Okay, here we go. Attached y'all find the full schematic of the DCB1XO I currently have in use.
It's a stereo 2-way 18dB/octave active crossover with baffle step compensation (BSC), adjustable global volume and relative adjustability of the low pass (LP). At the output of the LP there's an additional notch filter (with a unity-gain opamp) for taming a 38Hz room resonance. As shown, the LP x-over frequency is 2k5Hz and high pass (HP) x-over frequency is 3k5Hz. These numbers are dictated by my 2-way TQWTL speaker.
The resistors are either RN55C or RN60C, caps are mostly film and foil WIMA FKP1 high voltage types. The circuit shows actual, measured values. Ignore R35.
The BSC is a passive RC version from Active Filters and the notch filter is taken from Active Filters.
For an idea of the layout see posts #258 ff. http://www.diyaudio.com/forums/pass-labs/156094-b1-active-crossover-6.html#post3430410
Also attached y'all find an annotated version and a frequency plot.
I'll dig through my various piles tomorrow and see if I can find my notes on layout.
In the meantime I'm looking forward to your comments and questions.
It's a stereo 2-way 18dB/octave active crossover with baffle step compensation (BSC), adjustable global volume and relative adjustability of the low pass (LP). At the output of the LP there's an additional notch filter (with a unity-gain opamp) for taming a 38Hz room resonance. As shown, the LP x-over frequency is 2k5Hz and high pass (HP) x-over frequency is 3k5Hz. These numbers are dictated by my 2-way TQWTL speaker.
The resistors are either RN55C or RN60C, caps are mostly film and foil WIMA FKP1 high voltage types. The circuit shows actual, measured values. Ignore R35.
The BSC is a passive RC version from Active Filters and the notch filter is taken from Active Filters.
For an idea of the layout see posts #258 ff. http://www.diyaudio.com/forums/pass-labs/156094-b1-active-crossover-6.html#post3430410
Also attached y'all find an annotated version and a frequency plot.
I'll dig through my various piles tomorrow and see if I can find my notes on layout.
In the meantime I'm looking forward to your comments and questions.
That's great! I'm in for a stereo 2 way 24db\oct.
Maybe we can do 2 boards, HP&LP, each with level adjustment. In one of this boards we could place the BSC and then jump to the other xo board. Also a band limiting filter would be nice in the LP section ...
If many people are interested we could open a new thread...
Thank you all guys
Maybe we can do 2 boards, HP&LP, each with level adjustment. In one of this boards we could place the BSC and then jump to the other xo board. Also a band limiting filter would be nice in the LP section ...
If many people are interested we could open a new thread...
Thank you all guys
Rodeodave, as I wonder about a 3 ways, I was thinking about the current needed. 200mA per rail... does it mean "per channel (HP+LP)"?
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Ok, thanks, I will see later if running with one regulator per channel or one regulator for both, but I also like the idea (maybe a wrong one...) to keep separate left and right grounds.
If I am not wrong, the schematic Rush posted is the "original" VI order from Jaques Merdes.
Rush, do you have BSC or not ? I've still not understood where a BFC should be placed in this schematics and if it needs to be isolate from the filter by an additional buffer
If I am not wrong, the schematic Rush posted is the "original" VI order from Jaques Merdes.
Rush, do you have BSC or not ? I've still not understood where a BFC should be placed in this schematics and if it needs to be isolate from the filter by an additional buffer
Ok, thanks, I will see later if running with one regulator per channel or one regulator for both, but I also like the idea (maybe a wrong one...) to keep separate left and right grounds.
If I am not wrong, the schematic Rush posted is the "original" VI order from Jaques Merdes.
Rush, do you have BSC or not ? I've still not understood where a BFC should be placed in this schematics and if it needs to be isolate from the filter by an additional buffer
I have what is shown. Simple.
I do have a sub-woofer but it shakes the foundation and everything rattles in the house, so I stopped using it. I don't miss it either with my speakers. (Snell E3 with rear tweeter disconnected.)
Rush
Ok, thanks, I will see later if running with one regulator per channel or one regulator for both, but I also like the idea (maybe a wrong one...) to keep separate left and right grounds.
If I am not wrong, the schematic Rush posted is the "original" VI order from Jaques Merdes.
Rush, do you have BSC or not ? I've still not understood where a BFC should be placed in this schematics and if it needs to be isolate from the filter by an additional buffer
Regarding the BSC, I suggest reading Baffle Step Compensation with paying special attention to the text portion below figure 3 (tl;dr: buffer in front, high impedance after).
Thank you Rodeodave, I've read it ... I just post a schematic with two options that may meet the required conditions (buffer in front and high impedance after) but as I have not electronic background please don't consider it as a good one. I prefer to let other people here decide if put a BSC or not in the board, and where.
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... again on BSC, if the BSC is at the very end of the circuit (like I posted above), do we have then do deal with the capacitance of the interconnect and roll-off at high frequencies as for potentiometer ?
An article on that is the one by Joppa, I linked before.
In post 1, JM published a circuit with two potentiometers, one for the HP and the other for the LP. Then he changed the LP circuit because of stop-band issue and remove the potentiometer on the LP section.
Question: could we put the BSC at same place of the two potentiometers in post 1 (LP&HP), that is before the last buffer ?
An article on that is the one by Joppa, I linked before.
In post 1, JM published a circuit with two potentiometers, one for the HP and the other for the LP. Then he changed the LP circuit because of stop-band issue and remove the potentiometer on the LP section.
Question: could we put the BSC at same place of the two potentiometers in post 1 (LP&HP), that is before the last buffer ?
The need for a Buffer, or no need, depends on the output impedance of the stage and the capacitance that this Rs has to drive.
If the cable & parasitic capacitances are high, then a medium Rs will require a Buffer.
If the capacitances are medium, then a high Rs will require a Buffer, a medium Rs may not roll off the treble. (if this is the Mid of an active 3way, there may be no treble to concern roll-off).
If the capacitances are low, then you may find that no Buffer is required.
What is the output impedance of the BSC?
What are the capacitances?
If the cable & parasitic capacitances are high, then a medium Rs will require a Buffer.
If the capacitances are medium, then a high Rs will require a Buffer, a medium Rs may not roll off the treble. (if this is the Mid of an active 3way, there may be no treble to concern roll-off).
If the capacitances are low, then you may find that no Buffer is required.
What is the output impedance of the BSC?
What are the capacitances?
Thank AndrewT, as we are talking about boards intended for everyone wants to build this active crossover, I guess that the better would be to "isolate" BSC by a buffer...
If BSC cannot replace those two potentiometers that JM putted before the last buffer in post 1, maybe an other buffer stage should be added ad the end of LP.
But please don't let that a totally electronic ignorant guy like me designs these boards
Do you think we should open a new thread to "publicize" this project and involve more people?
If BSC cannot replace those two potentiometers that JM putted before the last buffer in post 1, maybe an other buffer stage should be added ad the end of LP.
But please don't let that a totally electronic ignorant guy like me designs these boards
Do you think we should open a new thread to "publicize" this project and involve more people?
How on earth do you get a B1 running @ 800 mA? I thought they drew ~20mA. Since this project requires 10 "stages" we would be looking @ 8A!!
I think that is the current in the shunt part of the shunt reg, not how much current the B1 part is drawing!
Tony.
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