MPP

[le´flu]

Phewwww, seven-hundred and something pages to search through...
thats hard work.
But thanks for the advice concering the bypass-C.

Concering the tweeter-C ... at the moment i´m really favourizing the vishay
mkp1840 - they are cheap at pollin and great

 

[Joachim Gerhard]

Yes, the MKP1840 is a great cap. Vishay even revived the great Roederstein name.

 

[hesener]

...
Study the spec sheet and look where the main cap has it´s minimum impedance and blend in the bypass where the main cap starts to be inductive.
...

excellent advice, applicable also to bypassing in power supplies

 

[RCruz]

You have to find out yourself. Sorry, no spoon feeding. You find it on this thread somewhere. It is not a secret, just a lot of listening and measurements. One Tip : the rule to bypass the main cap with a cap that is 1/10nth the value does not work. The bypass cap is much smaller.
Study the spec sheet and look where the main cap has it´s minimum impedance and blend in the bypass where the main cap starts to be inductive.
For speakers it it different because of the high currents that flow and the immense shaking. What matters most here is to suppress mechanical resonances.
A densely wound MKT can sound better then a teflon cap with loose windings.
Dielectric absorption is a minor problem in speakers because the cap can not build up much energy. The low impedance of the speaker short circuits the cap mostly all of the time.

I agree... After numerous experiments I found that bypassing a 4u7 MKP with a 15pF SM gives the best results in some of my preamp builds.

 

[Joachim Gerhard]

Ricardo, this is an extreme case but i trust your listening. I usually land in the 1 - 3.3nF range so it is more like 1/100 or a bit less. This could be also system dependent. That was the reason i said " no spoon feeding ". Had i given the makes and values people may have thought that they are the holy grail preventing them to do their own experimentation.

 

[RCruz]

I have a lot of bypassing caps with aligators soldered in it´s legs so I can swap them fast.

I start with 1nF and go down until I reach the desired subjective trebble response !

It also depends on the type of MKP used.

 

[Joachim Gerhard]

Maybe i prefer a somewhat brighter sound. I have no problem with sibilance though.

 

[Joachim Gerhard]

pdul, your transistors have arrived, many thanks. I have prepared 50 of yours and do the rest today.

 

[pdul]

Hope some of them will be good spouses for your 327s

 

[Joachim Gerhard]

I just setup the measurement. In 2 hours we know more.

 

[pdul]

I am just using a DY294 transistortester, probably not ultra precise, but works.

 

[Joachim Gerhard]

I am using the PEAK Atlas. It is ok. I wish i had a curve tracer.

 

[pdul]

Best case scenario, a transistor factory

 

[Joachim Gerhard]

OHH, NO, i worked in that environment in the 80th, astronaut clothes and all.
We had to tackle cooling water, DC, AC, Microwave, vacuum, Plasma and the like all at ones !

 

[pdul]

I meant, being able to order deliveries to your own specs.

 

[Joachim Gerhard]

The people that have that position are not much interested in HQ Audio it seems.
Still there is good stuff around.
That was very different in the 60th to 80th where music was a lifestyle of the masses.
Now the Internet rules.

 

[pdul]

Without the internet, my diy would be grounded, since there are not many serious component pushers left in my own country, and a place like this forum is worth gold for me.

 

[Joachim Gerhard]

Yes, the DIY movement has profited from the Internet but expensive High End as it was is dead here in Germany. I do good busyness with the far east though. That people appreciate German quality.

 

[pdul]

Yes the young people want a lot of blinking lights and fancy funktions, but basic good quality is down and out

 

[pdul]

Even German quality is dificult to come by now a days, without the well known sign on the back (Made in China)