BTW, where you thinking that it would be still good idea to have transimpedance on the first stage or these other one since it's low noise propriety?
You can purchase a kit from Pilgham Audio but i think you are more interested in the schematic. That is in Linear Audio volume 0.
I am quite tired today but i send you an e-mail with Jan´s e-mail address tomorrow.
In the meantime here is a basic circuit to do balanced without the need of a double RIAA.
It also has the Instrumentation Amplifier structure in simplified form.
I am quite tired today but i send you an e-mail with Jan´s e-mail address tomorrow.
In the meantime here is a basic circuit to do balanced without the need of a double RIAA.
It also has the Instrumentation Amplifier structure in simplified form.
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I would be curious to see what is the actual distortion loss by having double RIAA with better than 1% matching on the parts, which is the real case.
I would personally go if you guys are ok, with transimpedance 75uS first stage in balance mode and then second stage with possible a variant of what I have posted (waiting to get linear audio 0) or if some other better idea come up we can evalute them as we go.
As soon as we frooze the schematic I will make layouts and boards that I have decided to share with the guys who have been working on this with me which is Joachima and MiiB so we can all be on the same page.
Distortion is not the problem but loss of micro detail by cancelation of small gain differences over the scale, something you try to avoid by using ultra low loss precision passives.
Other then that you have my approval to go the 75usec transimpedance balanced in first stage road. That gives you a huge advantage in terms of " natural" distortion profile and overload margin where it most matters, in the treble where the dirt is. I would do the second stage active but that is your choice. The FPS is full active, double RIIA, shunt.
That is one other way because the super high treble is simply steered around the amplification stage. The treble caps shunts the active stage so i call that "forward coupling". Study the FPS article. It is long.
Other then that you have my approval to go the 75usec transimpedance balanced in first stage road. That gives you a huge advantage in terms of " natural" distortion profile and overload margin where it most matters, in the treble where the dirt is. I would do the second stage active but that is your choice. The FPS is full active, double RIIA, shunt.
That is one other way because the super high treble is simply steered around the amplification stage. The treble caps shunts the active stage so i call that "forward coupling". Study the FPS article. It is long.
And here ...Down the Rabbit Hole - Adventures in the Land of Phonostages
The article is called "Down the rabbit hole" out of good reason.
The article is called "Down the rabbit hole" out of good reason.
Sorry if I haven't replied any sooner.
I saw your posts last night but I was at the acoustic concert of Brendi Carla at a theather by the River in Miwaukee.
Let me catch up with the articles you posted.
You mentioned you would have send me an email with Jan's contact or something for the Linear Audio Issue, maybe you forgot...just wanted to remind you.
I would like to have a PDF version if possible, don't know if they are available in PDFs to purchase.
I saw your posts last night but I was at the acoustic concert of Brendi Carla at a theather by the River in Miwaukee.
Let me catch up with the articles you posted.
You mentioned you would have send me an email with Jan's contact or something for the Linear Audio Issue, maybe you forgot...just wanted to remind you.
I would like to have a PDF version if possible, don't know if they are available in PDFs to purchase.
Here is a noise simulation for 2 stage, differential arrangement. Stage 2 just for convenience now I used the one posted already (obviously it will change).
It shows the contrast of Paradise vs this configuration.
Noise is significantly higher and this is pretty much what I have experienced anytime I would attempt a 2 stage approach with Passive RIAA.
In series we have a 29K resistor along with the rest of the network to form the 3180uS and 318uS time constants.
However by doing this isn't basically putting a limit to what noise foor will be based on the series resistor of the fiter?
Here is the screen shot.
It shows the contrast of Paradise vs this configuration.
Noise is significantly higher and this is pretty much what I have experienced anytime I would attempt a 2 stage approach with Passive RIAA.
In series we have a 29K resistor along with the rest of the network to form the 3180uS and 318uS time constants.
However by doing this isn't basically putting a limit to what noise foor will be based on the series resistor of the fiter?
Here is the screen shot.
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