I'd use some OS CONs in parallel with polypropelenes over blackgates anyday

I read some diyaudio test on capacitor using large ceramic cap as bypass and have the THD scanned with good results. Too bad, I have lost that page.

Too high voltage for OSCON use.

Use blackgates AND bypass them with WIMA MKS2s, lol, i've already got the wimas, now just trying to find the BGs.

Ceramics are good stuffs. Especially anything X7R and above. X7R for PSU, COG/NPO for Signal path. (phase lead compensation)

don't want.

You can still find some rare OSCONS around that have sufficient voltage value. The beauty of differential drive is that by using less caps that are in the signal path (e.g. rail to ground) you force the active channels to do the work more. Plus rail cancellation pretty much makes noise moot. Not to mention Class A constant current drawing.


OS CONs (the light blue ones) also look better than blackgates.

What is the guide for choosing X7R for power supply, and COG/NPO for Signal path ? What is code and which brand and value is normally used?

X7R is temp stable, making them useful in really really hot PSU sections. Usually used for bypassing, usually anything between 200pF to 0.1uF are good depending on the noise from the PSU you with to defeat.

C0G/NP0 is low loss, low inductivity and low dissipation, this makes it good for high frequency circuits, usually a rail to rail solution with ultra short leads between the rail legs of the device can calm most unstable electronics. Generally 0.1uF to 1uF is the accepted general here, depending on the speed of the circuit.

I usually use Kemet GoldenMax.

EDIT: Damn empire23 for being faster.

Anyway, Kemet Golden series arent the only choices.

Vishay BCs are great too.

For COG/NPO grade, sometimes you can replace it with Silver Mica equivalents if you desire.

To add to empire23's points, you cant usually find higher capacitance values of the same efficient footprint with COG/NPOs. Which is why we compromise using X7R.

Grade 1 = COG/NPO
Grade 2 = X7R
Grade 3 = Z5U

Just to put the link, I hope to see a breakthru of the ceramic cap for bypass

http://en.wikipedia.org/wiki/NP0

http://en.wikipedia.org/wiki/X7R

and the comparisons of pp, X7R, NP0

http://www.wima.com/EN/characteristics.htm

Finally I found the thread that talks about the NP0 :-

http://www.diyaudio.com/forums/showthread.php?threadid=4562

This post has been edited by ccschua: Feb 9 2009, 11:09 PM

what about 10pf film caps??
does it have the same benefit as ceramic one?

by any chance anyone interested in a 20V regulated PSU with 100VA toroid transformer, slow start circuit and MUR820 ultra-fast diodes.

100VA 21V Toroid transformer
4xMUR820 full wave ultra-fast diode
LM338k metal can 5A high power regulator
slow start circuit to remove power spike and thumps
choke and line filter/conditioner at AC line with earth protection and fuse.
high quality Elna caps+tantalum caps.


Will retrim board, but no casing supplied. Im moving, clearing things in my room..seriously.

This post has been edited by ijan: Feb 10 2009, 09:21 PM

ceramics are special in the sense that they are very very small, and can be used very close to the circuit pins for lowest inductance, impedance and noise.

You cant get the same footprint/size given the same capacitance with the film caps. Depending on the application, ceramics are superior in this regard.

We normally don't use them for signal path though.

Something i've never gotten about modders, why the insane lead length? It just negates the quality of the part you just replaced lol.

Yeah I've mentioned that a few times too. But apparently no takers.


Maybe the added distortion/placebo is well worth it.

Heck I've even seen some people incapable of telling the difference between Discrete buffers and the BUF634, so I'm not really surprised at our own limitations.

hahahhahah like me!!!

When it concerns commercial amplifiers these days, having a larger "penis" works wonders.

It's all about pimping those testosterone into your amplifiers.

I don't care if you have FMs, but my OS CONS/blackgates will eat you alive.

it is good to have those 'cap' in the pocket. I would spend the money somewhere like the output stage, getting the BJT or JFETS matched, or even getting fully discrete IV Conversion with as little as components possible.

Selling amps is like selling bling lol, like telling people my amp has a negative feedback system and a push pull complementary output stage and a buffered divided rail dual voltage power supply

Bling for bling sake is nice, but the most important is that people don't get fleeced into believing the wrong things.

wow I have so many trans impedance BJT and JFET for trail on my IV conversion stage. just share some configuration here.



This post has been edited by ccschua: Feb 14 2009, 12:26 AM

A friend brought this over for some 'help'.
It's SOAP (Simple OpAm Pre).
I just need to connect the tranny and to adjust the regulator so that the output is 15VDC. Have not test it out yet.. This SOAP to be used with his GainClone which he is currently building...


Attached thumbnail(s)

ahh pcbs.

I guess most of us finally went from

Protoboards ---> self etched PCBs.