dac I/V convertion with very low distortion - Page 70

Joachim Gerhard · 22nd November 2012, 10:00 AM

Cool.

smms73 · 22nd November 2012, 10:53 AM

3D images of the board , but i have to do some modifications , change some traces from bottom to top to have a wider ground superficie in bottom, and add some connectors to input output and power, hope i have time this night to finish it.

MiiB · 22nd November 2012, 11:08 AM

what is the purpose of the second opamp...?? phase-inversion..??

you can make a second pole by splitting the servo input-resistor in two and then have a cap to gnd in between.

smms73 · 22nd November 2012, 12:09 PM

Yes MiiB, phase inversion. Is better to have the second pole in the output of servo to filter the noise of opamp.

I must say that is not a good idea to use this type of servo in a feedback loop of a power amplifier, but in a open loop circuit like this is oK.

RollE2k · 22nd November 2012, 10:11 PM

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)?

Shinja · 23rd November 2012, 05:45 AM

smms,
It seems you can route more wires on components side, not to devide ground plane.

the circuit conveys input current to output, and the current flows to ground through the IV resistor and paralleled capacitor, so it may be some benefit to separate ground return pass and ground plane.

smms73 · 12:47 PM

Yes Shinja, I have already changed some traces to the top side as i said in post #692.
I have take attention to the ground currents paths and the inductance of ground , important is to get the currents of the rail capacitors away from the path of the signal, there is no need to separate the ground.

smms73 · 23rd November 2012, 12:42 PM

RollE2k one pcb per channel , for stereo need 2 for balanced is 4 boards.

Shinja · 23rd November 2012, 01:44 PM

excuse me smms.
I took too much attention to the picture,so I did not read your post fully.

smms73 · 23rd November 2012, 04:05 PM

Im not that good to express myself, especially in English :-)

I will separate the ground return of the rail capacitors from the rest of the ground .
This weekend will be the audioshow in Lisbon so I will not have much time left , but I hope next week to have 2 prototype board made.l am very curious to listening the final results of all of this.

22nd November 2012, 11:08 AM	#693
MiiB diyAudio Member Join Date: May 2005 Location: Denmark	what is the purpose of the second opamp...?? phase-inversion..?? you can make a second pole by splitting the servo input-resistor in two and then have a cap to gnd in between. __________________ http://www.linkedin.com/pub/michael-...esen/a/a55/544 http://www.raidho.dk/

22nd November 2012, 12:09 PM	#694
smms73 diyAudio Member Join Date: Jul 2005 Location: Lisboa, Portugal	Yes MiiB, phase inversion. Is better to have the second pole in the output of servo to filter the noise of opamp. I must say that is not a good idea to use this type of servo in a feedback loop of a power amplifier, but in a open loop circuit like this is oK. __________________ Sérgio Santos

23rd November 2012, 12:39 PM	#697
smms73 diyAudio Member Join Date: Jul 2005 Location: Lisboa, Portugal	Yes Shinja, I have already changed some traces to the top side as i said in post #692. I have take attention to the ground currents paths and the inductance of ground , important is to get the currents of the rail capacitors away from the path of the signal, there is no need to separate the ground. __________________ Sérgio Santos Last edited by smms73; 23rd November 2012 at 12:47 PM.

23rd November 2012, 12:42 PM	#698
smms73 diyAudio Member Join Date: Jul 2005 Location: Lisboa, Portugal	RollE2k one pcb per channel , for stereo need 2 for balanced is 4 boards. __________________ Sérgio Santos

23rd November 2012, 04:05 PM	#700
smms73 diyAudio Member Join Date: Jul 2005 Location: Lisboa, Portugal	Im not that good to express myself, especially in English :-) I will separate the ground return of the rail capacitors from the rest of the ground . This weekend will be the audioshow in Lisbon so I will not have much time left , but I hope next week to have 2 prototype board made.l am very curious to listening the final results of all of this. __________________ Sérgio Santos


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22nd November 2012, 10:00 AM	#691
Joachim Gerhard diyAudio Member Join Date: Mar 2009	Cool.

22nd November 2012, 10:11 PM	#695
RollE2k diyAudio Member Join Date: Nov 2007	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)?

23rd November 2012, 05:45 AM	#696
Shinja diyAudio Member Join Date: Jul 2008	smms, It seems you can route more wires on components side, not to devide ground plane. the circuit conveys input current to output, and the current flows to ground through the IV resistor and paralleled capacitor, so it may be some benefit to separate ground return pass and ground plane.

23rd November 2012, 01:44 PM	#699
Shinja diyAudio Member Join Date: Jul 2008	excuse me smms. I took too much attention to the picture,so I did not read your post fully.

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