Mpp

[RCruz]

Yes but 1% is not enough in a situation like ours.... 11nF is way different from 11.11nF

Even 0.5% might not be enough ... I usually match pairs of caps and then top them off with 10pF SM in order to get a good soundstage

[Joachim Gerhard]

When the Teflons stray in the negative direction we could trim with Styroflex. I made good experience with caps from RS. They are made by LCR in England.

[RCruz]

Indeed, that is how I do it... select a slightly lower value and top with smaller SM or styroflex.

In the case of the trebble cap (11nF) the difference in cap used might produce dramatic results... micas are ver well defined but stark... styroflex sounds duller sometimes.. it is a question of taste.... If we could get teflons in the pico farad range

[RCruz]

I must confess I never experimented with V-caps or other expensive teflons.... I use FP-3 CCCP teflons for interstage with superior results but these "cheap" military units do not work for me in the riaa trebble cap position... the extension is awesome but lacks the "fullness" of a tin foil RT cap for example.

[Stefanoo]

Originally Posted by RCruz

I must confess I never experimented with V-caps or other expensive teflons.... I use FP-3 CCCP teflons for interstage with superior results but these "cheap" military units do not work for me in the riaa trebble cap position... the extension is awesome but lacks the "fullness" of a tin foil RT cap for example.

If you didn't you are missing something, performance of thse caps is a lot superior to anything else you ever tried.

[Stefanoo]

Originally Posted by RCruz

Yes but 1% is not enough in a situation like ours.... 11nF is way different from 11.11nF

Even 0.5% might not be enough ... I usually match pairs of caps and then top them off with 10pF SM in order to get a good soundstage

It is something I have to experiment with once boards get in.
It never happened to me that a 0.5% or even 1% tolerance on the RIAA could cause such a high displacement.
I guess that this high sensitivity to the nominal values might be due to the high output impedance of the gain stage.

Anyhow, like I said, parts I get are usually better than 0.5%

And even if it wouldn't be enough, do you have a precise LCR meter that can go lower than 0.1% tolerance on C measurements?
I think mine gets down to 0.05% I have to double check.

[FdW]

Originally Posted by RCruz

Yes but 1% is not enough in a situation like ours.... 11nF is way different from 11.11nF

Even 0.5% might not be enough ... I usually match pairs of caps and then top them off with 10pF SM in order to get a good soundstage

IMHO 0.5% = 1% / 2 = 0.25% x 2

The point is 11.11nF is NOT 'way different' from 11nF it is 1% we, being technicians, should not lose our self’s in Hi-end-techno-babble. We may agree that 1% is too much, we I am never going to agree that 'depending on situation 1% could be more (or less) then 1% (in some other situation).

Just MHO

The guys from the ATL do agree, and are mounting a fresh set of 0.0000001u% capacitors in there record player (Note: u% = 1/1000000 of an %) and complaining that the f% capacitors did not arive.

[RCruz]

I already had some heavy discussions about this subject with Thorsten and got no concensus.
Anyway, I can assure you 10pF difference in 11n will be audible in the trebble region. Maybe because these 10p come from a different kind of cap bypassing the main one... but it matters.

I also know that technicians tend to base their conclusions based on a math truth alone.... In that case a MKS should not differ from a teflon but........

In the begining I believed this design was so heavily "filtered" that it was inpervious to cap type changes.... now it seems the idea is growing in another way... this is cool.

I am already very happy that some of us agree on the idea that the riaa values can be trimmed to perfection and 9kr is different from 9.9kr.... fortunately we now have a very good base for testing.... If possible I will try the teflons (If I can afford those)

Fascinating subject

[FdW]

Originally Posted by RCruz

I already had some heavy discussions about this subject with Thorsten and got no concensus.
Anyway, I can assure you 10pF difference in 11n will be audible in the trebble region. Maybe because these 10p come from a different kind of cap bypassing the main one... but it matters.

My point was/is that 1% is 1% and it is not depending on circumstances. But I do agree (like the ATL guys) the 0.1% (even less) can make a big difference, but it is not depending on circumstances, there is a technical reason for that (even if we do not understand the reason).

[Benedetto]