Active XO help

[ben62670]

I need a little help designing an active XO. Using TJC filter designer it gives me cap values of .1uf, and resistor values of 795ohms. Does this seem like the optimal combination? What kind of caps should I use?
Thanks again guys.
Ben

[ben62670]

http://www.partsexpress.com/pe/showd...umber=020-1834
These any good?
Also what OPamp should I use. I have a choice of 8+,0,8- or15+,0,15-
Thanks guys
Ben

[AndrewT]

2.5% polypropylene, matched to better than 1%.
or
1% polystyrene.

10nF & 8k would be better for most active filters.

[SY]

Originally posted by ben62670
I need a little help designing an active XO. Using TJC filter designer it gives me cap values of .1uf, and resistor values of 795ohms. Does this seem like the optimal combination? What kind of caps should I use?
Thanks again guys.
Ben

795R is at least two orders of magnitude too low for a tube crossover. Try shooting for something in the 50k-200k range.

[ben62670]

Thanks guys. I am using the TJC filter designer with SS, not tube.

Also what OPamp should I use. I have a choice of 8+,0,8- or15+,0,15-

Thanks so much. Hopefully someday I can be somewhat helpful to newb's like myself.
Ben

[AndrewT]

+-15Vdc allows a max output of around 10Vac (~=+22dBm)
+-8Vdc allows a max output of around 5Vac (~=+16dBm)
You will be operating with 6dB less headroom.
Many recommend that 20dB of headroom be allowed for, throughout the reproduction chain, to minimise the risk of clipping transient peaks and also to keep the output well below the higher distortion levels typical of single ended ClassA stages.