AVS Forum banner
1 - 8 of 8 Posts

·
Registered
Joined
·
3,937 Posts
Discussion Starter · #1 ·
I'm looking to build a HPF possibly. I'd like something centered at 15 hz and from looking at different types a bessel or butterworth 2nd order is fine for my needs. Butterworth is preferable, but I can handle either one. Modeling response with the butterworth looks like it keeps more of the excursion over the entire frequency band. I may be wrong about that, so if I am let me know.


I have no clue as to how to build one, but have read that there's really not much involved. I've looked at some of the processor units available that have adjustable hpf's and they're great looking, but I'm not really wanting all the extra bells and whistles that go along with them, just the HPF.
 

·
Registered
Joined
·
2,256 Posts
Yup, just drop in an op amp made in this century. At least a 5558. Don't need to get carried away as it is in the sub only signal path. Personally, I would go higher than 15. Just me. Not into special effects.


By the way, even the TLO's were extremely static sensitive. Just waving them in the air on their way from the carbon mat to the board could do enough damage to the inputs that the input offset goes through the roof. Use proper procedures, or at least live in a damp climate.
 

·
Registered
Joined
·
3,937 Posts
Discussion Starter · #4 ·
My sub is tuned to 15.5 hz and messing around with the settings in winisd yielded better results at this frequency.
 

·
Registered
Joined
·
3,937 Posts
Discussion Starter · #6 ·
Yes collo, very good stuff. I will be reading it all over again over the next couple of days. It looks like exactly what I need.


The problem I have is that unlike most in here I am still learning about this stuff. A diagram doesn't really help me any yet. I am going to look into this some more, but right now if I see a circuit board or a diagram like us on that page it looks like a Picasso. Very nice, but I just don't understand it.


I will look into this some more, but more of a step by step for the completely clueless novice would help this completely clueless novice.
 

·
Registered
Joined
·
138 Posts

Quote:
Originally Posted by NEO Dan /forum/post/16967669


Collo,

....how about a version that converts to ballanced out for the proamp users?

The idea was to keep it as simple as possible. For driving a pro-amp, there are a couple of options.


- Use the circuit as is, with the gain set for around 14dB. This will lift a "consumer" level signal to the "pro" level. The higher level available often means the power amp can be turned down, reducing any cable induced noise in the process. This may mean that balanced cabling is not required.


- Build the simpler circuit with unity gain and use a modded cleanbox or Samson S-box to do the level and balanced conversions.


- Add a balanced driver to the circuit. I thought the [email protected] project had come to fruition, but it looks like there wasn't enough demand to make it viable for Chas and Thomas to have the boards made. Anyway, that link shows you a balanced driver circuit using the DRV135 chip that could be added to the project. (I should add that the the filter FAQ).

An alternative circuit using opamps could be based around this circuit from Rod Elliot
 

·
Registered
Joined
·
2,256 Posts
Balanced output is by using a balanced line driver for the output. Don't bother with any of the op-amp circuits as they are no where near balanced.

Read the Jansen Transformers site on balanced lines before you decide you need one.

"THAT" makes the very best electronic line drivers. Jansen the best transformers.


This is DIY, so I did not mention all the pre-built boxes.
 
1 - 8 of 8 Posts
Top