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Old 11th May 2012, 06:21 AM   #23031
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Well, I tell you what, Bonsai. It just so happens that the JC-3 phono stage is also made with IC's. It would be more expensive, much more expensive, if it was made of discrete jfets.
Of course, you can put together a throw-away piece of junk that will serve as a phono stage for less than $100. I suggest that you do that, but you will never win any listening comparisons with it. I like to win listening comparisons.
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Old 11th May 2012, 11:06 AM   #23032
Bonsai is online now Bonsai  Taiwan
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Nonsense John. Both approaches, if done well, have their merits and can produce fine results.
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Old 11th May 2012, 11:56 AM   #23033
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IC or discrete, a lot of the cost is in the execution & peripherals.

The 750 uses bus bars for power distribution across the main board.
Power lines and signal to the phono boards go through vertical bars, and not wimpy ones either.
Signal enters in the center of the board, with signal ground next to it.
It looks as if a raised resistor is soldered from the top, between the lead of R11 and signal ground, but after the phono board is mounted and soldered to the vertical bars for +/-15V, power ground, signal in, signal ground.

http://www.diyaudio.com/forums/attac...ii-soul750.jpg

(the 4-pin wire connector in the corner of the board is for Rel1 & Rel2)
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Last edited by jacco vermeulen; 11th May 2012 at 11:58 AM.
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Old 11th May 2012, 12:55 PM   #23034
a.wayne is offline a.wayne  United States
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Quote:
Originally Posted by vacuphile View Post
Long enough to have bought some of those opamps I initially thought they were in Akihabara in the beginning of the eighties.

Since you want to learn about me, let me learn about you. Have you yourself done any original electronic designs in the field of consumer or other electronics?
Dutchie !

Dutchie invented the first chillum pipe with an servo actuated door and reverse osmosis smoke degenerative system ...

lead to legalization, fully endorsed by Peter Tosh @the time



Quote:
Originally Posted by jacco vermeulen View Post
IC or discrete, a lot of the cost is in the execution & peripherals.

The 750 uses bus bars for power distribution across the main board.
Power lines and signal to the phono boards go through vertical bars, and not wimpy ones either.
Signal enters in the center of the board, with signal ground next to it.
It looks as if a raised resistor is soldered from the top, between the lead of R11 and signal ground, but after the phono board is mounted and soldered to the vertical bars for +/-15V, power ground, signal in, signal ground.

http://www.diyaudio.com/forums/attac...ii-soul750.jpg

(the 4-pin wire connector in the corner of the board is for Rel1 & Rel2)
Raise psu voltage to 25 and hear her sing .....

Last edited by a.wayne; 11th May 2012 at 12:58 PM.
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Old 11th May 2012, 01:13 PM   #23035
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Originally Posted by vacuphile View Post
Since the location of the tip of the robot arm is determined by the angular rotation at the joints, precission requires rigid arm segments, Any flex introduces errors. Because rigid=heavy, this introduces an arms race between the weight of the arm segments and the motors driving them. A lot of energy is wasted in the process, and it slows down things. So, the idea was to use light weight flexible arm segments, and measure the position of the arm tip to provide feedback to the control electronics.
vac
Cool stuff.

Nowadays, we're using articulated arms to measure positions of fiducials to +/- 15 microns, and an array of 12 laser trackers to get +/- 1 micron. (in a room controlled to +/- .5 degrees C.)

My own work involves that as well as 11 axis motion control to +/- 100 microinches using 7 axis in splined interpolation and 4 followers using algorithm blocks.. The math for this stuff is pretty interesting, no??

j
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Old 11th May 2012, 01:19 PM   #23036
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No!
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Old 11th May 2012, 01:36 PM   #23037
wahab is offline wahab  Algeria
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Quote:
Originally Posted by john curl View Post
.
Of course, you can put together a throw-away piece of junk that will serve as a phono stage for less than $100. I suggest that you do that, but you will never win any listening comparisons with it. I like to win listening comparisons.
100 USD or so are enough for an excellent phono preamp ,
perhaps even including a cheap aluminium dual casing ,
one for the preamp and another one for a PSU....

Just take a very good IC as an HA12017 , it can yield
70dB SNR with a MC head or 80dB with an MM.

If MC SNR is not good enough you can always add
a single discrete fet stage.

Anyway , i doubt that listening tests would show
any audible difference with four digits figures preamps.
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Old 11th May 2012, 01:49 PM   #23038
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Originally Posted by simon7000 View Post
No!
You vill pay for your insolence..
j
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Old 11th May 2012, 02:05 PM   #23039
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Originally Posted by jneutron View Post
You vill pay for your insolence..
j
Let's see you work for Uncle Sam. I pay taxes to fund them.

So we actually agree on something. I do pay for your salary!

(1e5/2e9=.005%!)
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Old 11th May 2012, 02:37 PM   #23040
a.wayne is offline a.wayne  United States
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Quote:
Originally Posted by wahab View Post
100 USD or so are enough for an excellent phono preamp ,
perhaps even including a cheap aluminium dual casing ,
one for the preamp and another one for a PSU....

Just take a very good IC as an HA12017 , it can yield
70dB SNR with a MC head or 80dB with an MM.

If MC SNR is not good enough you can always add
a single discrete fet stage.

Anyway , i doubt that listening tests would show
any audible difference with four digits figures preamps.
You vill ve proven wrong , differences abound ......
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