Mpp

[RCruz]

Originally Posted by hesener

It's actually quite impressive what good sound comes from Wima MKS2 caps, with this stage, so if the V-Caps better that, it should be an interesting experiment.... With all the efforts in the input stage and current mirrors and buffer, I think the Paradise will be very transparent to component changes.....

Those are really good news.... I will build severall riaa circuits to experiment with different kinds of components

I had a wonderfull experiment with Mouser and parts are arriving today ... way cool

I just downloaded the latest BOM from hesener's post on th GB thread... what is the purpose of R104b R204b resistor with X value ?

[hesener]

Originally Posted by RCruz

I just downloaded the latest BOM from hesener's post on th GB thread... what is the purpose of R104b R204b resistor with X value ?

these are just to finetune the current of the CCS in the power supply section. In most cases you will not need them, if your power resistors R104, R204 are reasonably good.

typically in shunt regulators you want to set the current at twice the load current, so that you operate well within the sweet spot of the regulator, and that is the case here. So the absolute value of the CCS current does nto really matter much.

but I will leave it to Frans (the PSU designer) to comment.....

[RCruz]

Originally Posted by Stefanoo

Ricardo,

I guarantee you that the V-Caps CuTFT are the ultimate in terms of sound quality!
Nothing can beat them in terms of precision, transparancy, 3D, musicality.

You should join us, you would be surprised with it.


Anyway....of course...I will post the final simulation for yours/ everybody's enjoyiment.

Thank you so much.... As you can see, my calculations give similar results to your simulation

[jacco vermeulen]

Originally Posted by Stefanoo

Nothing can beat them in terms of precision

Accuracy of all these PTFE caps is 5%, how were you going to solve that ?

[beetle]

A while ago I recommended micas from Jahre. They also do build to order. I think 1% is no problem. Why not go for them?


http://www.jahre.de/index.php?id=61

[FdW]

Originally Posted by RCruz

Those are really good news.... I will build severall riaa circuits to experiment with different kinds of components

I had a wonderfull experiment with Mouser and parts are arriving today ... way cool

I just downloaded the latest BOM from hesener's post on th GB thread... what is the purpose of R104b R204b resistor with X value ?

Originally Posted by RCruz

Those are really good news.... I will build severall riaa circuits to experiment with different kinds of components

I had a wonderfull experiment with Mouser and parts are arriving today ... way cool

I just downloaded the latest BOM from hesener's post on th GB thread... what is the purpose of R104b R204b resistor with X value ?

There are 3/4 parts that set the CCS current: Led L110, Vbe Q102 and R104/104b.

The CCS current = ( V(L110) – Vbe(Q102) ) / R104.

Some of these (all ) are a bit imprecise and may lead to slightly different currents in both CCS’s, to adjust these and ‘not needing to change the bulb’ – sorry replace the resistor (and possibly damage the board) an optional parallel resistor was introduced.

To make currents in both CCS’s equal, add power , measure the voltages across the resistors R104 and R204, then (for the side with the highest voltage) calculate the current Ih = Vh / Rh . Then for the side with the lowest voltage calculate a resistor Rl = Vl / Ih. (where h=High side, l=Low side).

Next we need to calculate the parallel resistor to introduce, 1/Rx = 1/Rl – 1/Rh.

I hope that this is clear


P.s. http://www.youtube.com/watch?v=Qa_gZ_7sdZg

[RCruz]

Originally Posted by beetle

A while ago I recommended micas from Jahre. They also do build to order. I think 1% is no problem. Why not go for them?


Richard Jahre GmbH: Bauform 53

Micas can sound stark... I only use them to "top up" and reach optimun values. They match well with larger vaules polypropylenes.

If the 11n are not carefully matched between channels, you might get an audible difference similar to gain difference between cahnnels.

[hesener]

Originally Posted by beetle

A while ago I recommended micas from Jahre. They also do build to order. I think 1% is no problem. Why not go for them?


Richard Jahre GmbH: Bauform 53

In my Paradise I matched the two channels to better than 0.1%, using 100pF, 220pF caps (in my case, Wima MKS2) as needed (and of course measuring them all) to combine to the perfect value. Similar for the resistors. This took me around 1hr to get it all sorted, but it really is worth the effort.

[RCruz]

Originally Posted by FdW

There are 3/4 parts that set the CCS current: Led L110, Vbe Q102 and R104/104b.

The CCS current = ( V(L110) – Vbe(Q102) ) / R104.

Some of these (all ) are a bit imprecise and may lead to slightly different currents in both CCS’s, to adjust these and ‘not needing to change the bulb’ – sorry replace the resistor (and possibly damage the board) an optional parallel resistor was introduced.

To make currents in both CCS’s equal, add power , measure the voltages across the resistors R104 and R204, then (for the side with the highest voltage) calculate the current Ih = Vh / Rh . Then for the side with the lowest voltage calculate a resistor Rl = Vl / Ih. (where h=High side, l=Low side).

Next we need to calculate the parallel resistor to introduce, 1/Rx = 1/Rl – 1/Rh.

I hope that this is clear


P.s. Blue alert - Red Dwarf - BBC comedy - YouTube

Perfectly clear... Thank you so much....

Can we modify the resistors values to "hot rod" the shunt so it works at higher ccs current ?

[RCruz]

Originally Posted by hesener

In my Paradise I matched the two channels to better than 0.1%, using 100pF, 220pF caps (in my case, Wima MKS2) as needed (and of course measuring them all) to combine to the perfect value. Similar for the resistors. This took me around 1hr to get it all sorted, but it really is worth the effort.

In the trebble cap (11n) I even use 10pF SM to reach a better acuracy