriate input. I would like to talk, once more, about 2 stage phono design vs single or 1 stage phono design. We have discussed the 1 stage phono design in some detail, some months ago. It can be made very cheaply, and was the design standard from many decades. Marantz, Mac, and Dyna phono stages in the '50's and the '60's, used this approach. Later, the Audio Research and the Mark Levinson JC-2 also used this approach, in the 1970's. However, by 1980, many other phono designers started to use 2 stage design. This included: Electrocompaniet, the JC-80, Vendetta Research, and certainly many others. In most cases, the 2 stage approach, whether made with vacuum tubes, solid state discrete, or IC's, tend to sound better, all else being equal. You will find a tube design here, on this website, by SY, an excellent example of this design technique. Perhaps if you reviewed his preamp and the write-up around it, you would gather most of what you need to know about the 2 stage approach. (More later, if possible.)