Pass Diy High Low Pass Please

[Fred Dieckmann]

"If this works the way my stories do, once I come up with a name, the rest will follow as day follows night."

Why not just call it the "Grey Delay" and get under way. I thought this thing was finished.

It would be ashamed if someone knocked out a design while you are waiting to think of a name. I think there are several people who could design a jfet second order filter and a buffered first order in about a couple of hours. I believe the circuit is simple enough to use a free Spice program to play with the filter Q and crossover frequencies when one is looking for for a specific crossover frequency. I think are even some plug and chug filter design programs on the web to figure out component values for Sallen Key filters.

Anyone?

[Duck-Twacy]

"no-Pass-ive"

[Bakmeel]

If you keep it a secret much longer, it will become an X-file .

Bouke

[GRollins]

Fred,
'It' [sic] might be ashamed, but I wouldn't. Just another difference between us, I suppose. If someone else wants to go ahead and post, do so with my blessing. The circuit's done, incidentally, since you seem to be concerned about that.
The Grey Delay is a cute name. Should I ever do a delay circuit, perhaps that's what I'll call it.
Time is my limiting factor. If you, like Jam, want to take me to task for not finishing something according to your schedule, then you'll have to find a way to give my days a transfusion of hours. Unless and until that comes to pass, I'll have to muddle on through with 24 hour days.
In the meantime, Fred, it's just a hobby. Don't take it so seriously.

Grey

[Variac]

yeah! chill out Fred. Become more Zen. After all this is the Pass area

[Fred Dieckmann]

"Time is my limiting factor. If you, like Jam, want to take me to task for not finishing something according to your schedule, then you'll have to find a way to give my days a transfusion of hours."

I understand that time is short and no one is giving you a schedule to meet. If you have a circuit, post it is all I am saying. some people can only sit through so many coming attractions before they expect to see the feature. First you tell us you are waiting on Pass labs to publish thiers and now you are waiting to name it. If I may be forgiven for my previous bit of teasing about a flippant name, I submit one in earnest, the ProCrosstination.


'Tis but thy name that is my enemy;
Thou art thyself, thought not a Montague.
What's Montague? it is nor hand, nor foot,
Nor arm, nor face, nor any other part
Belonging to a man. O, be some other name!
What's in a name? that which we call a rose
By any other name would smell as sweet;
So Romeo would, were he not Romeo call'd,
Retain that dear perfection which he owes
Without that title. Romeo, doff thy name,
And for thy name which is no part of thee,
Take all myself.


I take thee at thy word:
Call it but done, and I'll be new baptized;
Henceforth I never will plea..... Go please go.

[Fred Dieckmann]

Before being accused of not helping, here are some links on Sallen Key filters:

http://www.t-linespeakers.org/tech/f...allen-Key.html

I believe the Q calculation are fast and loose in this reference and you may want to look at the following for exact calculations. Don't be put off by the derivations of the equations. The actual caculation for the values of Fc and Q are very simple.

http://www.web-ee.com/primers/files/Sallen_Key.pdf

For a Spice text file (and most free student Spice programs should handle a GIU version of a circut this simple):

http://www.ecircuitcenter.com/Circui.../opsalkey1.htm

A good collection of filter design links:

http://www.circuitsage.com/filter.html

Filter pro from TI( One that I like to use that is pretty simple and has good documentation):

http://focus.ti.com/analog/docs/samp...igationId=9742

[macka]

Reminds me a bit of the Oliver Twist Novel............

Surely Grey is entitled to some breathing space here given the short notice to present his efforts.

I recall plenty of patience and respect for the publishing of the passdiy projects..ditto.

Greys work is also his intellectual property, so say grace and learn some table manners please,

Beggers can't be choosers.

Ian

[Fred Dieckmann]

"I've got such a circuit, complete with variable Q, selectable frequencies, etc. etc. etc. It's discrete, with JFET inputs. I've been holding off in order to let Nelson do his thing. I'm sure that people are more interested in his design."

Grey

Mr. Pass told him to go ahead and so am I.
It really doesn't matter I guess, since someone else will come along first with another design at this rate........ or as Grey
said about the Pass DIY crossover:

" Then maybe I'll post something to tide people over until the 'real thing' arrives."

[macka]

As an contemporary educational article and a great reference for practical audio filter design, this one by Borbely gives useful insights and practical tips for even the most experienced enthusiast.

http://www.borbelyaudio.com/xover.pdf

Ian