MOX - active crossover

[moamps]

Hi,

thank you all for positive feedback. It isn't my intention to make and sell PCB's. I'm going to post PCB pictures (not *.pcb files), which are very simple, and anyone will be able to redraw the design based on these pictures (hint - all resistors are standard 400mils). The design is free for personal use but if someone wants to make and sell PCBs on the DIYAudio, they may do so provided that a small percentage of their profits (ca 5%) goes to DIYAudio web server maintenance.

Regards

[moamps]

LPF filter PCB

[moamps]

HPF filter PCB

[BDP]

MOAMPS,

Nice job. How does it sound?

Is the balanced output stage the same as the XVR? The simplified XVR schematic has a balanced output stage that appears to be floating and not referenced to ground. What are the benefits of one over the other? What type of configuration is the XVR's and what is it called. I looked in a few op-amp books that I have and didn't see a similar circuit. The only draw back I can see is this configuration has different input impedances. Can anyone explain the XVR balanced output stage.

BDP

[jlm]

Hello,

Congratulations for your crossover filter.

It is the first time that I see an crossover filter with balanced inputs and balanced outputs for diyers.

With unbalanced input, is it necessary to connect the pin 3 to the ground ?

Can one add 1, 2, 3 highpass filters for to have 3, 4, 5 channels crossover filter ?

Thank you for your answer

Regards

[moamps]

Originally posted by BDP
Is the balanced output stage the same as the XVR? The simplified XVR schematic has a balanced output stage that appears to be floating and not referenced to ground. What are the benefits of one over the other? What type of configuration is the XVR's and what is it called. I looked in a few op-amp books that I have and didn't see a similar circuit. The only draw back I can see is this configuration has different input impedances.

Hi,

I heard this xover with moderate quality PS (LM317/337) in a PA system, and the sound was very good, with overall distortions under 0.05%. For home HIFI arrangements, I suggest using moderate quality parts to determine xover frequencies, Q's, etc., and then building the xover with fixed characteristics using higher quality caps, resistors etc.

I am not familiar with the details of the XVR's balanced output, but I don't think it is floating. Only transformer balanced outputs are truly floating, IMO. In literature, several ways to obtain an electronic balanced output can be found, one of them being the topology I have used. (see Rane schematics library). Drawbacks? Every topology has some.

Regards

[moamps]

Originally posted by jlm
With unbalanced input, is it necessary to connect the pin 3 to the ground ?]

Hi,
it isn't necessary but it is slightly better (higher gain, smaller noise, etc.)

Can one add 1, 2, 3 highpass filters for to have 3, 4, 5 channels crossover filter ?

Yes, of course. You can build 3,4,5 channel xover with any slope you need.

Regards

[bigparsnip]

Hi, this does look like a very useflu littile thing to build, but I have one question (which is probably obvoius but I just want to make sure).

In your first post you say that you want this to be variable from 6 - 24 dB/Octave but you boards apear to be only for one section allowing 6 or 12. So i take it that you mean to cascade two units to reach the higher levels?

[moamps]

Originally posted by bigparsnip
In your first post you say that you want this to be variable from 6 - 24 dB/Octave but you boards apear to be only for one section allowing 6 or 12. So i take it that you mean to cascade two units to reach the higher levels?

Hi,

yes,
look picture in post 5.

Regards

[Fred Dieckmann]

Please see post below:

http://www.diyaudio.com/forums/showt...945#post324945

I urge evryone to think twice about exploiting Mr. Pass's work.