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Old 1st April 2010, 01:30 AM   #241
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I am sure your findings are valid in your circuimstances. I think for opamps if they are not implemented correctly then they don't sound as good. That was why I suggested a high quality shunt reg. By the way, even with a very good shunt reg, proper implementation is critical for achieving the result.

For sure, 2sk170 is a lot cheaper, and it sounds good, and the jFET XO proposed in this thread is excellent. By all means go for it and have fun.

I was only suggesting that the best opamps are at least as good or better, if implemented properly with a very good regulator. (I used the same regulator, same layout when I compared the opa627 to the B1).
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Old 6th April 2010, 12:58 PM   #242
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Well I've "finalized" (if that is possible) my crossover design and since it has departed completely from Jacques' original design I'm not posting it here. But if anyone is interested in what I came up with it is posted in my blog It still uses B1's but not for the actual filter elements.

Thanks to Jacques for starting this thread because it was the catalyst I needed to come up with my own design not only in getting me thinking, but also in deciding to take the plunge and learn how to use spice!

Cheers,

Tony.
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Old 16th May 2010, 05:06 PM   #243
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Default I like this idea for a x-over to add to my Aleph J-X amp

I like this Project for the B1-x-over, I am currently building my Aleph J-X amplifier and it will require a 100Hz high pass x-over that will not dimminish the quality of the sound, I believe that all the x-overs using integrated op-amps circuits will ruin the quality of the sound in my system that I have so carfully assembled for state of the art sound quality.

Picture is of my speakers which require a 100Hz x-over between the 18in JBL2242 in a 14ft transmission line labyrinth(low frequency optimized backwave-frontwave cancellation is 20Hz) and a 12in JBL2202 mounted in a short backwave horn for use between 100Hz and 500Hz, from 500Hz to 4KHz I have a 1.75in titanium diaphram JBL2525 compression driver horn loaded, and above 4KHz a Foundtek 98db per watt 5inch ribbon. My speakers efficientcy is 98db per watt 100Hz to 40KHz which requires the quality of the B1 x-over, below 100Hz I am using a sub harmonic synthizer 26-100Hz.
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Old 21st June 2010, 07:51 PM   #244
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Hello Jacques,
I am a little late to this thread. Have you built the LR2 circuit that you posted in Post #24.
If you did what were the results? I have a bag full of 2SK170ís and would like to build one of the same.
DT
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Old 22nd June 2010, 04:19 AM   #245
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Quote:
Originally Posted by DualTriode View Post
Hello Jacques,
I am a little late to this thread. Have you built the LR2 circuit that you posted in Post #24.
If you did what were the results? I have a bag full of 2SK170ís and would like to build one of the same.
DT
All just for Fun!
No, I'm afraid I haven't as I've been extremely busy since the beginning of the year. I started to collect some parts but haven't been able to get to it yet :-(. I believe that a few folks on this thread have built that, or some variation on it.
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Old 27th July 2010, 01:21 AM   #246
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Has anyone built the circuit in Post #1?

I read about the stop band issue in Post #4, however it looks like 50db down.

Would that be even audible to anyone? Are people concerned about phase issues?

I'm thinking about building a simple buffered salen-key circuit, like Nelson describes in other posts, perhaps the simpler circuits are the B? series buffers.

Thanks.
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Old 1st June 2011, 04:25 PM   #247
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Default 4th order B1 buffer crossover Calcs

I am trying to put together a stereo 2 way 4th order crossover with preamp source switching (2 sources) and overall volume control.

I have a pair of Snell E with a crossover point of 2700 Hz.

To configure the values for this cross point I referred to the Grey Rollins' article: The Xenover - Part II Article And Design By Grey Rollins

The resister and capacitor numbers corresponds to Grey's Schematics as indicated. I don't have a way to change the values on the attached PDF.
Butterworth high pass (Schematic 7)

C = C1 = C2 = C3 = C4 =.002

1st section: R5 = 0.9239/(2*Π*F*C) = 27.2k

1st section to ground: R6 = 1.0824/(2*Π*F*C) = 32k

2nd section: R11 = 0.3827/(2*Π*F*C) = 11.3k

2nd section to ground: R12 = 2.6130/(2*Π*F*C) = 77k



Butterworth low pass (Schematic 8)

R = R5 = R6 = R12 = R13 = 22k

1st section: C1 = 1.0824/(2*Π*F*R) = .0029 uF

1st section to ground: C2 = 0.9239/(2*Π*F*R) = .00247 uF

2nd section: C3 = 2.6130/(2*Π*F*R) = .007 uF

2nd section to ground: C4 = 0.3827/(2*Π*F*R) = .001 uF

As I proceed with buying the resisters and capacitors I would like confirmation that those calculations will work for the B1 buffer crossover using 2SK170BL devises. I may use a discrete opamp for the preamp gain stage.
Attached Files
File Type: pdf LR4b DCB1XO 4th order.pdf (12.9 KB, 280 views)
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Old 3rd June 2011, 09:25 AM   #248
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set your capacitors to values you can buy at the accuracy you can afford.
Then calculate the resistor values. Use multiple series or parallel resistors to make the required accuracy values.
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Old 3rd June 2011, 02:16 PM   #249
Rush is offline Rush  United States
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Default Values

Thanks Andrew,

I take it the calculations are correct for this buffer crossover.

I will buy a 100ea 1000pF caps and some other values that can be paralleled to achieve the values above. I have a capacitor meter for matching. This will be perfboard construction so I can do what ever necessary to reach the values.

Thanks for the help.

Rush
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Old 24th April 2012, 11:30 AM   #250
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Whatever happened to this design?
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