JG´s Nobrainer and Nobrainer Discrete

[MiiB]

Good reading.. Thanks for the article(s)

 

[FdW]

No, i use bipolars all the time.
In power supplies they may have a disadvantage because they have more losses.
Whereas a good 1000uF low ESR elcap may have less then 10mOhm at 100kHz a comparable bipolar may have 100mOhm.
On the other hand a bipolar has less distortion so in the signal path it has an advantage over polar.
By the way a true bipolar has even less distortion then a " fake " back to back electrolytic.
See Bateman.

Yes I do know about these facts, but non of the sources (concerning polar bipolar) explains how DC-offset across the capacitor influences its behavior. Also there is no data on long term stability of this behavior. So the polarized input capacitors (schema above) still have my attention.

 

[Joachim Gerhard]

Bateman makes an end to the myth that a polar electrolytic works better with a DC polarisation. I was surprised, BIG TIME.

 

[Joachim Gerhard]

I think Bateman argues that a bipolar has only one oxide layer and thus is lower distortion then a fake bipolar. If a DC polarisation helps to make the cap more long life i do not know. Mostly there already is a DC voltage anyway or why whould we use an elcap in the first place ?

 

[RCruz]

So this discussion leads me to believe bipolar caps are different from two polar caps connected by it's minus (or plus) ends.... If we need a polarizing voltage in the polar caps in order to keep it's dielectric strength, then bipolar caps would also need it if they where built the same way.... This would lead us to three legged bipolar caps where the center tap would carry a polarizing voltage.... there is certainly a big difference in construction techniques so we can never mimmick a bipolar with two polar caps

 

[Joachim Gerhard]

No, we can not. A real bipolar is better in terms of distortion but two low ESR elcaps in anti parallel still have lower ESR.

 

[RCruz]

Cool exchange of ideas... thank you all


BTW, I use two 4700u in bipolar config in the output of my headphone preamp and can assure you it sounds much better than my previous film choice.... so it works.

 

[Joachim Gerhard]

That is what i wanted to say. We can always listen and forget for the moment the reason why.

 

[FdW]

Cool exchange of ideas... thank you all


BTW, I use two 4700u in bipolar config in the output of my headphone preamp and can assure you it sounds much better than my previous film choice.... so it works.

And that is a result

 

[FdW]

What tutorial (is it a kind of easter-eg ). Happy new year for all.

For the amplifier I am testing something like this, what do you think of this?

I'm dropping this idea, after checking 'Bateman' (again ) and Skype-ing with Joachim and after doing more simulations (where I can not create a 'plop-free' version) it is SCRAP! No 'forced-polar-electrolytic-capacitor-with-active-offset-generator' or FPECWAOG-technology for me.

 

[FdW]

Cool exchange of ideas... thank you all


BTW, I use two 4700u in bipolar config in the output of my headphone preamp and can assure you it sounds much better than my previous film choice.... so it works.

Now we want your listening report on these:
Nichicon nichicon ues Aluminum Electrolytic Capacitors - Leaded | Mouser

Also some impression/test/verdict on the colour/color

 

[RCruz]

Hehe.....cool nevertheless

Now I have another question..... I am using LM317 337 regs to power the opamp at 17v.... as the psu line will settle at 35v, I get a vdrop of 18v

What current should the opamp be drawing ? I am afraid I did not care about heatsinking the regs.... how noob can this be ?

 

[FdW]

Hehe.....cool nevertheless

Now I have another question..... I am using LM317 337 regs to power the opamp at 17v.... as the psu line will settle at 35v, I get a vdrop of 18v

What current should the opamp be drawing ? I am afraid I did not care about heatsinking the regs.... how noob can this be ?

One op-amp is 5mA (with safety 10mA) I x U = .01 * 18 = 180mW

Now check this out Thermal resistance - Wikipedia, the free encyclopedia

The verdickt it will work

 

[RCruz]

Now this was a fast good news answer... thank you

 

[RCruz]

Another thrill.... I have no 1k8 for the voltage divider feedback loop.

But I have some nice 2k holcos

Can I use 2k instead of 1k8 keeping the 15k or should I also change the 15k to 16k trying to keep the voltage drop around 1 : 0.11

 

[RCruz]

Ok... first channel almost ready.... decided to use 16k and 2k for the feedback voltage divider keeping the original 9.33 ratio.... On the input a 4u7 MKP.... looking good so far

 

[Joachim Gerhard]

Fine.
I found this but i do not think that it is of relevance :
Charge Coupled Crossovers Article By Jeff Poth
No measurements, no prove, nothing.

 

[FdW]

Fine.
I found this but i do not think that it is of relevance :
Charge Coupled Crossovers Article By Jeff Poth
No measurements, no prove, nothing.

So, that's it. I've found charge-coupling to dramatically improve the sound of inexpensive capacitors, and it's not very difficult or expensive to implement, so I can firmly recommend charge-coupling as a tweak for our people who know which end of a soldering iron is hot. Depending on the speaker and system it may require relocating crossovers outboard, but that's on a case-by-case basis. There are significant improvements in clarity, imaging, and listenability to be had, get to it kiddies!

Do I need to re-open my investigation into this

 

[Joachim Gerhard]

I do not think so. I try to avoid caps in the signal path anyway, especially elcaps.
Sometimes they are necesarry when you build single ended or you want to avoid a servo.
Also in my system i have at least one cap for safety. Actually i use it to roll off my main baffles in the bass so the cap serves a double purpose.
On the other hand there is the Self Precision Preamp. I can not remember exactly but from phono MC in to line out i counted around 14 elcaps, direct or indirect ( feedback DC blocker ) in the signal path. Measurements on static distortion and noise are still great though.

 

[RCruz]

Fine.
I found this but i do not think that it is of relevance :
Charge Coupled Crossovers Article By Jeff Poth
No measurements, no prove, nothing.

Well, there is no smoke without fire.... might try it some day