LabGruppen, what to do?

[TOINO]

At this distance it looks clean...

[Eva]

You could actually see me and my workbench in this picture...

[Workhorse]

Originally posted by Eva
You could actually see me and my workbench in this picture...

I Think we need X-Rated glasses to see superwoman Evita

[Workhorse]

[TOINO]

Originally posted by TOINO
They are no difference. I have investigated further and the SMPS looks like transferring the ripple from secondary to primary.
As simple as that.
Considering also that the audio loudspeaker circuit is closed in the secondary capacitors, is not a surprise that the sound in bass frequencies is a “little strange”. (I know that it is not very scientific statement and you could ignore it)
http://www.qscaudio.com/support/libr...eries/pl40.pdf page 2 only 3x470uF per rail.
Yes I know that the capacitors are charged 200K times per second, but don’t forget that they also pass the audio power signal…
I know, I know… is just a matter of increase the size of primary and secondary capacitors and this amplifier probably will sound as your bigger one…

Originally posted by Eva
I don't like those first generation QSC SMPS at all, they barely replaced the 50Hz iron by 50Khz ferrite, but without improving performance or reliability.

Workhorse

The picture you have posted show enough details to conclude that this is one of the kind of above posts.
As an ignorant, it seems to me that the solution will be “active ripple filtering” in primary and bigger capacitors on secondary.
Something thing like Eva’s PFC in front-end, followed by that thing.
With the actual component size, it will be much bigger than the today commercial proposals in the market.


Eva
I have tried hard but I couldn’t found you…
Could you show it on a smaller scale?...

[TOINO]

Hmm... nice place!
Sand beach at 200m! What a marvel!...

[Workhorse]

Originally posted by TOINO

Workhorse
The picture you have posted show enough details to conclude that this is one of the kind of above posts.
As an ignorant, it seems to me that the solution will be “active ripple filtering” in primary and bigger capacitors on secondary.
Something thing like Eva’s PFC in front-end, followed by that thing.
With the actual component size, it will be much bigger than the today commercial proposals in the market.

You want to start a new pro-smps revolution Toino, GO GO GO!
I have seen various commercial amps with PFC frontend + Quasi resonant mode smps...but in case of QSC their Discontinuous resonant mode always failed on poor Gensets...

[TOINO]

Originally posted by Workhorse

I have seen various commercial amps with PFC frontend + Quasi resonant mode smps...but in case of QSC their Discontinuous resonant mode always failed on poor Gensets...

Welcome to my club.

Yes, I see what you mean with "Discontinuous"

However before fail, it well shakes the loudspeakers!
Because of that, I suspect that is the way.

But, as I said, is big and heavy.(3U-24Kg)

[TOINO]

Eva

Concerning your PFC project, could you provide me (through my forum contact) an email address with more than 300Kb capacity?
I have a document that should be of your interest.

[Eva]

Send me a priv. msg. and I will reply from a suitable address