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Tube crossover for sub?

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G

GRollins

Member
Joined 2001
Joe,
Absolutely not a problem. You can use a tube in follower configuration and build a Sallen-Key filter around it (the cathode is the + input). More elaborate topologies are possible, too, if you want to make a really fierce-looking circuit.
Try www.tubecad.com for some nifty tube crossovers or roll your own. The stuff in the Xenover thread can be adapted, although it might be easier to visualize with the stuff I put in the earlier crossover thread a year or two ago, as I was using followers to illustrate the S-K hookup.

Grey
 
Brett

Brett

Member
Joined 2002
Joe, if its for <100Hz, especially if just low pass, then use opamps. The high pass you can adjust with a series cap in the amp if 6dB is enough.

If you want/need steeper slopes, then the tubecad article is fine, and John even sells some cheap software to design it.
 
Brett

Brett

Member
Joined 2002
burnedfingers said:
Brett

I have had a 24db per octave low pass electronic crossover in place for the last 15 or so years. Since I'm into tubes now it seems like Blasphemy to even consider using it now.
Click to expand...

So, I'm hardly Mr Sandamp, and I use them there. It still works really well. Just don't run the high pass signal through it.

Sand has it's places, and <100Hz is one of them.
 
B

Burnedfingers

Member
Joined 2002
Quote:

So, I'm hardly Mr Sandamp, and I use them there. It still works really well. Just don't run the high pass signal through it.

Sand has it's places, and <100Hz is one of them.

Thank you Brett for your opinion, however as I stated I already have a custom built crossover made with "sand components". To be exact it is a mono summing circuit followed by a 6th order 24db per octave high pass filter at 27hz followed by a 24db per octave low pass filter set at 80hz.

If I had wanted to continue using this I would. As stated in a prior post it is my intention to build a filter using a tube based design, Why? Because I want to.

Joe
 
K

Kalle

Member
Joined 2003
Hi Joe

I´m a new member to this forum since 10 minutes! I just wish to say that i´m using a tube crossover for sub and it sounds lovely. It is US made but i cant tell the name of it since i am at work. It is old though guess made in the 60s. It has variable crossover from 0,01Hz to 2kHz by combine a couple of switches and two pot´s, one for low cut freq. and one for high cut freq.

Best regards
Kalle
 
K

Kalle

Member
Joined 2003
Hi again

A little late answer it is but i have been out of order, so to say (catch a cold).
Joe, i am sorry i don´t have any drawings on the filter. I wish i had. But it is a Krohn-Hite model 330-A "Ultra-Low Frequency Band-Pass Filter" made in Cambridge Mass. If that is to any help.

Regards
Kalle
 
planet10

planet10

frugal-phile™
Joined 2001
planet10-hifi.com
Paid Member
fdegrove said:
BTW, did the Krohn-Hite use tubes?
Click to expand...

Yes. They were noted for their incredibly low measured distortion. I have chatted with a fellow in New Zealand who uses them with a set of IMF monitor clones and he loves them, and with another fellow in Calgary who builds & repairs amps -- he verifies their measured performance & says they are one of te worst sounding tube amps he has come across.

These amps were designed to be measurement amps in test kit.

dave
 
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