Analog active xover

[JensRasmussen]

Documentation for my filter

Hi,

I wrote a manual and a thing on sallen and key filters

Manual:
http://www.delta-audio.com/Manualer/Active filter one ver 1.0 dokumentation.pdf

Schematics:
http://www.delta-audio.com/Manualer/Active filter one ver 1.0 schematics.pdf

Sallen and Key formulars:
http://www.delta-audio.com/Manualer/Sallen And Key ver 1.0.pdf

Use them if you want to

\Jens

 

[thylantyr]

Let us know how it sounds and functions.

Looks like a fun project.

 

[JensRasmussen]

Layout files

Hi,

I just uploaded the layout files for the filter to my homepage.

They can be found at:

http://www.delta-audio.com/Active filter one.htm

Enjoy!

\Jens

 

[JensRasmussen]

Components arrived

Hi,

Opamps arrived today

AD826, For Input
OPA2134, For treble and midrange
NE5532, and LM833 General opamp for the rest

I can't wait to get the PCBs now....still 5 days to go

\Jens

 

[Luke123]

5th Element...

You Said:"My active xovers use polystyrene layer caps with 1% metal films and they sound very very good"

I'm looking for 1% Polystyrene caps. Where can I order some from? What brand? Phillips/BC Components? Or else?

Luke

 

[JensRasmussen]

Boards arrived wohoo!

Hi,

Boards arrived today.

Here is a pic

An externally hosted image should be here but it was not working when we last tested it.

\Jens

 

[moving_electron]

For the same capacitance value it has appeared to me in the past that the polystyrene capacitors are larger. Would that preclude use in this PC board or have you found them to be compact?

 

[JensRasmussen]

Caps

Hi,

I plan to use Metallized polyester capacitors from wima.
I can get up to 1.5µF to fit it the footprint on the board. Their Dielectriccum is polyethylene terephthalate film.
I think that is big enough.

\Jens

 

[JensRasmussen]

PC based measuring system

Hello all,

I have now assembled one channel of the PCB, but now I would like to measure the frequency and phase response. What is the easiest way of doing this (Without having to sit manually adjusting and measuring)

I’m looking for a PC based measuring system – any ideas?

Thanks

\Jens

 

[tg3]

I'm partial to Praxis, but there are surely lower cost alternatives.

 

[JensRasmussen]

Measuring system

Hello,

Thanks for the link to praxis, im looking into that however it seems that it needs external hardware to run?

\Jens

 

[JensRasmussen]

Progress at last

Hey all,

I have been busy on the filter for the mox clone, but have now had time to test this filter.

Initial testing has been performed without any problems, this includes the function of HP, LP and EQ sections.
The measured frequency response is within +-0.2 dB of the calculated witch is pretty much expected. I don't have any pictures of the measurement, but as soon as I get some I'll post them here.

\Jens

 

[tiroth]

Jens, audiotester is a great cheap ($30) application that even has a shareware version. It can easily do swept sine bandwidth measurements, very nice for crossover testing.

I am still using version 1.4.

http://www.audiotester.de/

 

[Davey]

Try

http://www.spectraplus.com

for crossover testing. If you use white noise for excitation and the dual channel transfer function mode you can generate precise curves.....even at low frequencies.

Works with any soundcard and the 30-day version is free.

Davey.

 

[JensRasmussen]

Measuments

Hello

I have added a picture of the freq response to the website.

An externally hosted image should be here but it was not working when we last tested it.

\Jens

 

[JensRasmussen]

Hi,

Here is a picture of the semi stuffed module I used for the measurements.

An externally hosted image should be here but it was not working when we last tested it.

All opamps in the signal path are Philips NE5532

\Jens

 

[JensRasmussen]

Caps and Resistors.

I used 5-10% caps and measured their value using a smart cap meter from Monacor it was about 70US$ and works great.

I just calculated the caps needed and found the approx value by means of simply going through a couble of caps - not a lot of work really.