Pro Audio Design Forum

Pete -

What are the gold thingy's, mute switches?

Wayne

Hi Wayne,

Yes they are switches made by CLARE, i got them out of an old Ward Beck console i think,

I have been looking for some thing to use them for ages.. big...and a problem to mount but very high quality..

yes i have used them for Mutes in the MS Matirx, but i think of them more as SOLO, mute of the Mid is infact a SOLO of the Side..

works for me anyway..

Pete

So they're a push/pull switch or momentary pushbutton? I've never seen those. They're beautiful switches.

What's the sleeved component on the back of the switch?

They are push toggle, you just push, then push again,

they are 4x single pole but alternate nc/no, so to get a double pole you common two together and you get your double pole action, so the sleeved component is just a link from one nc to a no and hey presto..

yes very beautiful switches...wish i could find more.

Looks like I'm finally going to have some time to build one of these up, and I'd like to know from the folks that have built one of these, what IC did you use for the lone non-THAT IC, and why. In the original build was the 5532, but I have seen mention of the NJM2114, the 2604, and the 33078. Anyone?
Thanks!
Bruno2000

http://www.syntech.co.yu/test%20matrix.jpg broken image link

Hi
Wayne this thing is GREAT and extremely useful at least for what I need. Thank you very much indeed, sir!!! Now a little troubleshooting:
The above is RMAA test figures of ms matrix & m audio audiophile 2496. I'm confused having cross talk figure as it is. The unit is quiet and works as it should apart from crosstalk. unbalanced in(-to gnd), unbalanced out(- to gnd), m out to m in balanced, s out to s in balanced, Br 1-4 not installed,test@~1.227v. any ideas?
Best
Milos

...and to answer my own question:"precision" bypass. forgot about that one entirely. test results updated in the previous post.

Milos -

Thanks for the test data. The 1646 line driver doesn't have as good a gain accuracy as the THAT1240 and 1246 line receivers do. You might swap the M and S 1646s and pick-up (or lose) a few dB. Loading by external gear will also have a great effect even if they are exactly unity gain.

It doesn't take much external series resistance in the precision mode to alter the crosstalk too. One test I did I introduced as little as 1 Ohm in mid or side and the numbers changed a lot.

We're in the tens of ppm range to get 90 dB.

Wayne

Thank you Wayne, my build is here viewtopic.php?f=7&t=326.
best
m

Wayne, thanks for the great pcb !!

I'm just building the MS-Matrix and still have a few questions:

1)
C1 C7 C17 C26 etc... are not mentioned in the BOM
they connect between V+ and V- are they needed or not?

2)
can I replace the 1240 with a 1200 line receiver (when i add the cap and cut the connection between pin5/6 as shown in the 1200 datasheet on page 11) ??
http://www.thatcorp.com/datashts/1200data.pdf

3)
I'd like to have mute switches on the frontpanel for mid and side signals
if the connection between "FM" or "FS" is open ... should I also connect the + or - input of U10 / U11 to ground?

4) is it possible to omit the 5532 stage by changing the 1240 to a 1246 (which has a 6db lower output) ?


thanks.
matthias