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Old 23rd November 2012, 04:24 PM   #701
smms73 is offline smms73  Portugal
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Quote:
Originally Posted by RollE2k View Post
PCB is for stereo channel single ended?
If you do a PCB for ESS9018 will it be balanced?
also, what is the approx power draw for this circuit (as it is right now)?
If I made a version for the 9018 it will be very similar with this, but with another input , and more power hungry. The ess9018 have very low output impedance when use with parallel output , and this makes very difficult to design a good I/V converter without the use of feedback. But first I will finish this project.

This circuits use 30ma for the I/V part 6.2ma for the offset current source , that have 2 jumpers to inhibit if not needed. And the power drawn by the opamp of DC servo , 4ma if use opa2134 as I will use . the voltage is plus minus 15 volts.
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Old 23rd November 2012, 05:34 PM   #702
avr300 is offline avr300  Denmark
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Quote:
Originally Posted by smms73 View Post
If I made a version for the 9018 it will be very similar with this, but with another input , and more power hungry.
I would be more than happy to try one. Keep up the good work
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Old 23rd November 2012, 06:26 PM   #703
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There are a bunch of people with 9018 DACs that would LOVE to try a version of this I/V Thanks from me too...
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Old 24th November 2012, 07:39 AM   #704
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I am thinking to step forward from separating ground return path,
not to separate "forward path" with SEPP as sen IVC not cen IVC ,though it is class A.
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Old 5th December 2012, 05:23 PM   #705
smms73 is offline smms73  Portugal
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Monday i made some home made board for testing, to be sure that every thing is ok before i send gerber files for production. I have already drill them but i stil need to buy components. Last week was a bit complicated and things advanced more slowly than i wish , but thats live.
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Old 5th December 2012, 05:44 PM   #706
smms73 is offline smms73  Portugal
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To increase flexibility and compatibility with more dac chips, I have included a reference voltage input , for use with dacs that need a offset voltage at the input, like ess9018 , ess9012. The new input is the one named "SET".
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Old 5th December 2012, 06:14 PM   #707
smms73 is offline smms73  Portugal
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Quote:
Originally Posted by Nikola Krivorov View Post
There are a bunch of people with 9018 DACs that would LOVE to try a version of this I/V Thanks from me too...
last week i visited a audio show with a lot of high end products, and that make me want to build an amplifier without feedback, and i am already testing some ideas to attain that. so a I/V converter design exclusively for ess9018 is not a priority right now.

But i have modified the pcb like i said in prior post, to use this I/V with the ess9018, but each pcb can only be connected to 2 dacs from ess9018 maximum, the ideal is one I/V pcb for each of the 8 dacs.
The output of the I/V converter boards will be paralleled, and only one servo and one buffer per channel will be needed the others 3 or 7 tagus pcb will run in slave and dont need the servo or the output buffer. I will post the connection schema for this.

In resume: is possible to use this pcb for the ess9018 , but we need at least 4 pcb per channel running in parallel. The ideal is 8 pcb per channel.
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Last edited by smms73; 5th December 2012 at 06:17 PM.
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Old 5th December 2012, 06:24 PM   #708
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Big project, good luck and i look forward for your amp design.
I do not think that using feedback in the voltage amplifying stage is a problem but to make the output separate from the input feedback is certainly a good idea. I still have good memory when i first heard the Threshold Stasis, no sharpness and grain at all and a HUGE soundstage.
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Old 5th December 2012, 06:40 PM   #709
smms73 is offline smms73  Portugal
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Some people have sent me PM asking if i will sell it, or organise a group Buy, i have never do that before, but i think if a certain number of people are interested , it is possible to sell it for 12,5 euros each board and 10 euros if more than 8 pcb are required.
I have made a new email adress for this. So if you want to have this PCB sent me a email with your email address, DAC chip that you want to use and number of boards that you require. this is just for me to know the quantity of boards that i need to order. You dont need to pay nothing just yet.

note that it may take a month until the pcb are ready to send. I only do this at my spare time , when i have spare time, as my regular job takes me much time.
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Old 5th December 2012, 07:00 PM   #710
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Hi Serg, the boards seem to be mono looking at the pic is that right?
So you need two for stereo @ 12.5euros each?
25euros for a stereo set?

Cheers George
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