MS Matrix

[Moses]

Hey there,

I have a bunch of Lundahl LL1517's kicking around at the moment, and Im wondering how they would work out if i hooked a pair up as an MS Matrix. Anyone done that with these?

Thanks,

Mo

 

[radiance]

It has been done...there might even be a drawing around....can't find it now.
Should be pretty easy...

L+R > sum 1 secondary from left and 1 from right
L-R > sum the other secondary from left and the other from right only connected reverse..


and so on....

Mathematically it works like this...

    M = L + R

    S = L - R

Therefore...

    M + S = (L + R) + (L - R)
    M + S = 2L

    M - S = (L + R) - (L - R)
    M - S = L + R - L + R
    M - S = 2R

 

[Moses]

Hi Radiance,

Thanks for the reply!! I've found a few schematics around for this, but it seems that people generally use 1527's for this job.. As the 1517 is an output trafo I am  wondering if Ill have any problems using it passively. The Lundahl datasheets suggests that I may!!

Mo

 

[radiance]

The Lundahl datasheets suggests that I may!!

Well...that's encouraging right 

 

[Jonte Knif]

Generally output trannies have too little inductance to work as all round matrix or splitters. The matrix will be hard to drive at low frequencies and will generate distortion and falling response. BUT, if you know where you put it, for example if it is connected to a good modern solid state output it _could_ work just fine. Try it, it's fast. Winding asymmetries can sometimes raise their ugly head, but probably not is this case.

-Jonte

 

[Moses]

Ok... So it might be worth building an input stage before the trafos then?

I have them wired up now, and am planning on testing them later on today... Ill let you know how I get on!!!

Thanks guys...

Mo

 

[Moses]

Hey!!

Well there's good news and bad news! Well, it does work passively(hurray!)... But (and there's always a but...!) there is a nice HF filter in there, so I think I'll have to devise a driver stage to pop in it...

Back to the drawing board!

Mo

 

[radiance]

You might find this thread interesting...

http://www.picocompressorforum.com/forum/php/viewtopic.php?f=6&t=112