This will get you started.
http://greygum.net/sbench/sbench101/Crossover/xover.gif
It is two way but cascading a HP and a LP will give you the third BP filter that you need.
http://greygum.net/sbench/sbench101/Crossover/xover.gif
It is two way but cascading a HP and a LP will give you the third BP filter that you need.
Here are couple.
Tube Active Crossover
Tube Crossover (Page 1): January's Circuit of the Month
But, what's wrong with SS active crossover?
Tube Active Crossover
Tube Crossover (Page 1): January's Circuit of the Month
But, what's wrong with SS active crossover?
In the schematic listed you will see a chart of R and C values for various crossovers. You can kind of work out ratios for other cut off frequencies from studying that chart. Using a spice simulator like LTspice can help you to confirm/tweak the values. Use the HP section at a suitable crossover for the top, use the LP section also at a suitable (different) crossover.
The middle will be a cascade of a HP and a LP at the above crossover frequencies to create a bandpass. So if the upper crossover was at 7kHz and the lower at 150Hz then your mid band would have a HP at 150Hz and a LP at 7kHz.
As an example my woofer output in this simulation is a band pass. Note I tweaked the values somewhat to get an over all slope that would compensate for open baffle losses but the topology is essentially the same.
The middle will be a cascade of a HP and a LP at the above crossover frequencies to create a bandpass. So if the upper crossover was at 7kHz and the lower at 150Hz then your mid band would have a HP at 150Hz and a LP at 7kHz.
As an example my woofer output in this simulation is a band pass. Note I tweaked the values somewhat to get an over all slope that would compensate for open baffle losses but the topology is essentially the same.
Attachments
This will get you started.
http://greygum.net/sbench/sbench101/Crossover/xover.gif
It is two way but cascading a HP and a LP will give you the third BP filter that you need.
I am thinking of going active for my ATC SCM20SL Pro.The built-in passive cross-over is a simple 12dB/octave LC filter with the cross-over frequency at 2.8khz.
Using the aboved tube cross-over to start with,what are the components` values should I changed so that it could be used?
Oops, sorry, I never included the link to the values chart...
http://greygum.net/sbench/sbench101/Crossover/ReadMeXO.txt
You will have to interpolate to get a starting point and then simulate to tweak.
http://greygum.net/sbench/sbench101/Crossover/ReadMeXO.txt
You will have to interpolate to get a starting point and then simulate to tweak.
Here is an SMD version of the LR 24 db/oct. I layed out.
If there is demand I can try and convert it to through hole.
I add the 2 way version I made in through hole as example too.
Of coarse its not tubes, but it shows you just how complex these little buggers can get, 12 opamps per channel in the 3 way...
If there is demand I can try and convert it to through hole.
I add the 2 way version I made in through hole as example too.
Of coarse its not tubes, but it shows you just how complex these little buggers can get, 12 opamps per channel in the 3 way...
Attachments
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Not tube, but similar to above, LR active crossover. Boards available and good support. I use these crossovers and a LR transform circuit with my tube system: Linkwitz-Riley Electronic Crossover Not affiliated in any way with Elliot Sound Products, just a happy customer.
Pete Millett sells a PCB board. You need one board for two way or 3 boards for three way. I bought two boards, but haven't started the build yet.
DIY PCB - Stereo tube active crossover | eBay
DIY PCB - Stereo tube active crossover | eBay
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