need a simple passiv line filter circuit

[Phattline]

Hi, I am on the way, to make my studio mobil - in two small racks - I own already a Mixer but this thing is to big!

So I was searching in the Internet on different Music stores for a small 16 chanal Rackmixer, - and I found it - but the mixers have no EQ or have a simple two way EQ. And trust me I am addictet to 3 Band EQ or parametric meedles....so I need per Instrument a different Frequenzy...And After I calibrate the EQ one time, I dont need them to calibrate it no more....ok

I think I need 16 severell passive line Filters, I dont need a amplifiing I only need Reduction.

I need a simple standart circuit, and with chanching severell Resistors or caps i can calibrate it.

The importent frequenzys are:

a 75 HZ 18db/oct cut of circuit - that meens all frequenzys under 75 hz are killed.

-//- the same but with 12 KHz - that meens all frequenzys over 12 Khz are killed.

and circuit for reduction severall frequenzys by replacing Resistors or caps

Anyone has done this bevore, or has a cool circuit,- post it please- greets Mike

[pwx]

hi

there are several different filter schematics listed in Google........also it should be no problem to build 3-Band EQ´s......  16times ;D

just google for "diy filter schematics" .... or something like that... have a look at some stompbox EQ schematics on the net,....

And: if you just want a fixed freq. ..... use a trimmpot on the board...

hope this helps

pwx :-\

[Phattline]

not really, hm, I already was searching on google, but I dont found somthing with the words: passiv line filter schematic

There are quite much schematics for MHz ciruits, quite much for active filters with op amps and they are all big ciruits-

I need schematic for the "nF" for the low Frequenzy, a small circuit and it must be analog because my Studio is analog.

Of course it would be cool when i can chance the frequenzy´s by using a pot.

Anybody a Idea for a small compact circuit, and a Term for it. It should be passiv, maybe a OPAmp so that I always have the same impedance-resistance- but all other parts should be Capacitor Resistor and Coil no Transistor or IC....because it should be built 16times ;D

Help needet

[pwx]

something like that ???   http://www.montagar.com/~patj/3btone.gif

pwx

[Jidis]

Mike, I believe I may have seen them in the audio section at epanorama.net. There was a whole section on a DIY mixer that was extremely modular (I think you could use most of the circuits as stand alone).

I know it's not the DIY thing you're looking for, but I bought a 16 channel, 3 space Speck parametric years back, which was made as an add-on for the new generation of compact 16 channel boards with limited EQ (Mackie). Mine is a cheaper one that never quite caught on. I think it's the 316. It's unbalanced i/o, but most of those boards use TRS insert jacks anyway, so you're already UB. There was a more expensive balanced version out later. It adds a nice smooth sound to some of that "basic" gear. Vince (Speck) seems to have a pretty good reputation for his compact analog circuits, but it's a bit pricey for me. I'm really big on highpass myself, and had considered adding passive filters to the bottom of that with toggles, but I can usually knock out the LF somewhere else anyway (I don't do live sound). That thing only has freq. and boost/cut for three bands per channel.

BTW- I've also had a blackface Alesis Studio 12R sitting around here that I've been trying to sell since the beginning of time. I had been using it just for the 8 mic pre-amps, with d.outs to an optical converter, but I replaced it all a while back with a pre-amp/lightpipe combo. The 12R only has the high-low shelf you're talking about. There's also a VLZ Mackie here, so I've got way too much of the same crap.

-George 

[Phattline]

Thanx, It must not be DIY, I was looking for DIY because I dont find Comerzial products.

Can you give me again the Types of Mixer or EQ´s.

316? form Mackie?

So du you sell your Alesis?- price? (not from USA?-Im in Austria), I can use it as Submixer....

[Jidis]

Mike,

The 316 is by a smaller company over here called "Speck". It was sort of a budget attempt by them, and was made as a supplement for stuff like the 16 channel Mackies,etc. I doubt it's really easy to find, but it doesn't have highpass/lowpass filters anyway.  I hope I didn't give the impression that it's for sale. That's one of the things I actually like. I found a picture here if you were wondering-

http://tinyurl.com/cqsgb

I doubt the 12R would be worth sending there. I was advertising it in a trade paper here for a while, and brought the price down a couple times, but got no calls. The last time it was $150, which I thought was good for it's "studio use" history. They were going on eBay for around that, up to over a couple hundred, and that was with people expecting to pay shipping and all with it. It's also the original black style. The majority of them are the newer gray colored ones (not quite as cool looking). I'll probably end up getting rid of it on eBay, but I've never tried to sell anything on there before.I have a feeling you can find one (or something like one) much closer to where you are, for less money overall, but this one should be here a while. Maybe someone more experienced could verify whether it's a hassle to get something like that over there from the US.

                                                         - Take Care

George   

[Phattline]

Oh yea, thats what I´m Looking for Speck 316, cool but expensive tool- I think its a must to get clear mixes on small Rack High Units- thanx alot.

You are from US- ah-  the shipping costs- expensive and high money transfair rates- I know.....

Greets from the sids - mike